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Progressive multifocal leukoencephalopathy (PML) is a rare opportunistic infection caused by JC virus (JCV) activation. We report an 85-years old man who had been diagnosed to have rheumatoid arthritis (RA) 1.5 years prior to diagnosis of PML, and had been treated with salazosulfapyridine (SASP). He developed weakness of the left upper limb, which progressed gradually for two months. A neurological examination on admission revealed severe palsy of the left upper limb without sensory disturbance, cognitive decline or gait disturbance. Brain MRI revealed white matter lesions in the right frontal lobe around the precentral gyrus. Cerebrospinal fluid (CSF) examination and peripheral lymphocyte counts were normal. HIV was ruled out serologically. There were no findings suggestive of malignancy. We suspected PML and stopped SASP. JCV-DNA was detected in CSF. There were enlarged nuclei positive with VP-1 immunostaining in the brain biopsy materials. Thus, the diagnosis of PML was definitive. Paralysis of the left upper limb began to improve one week after discontinuing SASP. Treatment with mefloquine and mirtazapine was initiated, but he developed severe interstitial pneumonia, which might be caused by mefloquine. Therefore, he underwent rehabilitation without medication. JCV-DNA became undetectable and white matter lesions decreased 6 months later. Paralysis improved and he had no problem with activities of daily living a year later. The risk factor for PML has changed over the last decade, and drugs such as biologics became significant risk factors for patients with autoimmune diseases. There are reports suggesting that systemic lupus erythematosus (SLE) and RA themselves might be independent risk factors for PML. Although there is no previous report of SASP inducing PML, SASP might be the culprit in our case. However, there is another possibility that SAPS and RA worked synergistically for the onset of PML.

We aimed to determine the association between acute platelet reactivity and clinical outcome in acute ischemic stroke (AIS) or transient ischemic attack (TIA) with large-artery atherosclerosis (LAA).In this prospective, 16-multicenter study, we enrolled AIS/TIA patients with LAA receiving clopidogrel. We assessed the association of P2Y12 reaction units (PRU) 24 hours after initiation of antiplatelets with the CYP2C19 genotype and recurrent ischemic stroke within 90 days, and the difference between acute (≤ 7 days) and subacute (8-90 days) phases.Among the 230 AIS/TIA patients enrolled, 225 with complete outcome data and 194 with genetic results were analyzed. A higher PRU was significantly associated with recurrent ischemic stroke within 90 days (frequency, 16%), and within 7 days (10%). Twenty-nine patients (15%) belonged to a CYP2C19 poor metabolizer group (CYP2C19Acute PRU evaluation possesses predictive value for recurrent ischemic stroke, especially within 7 days in AIS/TIA with LAA.

Background and Purpose: High blood pressure increases bleeding risk during treatment with antithrombotic medication. The association between blood pressure levels and the risk of recurrent stroke during long-term secondary stroke prevention with thienopyridines (particularly prasugrel) has not been well studied. Methods: This was a post hoc analysis of the randomized, double-blind, multicenter PRASTRO-I trial (Comparison of Prasugrel and Clopidogrel in Japanese Patients With Ischemic Stroke-I). Patients with noncardioembolic stroke were randomly assigned (1:1) to receive prasugrel 3.75 mg/day or clopidogrel 75 mg/day for 96 to 104 weeks. Risks of any ischemic or hemorrhagic stroke, combined ischemic events, and combined bleeding events were determined based on the mean level and visit-to-visit variability, including successive variation, of systolic blood pressure (SBP) throughout the observational period. These risks were also compared between quartiles of mean SBP level and successive variation of SBP. Results: A total of 3747 patients (age 62.1±8.5 years, 797 women), with a median average SBP level during the observational period of 132.5 mm Hg, were studied. All the risks of any stroke (146 events; hazard ratio, 1.318 [95% CI, 1.094–1.583] per 10-mm Hg increase), ischemic stroke (133 events, 1.219 [1.010–1.466]), hemorrhagic stroke (13 events, 3.247 [1.660–6.296]), ischemic events (142 events, 1.219 [1.020–1.466]), and bleeding events (47 events, 1.629 [1.172–2.261]) correlated with increasing mean SBP overall. Similarly, an increased risk of these events correlated with increasing successive variation of SBP (hazard ratio, 3.078 [95% CI, 2.220–4.225] per 10-mm Hg increase; 3.051 [2.179–4.262]; 3.276 [1.172–9.092]; 2.865 [2.042–4.011]; 2.764 [1.524–5.016], respectively). Event rates did not differ between the clopidogrel and prasugrel groups within each quartile of SBP or successive variation of SBP. Conclusions: Both high mean SBP level and high visit-to-visit variability in SBP were significantly associated with the risk of recurrent stroke during long-term medication with either prasugrel or clopidogrel after stroke. Control of hypertension would be important regardless of the type of antiplatelet drugs. Registration: URL: https://www.clinicaltrials.jp ; Unique identifier: JapicCTI-111582.

Background and purpose The detection rate of diffusion-weighted (DWI) hyperintense lesions varies widely in patients with transient global amnesia (TGA). The aim was to examine the association of hyperintense lesions on DWI magnetic resonance imaging (MRI) with patient characteristics, precipitating factors, clinical presentation and MRI settings in patients with TGA. Methods In this multicenter retrospective observational study, using the standardized diagnosis entry system of electronic health records of four tertiary medical centers in the Kansai district of Japan, TGA patients (n = 261) who underwent brain MRI within 28 days of onset were examined. When the onset time was unavailable, the discovery time was used. Results Diffusion-weighted hyperintense lesions were observed in 79 patients (30%). There were no significant differences in age, sex, vascular risk factors, precipitating factors or clinical presentation between patients with and without DWI lesions. The detection rate increased linearly 24 h after onset and then reached a plateau of 60%-80% by 84 h. After 84 h, the detection rate decreased rapidly. In a multivariate logistic regression model, MRI examination 24-84 h after onset (odds ratio 7.00, 95% confidence interval 3.50-13.99) and a thin-slice (≤3 mm) DWI sequence (odds ratio 7.59, 95% confidence interval 3.05-18.88) were independent predictors of DWI lesions. Conclusions This study suggests that DWI hyperintense lesions in TGA are not associated with patient characteristics and clinical presentation. Brain MRI examination 24-84 h after onset and thin-slice DWI sequences enhance the detection of DWI lesions in TGA patients.

An 80-year-old woman had an aortic valve replacement 1 month before admission and took warfarin for transient atrial fibrillation. She developed a disturbance of consciousness and left hemiplegia. On admission, the right radial artery was slightly palpable. Head MRI images showed a hyper-intense area in the right middle cerebral artery territory. MRA images showed an occlusion of the right M1 distal site and decreased signal at the right internal carotid artery. Contrast CT images of the ascending aorta showed an embolus in the innominate artery. She was diagnosed with an innominate artery saddle embolus and occlusion of the right cerebral artery due to cardiac embolism. She was treated with a heparin infusion and warfarin. She recovered consciousness and from hemiplegia gradually. Recanalization of the innominate artery and right cerebral artery was confirmed. In cases where the radial artery is slightly palpable, it is necessary to consider an innominate artery saddle embolus in addition to aortic dissection.

The epidemiology of patients with traumatic brain injury (TBI) has changed dramatically over recent decades as a result of rapid advances in aging societies. We assessed the influence of age on outcomes of patients with TBI and sought to identify prognostic factors for in-hospital mortality of TBI among elderly patients.Using a nationwide database, we analyzed data from 5651 patients with TBI. Univariate analysis was conducted to compare patient demographics, neurologic status on admission, radiologic findings, systemic complication rates, length of hospital stay, in-hospital mortality, and home discharge rates between elderly and nonelderly groups. Multivariable analysis was conducted to determine prognostic factors for in-hospital mortality among elderly patients.Overall in-hospital mortality was significantly higher in elderly patients (12.8% vs. 19.3%; P0.001). In-hospital mortality of elderly patients with mild TBI increased significantly at7 days after admission, whereas that of elderly patients with moderate or severe TBI was significantly higher immediately after admission. Age (odds ratio [OR], 1.62; P = 0.024), male sex (OR, 1.30; P = 0.004), Japan Coma Scale score on admission (OR, 5.95, P0.001), and incidence of acute subdural hematoma (OR, 1.89; P0.001) were associated with in-hospital mortality in elderly patients with TBI.Elderly patients with TBI showed significantly higher in-hospital mortality. Delayed increases in in-hospital mortality were observed among elderly patients with mild TBI. Level of consciousness on admission was the strongest predictor of in-hospital mortality among elderly patients.

BACKGROUND In Japan, warfarin treatment at prothrombin time-international normalized ratio (PT-INR) of 1.60-2.60 is recommended for elderly patients with nonvalvular atrial fibrillation (NVAF). But it remains unknown whether PT-INR 1.60-1.99 has a similar effect on stroke severity as a value >2.0. The purpose of this study was to clarify the association between infarct volume and PT-INR levels.Methods and Results:The 180 patients (mean age, 76 years [SD, 10 years], 53% male) selected from 429 consecutive ischemic stroke patients admitted within 48 h of onset between 2004 and 2014 with NVAF were included. We classified them into 4 groups according to their PT-INR values on admission: no warfarin (NW), 129 patients; PT-INR

We report a case of atrial fibrillation with rheumatic heart disease (RHD) who had intracardiac thrombus and cardiogenic cerebral embolism with rivaroxaban therapy. Intracardiac thrombus disappeared after switching from rivaroxaban to warfarin. Patients of RHD have the possibility of gradual progression of valvular disease even if they are old, so we need to distinguish nonvalvular atrial fibrillation from RHD before starting direct oral anticoagulants.

Objective The multicenter prospective cohort study (Japan Cooperative SPECT Study on Assessment of Mild Impairment of Cognitive Function: J-COSMIC) aimed to examine the value of 123I-N-isopropyl-4-iodoamphetamine cerebral blood flow (IMP-CBF) SPECT in regards to early diagnosis of Alzheimer’s disease (AD) in patients with mild cognitive impairment (MCI). Methods Three hundred and nineteen patients with amnestic MCI at 41 participating institutions each underwent clinical and neuropsychological examinations and 123I-IMP-CBF SPECT at baseline. Subjects were followed up periodically for 3 years, and progression to dementia was evaluated. SPECT images were classified as AD/DLB (dementia with Lewy bodies) pattern and non-AD/DLB pattern by central image interpretation and automated region of interest (ROI) analysis, respectively. Logistic regression analyses were used to assess whether baseline 123I-IMP-CBF SPECT was predictive of longitudinal clinical outcome. Results Ninety-nine of 216 amnestic MCI patients (excluding 3 cases with epilepsy (n = 2) or hydrocephalus (n = 1) and 100 cases with incomplete follow-up) converted to AD within the observation period. Central image interpretation and automated ROI analysis predicted conversion to AD with 56 and 58 % overall diagnostic accuracy (sensitivity, 76 and 81 %; specificity, 39 and 37 %), respectively. Multivariate logistic regression analysis identified SPECT as a predictor, which distinguished AD converters from non-converters. The odds ratio for a positive SPECT to predict conversion to AD with automated ROI analysis was 2.5 and combining SPECT data with gender and mini-mental state examination (MMSE) further improved classification (joint odds ratio 20.08). Conclusions 123I-IMP-CBF SPECT with both automated ROI analysis and central image interpretation was sensitive but relatively nonspecific for prediction of clinical outcome during the 3-year follow-up in individual amnestic MCI patients. A combination of statistically significant predictors, both SPECT with automated ROI analysis and neuropsychological evaluation, may increase predictive utility.

Purpose: This study was designed to investigate the specific cerebral blood flow (CBF) pattern in patients with idiopathic normal-pressure hydrocephalus (iNPH) and a predictive value for shunt responsiveness in a multicenter study (Study of Idiopathic Normal-Pressure Hydrocephalus on Neurological Improvement: SINPHONI). Methods: Eighty-four iNPH patients underwent shunt operations using MRI selection criteria from the SINPHONI and were subjected to CBF single photon emission computed tomography (SPECT). The perfusion patterns on SPECT were classified: anterior-dominant CBF reduction type (A type), posterior-dominant CBF reduction type (P type), and mixed or diffuse CBF reduction type (M type). The predictive value of the CBF pattern for favorable shunt outcome was evaluated. Results: Favorable outcomes were obtained in 76% (64/84) of patients, and shunt responsiveness was achieved in 85% (71/84) of patients. Areas of severely reduced relative CBF were demonstrated around the corpus callosum and in the sylvian fissure area, which included the effects of dilatations of the ventricles and sylvian fissures and relatively increased perfusion in the medial and lateral frontal, parietal, and occipital areas at high convexity. Forty-nine (58%) cases were A type, 25 (30%) cases were M type, and 10 (12%) cases were P type. A, M, and P type cases exhibited 83, 84, and 90% positive predictive values for shunt responsiveness, respectively. Mean modified Rankin scale and Mini-Mental State Examination scores of the A type group were significantly better than those of other groups. Conclusion: The iNPH patients showed various patterns of CBF reduction, but there was no significant difference in the predictive value among the three patterns, though CBF reduction patterns may suggest a severe condition of iNPH.

Objective As the pathophysiology of alcohol-related dementia (ARD) is unclear, we examined a patient with reversible ARD using neuropsychological tests and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). Methods Design: A five-year follow-up case study with neuropsychological tests and FDG-PET. Setting: Kyoto University Hospital. Patients A 42-year-old patient who was unable to perform his office duties because of slowly progressive amnesia with executive dysfunction. Results The initial evaluation with neuropsychological tests showed severe verbal memory disturbance. The patient did not discuss his excessive alcohol consumption in the initial history-taking session and thiamine deficiency was absent; therefore, early-stage Alzheimer's disease was suspected. Later, the patient revealed prior excessive alcohol intake and his cognitive function improved markedly after a period of abstinence. Retrospective analysis of initial FDG-PET images using a voxel-wise statistical method revealed glucose hypometabolism in the diencephalon and basal forebrain. Follow-up for 5 years after the initial evaluation showed improved cognitive function and recovery of glucose metabolism in the two brain regions. Conclusion Hypofunction in the diencephalon and basal forebrain was associated with cognitive decline in our patient. This case may provide evidence for the etiopathic brain regions in reversible type ARD.

To clarify the mechanisms underlying gait disturbance secondary to age-related white matter changes (ARWMC), cerebral perfusion was investigated during treadmill walking. Twenty subjects with extensive hyperintensities in the periventricular and deep white matter on T(2)-weighted magnetic resonance images (MRI) were recruited. The ARWMC subjects were classified into gait-disturbed (GD) and non-GD groups according to clinical criteria. All the subjects underwent gait analyses and cerebral perfusion measurements during both gait and rest by using single photon emission computed tomography. The GD group showed greater double support time/phase and stride width, and slower walking velocity, than the non-GD group. In an analysis of pooled data from all the subjects, gait-induced increases in cerebral perfusion were observed in the supplementary motor areas (SMA), lateral premotor cortex (PMC), primary motor and somatosensory areas, visual areas, basal ganglia and cerebellum. A between-group comparison of gait-induced perfusion changes showed relative underactivation of the SMA, thalamus and basal ganglia, together with relative overactivation of the PMC, in the GD group compared with the non-GD group. In a separate correlation analysis including all the subjects, as the double support phase was longer (that was, gait disturbance was more severe), the gait-induced perfusion changes were proportionally reduced in the SMA, visual cortex, and thalamus. The present study suggests that abnormalities in the basal ganglia-thalamo-cortical loops partly explain gait disturbance observed in a subset of subjects with ARWMC.

We report the case of a 32-year-old patient who presented with catatonic stupor during the course of acute aseptic encephalitis involving the right frontotemporal area. Flumazenil-PET performed during the stupor indicated decreased benzodiazepine receptor binding in the right frontotemporal area where glucose metabolism was preserved as revealed by FDG-PET. An injection of diazepam immediately ameliorated catatonic symptoms and reduced widespread high amplitude slow EEG activities with right frontotemporal predominance. Compared with a SPECT study performed a week earlier, there was no abnormal right-sided anteriorly predominant cerebral hyperperfusion after injection of diazepam. While neither flumazenil- nor FDG-PET could be repeated, and with the caveat that generalized convulsions occurred initially and epilepsia partialis continua was present for two weeks starting on the 23 rd day after illness onset, these findings suggest that in our case the presentation with catatonic stupor may be related to impairment of the cortical GABAergic inhibitory system.

We quantified in vivo brain nicotinic acetylcholine receptor (nAChR) distributions in patients with Parkinson's disease (PD) and evaluated correlations between nAChR distributions and clinical variables of the patients, especially dopaminergic medications. Ten patients with PD without dementia underwent 5- 123 I-iodo-3-(2( S )-azetidinylmethoxy)pyridine ( 123 I-5IA) single photon emission computed tomography (SPECT) and the data were compared with those of 10 age-matched healthy volunteers. Correlation analyses between 123 I-5IA distribution volumes (DVs) in each brain region and clinical variables of the patients were also performed. The PD group showed a statistically significant decrease (20–25%) in the brainstem and frontal cortex as compared with the control group. Although age, duration of disease, daily dose of levodopa, duration of PD medication use, and scores on the motor section of Unified Parkinson's Disease Rating Scale were not significantly correlated with DV values in any brain regions, high daily doses of dopamine agonist showed a significant negative correlation with DVs in the cerebellum, and temporal, parietal and occipital cortices. These findings suggest that patients with PD without dementia can show reductions especially in the brainstem and frontal cortex. They also suggest that dopamine agonists can have a negative influence on the distribution of nAChRs.

Recently, a number of evidences have been found that dysfunctions of cholinergic nerve systems play a substantial role in various types of dementia. Cholinesterase inhibitors were revealed to improve the cognitive symptoms of vascular dementia and dementia with Leby bodies (DLB) as well as those of Alzheimer's disease (AD). Postmortem studies showed the reduction of nicotinic acetylcholine receptors (nAChRs) in AD, DLB and Parkinson's disease (PD), especially α4β2 subtype. Recently, 5-iodo-3-(2(S)-azetidinylmethoxy) pyridine (5IA) has been synthesized as a radioligand for imaging nAChR with SPECT. It shows high affinity toward α4β2 subtype and good safety. We investigated 5IA SPECT in patients with AD and PD. The reductions of nAChR were shown in almost all brain regions of both diseases, which is consistent with autoradiographic studies. Therefore, 5IA SPECT may become a useful tool for a wide range of dementia.

Residual inhibition is a transient suppression of tinnitus after auditory stimulation has stopped. We used positron emission tomography to study brain regions underlying residual inhibition in three tinnitus patients with cochlear implants and six normal hearing controls. Regional cerebral blood flow was measured and compared under two conditions: with tinnitus and during the residual inhibition of tinnitus. The right anterior middle and superior temporal gyri (Brodmann areas 21 and 38) were activated during residual inhibition, while the right cerebellum was activated during tinnitus perception in the tinnitus patients. No significant activation was observed in the normal controls. Our results suggest that tinnitus and residual inhibition are related to cortical networks of auditory higher-order processing, memory and attention.

Objective: The response of cerebral blood flow (CBF) to acetazolamide (ACZ) challenge is frequently determined in clinical settings to evaluate cerebrovascular reserve (CVR). A reduced CVR can indicate patients with occlusive cerebrovascular disease and compromised hemodynamics who may be at increased risk of cerebral ischemia. However, how precisely ACZ reflects cerebral hemodynamic impairment remains obscure. The present study aims to clarify the pathological significance of CVR in patients with occluded carotid arteries. Methods: We recruited seventeen patients with occlusive lesions in the internal carotid artery (ICA) or middle cerebral artery (MCA). We assessed these patients in terms of resting cerebral blood flow (CBF) and the CVR response to ACZ challenge using H2O positron emission tomography (PET). In addition, we evaluated hemodynamic parameters including oxygen extraction fraction (OEF) using Gas-PET. Results: We identified a significant negative correlation between the CVR and OEF or the cerebral blood volume (CBV)/CBF ratio, as a potential index of cerebral perfusion pressure. Although the CVR values were reduced in all regions with elevated OEF (Stage II), these values were highly variable regardless of the CBV/CBF ratios. The cut-off value of CVR alone could not detect Stage II, but when combined with resting CBF, misery perfusion accompanied by increased OEF was detected with high sensitivity (6/7) and specificity (61/62). Conclusion: CVR could be applied as an index reflecting both autoregulatory capacity and OEF. The present study also supported the notion that SPECT with ACZ challenge can be clinically applied to detect misery perfusion.

✓ The mechanisms underlying poststroke pain have not been clearly identified. Although motor cortex stimulation (MCS) sometimes reduces poststroke pain successfully, the exact mechanism is not yet known. For further investigation of the neural pathways involved in the processing of poststroke pain and in pain reduction by MCS, the authors used positron emission tomography (PET) scanning to determine significant changes in regional cerebral blood flow (rCBF). This 58-year-old right-handed man suffered from right-sided poststroke pain for which he underwent implantation of a stimulation electrode in the right motor cortex. After 30 minutes of stimulation, his pain was remarkably reduced (Visual Analog Scale scores decreased 8 to 1) and he felt warmth in his left arm. The rCBF was studied using PET scanning with 15O-labeled water when the patient was in the following states: before MCS (painful condition, no stimulation) and after successful MCS (painless condition, no stimulation). The images were analyzed using statistical parametric mapping software. State-dependent differences in global blood flow were covaried using analysis of covariance. Comparisons of the patient's rCBF in the painful condition with that in the painless condition revealed significant rCBF increases in the left rectus gyrus (BA11), left superior frontal lobe (BA9), left anterior cingulate gyrus (BA32), and the left thalamus (p < 0.05, corrected). On the other hand, there were significant decreases in rCBF in the right superior temporal gyrus (BA22, p < 0.01, corrected) and the left middle occipital gyrus (BA19, p < 0.05, corrected). The efficacy of MCS was mainly related to increased synaptic activity in the thalamus, whereas the activations in the rectus gyrus, anterior cingulate gyrus, and superior frontal cortex as well as the inactivation of the superior temporal lobe may be related to emotional processes. This is the first report in which the contralateral thalamus was significantly activated and pain relief was achieved using MCS.

A cognitive bias task (CBT) delineates two different cognitive selection mechanisms in the prefrontal cortex. To identify functional anatomy of context-dependent reasoning, we used technetium- 99m hexamethyl- propyleneamine oxime ( 99m Tc HM-PAO) single photon emission computed tomography (SPECT) and statistical parametric mapping. Twelve right-handed men 20–24 years old were instructed to look at a target card and then select the choice card (among two) that they preferred (modified CBT; mCBT). They also selected a choice card 2 weeks later without prior presentation of a target card (control task). In both tasks, 99m Tc HM-PAO was injected intravenously about 15 s after initiation of the mCBT or control task. Brain images were obtained using a gamma camera and reconstructed by a UNIX-based workstation. Statistical analysis compared all activated images to control images. Results associated with P values of less than 0.01 ( Z score >2.36) were depicted on T 1 -weighted magnetic resonance images. All subjects preferred choices more similar to the target. SPECT activation occurred bilaterally in the dorsolateral prefrontal cortices and middle temporal gyri during performance of the CBT. Additionally, the left inferior prefrontal cortex and left fusiform gyrus showed significant activation compared with the control task. A neural network linking the temporal and prefrontal cortices prominently seen in the left hemisphere participates in context-dependent reasoning. Knowledge of such neural systems is essential for understanding prefrontal lobe function and dysfunction.

Background and Purpose— Patients with carotid occlusive disease and stage 2 cerebral hemodynamic failure, characterized by an increased oxygen extraction fraction (OEF) as measured by positron emission tomography (PET) and otherwise known as misery perfusion, have a high risk of cerebral ischemia and subsequent stroke. In clinical practice, the detection of patients with misery perfusion through the use of widely available, noninvasive, and cost-effective modalities such as single-photon emission computed tomography (SPECT) is extremely important. Methods— We evaluated the relationships between the regional hemodynamic status of cerebral circulation, measured with split-dose [ 123 I] N -isopropyl-p-iodoamphetamine SPECT ( 123 I-IMP SPECT) and an acetazolamide challenge, and hemodynamic parameters, including OEF measured with PET, in 27 patients with both unilateral and bilateral carotid occlusive diseases. Results— A significant negative correlation was found between the SPECT-measured cerebrovascular reserve after acetazolamide administration and both the PET-measured OEF and cerebral blood volume. Neither the cerebrovascular reserve nor the cerebral blood flow index, when expressed as a SPECT-measured cerebrum-to-cerebellum ratio, was useful for detecting lesions with an elevated OEF. However, a combination of the cerebrovascular reserve and cerebral blood flow index showed high sensitivity, specificity, and positive predictive value for the detection of misery perfusion. Conclusions— Our study suggests that split-dose 123 I-IMP SPECT with an acetazolamide challenge could be useful for screening patients with misery perfusion in carotid occlusive diseases.

To investigate the effects of iterative reconstruction in 18F-fluorodeoxyglucose (FDG) gamma camera coincidence imaging (GCI), image contrast and visual detection obtained by using the iterative ordered-subsets expectation maximization (OSEM) reconstruction, in a phantom and in patients with lung cancer and breast cancer, were compared with those obtained by using the conventional filtered backprojection (FBP) reconstruction. Images of a cylindrical phantom containing hot spheres of various sizes (10-38 mm) were acquired by positron emission tomography (PET) and GCI at various sphere-to-background activity ratios. Forty-one consecutive patients with biopsy-proven cancer of lung (n = 20) and breast (n = 21) underwent PET and GCI on the same day after intravenous injection of 370 MBq of FDG. GCI images reconstructed by the OSEM and the FBP were compared. FDG PET was considered as the standard of reference. In GCI phantom images, OSEM yielded better contrast and signal-to-noise ratio (SNR) than FBP over the range of sphere sizes. Attenuation correction improved both the image measures and sphere detection obtained by the OSEM in GCI. In the study involving patients, FDG PET depicted 41 primary tumours and 25 metastatic lymph nodes. All of the tumours >2 cm in diameter (n = 25), six of the nine tumours 1.5-2.0 cm in diameter (67%), two of seven tumours

Two positron emission tomography (PET) studies were performed on 18 normal volunteers to investigate regional cortical and subcortical activation induced by the repetitive lifting-holding-replacing of an object using a precision grip between the index finger and thumb. A three-dimensional PET was performed using H215O as a tracer. The first study was aimed to investigate the brain areas involved in a grasp-lift-hold-replace action and the effect of object weight. Data were obtained for 10 subjects under three object weight conditions (4, 200, and 600 g) and a rest condition. Grip and lift forces on a similar object and the activity of selected muscles in the hand, arm, and shoulder were also recorded in separate lifting trials. An external auditory beep sounded every 3.5 seconds to initiate the lifting action. The subjects repeated the lifting action 20-22 times during each PET scanning. A comparison between all movement conditions and the rest condition revealed significant activation of the primary motor (M1), primary sensory (S1), dorsocaudal premotor (PM), caudal supplementary motor (SMA), and cingulate motor (CMA) cortices contralateral to the hand used. On the ipsilateral side, activation of the M1, caudal SMA, and inferior parietal (BA40) was found. In the subcortical areas, the hemispheres of the bilateral cerebellum, left basal ganglia, and thalamus were activated. Behavioral adaptation to a heavier object weight was revealed in a nearly proportional increase of both grip and lift forces, and a higher level of hand and arm muscle activities. An increase in the rCBF associated with these changes was noted in several cortical and subcortical areas. Consistent object-weight-dependent activation, however, was observed only in the M1/S1 contralateral to the hand used and to some extent in the ipsilateral cerebellum.The second study was aimed at investigating the brain areas involved in each of the preparatory and execution phases for lifting of an object. In addition, the difference in brain activation between right (dominant) and left (non-dominant) hands was also investigated. Eight subjects were scanned under four conditions. The first condition was preparing and executing the task by the right hand, and the second was preparing only. The third condition was preparing and executing the task by the left hand, and the fourth was resting as a control condition. The subjects were cued for preparation for grasp by a tape-recorded voice saying “prepare, ” which was followed by a beep at some interval (4-8 seconds). For the execute condition, the subjects grasped and lifted the object at the beep sound, while for the prepare-only condition, the subjects stopped the preparatory state. This was repeated 10 or 11 times during each PET scanning. For the prepare and execute condition, results were similar to the activated areas for lifting action in the first study. BA40, however, was activated in the left side this time. For the prepare-only condition, after subtracting the resting condition, left SMA and S1 were the activated areas, and for the execute-only condition (the prepare-execute condition minus the prepare-only condition), left M1 and thalamus, and right cerebellum hemisphere were activated. When the task was performed by the left hand, there was nearly a mirror image of the activated areas seen in the right-hand lifting condition. These findings provided fundamental data for understanding the neural network governing control of fingers in grip-lift-replacement actions.

Positron emission tomography scans were obtained in 13 normal subjects during perceptual and conceptual word priming tasks with the aim to investigate the neural system specific to the two priming conditions. In the prescan phase, subjects were primed perceptually or conceptually with two separate procedures, while in the scan phase, they performed the same stem completion task. Therefore we could compare the results of the two priming tasks in a direct manner. A fixation control task and a baseline task (completion of stems that did not correspond to previously seen words) were also given. A specific blood flow decrease was found in the left inferior temporal cortex in the perceptual word priming condition and in the left superior temporal / inferior parietal cortex in the conceptual word priming condition. Each blood flow change may reflect transient changes in the cortical areas subserving the processing of the perceptual and conceptual components of word priming.

To investigate the neural substrate underlying the mechanisms of Kanji and Kana writing, we conducted a PET activation study during mental writing task in eight right-handed normal Japanese subjects. During scans subjects were required to mentally write a Kanji or three Kana letters with their right hand, for each stimulant word presented auditorily. The direct comparisons between Kanji writing and Kana writing revealed that the left posterior inferior temporal gyrus was activated in Kanji writing while the left angular gyrus was activated in Kana writing. In addition, more extensive areas were activated in Kanji writing compared with Kana writing. These results suggest that different respective neural substrates are involved in Kanji and Kana writing respectively.

Dynamic images of positron distribution in artery was measured from the skin surface of human subject using beta camera for noninvasive measurement of the input function. After estimating the possibility of the method by some phantom studies, the beta camera was attached from the skin surface on the artery of wrist during the PET measurement using the O-15 water injection method. After injection of O-15 water, dynamic images of the artery were measured. Regions of interest (ROIs) were set on the artery and on the adjacent area of the artery. From the ROIs analysis, a time activity curve similar to that measured by the invasive technique was noninvasively obtained.

We compared the cognitive functions and interictal cerebral glucose metabolism of 11 patients with mesial temporal lobe epilepsy (MTLE) with frequent seizures to those of 10 patients with MTLE with rare seizures; the groups were matched for age, sex, education, IQ, and focus side. The frequent-seizure group had more set-shifting impairment that correlated with glucose hypometabolism in the prefrontal cortices. Our results suggest that frequent seizures in MTLE are associated with hypofunction of the prefrontal cortex.

This report concerns longitudin's investigations with comprehensive neuropsychologic's assessments and precise morphologic's, CT and MRI scan-based, and function's, SPECT scan-based brain imaging examinations of seven patients who had selective progressive amnesia on their initi's visit. Progressive loss of recent memory remained for sever's years the single most s'sient feature in six of them. The atrophy of the hippocamp's region was observed morphologic'sly, and dysfunction confined to the bilater's medi's tempor's lobe involving the hippocamp's area was demonstrated function'sly. These findings are consistent with recently reported atypic's cases of 'Szheimer's disease with unique neur-opathologic's changes, namely the presence of numerous neurofibrillary tangles and few plaques in the hippocamp's region only.

The first pupose of this study was to assess the availability of transcranial Doppler ultrasonography (TCD) for detecting occlusive vascular lesions in the carotid territory. Secondly, we investigated the hypothesis that TCD reflects the state of cerebral perfusion, compared with single photon emision tomography (SPELT) .In 57 control subjects, the normal range was defined as a 95% confidence interval of flow velocity in the middle cerebral artery (MCA) (peak flow velocity; MCAPF, mean flow velocity; MCAMF) . We investigated the diagnostic accuracy for detecting occlusive vasclar lesions in 46 patients who had undergone both TCD and carotid angiography. Unilateral occlusion of the internal carotld artery (ICA) was shown in 15 patients (UIO), unilateral severe stenosis of ICA was seen in 9 (UIS), unilateral severe stenosis of MCA truncns was seen in 15 (UMS) and no abnormal findings in the major cerebral arteries in 7 (NF) . Side-to-side differences in the MCA territory of the cerebral blood flow was analyzed by SPECT in 27 patients (UIO; 9, UIS; 4, UMS; 15, NF; 7) .The normal ranges are as follows; 52

A 11–year-old right-handed boy showed global aphasia after an infarct in the distribution of the left middle cerebral artery involving the whole language area, following an operation for ‘moya-moya disease’. Thus, anatomoclinical correlation between the CT lesion site and the resulting aphasic syndrome in this case was similar to that described in adults. However, he demonstrated rapid recovery of language fluency with poor recovery of language comprehension, in contrast to comparable adult cases. Consequently, his global aphasia resolved into transcortical sensory aphasia. This case seems to support the current view that recovery of fluency in childhood aphasia is quicker and more extensive than in adults.

This report concerns a 65-year-old right-handed woman with cerebral hemorrhage who presented with mild right-sided hemiparesis. Computed tomography (CT) revealed hematoma in the left thalamus and compression of the posterior limb of the internal capsule by a brain edema surrounding the lesion. 99mTc-hexamethylpropyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) images obtained 4 days after onset showed hypoperfusion in the left thalamus containing a hematoma as well as contralateral cerebellar hypoperfusion to the supratentorial lesion, which is well recognized as crossed cerebellar diaschisis (CCD) after stroke. CT 14 days after the onset revealed reduction of the brain edema of the posterior limb of the internal capsule accompanied by gradual neurological improvement. SPECT obtained 14 and 28 days later showed that CCD had disappeared. In this case report, the authors discuss the disappearance of CCD due to transient edematous compression of the internal capsule following thalamic hemorrhage on serial 99mTc-HMPAO SPECT scans. CCD was possibly caused by the lesion confined to the posterior limb of the internal capsule, which anatomically constitutes the cerebropontocerebellar pathway.

語の意味の選択的障害を，語義失語像を呈する葉性萎縮７例およびヘルペス脳炎１例で検討した。前者では，再認の障害がみられる語に一貫性があり，語頭音効果に乏しく，かつ補完現象が認められないことより，語彙そのものの喪失・貧困化あるいは語の意味が表象として成立しえない状態が，一方後者では，再認の障害がみられる語に浮動性があり，語頭音効果もしばしばみられ，かつ補完現象が顕著に認められることより，語の名と意味の共生関係の障害あるいは語の意味表象の薄弱化か，その病態機制であると考察した。前者では，全例左側頭葉前方部に限局性の著明な萎縮がみられ，機能不全部位はさらに中間部にまで及び，右側頭葉により強い萎縮を有する１例では相貌の認知障害をも有していた。後者でも，左側頭葉前方部が主として障害されていた。文献的考察をもふまえると，語の意味記憶を担う神経基盤として優位半球の海馬領域と側頭連合野が，相貌の意味記憶を担う神経基盤として劣位半球の相同部位が重視される。加えて，側頭葉を主として侵す葉性萎縮過程は，単に部位ということだけにとどまらず，意味記憶を支える系あるいはneural networkを単位的に損なう可能性が示唆される。

We have reported a case of autosomal recessive juvenile parkinsonism PARK6 with a 30-year history. She developed tremor of right lower limb at the age of 23. At the age of 28, she received a clinical diagnosis of early-onset Parkinson's disease. She showed clinical improvements by the treatment with trihexyphenidyl, but symptoms showed slow progression over the subsequent years. L-DOPA therapy was introduced at the age of 42, and five years later, L-DOPA-induced dyskinesia developed. Dystonia, diurnal fluctuation and sleep benefit were absent. She carried a homozygous missense mutation in PINK1 gene, and was diagnosed as PARK6. The brain MRI did not show apparent abnormality. 18F-FDG-positron emission topography (PET) displayed normal uptake in the brain, suggesting normal glucose metabolism. PET imaging with a dopamine D2 receptor ligand 11C-raclopride revealed that postsynaptic 11C-raclopride uptake was normal in the bilateral putamen. After the introduction of pramipexisol, she showed clinical improvements. L-DOPA-induced dyskinesia disappeared with the gradual tapering and withdrawal of L-DOPA. In this PARK6 case, postsynaptic D2 receptors of the nigro-striatal dopaminergic neurons were thought to be maintained despite a long disease history.

BACKGROUND In patients with mild cognitive impairment (MCI), poor performances on delayed recall and executive function are risk factors of progression to dementia. The aim of the present study was to clarify neural correlates of these neuropsychological deficits. METHODS Thirty patients with amnestic MCI and 15 control subjects underwent neuropsychological tests including three-word delayed recall, visual delayed recall of Rey complex figure (RCF), and two-relational reasoning of Raven's colored progressive matrices (RCPM) with a 18F-fluorodeoxyglucose (FDG)-position emission tomography (PET) measurement of resting state. We evaluated a relationship between performance of neuropsychological tests and regional cerebral glucose metabolism using voxel-based analysis. RESULTS Poor performance in three-word delayed recall was related to glucose hypometabolism in the right medial temporal, right prefrontal, and left superior parietal cortices. The deficit in visual delayed recall of RCF correlated positively with hypometabolism in the bilateral posterior cingulate. The impairment in two-relational reasoning was associated with hypometabolism in the right prefrontal cortex. CONCLUSIONS The present findings suggest that hypometabolism in the right medial temporal cortex, right prefrontal cortex, left superior parietal cortex, and bilateral posterior cingulate reflects impairments in delayed recall while hypometabolism in the right prefrontal cortex mirrors deficits in executive function in MCI. J Neuroimaging 2010;20:29-36.

We treated a patient with levodopa-resistant akinesia with motor cortex stimulation (MCS), and she showed dramatic improvement more than 1 year. On admission, the patient presented severe akinesia and gait disturbance without tremor and rigidity, and did not respond to levodopa test. The patient was suspected pure akinesia and progressive supranuclear palsy. First, high-frequency rTMS of primary motor cortex was examined, and showed the dramatic improvement. Next, chronic subdural electrodes were implanted over the motor cortex bilaterally. One year after surgery, the Unified Parkinson's Disease Rating Scale had improved remarkably, and she could walk four times faster than before. The H2 15O PET study showed a significant increase of rCBF in the left SMA and right dorsolateral prefrontal cortex after bilateral MCS. MCS may be an alternative treatment for patients with akinesia, including those with PD, and particularly for levodopa-resistant patients, who respond well to rTMS.

The peripheral benzodiazepine receptor (PBR) is a 18 kDa molecule mainly involved in cholesterol transport through the mitochondrial membrane. In mi- croglia, PBR is expressed from the earliest stages of activation and appears to exert a pro-inflammatory function. This molecule is commonly up-regulated in inflammatory, degenerative, infective and ischaemic le- sions of the central nervous system but it has never been reported in glioma-infiltrating microglia. We examined two anaplastic astrocytomas showing minimal contrast- enhancement and therefore little damage of the blood brain barrier to minimise the presence of blood borne macrophages within tumour tissue. The two lesions were studied in vivo using positron emission tomography (PET) with the specific PBR ligand ( 11 C)(R)-PK11195 and the corresponding tumour tissue was investigated with an anti-PBR antibody. Glioma-infiltrating microglia were characterised for molecules involved in antigen presentation and cytotoxic activity. As comparison, PBR was investigated in three brains with multiple sclerosis (MS) and three with Parkinson's disease (PD). The expression profile of four anaplastic astrocytomas was also exploited and results were compared to the profile of eleven samples of normal temporal lobe and nine cases of PD. PET studies showed that ( 11 C)(R)-PK11195 binding was markedly lower in tumours than in the contralateral grey matter. Pathological investigation revealed that gli- oma-infiltrating microglia failed to express PBR and cytotoxic molecules although some cells still expressed antigen presenting molecules. PBR and cytotoxic mole- cules were highly represented in MS and PD. Evaluation of microarray datasets confirmed these differences. Our results demonstrated PBR suppression in glioma-infiltrating microglia and suggested that PBR may have a relevant role in modulating the anti-tumour inflammatory response in astrocytic tumours.

Patients with Parkinson disease (PD) often experience visual hallucinations (VH) with retained insight (nonpsychotic) but the precise mechanism remains unclear.To clarify which neural substrates participate in nonpsychotic VH in PD, the authors evaluated regional cerebral blood flow (rCBF) changes in patients with PD and VH.The authors compared 24 patients with PD who had nonpsychotic VH (hallucinators) and 41 patients with PD who had never experienced VH (non-hallucinators) using SPECT images with N-isopropyl-p-[(123)I]iodoamphetamine. There were no significant differences in age, sex, duration of disease, doses of PD medications, Hoehn and Yahr scale, or Mini-Mental State Examination (MMSE) scores between the two groups. The rCBF data were analyzed using statistical parametric mapping (SPM).The rCBF in the right fusiform gyrus was lower in the hallucinators than in the non-hallucinators (corrected p0.05 at cluster levels). The hallucinators revealed higher rCBF in the right superior and middle temporal gyri than the non-hallucinators (uncorrected p0.001). These significant differences were demonstrated after MMSE scores and duration of disease, which are the relevant factors associated with VH, were covariated out.Nonpsychotic visual hallucinations in Parkinson disease (PD) may be associated with hypoperfusion in the right fusiform gyrus and hyperperfusion in the right superior and middle temporal gyri. These temporal regions are important for visual object recognition and these regional cerebral blood flow changes are associated with inappropriate visual processing and are responsible for nonpsychotic visual hallucinations in PD.

Adoption of standard input function (SIF) has been proposed for kinetic analysis of receptor binding potential (BP), instead of invasive frequent arterial samplings. The purpose of this study was to assess the SIF method in quantitative analysis of [123I]iomazenil (IMZ), a central benzodiazepine antagonist, for SPECT. SPECT studies were performed on 10 patients with cerebrovascular disease or Alzheimer disease. Intermittent dynamic SPECT scans were performed from 0 to 201 min after IMZ-injection. BPs calculated from SIFs obtained from normal volunteers (BPs) were compared with those of individual arterial samplings (BPo). Good correlations were shown between BP(o)s and BP(s)s in the 9 subjects, but maximum BP(s)s were four times larger than the corresponding BP(o)s in one case. There were no abnormal laboratory data in this patient, but the relative arterial input count in the late period was higher than the SIF. Simulation studies with modified input functions revealed that height in the late period can produce significant errors in estimated BPs. These results suggested that the simplified method with one-point arterial sampling and SIF can not be applied clinically. One additional arterial sampling in the late period may be useful.

We reviewed the roles of functional neuroimaging in the diagnosis of Parkinson's disease and related disorders. Positron emission tomography or single photon emission computed tomography measurements in combination with various markers for brain metabolism and pre- and post-synaptic dopamine systems have a potential to enhance an accurate pre-mortem diagnosis of akinetic-rigid syndrome. Using information from magnetic resonance imaging technique seems helpful, too. Furthermore, these methods appear to be useful in pre-morbid diagnosis of Parkinson's disease and longitudinal follow-up for reassessing the rationality of treatment. The sensitivity and specificity of these diagnostic tools still wait for future evaluation, and we foresee further refinement of imaging and analytic methods.

Somatic hallucinations are subjective experience of false, strange sensations of things occurring in or to the body. They can be seen in psychotic disorders, but have not been well described as an ictal psychosis in patients with nonconvulsive status epilepticus (NCSE) of frontal origin. We reported a 69-year-old woman who had NCSE of frontal origin manifesting prolonged somatic hallucinations mimicking a psychiatric disorder and initially treated as such. Ictal EEG revealed the frontal focus and ictal single-photon emission computed tomography (SPECT) showed the activation, not only in the frontal area but also in the parietal area as the projected regions, both of which might be associated with the development of her symptoms. She also had two generalized tonic-chronic seizures out of psychosis. Her psychosis and ictal rhythmic discharges on EEG ceased with valproate and she has since remained free from the symptoms. The current case suggests that long-lasting somatic hallucinations could be an ictal psychosis in frontal NCSE and thus an EEG study is needed for an early diagnosis and treatment.

We report herein the modulation of dopamine release in the basal ganglia during peripheral electrical stimulation in animals. The endogenous dopamine release during electrical stimulation was measured in anesthetized cats by positron emission tomography (PET) using the D2 receptor agonist [11C]-raclopride. Binding potential (BP) parametric maps were calculated using a simplified reference region model. The regional dopamine release evoked by electrical stimulation was estimated both by region of interest (ROI) analysis and statistical parametric mapping (SPM 99). Both ROI analysis and statistical parametric mapping showed significant release of endogenous dopamine in the nucleus accumbens and the striatum contralateral to the stimulated side as compared to the resting condition as well as the ipsilateral side. Accordingly, we suggest that the activity of the dopaminergic neurons in the midbrain projecting to the nucleus accumbens and the striatum is modulated by the input from the afferent nerves. This provides an in vivo evidence for the importance of the basal ganglia in the processing of peripheral information required for normal movement. This may also explain the clinically observed sensory system abnormalities in patients with movement disorders.

The authors describe a patient who showed paroxysmal dysarthria and right-limb ataxia after midbrain infarction. SPECT imaging showed marked hypoperfusion in the left parietal lobe while the patient was having frequent paroxysmal attacks. After treatment with phenytoin, the symptoms and hypoperfusion in SPECT imaging improved. The authors conclude that dysfunction of the cerebellothalamocortical pathway after midbrain infarction may cause paroxysmal dysarthria and ataxia.

Donepezil is a selective acetylcholinesterase inhibitor approved for the symptomatic treatment of mild to moderate Alzheimer's disease (AD). Since behavioral symptoms severely affect quality of life for AD patients and their caregivers, predicting behavioral responses to donepezil will be useful in managing patients with AD. In this study, we analyzed 70 consecutive cases with mild to moderate AD. Caregivers were interviewed with the Neuropsychiatric Inventory for behavioral assessment and 4-point improvement at week 12 was accepted as a treatment response. Twenty-one (30.0%) patients showed a behavioral response, while 42 (60.0%) showed no behavioral change and 7 (10.0%) worsened. Dysphoria, anxiety and apathy significantly improved after treatment among the responder group. The baseline profile including age, sex, Mini-Mental State Examination (MMSE), the Alzheimer's Disease Assessment Scale (ADAS-cog) and the Geriatric Depression Scale did not differ significantly among the three groups. Statistical Parametric Mapping analysis of single photon emission computed tomography (SPECT) images at baseline showed that cerebral blood flow in the premotor and parietotemporal cortices was significantly higher in the responder group than in the worse group. The present study suggested usefulness of SPECT imaging in the prediction of behavioral response to donepezil among AD patients even with similar psychiatric symptoms and cognitive functions.

Background and Purpose— [ 11 C]flumazenil (FMZ), a ligand that selectively binds to the central benzodiazepine receptor in the neuronal membrane, is useful for evaluating neuronal viability in a positron emission tomography (PET) scan. Using this ligand, we investigated whether there was a correlation between neuronal integrity in various brain structures and dementia in patients with leukoaraiosis. Methods— Twelve patients with extensive leukoaraiosis on magnetic resonance imaging were divided into groups of patients with or without dementia. Based on a 2-compartment, 2-parameter model that included metabolite-corrected arterial input and PET-measured cerebral radioactivity, the distribution volume of FMZ (FMZ-V d ) was calculated in various regions of interest by nonlinear curve fitting. Additionally, tracer kinetic analysis was applied for voxel-by-voxel quantification of FMZ-V d , and data analysis was performed by statistical parametric mapping. Results— The presence of dementia was associated with a reduced FMZ-V d in widespread areas of the cerebral cortex, including the bilateral frontopolar and frontal/insular areas, the left temporo-occipital border areas, and the left marginal cortical areas. Conclusions— Differences in neuronal integrity in the cerebral cortex might determine whether patients with leukoaraiosis become symptomatic or not.

A cognitive bias task (CBT) delineates two different cognitive selection mechanisms in the prefrontal cortex. To identify functional anatomy of context-dependent reasoning, we used technetium-99mhexamethyl- propyleneamine oxime (99mTc HM-PAO) single photon emission computed tomography (SPECT) and statistical parametric mapping. Twelve right-handed men 20-24 years old were instructed to look at a target card and then select the choice card (among two) that they preferred (modified CBT; mCBT). They also selected a choice card 2 weeks later without prior presentation of a target card (control task). In both tasks, 99mTc HM-PAO was injected intravenously about 15 s after initiation of the mCBT or control task. Brain images were obtained using a gamma camera and reconstructed by a UNIX-based workstation. Statistical analysis compared all activated images to control images. Results associated with P values of less than 0.01 (Z score2.36) were depicted on T1-weighted magnetic resonance images. All subjects preferred choices more similar to the target. SPECT activation occurred bilaterally in the dorsolateral prefrontal cortices and middle temporal gyri during performance of the CBT. Additionally, the left inferior prefrontal cortex and left fusiform gyrus showed significant activation compared with the control task. A neural network linking the temporal and prefrontal cortices prominently seen in the left hemisphere participates in context-dependent reasoning. Knowledge of such neural systems is essential for understanding prefrontal lobe function and dysfunction.

Using duplex ultrasonography (US), the authors showed compression of the extracranial vertebral artery (ECVA) during neck rotation in 5.0% of 1,108 patients. Age (per 10-year increase, OR 0.80, 95% CI 0.67 to 0.96), vessel diameters (per 0.5-mm diameter increase, OR 0.63, 95% CI 0.51 to 0.79), and symptoms upon neck rotation (OR 4.01, 95% CI 1.35 to 11.9) were associated with vessel compression. In one case, SPECT revealed decreased cerebral perfusion of the hindbrain during rotation. ECVA US is useful in identifying vessel compression, especially in patients with symptoms on neck rotation.

Background: In vascular dementia (VaD), assessment of cerebral blood flow by single photon emission computed tomography (CBF SPECT) has been used to detect a patchy decrease of blood flow or a frontal reduction. In addition to reduced blood flow, the heterogeneous distribution of cerebral blood flow is often observed in VaD. However, no objective method to evaluate the heterogeneity has been established. In this study, we applied three-dimensional fractal analysis (3D-FA) to CBF SPECT images as a method for assessing the heterogeneity of the cerebral blood flow distribution in VaD. Subjects and Methods: The subjects included 18 patients with a diagnosis of VaD (aged 69.7 ± 8.3) based on neuropsychological testing and imaging findings and 18 age-matched controls (aged 66.9 ± 10.3). CBF SPECT images were obtained with 99mTc-hexamethyl propyleneamine oxime. On the reconstructed images, we obtained a linear regression equation between the cut-off values (from 35 to 50 %) and the number of voxels with a radioactivity exceeding the cut-off value transformed into natural logarithms, and then calculated the fractal dimension from the slope of the regression line thus obtained. The Mini-Mental State Examination (MMSE) was used to evaluate cognitive function. Results: The fractal dimensions were 1.084 ± 0.153 and 0.853 ± 0.062 (mean ± SD) in the VaD and control groups, respectively. The fractal dimension was significantly greater in the VaD group than in the control group (p < 0.0001). A significant negative correlation was observed between the fractal dimension and the MMSE score in the VaD group (r = 0.871, p < 0.0001). Conclusions: Because the CBF SPECT images of VaD patients showed a higher fractal dimension, these images were quantitatively more heterogeneous than those of age-matched controls. In the VaD group, cognitive function was shown to decline as the fractal dimension increased and images became more heterogeneous.