52 results on '"Guedj, E."'
Search Results
2. 18F-FDG brain PET: a metabolic predictive factor for gait improvement after cerebrospinal fluid shunting in normal pressure hydrocephalus?
- Author
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Horowitz T, Grimaldi S, Dufour H, Graillon T, Azulay JP, and Guedj E
- Subjects
- Humans, Male, Female, Aged, Retrospective Studies, Cerebrospinal Fluid Shunts, Gait, Middle Aged, Aged, 80 and over, Treatment Outcome, Hydrocephalus, Normal Pressure diagnostic imaging, Hydrocephalus, Normal Pressure surgery, Hydrocephalus, Normal Pressure metabolism, Fluorodeoxyglucose F18, Positron-Emission Tomography, Brain diagnostic imaging, Brain metabolism
- Abstract
Background: The pathophysiology of normal pressure hydrocephalus (NPH) has not been fully elucidated. Treating NPH with cerebrospinal fluid shunts to improve gait disturbances may have some risks and inconsistent benefits. No clear predictive factor has been identified thus far. This preliminary study aimed to evaluate the predictive value of preoperative brain
18 F-FDG positron emission tomography (PET) on overall gait response in patients with NPH., Methods: Sixteen patients with NPH who underwent18 F-FDG PET before shunt surgery between 2012 and 2022 were included retrospectively and separated into two groups based on their gait response one year after surgery: responders (R) or nonresponders (NR). Brain glucose metabolism was assessed using visual and semiquantitative analyses using SPM8 software (Welcome Department of Cognitive Neurology, University College, London, UK). Five regions of interest were selected: global cortex, cerebellum, thalamus, striatum, and midbrain., Results: Visual interpretation showed more frequent hypometabolism of the striatum, thalamus and global cortex in NR. None of the patients showing hypometabolism of these regions were R. Based on these results, the visual interpretation allowed us to identify 3/8 NR and 8/8 R. Semiquantitative analysis confirmed significantly lower thalamic metabolism in the NR group (P=0.037) and a trend towards lower metabolism of the striatum (P=0.075) with an area under the curve of 0.77 for thalamic metabolism to discriminate between R and NR., Conclusions: This preliminary study using brain18 F-FDG PET suggests that reduced brain metabolism in the thalamus and striatum along with cortical hypometabolism may be associated with poorer gait response to CSF shunting in normal pressure hydrocephalus (NPH). Although these findings suggest that preoperative brain 18F-FDG PET could potentially aid in selecting appropriate candidates for shunt surgery, further research with larger sample sizes is needed to confirm these results.- Published
- 2024
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3. Persistent brain metabolic impairment in long COVID patients with persistent clinical symptoms: a nine-month follow-up [ 18 F]FDG-PET study.
- Author
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Horowitz T, Dudouet P, Campion JY, Kaphan E, Radulesco T, Gonzalez S, Cammilleri S, Ménard A, and Guedj E
- Subjects
- Humans, Male, Female, Middle Aged, Aged, Adult, Follow-Up Studies, Retrospective Studies, Radiopharmaceuticals pharmacokinetics, COVID-19 diagnostic imaging, COVID-19 complications, COVID-19 metabolism, Fluorodeoxyglucose F18, Brain diagnostic imaging, Brain metabolism, Positron-Emission Tomography
- Abstract
Purpose: A hypometabolic profile involving the limbic areas, brainstem and cerebellum has been identified in long COVID patients using [
18 F]fluorodeoxyglucose (FDG)-PET. This study was conducted to evaluate possible recovery of brain metabolism during the follow-up of patients with prolonged symptoms., Methods: Fifty-six adults with long COVID who underwent two brain [18 F]FDG-PET scans in our department between May 2020 and October 2022 were retrospectively analysed, and compared to 51 healthy subjects. On average, PET1 was performed 7 months (range 3-17) after acute COVID-19 infection, and PET2 was performed 16 months (range 8-32) after acute infection, because of persistent severe or disabling symptoms, without significant clinical recovery. Whole-brain voxel-based analysis compared PET1 and PET2 from long COVID patients to scans from healthy subjects (p-voxel < 0.001 uncorrected, p-cluster < 0.05 FWE-corrected) and PET1 to PET2 (with the same threshold, and secondarily with a less constrained threshold of p-voxel < 0.005 uncorrected, p-cluster < 0.05 uncorrected). Additionally, a region-of-interest (ROI) semiquantitative anatomical approach was performed for the same comparisons (p < 0.05, corrected)., Results: PET1 and PET2 revealed voxel-based hypometabolisms consistent with the previously reported profile in the literature. This between-group analysis comparing PET1 and PET2 showed minor improvements in the pons and cerebellum (8.4 and 5.2%, respectively, only significant under the less constrained uncorrected p-threshold); for the pons, this improvement was correlated with the PET1-PET2 interval (r = 0.21, p < 0.05). Of the 14,068 hypometabolic voxels identified on PET1, 6,503 were also hypometabolic on PET2 (46%). Of the 7,732 hypometabolic voxels identified on PET2, 6,094 were also hypometabolic on PET1 (78%). The anatomical ROI analysis confirmed the brain hypometabolism involving limbic region, the pons and cerebellum at PET1 and PET2, without significant changes between PET1 and PET2., Conclusion: Subjects with persistent symptoms of long COVID exhibit durable deficits in brain metabolism, without progressive worsening., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2024
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4. The impact of COVID-19 lockdown on brain metabolism.
- Author
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Guedj E, Campion JY, Horowitz T, Barthelemy F, Cammilleri S, and Ceccaldi M
- Subjects
- Aged, Aged, 80 and over, Brain diagnostic imaging, Emotions, Exercise, Female, Fluorodeoxyglucose F18, Humans, Longitudinal Studies, Male, Middle Aged, Motor Cortex diagnostic imaging, Motor Cortex metabolism, Nerve Net metabolism, Positron-Emission Tomography, Radiopharmaceuticals, Retrospective Studies, Social Isolation, Somatosensory Cortex diagnostic imaging, Somatosensory Cortex metabolism, Post-Acute COVID-19 Syndrome, Brain metabolism, COVID-19 complications, COVID-19 metabolism, Pandemics, Quarantine
- Abstract
This study aims to evaluate the impact of French national lockdown of 55 days on brain metabolism of patients with neurological disorders. Whole-brain voxel-based PET analysis was used to correlate
18 F-FDG metabolism to the number of days after March 17, 2020 (in 95 patients; mean age: 54.3 years ± 15.7; 59 men), in comparison to the same period in 2019 before the SARS-CoV-2 outbreak (in 212 patients; mean age: 59.5 years ± 15.8; 114 men), and to the first 55 days of deconfinement (in 188 patients; mean age: 57.5 years ± 16.5; 93 men). Lockdown duration was negatively correlated to the metabolism of the sensory-motor cortex with a prevailing effect on the left dominant pyramidal tract and on younger patients, also including the left amygdala, with only partial reversibility after 55 days of deconfinement. Weak overlap was found with the reported pattern of hypometabolism in long COVID (<9%). Restriction of physical activities, and possible related deconditioning, and social isolation may lead to functional disturbances of sensorimotor and emotional brain networks. Of note, this metabolic pattern seems distinct to those reported in long COVID. Further longitudinal studies with longer follow-up are needed to evaluate clinical consequences and relationships on cognitive and mental health against functional deactivation hypothesis, and to extend these findings to healthy subjects in the context of lockdown., (© 2021 The Authors. Human Brain Mapping published by Wiley Periodicals LLC.)- Published
- 2022
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5. 18 F-FDG brain PET hypometabolism in post-SARS-CoV-2 infection: substrate for persistent/delayed disorders?
- Author
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Guedj E, Million M, Dudouet P, Tissot-Dupont H, Bregeon F, Cammilleri S, and Raoult D
- Subjects
- COVID-19 diagnostic imaging, Fluorodeoxyglucose F18, Humans, Male, Middle Aged, Radiopharmaceuticals, Post-Acute COVID-19 Syndrome, Anosmia diagnostic imaging, Brain diagnostic imaging, COVID-19 complications, Pain diagnostic imaging, Positron-Emission Tomography
- Abstract
Purpose: Several brain complications of SARS-CoV-2 infection have been reported. It has been moreover speculated that this neurotropism could potentially cause a delayed outbreak of neuropsychiatric and neurodegenerative diseases of neuroinflammatory origin. A propagation mechanism has been proposed across the cribriform plate of the ethmoid bone, from the nose to the olfactory epithelium, and possibly afterward to other limbic structures, and deeper parts of the brain including the brainstem., Methods: Review of clinical examination, and whole-brain voxel-based analysis of
18 F-FDG PET metabolism in comparison with healthy subjects (p voxel < 0.001, p-cluster < 0.05, uncorrected), of two patients with confirmed diagnosis of SARS-CoV-2 explored at the post-viral stage of the disease., Results: Hypometabolism of the olfactory/rectus gyrus was found on the two patients, especially one with 4-week prolonged anosmia. Additional hypometabolisms were found within amygdala, hippocampus, parahippocampus, cingulate cortex, pre-/post-central gyrus, thalamus/hypothalamus, cerebellum, pons, and medulla in the other patient who complained of delayed onset of a painful syndrome., Conclusion: These preliminary findings reinforce the hypotheses of SARS-CoV-2 neurotropism through the olfactory bulb and the possible extension of this impairment to other brain structures.18 F-FDG PET hypometabolism could constitute a cerebral quantitative biomarker of this involvement. Post-viral cohort studies are required to specify the exact relationship between such hypometabolisms and the possible persistent disorders, especially involving cognitive or emotion disturbances, residual respiratory symptoms, or painful complaints.- Published
- 2021
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6. Brain 18F-fluorodeoxyglucose positron emission tomography/computed tomography detection of neuropsychiatric lupus with normal cerebral magnetic resonance imaging.
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Soubrier C, Faucher B, Guedj E, Kaphan E, Ebbo M, De Sainte Marie B, and Schleinitz N
- Subjects
- Adolescent, Female, Humans, Magnetic Resonance Imaging, Positron Emission Tomography Computed Tomography, Brain diagnostic imaging, Lupus Vasculitis, Central Nervous System diagnostic imaging
- Published
- 2020
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7. Posttraumatic Stress Disorder is associated with altered reward mechanisms during the anticipation and the outcome of monetary incentive cues.
- Author
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Boukezzi S, Baunez C, Rousseau PF, Warrot D, Silva C, Guyon V, Zendjidjian X, Nicolas F, Guedj E, Nazarian B, Trousselard M, Chaminade T, and Khalfa S
- Subjects
- Adult, Basal Ganglia diagnostic imaging, Basal Ganglia physiopathology, Brain diagnostic imaging, Brain Mapping, Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Psychomotor Performance physiology, Reaction Time physiology, Young Adult, Anticipation, Psychological physiology, Brain physiopathology, Cues, Motivation physiology, Psychological Trauma physiopathology, Reward, Stress Disorders, Post-Traumatic physiopathology
- Abstract
Background: Recent studies suggest that Posttraumatic Stress Disorder (PTSD) might be associated with dysfunctional reward circuitry. However, further research is needed to understand the key role of the reward system in PTSD symptomatology., Methods: Twenty participants with PTSD and 21 Trauma-Exposed matched Controls (TECs) completed the Monetary Incentive Delay (MID) task during an MRI session. Reaction times (RTs) and hit rates were recorded. Brain activity was investigated during the anticipation and the outcome of monetary gains and losses., Results: During the anticipation of monetary loss, PTSD participants had higher RTs than TECs. However, the groups did not differ at the neurofunctional level. During successful avoidance of monetary loss, PTSD patients showed higher activation than TECs in the left caudate nucleus. During the anticipation of monetary gains, no differences in RTs were found between groups. PTSD patients had specific activations in the right amygdala, nucleus accumbens, putamen, and middle frontal gyrus (p < 0.05 family-wise error (FWE)-corrected), while TECs had specific activation in the anterior cingulate cortex. When obtaining monetary gains, PTSD patients had specific activation in the caudate nucleus, while TECs had specific activations in the right hypothalamus, subthalamic nucleus, and left inferior frontal gyrus., Conclusion: For the first time, functional brain activation during both the anticipation and the outcome of monetary rewards is reported altered in PTSD patients. These alterations might be associated with the complex symptomatology of PTSD., Competing Interests: Declaration of Competing Interest The authors report no biomedical financial interests or potential conflicts of interest., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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8. Multiple System Atrophy: Phenotypic spectrum approach coupled with brain 18-FDG PET.
- Author
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Grimaldi S, Boucekine M, Witjas T, Fluchère F, Renaud M, Azulay JP, Guedj E, and Eusebio A
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- Accidental Falls, Aged, Cognitive Dysfunction diagnostic imaging, Cognitive Dysfunction psychology, Female, Fluorodeoxyglucose F18, Humans, Hypotension, Orthostatic physiopathology, Laryngeal Diseases physiopathology, Latent Class Analysis, Male, Middle Aged, Multiple System Atrophy classification, Multiple System Atrophy diagnostic imaging, Multiple System Atrophy psychology, Muscular Atrophy, Spinal physiopathology, Pharyngeal Diseases physiopathology, Phenotype, Positron-Emission Tomography, REM Sleep Behavior Disorder physiopathology, Radiopharmaceuticals, Retrospective Studies, Spinal Curvatures physiopathology, Urinary Incontinence physiopathology, Basal Ganglia Diseases physiopathology, Brain diagnostic imaging, Cerebellar Diseases physiopathology, Cognitive Dysfunction physiopathology, Gait Disorders, Neurologic physiopathology, Multiple System Atrophy physiopathology
- Abstract
Objective: The 2008 diagnostic criteria classify Multiple System Atrophy (MSA) patients in a predominantly parkinsonian (MSA-P) or cerebellar (MSA-C) type. Phenotypic descriptions have since highlighted a clinical heterogeneity among patients (e.g., mixed-type, cognitive impairment, atypical longer survival). This study attempts to identify different phenotypes of patients with MSA and to describe corresponding brain 18-FDG Positron Emission Tomography (PET) patterns., Methods: Patients with a "probable" MSA diagnosis for whom a brain 18-FDG PET was performed were included. A retrospective analysis (from 2006 to 2017) was conducted using standardized data collection. We used Latent Class Analysis (LCA), an innovative statistical approach, to identify profiles of patients based on common clinical characteristics. Brain metabolism of different groups was studied at rest., Results: Eighty-five patients were included. Three different profiles were revealed (entropy = 0.835): 1. extrapyramidal, axial, laryngeal-pharyngeal involvement (LPI) and cerebellar symptoms (n = 46, 54.1%); 2. cerebellar and LPI symptoms (n = 30, 35.3%); 3. cerebellar and cognitive symptoms (n = 9, 10.6%). Brain metabolism analyses (k > 89; p < 0.001) showed hypometabolism of the basal ganglia, frontal/prefrontal, temporal cortices and left posterior cerebellum in profile 1. In profile 2 there was hypometabolism of the medulla, prefrontal, temporal, cingular cortices, putamen and bilateral cerebellar hemispheres. In profile 3 there was hypometabolism of bilateral posterior cerebellar hemispheres and vermis., Conclusion: Beyond the two most common phenotypes of MSA, a third and particularly atypical profile with cerebellar and cognitive symptoms but without LPI involvement is described. These profiles are supported by different brain metabolic abnormalities which could be useful for diagnostic purposes., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2019
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9. Multilevel Feature Representation of FDG-PET Brain Images for Diagnosing Alzheimer's Disease.
- Author
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Pan X, Adel M, Fossati C, Gaidon T, and Guedj E
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- Algorithms, Cognitive Dysfunction diagnostic imaging, Databases, Factual, Fluorodeoxyglucose F18, Humans, Neuroimaging methods, Support Vector Machine, Alzheimer Disease diagnostic imaging, Brain diagnostic imaging, Image Interpretation, Computer-Assisted methods, Machine Learning, Positron-Emission Tomography methods
- Abstract
Using a single imaging modality to diagnose Alzheimer's disease (AD) or mild cognitive impairment (MCI) is a challenging task. FluoroDeoxyGlucose Positron Emission Tomography (FDG-PET) is an important and effective modality used for that purpose. In this paper, we develop a novel method by using single modality (FDG-PET) but multilevel feature, which considers both region properties and connectivities between regions to classify AD or MCI from normal control. First, three levels of features are extracted: statistical, connectivity, and graph-based features. Then, the connectivity features are decomposed into three different sets of features according to a proposed similarity-driven ranking method, which can not only reduce the feature dimension but also increase the classifier's diversity. Last, after feeding the three levels of features to different classifiers, a new classifier selection strategy, maximum Mean squared Error (mMsE), is developed to select a pair of classifiers with high diversity. In order to do the majority voting, a decision-making scheme, a nested cross validation technique is applied to choose another classifier according to the accuracy. Experiments on Alzheimer's Disease Neuroimaging Initiative database show that the proposed method outperforms most FDG-PET-based classification algorithms, especially for classifying progressive MCI (pMCI) from stable MCI (sMCI).
- Published
- 2019
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10. Physiological Whole-Brain Distribution of [ 18 F]FDOPA Uptake Index in Relation to Age and Gender: Results from a Voxel-Based Semi-quantitative Analysis.
- Author
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Toch SR, Poussier S, Micard E, Bertaux M, Van Der Gucht A, Chevalier E, Marie PY, Guedj E, and Verger A
- Subjects
- Adult, Age Factors, Aged, Aged, 80 and over, Corpus Striatum metabolism, Dihydroxyphenylalanine chemistry, Female, Humans, Linear Models, Male, Middle Aged, Positron-Emission Tomography, Tissue Distribution, Young Adult, Brain diagnostic imaging, Brain physiology, Dihydroxyphenylalanine analogs & derivatives
- Abstract
Purpose: 6-[
18 F]fluoro-L-DOPA ([18 F]FDOPA), a positron emission tomography (PET) amino-acid tracer of brain decarboxylase activity, is used to assess the brain dopaminergic system. Using a voxel-based semi-quantitative analysis, this study aimed to determine whether a current brain uptake index of [18 F]FDOPA, expressed relative to the occipital background level, varies according to age and gender., Procedures: One hundred and seventy-seven subjects were retrospectively included. A whole-brain statistical parametric mapping analysis of the [18 F]FDOPA uptake index in parametric PET images was performed at a voxel threshold of p < 0.05 (corrected) and p < 0.005 (uncorrected, k cluster > 125)., Results: Striatal uptake indices were influenced by age, negatively for the caudate nucleus and positively for the putamen, as well as by gender, with a lower left putaminal uptake index in women. Extra-striatal uptake indices were influenced by age, negatively for the frontal cortex and brainstem and positively for the occipital cortex and cerebellum, as well as by gender (diffuse increase in women)., Conclusions: The uptake index of [18 F]FDOPA exhibited significant physiological variations according to age and gender and should therefore be considered for PET interpretation.- Published
- 2019
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11. Semi-quantification and grading of amyloid PET: A project of the European Alzheimer's Disease Consortium (EADC).
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Chincarini A, Peira E, Morbelli S, Pardini M, Bauckneht M, Arbizu J, Castelo-Branco M, Büsing KA, de Mendonça A, Didic M, Dottorini M, Engelborghs S, Ferrarese C, Frisoni GB, Garibotto V, Guedj E, Hausner L, Hugon J, Verhaeghe J, Mecocci P, Musarra M, Queneau M, Riverol M, Santana I, Guerra UP, and Nobili F
- Subjects
- Adult, Aged, Aged, 80 and over, Alzheimer Disease epidemiology, Alzheimer Disease metabolism, Brain metabolism, Cohort Studies, Europe epidemiology, Female, Fluorine Radioisotopes metabolism, Humans, Male, Middle Aged, Plaque, Amyloid metabolism, Positron-Emission Tomography trends, Retrospective Studies, Alzheimer Disease diagnostic imaging, Brain diagnostic imaging, Plaque, Amyloid diagnostic imaging, Positron-Emission Tomography methods
- Abstract
Background: amyloid-PET reading has been classically implemented as a binary assessment, although the clinical experience has shown that the number of borderline cases is non negligible not only in epidemiological studies of asymptomatic subjects but also in naturalistic groups of symptomatic patients attending memory clinics. In this work we develop a model to compare and integrate visual reading with two independent semi-quantification methods in order to obtain a tracer-independent multi-parametric evaluation., Methods: We retrospectively enrolled three cohorts of cognitively impaired patients submitted to
18 F-florbetaben (53 subjects),18 F-flutemetamol (62 subjects),18 F-florbetapir (60 subjects) PET/CT respectively, in 6 European centres belonging to the EADC. The 175 scans were visually classified as positive/negative following approved criteria and further classified with a 5-step grading as negative, mild negative, borderline, mild positive, positive by 5 independent readers, blind to clinical data. Scan quality was also visually assessed and recorded. Semi-quantification was based on two quantifiers: the standardized uptake value (SUVr) and the ELBA method. We used a sigmoid model to relate the grading with the quantifiers. We measured the readers accord and inconsistencies in the visual assessment as well as the relationship between discrepancies on the grading and semi-quantifications., Conclusion: It is possible to construct a map between different tracers and different quantification methods without resorting to ad-hoc acquired cases. We used a 5-level visual scale which, together with a mathematical model, delivered cut-offs and transition regions on tracers that are (largely) independent from the population. All fluorinated tracers appeared to have the same contrast and discrimination ability with respect to the negative-to-positive grading. We validated the integration of both visual reading and different quantifiers in a more robust framework thus bridging the gap between a binary and a user-independent continuous scale., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2019
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12. Head-to-Head Comparison among Semi-Quantification Tools of Brain FDG-PET to Aid the Diagnosis of Prodromal Alzheimer's Disease.
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Brugnolo A, De Carli F, Pagani M, Morbelli S, Jonsson C, Chincarini A, Frisoni GB, Galluzzi S, Perneczky R, Drzezga A, van Berckel BNM, Ossenkoppele R, Didic M, Guedj E, Arnaldi D, Massa F, Grazzini M, Pardini M, Mecocci P, Dottorini ME, Bauckneht M, Sambuceti G, and Nobili F
- Subjects
- Aged, Aged, 80 and over, Disease Progression, Early Diagnosis, Female, Fluorodeoxyglucose F18, Humans, Male, Middle Aged, Prodromal Symptoms, Support Vector Machine, Alzheimer Disease diagnostic imaging, Brain diagnostic imaging, Image Processing, Computer-Assisted, Positron-Emission Tomography methods
- Abstract
Background: Several automatic tools have been implemented for semi-quantitative assessment of brain [18]F-FDG-PET., Objective: We aimed to head-to-head compare the diagnostic performance among three statistical parametric mapping (SPM)-based approaches, another voxel-based tool (i.e., PALZ), and a volumetric region of interest (VROI-SVM)-based approach, in distinguishing patients with prodromal Alzheimer's disease (pAD) from controls., Methods: Sixty-two pAD patients (MMSE score = 27.0±1.6) and one hundred-nine healthy subjects (CTR) (MMSE score = 29.2±1.2) were enrolled in five centers of the European Alzheimer's Disease Consortium. The three SPM-based methods, based on different rationales, included 1) a cluster identified through the correlation analysis between [18]F-FDG-PET and a verbal memory test (VROI-1), 2) a VROI derived from the comparison between pAD and CTR (VROI-2), and 3) visual analysis of individual maps obtained by the comparison between each subject and CTR (SPM-Maps). The VROI-SVM approach was based on 6 VROI plus 6 VROI asymmetry values derived from the pAD versus CTR comparison thanks to support vector machine (SVM)., Results: The areas under the ROC curves between pAD and CTR were 0.84 for VROI-1, 0.83 for VROI-2, 0.79 for SPM maps, 0.87 for PALZ, and 0.95 for VROI-SVM. Pairwise comparisons of Youden index did not show statistically significant differences in diagnostic performance between VROI-1, VROI-2, SPM-Maps, and PALZ score whereas VROI-SVM performed significantly (p < 0.005) better than any of the other methods., Conclusion: The study confirms the good accuracy of [18]F-FDG-PET in discriminating healthy subjects from pAD and highlights that a non-linear, automatic VROI classifier based on SVM performs better than the voxel-based methods.
- Published
- 2019
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13. The renaissance of functional 18 F-FDG PET brain activation imaging.
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Verger A and Guedj E
- Subjects
- Humans, Brain diagnostic imaging, Brain physiology, Fluorodeoxyglucose F18, Positron-Emission Tomography
- Published
- 2018
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14. Brain PET substrate of impulse control disorders in Parkinson's disease: A metabolic connectivity study.
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Verger A, Klesse E, Chawki MB, Witjas T, Azulay JP, Eusebio A, and Guedj E
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- Brain diagnostic imaging, Brain Mapping, Disruptive, Impulse Control, and Conduct Disorders diagnostic imaging, Female, Fluorodeoxyglucose F18, Humans, Male, Middle Aged, Neural Pathways diagnostic imaging, Neural Pathways metabolism, Parkinson Disease diagnostic imaging, Parkinson Disease psychology, Radiopharmaceuticals, Brain metabolism, Disruptive, Impulse Control, and Conduct Disorders metabolism, Parkinson Disease metabolism, Positron-Emission Tomography
- Abstract
Impulse control disorders (ICDs) have received increased attention in Parkinson's disease (PD) because of potentially dramatic consequences. Their physiopathology, however, remains incompletely understood. An overstimulation of the mesocorticolimbic system has been reported, while a larger network has recently been suggested. The aim of this study is to specifically describe the metabolic PET substrate and related connectivity changes in PD patients with ICDs. Eighteen PD patients with ICDs and 18 PD patients without ICDs were evaluated using cerebral 18F-fluorodeoxyglucose positron emission tomography. SPM-T maps comparisons were performed between groups and metabolic connectivity was evaluated by interregional correlation analysis (IRCA; p < .005, uncorrected; k > 130) and by graph theory (p < .05). PD patients with ICDs had relative increased metabolism in the right middle and inferior temporal gyri compared to those without ICDs. The connectivity of this area was increased mostly with the mesocorticolimbic system, positively with the orbitofrontal region, and negatively with both the right parahippocampus and the left caudate (IRCA). Moreover, the betweenness centrality of this area with the mesocorticolimbic system was lost in patients with ICDs (graph analysis). ICDs are associated in PD with the dysfunction of a network exceeding the mesocorticolimbic system, and especially the caudate, the parahippocampus, and the orbitofrontal cortex, remotely including the right middle and inferior temporal gyri. This latest area loses its central place with the mesocorticolimbic system through a connectivity dysregulation., (© 2018 Wiley Periodicals, Inc.)
- Published
- 2018
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15. Added value of 18 F-florbetaben amyloid PET in the diagnostic workup of most complex patients with dementia in France: A naturalistic study.
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Ceccaldi M, Jonveaux T, Verger A, Krolak-Salmon P, Houzard C, Godefroy O, Shields T, Perrotin A, Gismondi R, Bullich S, Jovalekic A, Raffa N, Pasquier F, Semah F, Dubois B, Habert MO, Wallon D, Chastan M, Payoux P, Stephens A, and Guedj E
- Subjects
- Aged, Brain metabolism, Dementia metabolism, Diagnosis, Differential, Female, France, Humans, Male, Amyloid metabolism, Aniline Compounds, Brain diagnostic imaging, Dementia diagnostic imaging, Positron-Emission Tomography, Radiopharmaceuticals, Stilbenes
- Abstract
Introduction: Although some studies have previously addressed the clinical impact of amyloid positron emission tomography (PET), none has specifically addressed its selective and hierarchical implementation in relation to cerebrospinal fluid analysis in a naturalistic setting., Methods: This multicenter study was performed at French tertiary memory clinics in patients presenting with most complex clinical situations (i.e., early-onset, atypical clinical profiles, suspected mixed etiological conditions, unexpected rate of progression), for whom cerebrospinal fluid analysis was indicated but either not feasible or considered as noncontributory (ClinicalTrials.gov: NCT02681172)., Results: Two hundred five patients were enrolled with evaluable florbetaben PET scans; 64.4% of scans were amyloid positive. PET results led to changed diagnosis and improved confidence in 66.8% and 81.5% of patients, respectively, and altered management in 80.0% of cases., Discussion: High-level improvement of diagnostic certainty and management is provided by selective and hierarchical implementation of florbetaben PET into current standard practices for the most complex dementia cases., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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16. Brain molecular imaging in pharmacoresistant focal epilepsy: Current practice and perspectives.
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Verger A, Lagarde S, Maillard L, Bartolomei F, and Guedj E
- Subjects
- Electroencephalography, Fluorodeoxyglucose F18, Humans, Magnetic Resonance Imaging, Positron-Emission Tomography, Radiopharmaceuticals, Tomography, Emission-Computed, Single-Photon, Brain diagnostic imaging, Drug Resistant Epilepsy diagnostic imaging, Epilepsies, Partial diagnostic imaging, Molecular Imaging methods
- Abstract
This review aims to synthesize all the available data on brain molecular imaging, such as single-photon emission computed tomography (SPECT) and interictal fluorodeoxyglucose positron emission tomography (FDG-PET), in focal epilepsies. SPECT imaging is able to measure regional cerebral blood flow and its major innovation remains its ictal imaging value. On the other hand, FDG-PET, which has higher spatial resolution and lower background activity than SPECT, enables glycolytic metabolism to be identified in interictal states. Therefore, interictal FDG-PET has greater sensitivity than interictal SPECT, especially in temporal lobe epilepsies (TLEs). Thus,
18 F-FDG-PET is a necessary step in the presurgical evaluation of TLEs, but also of extratemporal epilepsies (ETEs), contributing to >30% of the decision to undertake surgery. In addition, FDG-PET has particular diagnostic value in focal epilepsies showing normal magnetic resonance imaging (MRI). PET also has good prognostic value for post-surgical outcomes as well as cognitive impairment, especially in cases where the hypometabolism extent is limited. Moreover, the notion of an epileptic network is well highlighted by functional PET imaging, allowing better understanding of the pathological substrates of these disorders. Future development of quantitative analysis software and of novel radiotracers and cameras will certainly enhance its clinical usefulness., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)- Published
- 2018
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17. Defining functioning levels in patients with schizophrenia: A combination of a novel clustering method and brain SPECT analysis.
- Author
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Faget-Agius C, Vincenti A, Guedj E, Michel P, Richieri R, Alessandrini M, Auquier P, Lançon C, and Boyer L
- Subjects
- Adult, Brain physiopathology, Female, Gyrus Cinguli diagnostic imaging, Gyrus Cinguli physiopathology, Humans, Male, Parietal Lobe diagnostic imaging, Parietal Lobe physiopathology, Reproducibility of Results, Schizophrenia classification, Schizophrenia diagnosis, Brain diagnostic imaging, Cluster Analysis, Neuroimaging, Schizophrenia diagnostic imaging, Schizophrenia physiopathology, Tomography, Emission-Computed, Single-Photon
- Abstract
This study aims to define functioning levels of patients with schizophrenia by using a method of interpretable clustering based on a specific functioning scale, the Functional Remission Of General Schizophrenia (FROGS) scale, and to test their validity regarding clinical and neuroimaging characterization. In this observational study, patients with schizophrenia have been classified using a hierarchical top-down method called clustering using unsupervised binary trees (CUBT). Socio-demographic, clinical, and neuroimaging SPECT perfusion data were compared between the different clusters to ensure their clinical relevance. A total of 242 patients were analyzed. A four-group functioning level structure has been identified: 54 are classified as "minimal", 81 as "low", 64 as "moderate", and 43 as "high". The clustering shows satisfactory statistical properties, including reproducibility and discriminancy. The 4 clusters consistently differentiate patients. "High" functioning level patients reported significantly the lowest scores on the PANSS and the CDSS, and the highest scores on the GAF, the MARS and S-QoL 18. Functioning levels were significantly associated with cerebral perfusion of two relevant areas: the left inferior parietal cortex and the anterior cingulate. Our study provides relevant functioning levels in schizophrenia, and may enhance the use of functioning scale., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
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18. Evaluation of factors influencing 18 F-FET uptake in the brain.
- Author
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Verger A, Stegmayr C, Galldiks N, Van Der Gucht A, Lohmann P, Stoffels G, Shah NJ, Fink GR, Eickhoff SB, Guedj E, and Langen KJ
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Body Mass Index, Brain metabolism, Brain Neoplasms metabolism, Female, Humans, Male, Middle Aged, Reference Standards, Retrospective Studies, Sex Factors, Tyrosine pharmacokinetics, Young Adult, Brain diagnostic imaging, Brain Neoplasms diagnostic imaging, Positron-Emission Tomography methods, Tyrosine analogs & derivatives
- Abstract
PET using the amino-acid O-(2-
18 F-fluoroethyl)-l-tyrosine (18 F-FET) is gaining increasing interest for brain tumour management. Semi-quantitative analysis of tracer uptake in brain tumours is based on the standardized uptake value (SUV) and the tumour-to-brain ratio (TBR). The aim of this study was to explore physiological factors that might influence the relationship of SUV of18 F-FET uptake in various brain areas, and thus affect quantification of18 F-FET uptake in brain tumours. Negative18 F-FET PET scans of 107 subjects, showing an inconspicuous brain distribution of18 F-FET, were evaluated retrospectively. Whole-brain quantitative analysis with Statistical Parametric Mapping (SPM) using parametric SUV PET images, and volumes of interest (VOIs) analysis with fronto-parietal, temporal, occipital, and cerebellar SUV background areas were performed to study the effect of age, gender, height, weight, injected activity, body mass index (BMI), and body surface area (BSA). After multivariate analysis, female gender and high BMI were found to be two independent factors associated with increased SUV of18 F-FET uptake in the brain. In women, SUVmean of18 F-FET uptake in the brain was 23% higher than in men (p < 0.01). SUVmean of18 F-FET uptake in the brain was positively correlated with BMI (r = 0.29; p < 0.01). The influence of these factors on SUV of18 F-FET was similar in all brain areas. In conclusion, SUV of18 F-FET in the normal brain is influenced by gender and weakly by BMI, but changes are similar in all brain areas.- Published
- 2017
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19. FDG Brain PET/CT Revealing Bilateral Thalamostriatal Activation During a Symptomatic Episode in a Patient With Kleine-Levin Syndrome.
- Author
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Drouet C, Morel O, Verger A, Guedj E, and Boulahdour H
- Subjects
- Adolescent, Female, Fluorodeoxyglucose F18, Humans, Radiopharmaceuticals, Brain diagnostic imaging, Kleine-Levin Syndrome diagnostic imaging, Positron Emission Tomography Computed Tomography
- Abstract
We report the case of a 14-year-old girl with clinically diagnosed Kleine-Levin syndrome. Electroencephalogram and brain MRI were unremarkable. An FDG PET/CT scan was acquired during a symptomatic episode, while she was asleep, and another PET scan was obtained when she was asymptomatic, awake, and quiet. Comparison of both examinations demonstrated a bilateral activation of thalami, caudate nuclei, and lenticular nuclei. These findings may be linked to the implication of thalamostriatal structures in the regulation of sleep and wakefulness.
- Published
- 2017
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20. Brain 18 F-FDG PET Metabolic Abnormalities in Patients with Long-Lasting Macrophagic Myofascitis.
- Author
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Van Der Gucht A, Aoun Sebaiti M, Guedj E, Aouizerate J, Yara S, Gherardi RK, Evangelista E, Chalaye J, Cottereau AS, Verger A, Bachoud-Levi AC, Abulizi M, Itti E, and Authier FJ
- Subjects
- Adolescent, Adult, Aged, Brain diagnostic imaging, Brain Diseases, Metabolic diagnostic imaging, Chronic Disease, Cognition Disorders diagnostic imaging, Fasciitis diagnostic imaging, Female, Fluorodeoxyglucose F18 pharmacokinetics, Humans, Male, Middle Aged, Myositis diagnostic imaging, Radiopharmaceuticals pharmacokinetics, Reproducibility of Results, Sensitivity and Specificity, Young Adult, Brain metabolism, Brain Diseases, Metabolic metabolism, Cognition Disorders metabolism, Fasciitis metabolism, Glucose metabolism, Myositis metabolism, Positron-Emission Tomography methods
- Abstract
The aim of this study was to characterize brain metabolic abnormalities in patients with macrophagic myofascitis (MMF) and the relationship with cognitive dysfunction through the use of PET with
18 F-FDG. Methods: F-FDG PET brain imaging and a comprehensive battery of neuropsychological tests were performed in 100 consecutive MMF patients (age [mean ± SD], 45.9 ± 12 y; 74% women). Images were analyzed with statistical parametric mapping (SPM12). Through the use of analysis of covariance, all18 F-FDG PET brain images of MMF patients were compared with those of a reference population of 44 healthy subjects similar in age (45.4 ± 16 y;18 F-FDG PET brain images of MMF patients were compared with those of a reference population of 44 healthy subjects similar in age (45.4 ± 16 y; P = 0.87) and sex (73% women; P = 0.88). The neuropsychological assessment identified 4 categories of patients: those with no significant cognitive impairment ( n = 42), those with frontal subcortical (FSC) dysfunction ( n = 29), those with Papez circuit dysfunction ( n = 22), and those with callosal disconnection ( n = 7). Results: In comparison with healthy subjects, the whole population of patients with MMF exhibited a spatial pattern of cerebral glucose hypometabolism ( P < 0.001) involving the occipital lobes, temporal lobes, limbic system, cerebellum, and frontoparietal cortices, as shown by analysis of covariance. The subgroup of patients with FSC dysfunction exhibited a larger extent of involved areas (35,223 voxels vs. 13,680 voxels in the subgroup with Papez circuit dysfunction and 5,453 voxels in patients without cognitive impairment). Nonsignificant results were obtained for the last subgroup because of its small population size. Conclusion: Our study identified a peculiar spatial pattern of cerebral glucose hypometabolism that was most marked in MMF patients with FSC dysfunction. Further studies are needed to determine whether this pattern could represent a diagnostic biomarker of MMF in patients with chronic fatigue syndrome and cognitive dysfunction., (© 2017 by the Society of Nuclear Medicine and Molecular Imaging.)- Published
- 2017
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21. Temporal epilepsy lesions may be detected by the voxel-based quantitative analysis of brain FDG-PET images using an original block-matching normalization software.
- Author
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Verger A, Yagdigul Y, Van Der Gucht A, Poussier S, Guedj E, Maillard L, Malandain G, Hossu G, Fay R, Karcher G, and Marie PY
- Subjects
- Adult, Brain metabolism, Calibration, Epilepsy, Temporal Lobe metabolism, Female, Humans, Male, Retrospective Studies, Brain diagnostic imaging, Epilepsy, Temporal Lobe diagnostic imaging, Image Processing, Computer-Assisted methods, Positron-Emission Tomography, Software
- Abstract
Introduction: Statistical parametric mapping (SPM) provides useful voxel-by-voxel analyses of brain images from (18)F-fluorodesoxyglucose positron emission tomography (FDG-PET) after an initial step of spatial normalization through an anatomical template model. In the setting of the preoperative workup of patients with temporal epilepsy, this study aimed at assessing a block-matching (BM) normalization method, where most transformations are computed through small blocks, a principle that minimizes artefacts and overcomes additional image-filtering., Methods: Brain FDG-PET images from 31 patients with well-characterised temporal lobe epilepsy and among whom 22 had common mesial temporal lobe epilepsy were retrospectively analysed using both BM and conventional SPM normalization methods and with PET images from age-adjusted controls. Different threshold p values corrected for cluster volume were considered (0.01, 0.005, and 0.001)., Results: The use of BM provided equivalent values to those of SPM with regard to the overall volumes of temporal and extra-temporal hypometabolism, as well as similar sensitivity for detecting the involved temporal lobe, reaching 87 and 94 % for SPM and BM, respectively, at a threshold p value of 0.01. However, the ability to more accurately localize brain lesions within the mesial portion of the temporal lobe was a little higher with BM than with SPM with respective sensitivities reaching 78 % for BM and 45 % for SPM (p < 0.05)., Conclusions: BM normalization compares well with conventional SPM for the voxel-based quantitative analysis of the FDG-PET images from temporal epilepsy patients. Further studies in different population are needed to determine whether BM is truly an accurate alternative to SPM in this setting.
- Published
- 2016
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22. Functional brain substrate of quality of life in patients with schizophrenia: A brain SPECT multidimensional analysis.
- Author
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Faget-Agius C, Boyer L, Richieri R, Auquier P, Lançon C, and Guedj E
- Subjects
- Adult, Brain diagnostic imaging, Brain Mapping methods, Cerebral Cortex diagnostic imaging, Cerebral Cortex physiopathology, Cerebrovascular Circulation physiology, Female, Humans, Male, Occipital Lobe diagnostic imaging, Occipital Lobe physiopathology, Parietal Lobe diagnostic imaging, Parietal Lobe physiopathology, Retrospective Studies, Surveys and Questionnaires, Temporal Lobe diagnostic imaging, Temporal Lobe physiopathology, Brain physiopathology, Quality of Life, Schizophrenia physiopathology, Schizophrenic Psychology, Tomography, Emission-Computed, Single-Photon methods
- Abstract
The aim of this study was to investigate the functional brain substrate of quality of life (QoL) in patients with schizophrenia. Participants comprised 130 right-handed patients with schizophrenia who underwent whole-brain single photon emission computed tomography (SPECT) with (99m)Tc-labeled ethylcysteinate dimer ((99m)Tc-ECD) for exploring correlations of regional cerebral blood flow (rCBF) with the eight dimensions score of the Schizophrenia Quality of Life questionnaire (S-QoL 18). A significant positive correlation was found between the global index of the S-QoL 18 and rCBF in the right superior temporal sulcus and between psychological well-being dimension and rCBF in Brodmann area (BA)6, BA8, BA9, and BA10 and between self-esteem dimension and rCBF in striatum and between family relationship dimension and rCBF in BA1, BA2, BA3, BA4, BA8, BA22, BA40, BA42 and BA44 and between relationship with friends dimension and rCBF in BA44 and between physical well-being dimension and rCBF in parahippocampal gyrus, and finally between autonomy dimension and rCBF in cuneus and precuneus. A significant negative correlation was found between resilience dimension and rCBF in precuneus and between sentimental life dimension and rCBF in BA10. Our findings provide neural correlates of QoL. Brain regions involved in cognitions, emotional information processing and social cognition underlie the different QoL dimensions., (Copyright © 2016. Published by Elsevier Ireland Ltd.)
- Published
- 2016
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23. Early-onset and late-onset Alzheimer's disease are associated with distinct patterns of memory impairment.
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Joubert S, Gour N, Guedj E, Didic M, Guériot C, Koric L, Ranjeva JP, Felician O, Guye M, and Ceccaldi M
- Subjects
- Age Factors, Age of Onset, Aged, Aged, 80 and over, Alzheimer Disease diagnostic imaging, Alzheimer Disease pathology, Brain pathology, Executive Function physiology, Female, Humans, Magnetic Resonance Imaging, Male, Memory Disorders diagnostic imaging, Memory Disorders pathology, Middle Aged, Neuropsychological Tests, Alzheimer Disease psychology, Brain diagnostic imaging, Language, Memory physiology, Memory Disorders psychology
- Abstract
The goal of this study was to investigate the specific patterns of memory breakdown in patients suffering from early-onset Alzheimer's disease (EOAD) and late-onset Alzheimer's disease (LOAD). Twenty EOAD patients, twenty LOAD patients, twenty matched younger controls, and twenty matched older controls participated in this study. All participants underwent a detailed neuropsychological assessment, an MRI scan, an FDG-PET scan, and AD patients had biomarkers as supporting evidence of both amyloïdopathy and neuronal injury. Results of the neuropsychological assessment showed that both EOAD and LOAD groups were impaired in the domains of memory, executive functions, language, praxis, and visuoconstructional abilities, when compared to their respective control groups. EOAD and LOAD groups, however, showed distinct patterns of memory impairment. Even though both groups were similarly affected on measures of episodic, short term and working memory, in contrast semantic memory was significantly more impaired in LOAD than in EOAD patients. The EOAD group was not more affected than the LOAD group in any memory domain. EOAD patients, however, showed significantly poorer performance in other cognitive domains including executive functions and visuoconstructional abilities. A more detailed analysis of the pattern of semantic memory performance among patient groups revealed that the LOAD was more profoundly impaired, in tasks of both spontaneous recall and semantic recognition. Voxel-Based Morphometry (VBM) analyses showed that impaired semantic performance in patients was associated with reduced gray matter volume in the anterior temporal lobe (ATL) region, while PET-FDG analyses revealed that poorer semantic performance was associated with greater hypometabolism in the left temporoparietal region, both areas reflecting key regions of the semantic network. Results of this study indicate that EOAD and LOAD patients present with distinct patterns of memory impairment, and that a genuine semantic impairment may represent one of the clinical hallmarks of LOAD., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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24. Age-related changes in FDG brain uptake are more accurately assessed when applying an adaptive template to the SPM method of voxel-based quantitative analysis.
- Author
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Van Der Gucht A, Verger A, Guedj E, Malandain G, Hossu G, Yagdigul Y, Roch V, Poussier S, Maillard L, Karcher G, and Marie PY
- Subjects
- Adolescent, Adult, Aged, Algorithms, Biological Transport, Female, Humans, Male, Middle Aged, Young Adult, Aging, Brain diagnostic imaging, Brain metabolism, Fluorodeoxyglucose F18 metabolism, Image Processing, Computer-Assisted, Positron-Emission Tomography
- Abstract
Introduction: The impact of age is crucial and must be taken into account when applying a voxel-based quantitative analysis on brain images from [¹⁸F]-fluorodeoxyglucose Positron Emission Tomography (FDG-PET). This study aimed to determine whether age-related changes in brain FDG-PET images are more accurately assessed when the conventional statistical parametric mapping (SPM) normalization method is used with an adaptive template, obtained from analysed PET images using a Block-Matching (BM) algorithm to fit with the characteristics of these images., Methods: Age-related changes in FDG-PET images were computed with linear models in 84 neurologically healthy subjects (35 women, 19 to 82-year-old), and compared between results provided by the SPM normalization algorithm applied on its dedicated conventional template or on the adaptive BM template. A threshold P value of 0.05 was used together with a family-wise error correction., Results: The age-related changes in FDG-PET images were much more apparent when computed with the adaptive template than with the conventional template as evidenced by: (1) stronger correlation coefficients with age for the overall frontal and temporal uptake values (respective R² values of 0.20 and 0.07) and (2) larger extents of involved areas (13 and 5% of whole brain template volume, respectively), leading to reveal several age-dependent areas (especially in dorsolateral prefrontal, inferior temporal/fusiform and primary somatosensory cortices)., Conclusion: Age-related changes in brain FDG uptake may be more accurately determined when applying the SPM method of voxel-based quantitative analysis on a template that best fits the characteristics of the analysed TEP images.
- Published
- 2015
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25. A preoperative metabolic marker of parkinsonian apathy following subthalamic nucleus stimulation.
- Author
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Gesquière-Dando A, Guedj E, Loundou A, Carron R, Witjas T, Fluchère F, Delfini M, Mundler L, Regis J, Azulay JP, and Eusebio A
- Subjects
- Aged, Brain diagnostic imaging, Brain drug effects, Female, Fluorodeoxyglucose F18 pharmacokinetics, Humans, Image Processing, Computer-Assisted, Logistic Models, Male, Middle Aged, Parkinsonian Disorders diagnostic imaging, Positron-Emission Tomography, Treatment Outcome, Apathy physiology, Brain metabolism, Deep Brain Stimulation, Parkinsonian Disorders metabolism, Parkinsonian Disorders therapy, Subthalamic Nucleus physiology
- Abstract
Background: Subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson's disease (PD) has been associated with the development of postoperative apathy. Debate on the causes of postoperative apathy continues, and the dominant hypothesis is that stimulation or dopaminergic drug reductions are causal in its development. We hypothesized that a preoperative predisposition to apathy also could exist. To this end, we sought to identify a preoperative metabolic pattern using [(18)]Fluorodeoxyglucose Positron Emission Tomography (PET), which could be associated with the occurrence of postoperative apathy after STN-DBS for PD., Methods: Thirty-four patients with PD, not clinically apathetic, underwent an [(18)]Fluorodeoxyglucose-PET scan before surgery of STN-DBS, and were tested for the occurrence of apathy 1 y after surgery. Whole-brain voxel-based PET intergroup comparison (P < 0.005; corrected for the cluster) was evaluated between patients who developed apathy at 1 y and those who did not., Results: Eight patients (23.5%) became apathetic after surgery. Motor improvement and decrease in dopaminergic treatment were similar in both postoperative apathy and non-apathy groups. We found a cluster of significantly greater metabolism in the postoperative apathy group within the cerebellum, brainstem (in particular ventral tegmental area), temporal lobe, insula, amygdala, lentiform nucleus, subgenual anterior cingulate, and inferior frontal gyrus. A metabolic value above 68 could discriminate patients who would develop postoperative apathy with 100% sensitivity and 88.5% specificity., Conclusions: We describe a preoperative metabolic pattern associated with the development of apathy after STN-DBS in PD. This suggests the existence of a predisposition to apathy, which may further be triggered by perioperative drug modifications., (© 2015 International Parkinson and Movement Disorder Society.)
- Published
- 2015
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26. Central pulse pressure is a determinant of heart and brain remodeling in the elderly: a quantitative MRI and PET pilot study.
- Author
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Verger A, van der Gucht A, Guedj E, Marie PY, Hossu G, Mandry D, Morel O, Perrin M, Fay R, Benetos A, and Joly L
- Subjects
- Aged, Aged, 80 and over, Blood Pressure Determination, Brain metabolism, Female, Humans, Hypertension physiopathology, Magnetic Resonance Imaging, Male, Myocardium metabolism, Pilot Projects, Pulse, Blood Pressure, Brain pathology, Myocardium pathology
- Abstract
Objective: The sustained elevation of blood pressure (BP) and especially of central pulse pressure (cPP) leads to heart and brain damage. This pilot study was aimed to precise the relationships between peripheral and central BP levels, and the remodeling of heart and brain as objectively quantified by cardiac MRI and brain F-fluorodeoxyglucose (FDG)-PET imaging in the elderly., Methods: Twenty-eight apparently healthy elderly individuals (66-85 years old, 14 women) were prospectively recruited and allocated into two half groups, one with and one without hypertension, and all were referred for the quantitative determinations of peripheral and central BP using applanation tonometry, indexed left ventricular mass (per m of body surface area) using cardiac MRI, and brain metabolism with a voxel-based analysis of FDG-PET images adjusted for age and sex., Results: Indexed left ventricular mass, reflecting cardiac remodeling, was correlated with the overall pressure variables involving both peripheral and central levels of systolic and pulse pressure (all P ≤ 0.001). By contrast, brain metabolism was significantly correlated with only cPP (P < 0.02). A cPP of at least 50 mmHg was associated with both a lower metabolism in frontal areas (P = 0.005) and a higher indexed left ventricular mass (P = 0.03)., Conclusion: This pilot study suggests that, when quantified by MRI and PET imaging, left ventricular mass and brain metabolism of elderly individuals are related to the cPP and to the 50 mmHg threshold, corresponding to what has previously been documented for the risk of cardiovascular event.
- Published
- 2015
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27. rTMS in fibromyalgia: a randomized trial evaluating QoL and its brain metabolic substrate.
- Author
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Parkitny L, Alto P, O'Connell NE, Guedj E, and Boyer L
- Subjects
- Female, Humans, Male, Brain metabolism, Fibromyalgia metabolism, Fibromyalgia therapy, Quality of Life, Transcranial Magnetic Stimulation
- Published
- 2014
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28. Neurophysiological correlates of metabolic syndrome and cognitive impairment in schizophrenia: a structural equation modeling approach.
- Author
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Boyer L, Testart J, Michel P, Richieri R, Faget-Agius C, Vanoye V, Auquier P, Lancon C, and Guedj E
- Subjects
- Adult, Brain diagnostic imaging, Cerebrovascular Circulation physiology, Cognition Disorders complications, Cognition Disorders diagnostic imaging, Cross-Sectional Studies, Female, Humans, Male, Metabolic Syndrome complications, Metabolic Syndrome diagnostic imaging, Middle Aged, Neuropsychological Tests, Radionuclide Imaging, Schizophrenia complications, Schizophrenia diagnostic imaging, Brain physiopathology, Cognition Disorders physiopathology, Metabolic Syndrome physiopathology, Models, Theoretical, Schizophrenia physiopathology
- Abstract
Objective: We aimed to investigate the brain functional substrate underlying relationships between metabolic syndrome (MetS) and cognitive impairment in schizophrenia., Methods: In this cross-sectional study, we collected socio-demographic, clinical, anthropometric, blood, and cognition data and performed brain 99mTc-ECD-SPECT imaging of cerebral blood flow in patients with schizophrenia. Patients were grouped according to the absence or presence of MetS. Whole-brain perfusion SPECTs were compared at voxel level between these two groups, and voxel-wise interregional correlation was performed to compare functional connectivity (voxel level significance of p<0.005, uncorrected; p<0.05 for the cluster, uncorrected; using SPM8). A structural equation model (SEM) was applied to examine the relationships between brain perfusion, connectivity between brain areas, and cognition., Results: Of the 55 patients, 17 had MetS. They performed significantly worse than patients without MetS on tests of executive functions (processing speed p=0.005 for TMT-A; and reactive flexibility p=0.014 for TMT-B), attention (D2 attention task p=0.007), and memory (California Verbal Learning Test p=0.039). In comparison to patients without MetS, those with MetS exhibited significant hypoperfusion within the left orbital prefrontal cortex and greater functional connectivity from this left frontal cluster within the left insula and middle/superior frontal gyrus. SEM confirmed the effect on executive functions of brain hypoperfusion and of increased connectivity, suggesting possible compensatory networks in patients with MetS., Conclusion: Our study identifies the brain functional impact of MetS on cognition, with orbital prefrontal impairment and possible compensatory networks., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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29. Volume of interest-based [18F]fluorodeoxyglucose PET discriminates MCI converting to Alzheimer's disease from healthy controls. A European Alzheimer's Disease Consortium (EADC) study.
- Author
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Pagani M, De Carli F, Morbelli S, Öberg J, Chincarini A, Frisoni GB, Galluzzi S, Perneczky R, Drzezga A, van Berckel BN, Ossenkoppele R, Didic M, Guedj E, Brugnolo A, Picco A, Arnaldi D, Ferrara M, Buschiazzo A, Sambuceti G, and Nobili F
- Subjects
- Aged, Aged, 80 and over, Disease Progression, Female, Fluorodeoxyglucose F18, Humans, Male, Middle Aged, Positron-Emission Tomography, Radiopharmaceuticals, Alzheimer Disease diagnostic imaging, Brain diagnostic imaging, Cognitive Dysfunction diagnostic imaging, Image Interpretation, Computer-Assisted methods
- Abstract
An emerging issue in neuroimaging is to assess the diagnostic reliability of PET and its application in clinical practice. We aimed at assessing the accuracy of brain FDG-PET in discriminating patients with MCI due to Alzheimer's disease and healthy controls. Sixty-two patients with amnestic MCI and 109 healthy subjects recruited in five centers of the European AD Consortium were enrolled. Group analysis was performed by SPM8 to confirm metabolic differences. Discriminant analyses were then carried out using the mean FDG uptake values normalized to the cerebellum computed in 45 anatomical volumes of interest (VOIs) in each hemisphere (90 VOIs) as defined in the Automated Anatomical Labeling (AAL) Atlas and on 12 meta-VOIs, bilaterally, obtained merging VOIs with similar anatomo-functional characteristics. Further, asymmetry indexes were calculated for both datasets. Accuracy of discrimination by a Support Vector Machine and the AAL VOIs was tested against a validated method (PALZ). At the voxel level SMP8 showed a relative hypometabolism in the bilateral precuneus, and posterior cingulate, temporo-parietal and frontal cortices. Discriminant analysis classified subjects with an accuracy ranging between .91 and .83 as a function of data organization. The best values were obtained from a subset of 6 meta-VOIs plus 6 asymmetry values reaching an area under the ROC curve of .947, significantly larger than the one obtained by the PALZ score. High accuracy in discriminating MCI converters from healthy controls was reached by a non-linear classifier based on SVM applied on predefined anatomo-functional regions and inter-hemispheric asymmetries. Data pre-processing was automated and simplified by an in-house created Matlab-based script encouraging its routine clinical use. Further validation toward nonconverter MCI patients with adequately long follow-up is needed.
- Published
- 2014
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30. Brain PET metabolic abnormalities in a case of varicella-zoster virus encephalitis.
- Author
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Coiffard B, Guedj E, Daumas A, Leveque P, and Villani P
- Subjects
- Aged, Aged, 80 and over, Case-Control Studies, Female, Humans, Radionuclide Imaging, Brain diagnostic imaging, Encephalitis, Varicella Zoster diagnostic imaging
- Abstract
The role of brain 18F-FDG PET in the diagnostic evaluation of encephalitis has been recently suggested, especially in limbic encephalitis, but descriptions are mainly limited to small case reports. However, the evaluation of cerebral metabolism by 18F-FDG PET has never been described for varicella-zoster virus encephalitis. We report the first case of varicella-zoster virus encephalitis in which 18F-FDG PET revealed brain metabolic abnormalities. Brain metabolic PET imaging was analyzed by comparing the patient's brain 18F-FDG PET scans to that of 12 healthy subjects. Compared with healthy subjects, significant hypometabolism and hypermetabolism were found and evolved over time with treatment.
- Published
- 2014
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31. rTMS in fibromyalgia: a randomized trial evaluating QoL and its brain metabolic substrate.
- Author
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Boyer L, Dousset A, Roussel P, Dossetto N, Cammilleri S, Piano V, Khalfa S, Mundler O, Donnet A, and Guedj E
- Subjects
- Adult, Aged, Brain pathology, Brain Mapping methods, Double-Blind Method, Female, Fibromyalgia physiopathology, Humans, Male, Middle Aged, Surveys and Questionnaires, Treatment Outcome, Brain metabolism, Fibromyalgia metabolism, Fibromyalgia therapy, Quality of Life, Transcranial Magnetic Stimulation methods
- Abstract
Objective: This double-blind, randomized, placebo-controlled study investigated the impact of repetitive transcranial magnetic stimulation (rTMS) on quality of life (QoL) of patients with fibromyalgia, and its possible brain metabolic substrate., Methods: Thirty-eight patients were randomly assigned to receive high-frequency rTMS (n = 19) or sham stimulation (n = 19), applied to left primary motor cortex in 14 sessions over 10 weeks. Primary clinical outcomes were QoL changes at the end of week 11, measured using the Fibromyalgia Impact Questionnaire (FIQ). Secondary clinical outcomes were mental and physical QoL component measured using the 36-Item Short Form Health Survey (SF-36), but also pain, mood, and anxiety. Resting-state [(18)F]-fluorodeoxyglucose-PET metabolism was assessed at baseline, week 2, and week 11. Whole-brain voxel-based analysis was performed to study between-group metabolic changes over time., Results: At week 11, patients of the active rTMS group had greater QoL improvement in the FIQ (p = 0.032) and in the mental component of the SF-36 (p = 0.019) than the sham stimulation group. No significant impact was found for other clinical outcomes. Compared with the sham stimulation group, patients of the active rTMS group presented an increase in right medial temporal metabolism between baseline and week 11 (p < 0.001), which was correlated with FIQ and mental component SF-36 concomitant changes (r = -0.38, p = 0.043; r = 0.51, p = 0.009, respectively). QoL improvement involved mainly affective, emotional, and social dimensions., Conclusion: Our study shows that rTMS improves QoL of patients with fibromyalgia. This improvement is associated with a concomitant increase in right limbic metabolism, arguing for a neural substrate to the impact of rTMS on emotional dimensions involved in QoL., Classification of Evidence: This study provides Class II evidence that rTMS compared with sham rTMS improves QoL in patients with fibromyalgia.
- Published
- 2014
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32. Distinct patterns of medial temporal impairment in degenerative dementia: a brain SPECT perfusion study in Alzheimer's disease and frontotemporal dementia.
- Author
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Basely M, Ceccaldi M, Boyer L, Mundler O, and Guedj E
- Subjects
- Aged, Aged, 80 and over, Alzheimer Disease diagnosis, Case-Control Studies, Female, Frontotemporal Dementia diagnosis, Hippocampus pathology, Humans, Male, Middle Aged, Perfusion, ROC Curve, Time Factors, Alzheimer Disease diagnostic imaging, Brain pathology, Dementia diagnosis, Dementia pathology, Frontotemporal Dementia diagnostic imaging, Tomography, Emission-Computed, Single-Photon
- Abstract
Purpose: Medial temporal impairment can be detected clinically and by morphological imaging during Alzheimer's disease (AD), but the existence of a functional impairment in this area seems to be less well established. Yet such functional impairment is classically found in other degenerative cortical dementias, such as the frontal variant of frontotemporal dementia (fv-FTD). The aim of this study was to characterize and compare brain SPECT perfusion of the medial temporal lobe in AD and fv-FTD., Methods: Voxel-based comparisons were performed using SPM8 between cerebral SPECT images from 85 AD patients, 25 fv-FTD patients and 12 healthy controls at the whole-brain level and the medial temporal lobe level using a region of interest approach (p < 0.001, corrected for the cluster)., Results: In the free and cued selective reminding test, used to evaluate medial temporal memory function, AD patients had significantly lower scores than the fv-FTD patients (p < 0.005). AD and fv-FTD patients showed hypoperfused medial temporal structures in comparison to normal controls. However, fv-FTD patients had more pronounced hypoperfusion in this area, with a different topography, more anterior and more parahippocampal., Conclusion: These results show that medial temporal hypoperfusion can be detected in degenerative dementias by SPECT. Paradoxically, the hypoperfusion is more severe in fv-FTD than in AD patients, even though the mnesic profile of AD is more altered, suggesting the existence of inefficient compensatory mechanisms.
- Published
- 2013
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33. Combining neurophysiological and functional neuroimaging biomarkers to predict rTMS non-response in depression.
- Author
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Micoulaud-Franchi JA, Richieri R, Boyer L, Lançon C, Vion-Dury J, and Guedj E
- Subjects
- Electroencephalography, Female, Fourier Analysis, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Oxygen, Positron-Emission Tomography, ROC Curve, Regional Blood Flow, Tomography, Emission-Computed, Single-Photon, Brain blood supply, Brain diagnostic imaging, Brain pathology, Depressive Disorder, Major diagnosis, Depressive Disorder, Major therapy, Functional Neuroimaging, Transcranial Magnetic Stimulation
- Published
- 2013
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34. Relationship between emotional experience and resilience: an fMRI study in fire-fighters.
- Author
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Reynaud E, Guedj E, Souville M, Trousselard M, Zendjidjian X, El Khoury-Malhame M, Fakra E, Nazarian B, Blin O, Canini F, and Khalfa S
- Subjects
- Amygdala blood supply, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Oxygen blood, Photic Stimulation, Young Adult, Adaptation, Psychological physiology, Brain blood supply, Brain physiology, Brain Mapping, Emotions physiology, Firefighters psychology
- Abstract
Resilience refers to the capacity to cope effectively in stressful situations or adversity. It may involve the ability to experience emotions matching the demands of environmental circumstances. The brain mechanisms underlying resilience remain unclear. In this study, we aim to investigate the relationship between the neural basis of emotional experience and resilience. Thirty-six fire-fighters were included. They performed an fMRI script-driven paradigm comprising relaxing and trauma-related scripts to evaluate the cerebral substrate of emotional experience (p<0.05, FDR-corrected). Correlations were examined between fMRI activations and the resilience DRS15 scale (p<0.05). Resilience was positively correlated with the right amygdala and left orbitofrontal activations when performing the contrast of trauma vs. relaxing script. The present study provides neural data on the mechanisms underlying resilience and their relationship with emotional reactivity, suggesting that appropriate emotional response in stressful situations is essential for coping with aversive events in daily life., (Published by Elsevier Ltd.)
- Published
- 2013
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35. Voxel-based analysis of whole-brain effects of age and gender on dopamine transporter SPECT imaging in healthy subjects.
- Author
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Eusebio A, Azulay JP, Ceccaldi M, Girard N, Mundler O, and Guedj E
- Subjects
- Adult, Age Factors, Aged, Female, Humans, Male, Middle Aged, Sex Characteristics, Tropanes metabolism, Brain diagnostic imaging, Dopamine Plasma Membrane Transport Proteins metabolism, Tomography, Emission-Computed, Single-Photon
- Abstract
Purpose: Several studies have shown age- and gender-related differences in striatal dopamine transporter (DaT) binding. These studies were based on a striatal region on interest approach that may have underestimated these effects and could not evaluate extrastriatal regions. Our aim was to determine the effects at the voxel level of age and gender on whole-brain DaT distribution using [(123)I]FP-CIT SPECT in healthy subjects., Methods: We performed a whole-brain [(123)I]FP-CIT SPECT voxel-based analysis using SPM8 and a standardized normalization template (p < 0.05, corrected using the false discovery rate method) in 51 healthy subjects aged from 21 to 79 years., Results: We found an age-related DaT binding decrease in the striatum, anterior cingulate/medial frontal cortices and insulo-opercular cortices. Also DaT binding ratios were higher in women than men in the striatum and opercular cortices., Conclusion: This study showed both striatal and extrastriatal age-related and gender-related differences in DaT binding in healthy subjects using a whole-brain voxel-based non-a priori approach. These differences highlight the need for careful age and gender matching in DaT analyses of neuropsychiatric disorders.
- Published
- 2012
- Full Text
- View/download PDF
36. Kleine-Levin syndrome: functional imaging correlates of hypersomnia and behavioral symptoms.
- Author
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Haba-Rubio J, Prior JO, Guedj E, Tafti M, Heinzer R, and Rossetti AO
- Subjects
- Adolescent, Brain diagnostic imaging, Brain metabolism, Disorders of Excessive Somnolence metabolism, Female, Fluorodeoxyglucose F18, Humans, Kleine-Levin Syndrome metabolism, Male, Radiopharmaceuticals, Brain physiopathology, Disorders of Excessive Somnolence diagnostic imaging, Disorders of Excessive Somnolence physiopathology, Kleine-Levin Syndrome diagnostic imaging, Kleine-Levin Syndrome physiopathology, Positron-Emission Tomography methods
- Published
- 2012
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- View/download PDF
37. Metabolic brain PET pattern underlying hyperkinetic seizures.
- Author
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Guedj E, McGonigal A, Vaugier L, Mundler O, and Bartolomei F
- Subjects
- Adolescent, Adult, Brain metabolism, Brain Mapping, Child, Child, Preschool, Female, Humans, Hyperkinesis metabolism, Male, Middle Aged, Radionuclide Imaging, Seizures metabolism, Brain diagnostic imaging, Hyperkinesis diagnostic imaging, Seizures diagnostic imaging
- Abstract
This study aims to contribute to the identification of selective brain regions involved in hyperkinetic behaviors. We studied the whole-brain voxel-based interictal metabolic 18FDG-PET pattern of 23 patients with hyperkinetic seizures, in comparison with both 15 healthy subjects similar for age and gender, and 23 patients without hyperkinetic seizures. Patients were in particular similar for the localization of the epileptogenic zone, this having been defined using stereoelectroencephalography (SEEG) when clinically indicated (15/23 patients with hyperkinetic seizures and 13/23 patients without hyperkinetic seizures). Using conjunction voxel-based analysis, patients with hyperkinetic seizures exhibited significant hypometabolism within bilateral midbrain and the right caudate head, in comparison both to healthy subjects (p<0.05, FDR-corrected for the voxel) and to patients without hyperkinetic seizures (p<0.0167, uncorrected for the voxel). Findings were secondarily confirmed separately in each subgroup of patients with frontal, temporal or posterior epilepsy. These findings argue for a specific subcortical metabolic impairment in patients with hyperkinetic seizures, within brain structures supposed to be involved in the generation of primitive motor programs., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
38. Predictive value of brain perfusion SPECT for rTMS response in pharmacoresistant depression.
- Author
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Richieri R, Boyer L, Farisse J, Colavolpe C, Mundler O, Lancon C, and Guedj E
- Subjects
- Cerebrovascular Circulation, Cysteine analogs & derivatives, Depressive Disorder, Major diagnostic imaging, Depressive Disorder, Major drug therapy, Depressive Disorder, Major physiopathology, Female, Humans, Male, Middle Aged, Organotechnetium Compounds, Predictive Value of Tests, ROC Curve, Treatment Outcome, Brain blood supply, Brain diagnostic imaging, Depressive Disorder, Major therapy, Drug Resistance, Perfusion Imaging, Tomography, Emission-Computed, Single-Photon, Transcranial Magnetic Stimulation
- Abstract
Purpose: The aim of this study was to determine the predictive value of whole-brain voxel-based regional cerebral blood flow (rCBF) for repetitive transcranial magnetic stimulation (rTMS) response in patients with pharmacoresistant depression., Methods: Thirty-three right-handed patients who met DSM-IV criteria for major depressive disorder (unipolar or bipolar depression) were included before rTMS. rTMS response was defined as at least 50% reduction in the baseline Beck Depression Inventory scores. The predictive value of (99m)Tc-ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) for rTMS response was studied before treatment by comparing rTMS responders to non-responders at voxel level using Statistical Parametric Mapping (SPM) (p < 0.001, uncorrected)., Results: Of the patients, 18 (54.5%) were responders to rTMS and 15 were non-responders (45.5%). There were no statistically significant differences in demographic and clinical characteristics (p > 0.10). In comparison to responders, non-responders showed significant hypoperfusions (p < 0.001, uncorrected) in the left medial and bilateral superior frontal cortices (BA10), the left uncus/parahippocampal cortex (BA20/BA35) and the right thalamus. The area under the curve for the combination of SPECT clusters to predict rTMS response was 0.89 (p < 0.001). Sensitivity, specificity, positive predictive value and negative predictive value for the combination of clusters were: 94, 73, 81 and 92%, respectively., Conclusion: This study shows that, in pharmacoresistant depression, pretreatment rCBF of specific brain regions is a strong predictor for response to rTMS in patients with homogeneous demographic/clinical features.
- Published
- 2011
- Full Text
- View/download PDF
39. Long-term consolidation of declarative memory: insight from temporal lobe epilepsy.
- Author
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Tramoni E, Felician O, Barbeau EJ, Guedj E, Guye M, Bartolomei F, and Ceccaldi M
- Subjects
- Adult, Analysis of Variance, Brain diagnostic imaging, Brain pathology, Female, Fluorodeoxyglucose F18, Humans, Magnetic Resonance Spectroscopy methods, Male, Memory Disorders diagnosis, Mental Recall physiology, Middle Aged, Neuropsychological Tests, Positron-Emission Tomography methods, Recognition, Psychology physiology, Time Factors, Brain metabolism, Epilepsy, Temporal Lobe complications, Memory Disorders etiology
- Abstract
Several experiments carried out with a subset of patients with temporal lobe epilepsy have demonstrated normal memory performance at standard delays of recall (i.e. minutes to hours) but impaired performance over longer delays (i.e. days or weeks), suggesting altered long-term consolidation mechanisms. These mechanisms were specifically investigated in a group of five adult-onset pharmaco-sensitive patients with temporal lobe epilepsy, exhibiting severe episodic memory complaints despite normal performance at standardized memory assessment. In a first experiment, the magnitude of autobiographical memory loss was evaluated using retrograde personal memory tasks based on verbal and visual cues. In both conditions, results showed an unusual U-shaped pattern of personal memory impairment, encompassing most of the patients' life, sparing however, periods of the childhood, early adulthood and past several weeks. This profile was suggestive of a long-term consolidation impairment of personal episodes, adequately consolidated over 'short-term' delays but gradually forgotten thereafter. Therefore, in a subsequent experiment, patients were submitted to a protocol specifically devised to investigate short and long-term consolidation of contextually-bound experiences (episodic memory) and context-free information (semantic knowledge and single-items). In the short term (1 h), performance at both contextually-free and contextually-bound memory tasks was intact. After a 6-week delay, however, contextually-bound memory performance was impaired while contextually-free memory performance remained preserved. This effect was independent of task difficulty and the modality of retrieval (recall and recognition). Neuroimaging studies revealed the presence of mild metabolic changes within medial temporal lobe structures. Taken together, these results show the existence of different consolidation systems within declarative memory. They suggest that mild medial temporal lobe dysfunction can impede the building and stabilization of episodic memories but leaves long-term semantic and single-items mnemonic traces intact.
- Published
- 2011
- Full Text
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40. Which memory system is impaired first in Alzheimer's disease?
- Author
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Didic M, Barbeau EJ, Felician O, Tramoni E, Guedj E, Poncet M, and Ceccaldi M
- Subjects
- Brain metabolism, Humans, Neurofibrillary Tangles metabolism, Neurofibrillary Tangles pathology, Alzheimer Disease complications, Alzheimer Disease pathology, Brain pathology, Memory Disorders etiology
- Abstract
Diagnosis of Alzheimer's disease (AD) in its earliest stages becomes increasingly important as disease modifying agents are being developed. In this area of research, many clinical and neuroimaging studies focus on markers of hippocampal dysfunction. However, during the "transentorhinal stage" of AD, neurofibrillary tangles (NFT), related to tau protein pathology, develop in the anterior subhippocampal (perirhinal/entorhinal) cortex before the hippocampus. NFT are tightly correlated with clinical symptoms. Therefore, an accurate understanding of the behavioral correlate of transentorhinal dysfunction could critically contribute to the early diagnosis of the disease. Recent findings from studies in animals and human brain-damaged patients suggest that the anterior subhippocampal region, functionally integrated into an anterior mesiotemporal network, is involved in object based context-free memory. In this article, we evaluate the hypothesis according to which tau deposition in the anterior subhippocampal region during the earliest stages of the most common form of AD, with predominant MTL dysfunction, will lead to dysfunction of neural networks implicated in context-free memory. We challenge the view that impaired episodic memory is the hallmark of early AD. Instead, a model that integrates the localization and temporal sequence of NFT within the mesial temporal lobe (MTL) is proposed. Paralleling the development of NFT in anterior subhippocampal areas, impaired context-free, object-based, memory could be the first detectable sign in AD. In a subsequent, "hippocampal" stage, context-rich, episodic and spatial memory, becomes altered as well. The question as to the "episodic" nature of "episodic memory tasks" is also addressed.
- Published
- 2011
- Full Text
- View/download PDF
41. Route and survey processing of topographical memory during navigation.
- Author
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Latini-Corazzini L, Nesa MP, Ceccaldi M, Guedj E, Thinus-Blanc C, Cauda F, D'Agata F, and Péruch P
- Subjects
- Adult, Brain Mapping, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Photic Stimulation, Psychomotor Performance physiology, Space Perception physiology, User-Computer Interface, Brain physiology, Exploratory Behavior physiology, Memory physiology, Spatial Behavior physiology
- Abstract
We investigated the characteristics of route and survey processing of a unique complex virtual environment both at the behavioral and brain levels. Prior to fMRI scanning, participants were trained to follow a route and to learn the spatial relationships between several places, acquiring both route and survey knowledge from a ground-level perspective. During scanning, snapshots of the environment were presented, and participants were required to either indicate the direction to take to follow the route (route task), or to locate unseen targets (survey task). Data suggest that route and survey processing are mainly supported by a common occipito-fronto-parieto-temporal neural network. Our results are consistent with those gathered in studies concerning the neural bases of route versus survey knowledge acquired either from different perspectives or in different environments. However, rather than arguing for a clear distinction between route and survey processing, "mixed" strategies are likely to be involved when both types of encoding take place in the same environment.
- Published
- 2010
- Full Text
- View/download PDF
42. Déjà-vu in temporal lobe epilepsy: metabolic pattern of cortical involvement in patients with normal brain MRI.
- Author
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Guedj E, Aubert S, McGonigal A, Mundler O, and Bartolomei F
- Subjects
- Adult, Brain diagnostic imaging, Brain Mapping, Case-Control Studies, Female, Fluorodeoxyglucose F18 metabolism, Functional Laterality, Humans, Magnetic Resonance Imaging methods, Male, Middle Aged, Neuropsychological Tests, Positron-Emission Tomography methods, Young Adult, Brain metabolism, Deja Vu, Epilepsy, Temporal Lobe complications, Epilepsy, Temporal Lobe pathology, Memory Disorders etiology
- Abstract
To contribute to the identification of brain regions involved in déjà-vu, we studied the metabolic pattern of cortical involvement in patients with seizures of temporal lobe origin presenting with or without déjà-vu. Using voxel-based analysis of 18FDG-PET brain scans, we compared glucose metabolic rate of 8 patients with déjà-vu, 8 patients without déjà-vu, and 20 age-matched healthy subjects. Patients were selected after comprehensive non-invasive presurgical evaluation, including normal brain MRI and surface electroclinical features compatible with unilateral temporal lobe epilepsy (TLE). Patients with and without déjà-vu did not differ in terms of age, gender, epilepsy lateralization, epilepsy onset, epilepsy duration, and other subjective ictal manifestations. TLE patients with déjà-vu exhibited ipsilateral hypometabolism of superior temporal gyrus and of parahippocampal region, in the vicinity of perirhinal/entorhinal cortex, in comparison either to healthy subjects or to TLE patients without déjà-vu (p<0.05 FDR-corrected). By contrast, no difference was found between patient subgroups for hypometabolism of hippocampus and amygdala. At an individual-level, in comparison to healthy subjects, hypometabolism of both parahippocampal region and superior temporal gyrus was present in 7/8 patients with déjà-vu. Hippocampal metabolism was spared in 3 of these 7 patients. These findings argue for metabolic dysfunction of a medial-lateral temporal network in patients with déjà-vu and normal brain MRI. Within the medial temporal lobe, specific involvement of the parahippocampal region, often in the absence of hippocampal impairment, suggests that the feeling of familiarity during seizures greatly depends on alteration of the recognition memory system., (Copyright 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
43. Neuroimaging findings in fibromyalgia: what clinical impact?
- Author
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Guedj E
- Subjects
- Brain blood supply, Cerebrovascular Circulation, Fibromyalgia complications, Fibromyalgia physiopathology, Humans, Magnetic Resonance Imaging methods, Pain etiology, Pain physiopathology, Tomography, Emission-Computed, Single-Photon methods, Brain pathology, Diagnostic Imaging methods, Fibromyalgia diagnosis, Pain diagnosis
- Published
- 2009
- Full Text
- View/download PDF
44. Clinical correlate of brain SPECT perfusion abnormalities in fibromyalgia.
- Author
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Guedj E, Cammilleri S, Niboyet J, Dupont P, Vidal E, Dropinski JP, and Mundler O
- Subjects
- Adult, Anxiety complications, Case-Control Studies, Depression complications, Female, Fibromyalgia complications, Humans, Middle Aged, Pain, Pregnancy, Statistics as Topic, Tomography, Emission-Computed, Single-Photon, Brain blood supply, Brain diagnostic imaging, Fibromyalgia diagnostic imaging, Fibromyalgia physiopathology
- Abstract
Unlabelled: The purpose of this study was to investigate the specific clinical correlate of brain SPECT perfusion abnormalities reported in fibromyalgia., Methods: We performed a whole-brain voxel-based correlation analysis involving regional cerebral blood flow and various parameters related to pain (Visual Analog Scale, Tubingen Pain Behavior Scale, and Questionnaire Douleur de Saint-Antoine Scale), disability (Fibromyalgia Impact Questionnaire [FIQ]), and anxiety and depression status (Hospital Anxiety and Depression scale) in 20 patients with fibromyalgia (P voxel < 0.005). Ten healthy control women were also included, in order to determine areas of significant hypo- and hyperperfusions in patients., Results: FIQ total score was positively correlated with bilateral parietal perfusion, including postcentral cortex. These clusters of correlation were included in the areas of significant hyperperfusion. FIQ total score was also negatively correlated with perfusion of a left anterior temporal cluster, included in the areas of significant hypoperfusions. No other clinical correlation was observed with regional cerebral blood flow., Conclusion: These results show that brain perfusion abnormalities in patients with fibromyalgia are correlated with the clinical severity of the disease.
- Published
- 2008
- Full Text
- View/download PDF
45. A case of cerebello-thalamo-cortical diaschisis.
- Author
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Guedj E, Barrie M, Fuentes S, Chinot O, and Mundler O
- Subjects
- Humans, Male, Middle Aged, Radionuclide Imaging, Radiopharmaceuticals, Brain diagnostic imaging, Brain Diseases diagnostic imaging, Fluorodeoxyglucose F18
- Published
- 2008
- Full Text
- View/download PDF
46. Follow-up of pain processing recovery after ketamine in hyperalgesic fibromyalgia patients using brain perfusion ECD-SPECT.
- Author
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Guedj E, Cammilleri S, Colavolpe C, de Laforte C, Niboyet J, and Mundler O
- Subjects
- Adult, Aged, Anesthetics, Dissociative therapeutic use, Female, Follow-Up Studies, Humans, Male, Middle Aged, Pain diagnostic imaging, Pain prevention & control, Pain Measurement drug effects, Radiopharmaceuticals, Tomography, Emission-Computed, Single-Photon methods, Treatment Outcome, Brain diagnostic imaging, Cysteine analogs & derivatives, Fibromyalgia diagnostic imaging, Fibromyalgia drug therapy, Hyperalgesia diagnostic imaging, Hyperalgesia prevention & control, Ketamine therapeutic use, Organotechnetium Compounds, Pain Measurement methods
- Abstract
Purpose: The aim of this study was to determine whether the follow-up of pain processing recovery in hyperalgesic fibromyalgia (FM) could be objectively evaluated with brain perfusion ethyl cysteinate dimer single photon computerized tomography (ECD-SPECT) after administration of ketamine., Materials and Methods: We enrolled 17 hyperalgesic FM women patients (48.5 +/- 11 years, range 25-63). After treatment with subcutaneous ketamine, 11 patients were considered as "good responders", with a decrease in pain intensity, evaluated by visual analog scale (VAS), greater than 50%. On the other hand, six patients were considered as "poor responders". A voxel-based analysis of regional cerebral blood flow (rCBF) was conducted (p (voxel) < 0.001uc), in the two subgroups of patients, before and after treatment, in comparison to a group of ten healthy subjects, matched for age and gender., Results: In comparison to baseline brain SPECT, midbrain rCBF showed a greater increase after ketamine in the responder group than in the nonresponder group (p (cluster) = 0.016c). In agreement with the clinical response, the change in midbrain rCBF after ketamine was highly correlated with the reduction of VAS pain score (r = 0.7182; p = 0.0041)., Conclusion: This prospective study suggests that blockade of facilitatory descending modulation of pain with ketamine can be evaluated in the periaqueductal grey with brain perfusion SPECT.
- Published
- 2007
- Full Text
- View/download PDF
47. Brain spect perfusion of frontotemporal dementia associated with motor neuron disease.
- Author
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Guedj E, Le Ber I, Lacomblez L, Dubois B, Verpillat P, Didic M, Salachas F, Vera P, Hannequin D, Lotterie JA, Puel M, Decousus M, Thomas-Antérion C, Magne C, Vercelletto M, Bernard AM, Golfier V, Pasquier J, Michel BF, Namer I, Sellal F, Bochet J, Volteau M, Brice A, Meininger V, and Habert MO
- Subjects
- Aged, Brain blood supply, Brain Mapping, Cerebral Arteries diagnostic imaging, Cerebral Arteries physiopathology, Cerebrovascular Circulation physiology, Comorbidity, Dementia complications, Female, Humans, Image Processing, Computer-Assisted, Male, Middle Aged, Motor Neuron Disease complications, Predictive Value of Tests, Tomography, Emission-Computed, Single-Photon, Brain diagnostic imaging, Brain physiopathology, Dementia diagnostic imaging, Dementia physiopathology, Motor Neuron Disease diagnostic imaging, Motor Neuron Disease physiopathology
- Published
- 2007
- Full Text
- View/download PDF
48. 99mTc-ECD brain perfusion SPECT in hyperalgesic fibromyalgia.
- Author
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Guedj E, Taieb D, Cammilleri S, Lussato D, de Laforte C, Niboyet J, and Mundler O
- Subjects
- Adult, Female, Humans, Male, Middle Aged, Perfusion methods, Radiopharmaceuticals, Reproducibility of Results, Sensitivity and Specificity, Brain diagnostic imaging, Cysteine analogs & derivatives, Fibromyalgia complications, Fibromyalgia diagnostic imaging, Hyperalgesia diagnostic imaging, Hyperalgesia etiology, Organotechnetium Compounds, Tomography, Emission-Computed, Single-Photon methods
- Abstract
Purpose: Neuro-imaging studies with (99m)Tc-HMPAO SPECT in fibromyalgia (FM) patients have reported only limited subcortical hypoperfusion. (99m)Tc-ECD SPECT is known to provide better evaluation of areas of high cerebral blood flow and regional metabolic rate. We evaluated a homogeneous group of hyperalgesic patients with FM using (99m)Tc-ECD SPECT. The aim of this study was to investigate brain processing associated with spontaneous pain in FM patients., Methods: Eighteen hyperalgesic FM women (mean age 49 years, range 25-63 years; American College of Rheumatology criteria) and ten healthy women matched for age were enrolled in the study. A voxel-by-voxel group analysis was performed using SPM2 (p<0.05, corrected for multiple comparisons). Visual Analogue Scale score for pain was 82+/-4 at the time of the SPECT study., Results: Compared with control subjects, we observed individual brain SPECT abnormalities in FM patients, confirmed by SPM2 analysis, with hyperperfusion of the somatosensory cortex and hypoperfusion of the frontal, cingulate, medial temporal and cerebellar cortices., Conclusion: In the present study, performed without noxious stimuli in hyperalgesic FM patients, we found significant hyperperfusion in regions of the brain known to be involved in the sensory dimension of pain processing and significant hypoperfusion in areas assumed to be associated with the affective-attentional dimension. As current pharmacological and non-pharmacological therapies act differently on the two components of pain, we hypothesise that SPECT could be a valuable and readily available tool to guide individual therapeutic strategy and provide objective follow-up of pain processing recovery under treatment.
- Published
- 2007
- Full Text
- View/download PDF
49. Demographic, neurological and behavioural characteristics and brain perfusion SPECT in frontal variant of frontotemporal dementia.
- Author
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Le Ber I, Guedj E, Gabelle A, Verpillat P, Volteau M, Thomas-Anterion C, Decousus M, Hannequin D, Véra P, Lacomblez L, Camuzat A, Didic M, Puel M, Lotterie JA, Golfier V, Bernard AM, Vercelletto M, Magne C, Sellal F, Namer I, Michel BF, Pasquier J, Salachas F, Bochet J, Brice A, Habert MO, and Dubois B
- Subjects
- Adult, Age of Onset, Aged, Brain physiopathology, Brain Mapping methods, Brain Stem diagnostic imaging, Cerebrovascular Circulation, Cross-Sectional Studies, Dementia diagnostic imaging, Dementia genetics, Disease Progression, Female, Humans, Male, Middle Aged, Neuropsychological Tests, Prognosis, Survival Analysis, Tomography, Emission-Computed, Single-Photon, Brain diagnostic imaging, Dementia psychology, Social Behavior Disorders etiology
- Abstract
We conducted a French multicentric cross-sectional study to describe in detail the demographic, neurological and behavioural characteristics of the frontal variant of frontotemporal dementia (fvFTD) and to characterize the pattern of brain perfusion SPECT in comparison to a healthy control group. A total of 68 fvFTD patients had technetium-99m-ECD brain perfusion SPECT at inclusion, 61 of which also underwent an in-depth evaluation including 70 items assessing behaviour, language and affect/emotion at onset and at inclusion. The mean age-at-onset was 60.4 +/- 7.8 years (35-75). Twenty-six per cent of the patients were older than 65 at onset. A positive familial history consistent with an autosomal dominant inheritance was found in 18% of the patients. At onset, the behavioural profile was predominantly inert in 25% of the patients, disinhibited in 18% and mixed in others. The behavioural features progressed to predominantly mixed or inert forms. Although, inertia was associated with predominant medial frontal and cingulate hypoperfusion, and patients with disinhibition exhibited predominant ventromedial prefrontal and temporal hypoperfusion, there were no major clinical differences between disinhibited and inert patients. Forty-five per cent of the deceased patients survived <6 years (short survival), and 34% of the patients survived >8 years (long survival). This shows that the final outcome of fvFTD is highly variable. No clinical factors predictive of short or long survival were identified. Unexpected, however, was the finding that brainstem hypoperfusion distinguished patients with a short survival from patients with long survival. In conclusion, this study shows that fvFTD is clinically a rather homogeneous entity. It also provides evidence that different behavioural presentations at onset are related to different anatomical localizations of degenerative damage. Finally, it demonstrates the prognostic value of brainstem hypoperfusion in a subgroup of patients with a short survival.
- Published
- 2006
- Full Text
- View/download PDF
50. Similitude of brain perfusion pattern in hypothyroidism and early Alzheimer's disease: physiopathologic considerations.
- Author
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Guedj E, Taïeb D, De Laforte C, Ceccaldi M, and Mundler O
- Subjects
- Adult, Alzheimer Disease diagnosis, Alzheimer Disease etiology, Brain drug effects, Cerebrovascular Circulation drug effects, Diagnosis, Differential, Female, Humans, Hypothyroidism complications, Hypothyroidism diagnosis, Middle Aged, Prognosis, Tomography, Emission-Computed, Single-Photon methods, Treatment Outcome, Alzheimer Disease diagnostic imaging, Alzheimer Disease drug therapy, Brain blood supply, Brain diagnostic imaging, Hypothyroidism diagnostic imaging, Hypothyroidism drug therapy, Thyroxine therapeutic use
- Published
- 2005
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