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Key Clinical Message: Our case report highlights that Prompt recognition of cerebellar mutism syndrome (CMS) is critical in clinical practice, as it is often misdiagnosed as just being reduction in the level of consciousness, particularly in pediatrics trauma patients. Cerebellar mutism syndrome is defined as transient mutism following posterior fossa surgery, hemorrhage or traumatic insults involving the cerebellum. Cerebellar mutism syndrome (CMS) is now recognized as a form of cerebellar cognitive affective syndrome (CCAS/Schmahmann syndrome). CMS following head injury is exceedingly rare with very few cases reported. Five years old boy with normal developmental milestones and no significant medical history, sustained closed head injury following road traffic accident, the clinical scenario in addition to the radiological findings led to the diagnosis of cerebellar mutism syndrome. CMS is defined as of neurologic and cognitive disorders, mainly speech disorder. Patient non‐motor signs recovered in a period of few weeks from the mutism syndrome with remaining mild motor deficit. CMS is a set of neurologic and cognitive disorders, the most distinct of which is speech disorder (usually reversible), what is unique about this case is the selective site of the contusion at the region of the dentate nucleus and superior cerebellar peduncle. Such cases offer a better understanding to the function of the cerebellum and its role in cognition. Additionally, the knowledge of this aspect of cerebellar function helps in better predicting the clinical course of such lesions which in turn helps in communication and explanation to patient's families. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusions Describe the yield of computed tomography brain (CTB) scans in patients intubated for drug overdose.Retrospective descriptive study using existing registry data from two Australian EDs between February 2021 and June 2022.Two hundred and six patients were intubated; 159 (77%) received a post‐intubation CTB scan. Of these, 38 out of 159 (24%) had a documented indication (i.e. head injury and seizure) for their scans, with a yield of 5.3% (95% confidence interval [CI] = 1.5–17%). Of the 121 out of 159 (76%) patients without an indication, the yield of CTB was 0% (95% CI = 0–3%).Routine imaging of patients intubated for overdose without clinical indication is unjustified. [ABSTRACT FROM AUTHOR]

Resting state electroencephalographic (EEG) activity in schizophrenia (SZ) is frequently characterised by increased power at slow frequencies and/or a reduction of peak alpha frequency. Here we investigated the nature of these effects. As most studies to date have been limited by reliance on a priori frequency bands which impose an assumed structure on the data, we performed a data‐driven analysis of resting EEG recorded in SZ patients and healthy controls (HC). The sample consisted of 39 chronic SZ and 36 matched HC. The EEG was recorded with a dense electrode array. Power spectral densities were decomposed via Varimax‐rotated principal component analysis (PCA) over all participants and for each group separately. Spectral PCA was repeated at the cortical level on cortical current source density computed from standardised low resolution brain electromagnetic tomography. There was a trend for power in the theta/alpha range to be increased in SZ compared to HC, and peak alpha frequency was significantly reduced in SZ. PCA revealed that this frequency shift was because of the presence of a spectral component in the theta/alpha range (6–9 Hz) that was unique to SZ. The source distribution of the SZ > HC theta/alpha effect involved mainly prefrontal and parahippocampal areas. Abnormal low frequency resting EEG activity in SZ was accounted for by a unique theta/alpha oscillation. Other reports have described a similar phenomenon suggesting that the neural circuits oscillating in this range are relevant to SZ pathophysiology. [ABSTRACT FROM AUTHOR]

Purpose: Several reconstruction methods for MR‐based electrical properties tomography (EPT) have been developed. However, the lack of common data makes it difficult to objectively compare their performances. This is, however, a necessary precursor for standardizing and introducing this technique in the clinical setting. To enable objective comparison of the performances of reconstruction methods and provide common data for their training and testing, we created ADEPT, a database of simulated data for brain MR‐EPT reconstructions. Methods: ADEPT is a database containing in silico data for brain EPT reconstructions. This database was created from 25 different brain models, with and without tumors. Rigid geometric augmentations were applied, and different electrical properties were assigned to white matter, gray matter, CSF, and tumors to generate 120 different brain models. These models were used as input for finite‐difference time‐domain simulations in Sim4Life, used to compute the electromagnetic fields needed for MR‐EPT reconstructions. Results: Electromagnetic fields from 84 healthy and 36 tumor brain models were simulated. The simulated fields relevant for MR‐EPT reconstructions (transmit and receive RF fields and transceive phase) and their ground‐truth electrical properties are made publicly available through ADEPT. Additionally, nonattainable fields such as the total magnetic field and the electric field are available upon request. Conclusion: ADEPT will serve as reference database for objective comparisons of reconstruction methods and will be a first step toward standardization of MR‐EPT reconstructions. Furthermore, it provides a large amount of data that can be exploited to train data‐driven methods. It can be accessed from https://doi.org/10.34894/V0HBJ8. [ABSTRACT FROM AUTHOR]

Background: Several studies found that patients with new‐onset epilepsy (NOE) have higher seizure recurrence rates if they presented already prior seizures. These observations suggest that timing of antiseizure medication (ASM) is crucial and should be offered immediately after the first seizure. Here, we wanted to assess whether immediate ASM is associated with improved outcome. Methods: Single‐center study of 1010 patients (≥16 years) who presented with a possible first seizure in the emergency department between 1 March 2010 and 1 March 2017. A comprehensive workup was launched upon arrival, including routine electroencephalography (EEG), brain computed tomography/magnetic resonance imaging, long‐term overnight EEG and specialized consultations. We followed patients for 5 years comparing the relapse rate in patients treated within 48 h to those with treatment >48 h. Results: A total of 487 patients were diagnosed with NOE. Of the 416 patients (162 female, age: 54.6 ± 21.1 years) for whom the treatment start could be retrieved, 80% (333/416) were treated within 48 h. The recurrence rate after immediate treatment (32%; 107/333) was significantly lower than in patients treated later (56.6%; 47/83; p < 0.001). For patients for whom a complete 5‐year‐follow‐up was available (N = 297, 123 female), those treated ≤48 h (N = 228; 76.8%) had a significantly higher chance of remaining seizure‐free compared with patients treated later (N = 69; 23.2%; p < 0.001). Conclusions: In this retrospective study, immediate ASM therapy (i.e., within 48 h) was associated with better prognosis up to 5 years after the index event. Prospective studies are required to determine the value of immediate workup and drug therapy in NOE patients. [ABSTRACT FROM AUTHOR]

Background and purpose: Alcohol withdrawal seizures (AWS) are a well‐known complication of chronic alcohol abuse, but there is currently little knowledge of their long‐term relapse rate and prognosis. The aims of this study were to identify risk factors for AWS recurrence and to study the overall outcome of patients after AWS. Methods: In this retrospective single‐center study, we included patients who were admitted to the Emergency Department after an AWS between January 1, 2013 and August 10, 2021 and for whom an electroencephalogram (EEG) was requested. AWS relapses up until April 29, 2022 were researched. We compared history, treatment with benzodiazepines or antiseizure medications (ASMs), laboratory, EEG and computed tomography findings between patients with AWS relapse (r‐AWS) and patients with no AWS relapse (nr‐AWS). Results: A total of 199 patients were enrolled (mean age 53 ± 12 years; 78.9% men). AWS relapses occurred in 11% of patients, after a median time of 470.5 days. Brain computed tomography (n = 182) showed pathological findings in 35.7%. Risk factors for relapses were history of previous AWS (p = 0.013), skull fractures (p = 0.004) at the index AWS, and possibly epileptiform EEG abnormalities (p = 0.07). Benzodiazepines or other ASMs, taken before or after the index event, did not differ between the r‐AWS and the nr‐AWS group. The mortality rate was 2.9%/year of follow‐up, which was 13 times higher compared to the general population. Risk factors for death were history of AWS (p < 0.001) and encephalopathic EEG (p = 0.043). Conclusions: Delayed AWS relapses occur in 11% of patients and are associated with risk factors (previous AWS >24 h apart, skull fractures, and pathological EEG findings) that also increase the epilepsy risk, that is, predisposition for seizures, if not treated. Future prospective studies are mandatory to determine appropriate long‐term diagnostic and therapeutic strategies, in order to reduce the risk of relapse and mortality associated with AWS. [ABSTRACT FROM AUTHOR]

Objective: This study was undertaken to establish whether advanced workup including long‐term electroencephalography (LT‐EEG) and brain magnetic resonance imaging (MRI) provides an additional yield for the diagnosis of new onset epilepsy (NOE) in patients presenting with a first seizure event (FSE). Methods: In this population‐based study, all adult (≥16 years) patients presenting with FSE in the emergency department (ED) between March 1, 2010 and March 1, 2017 were assessed. Patients with obvious nonepileptic or acute symptomatic seizures were excluded. Routine EEG, LT‐EEG, brain computed tomography (CT), and brain MRI were performed as part of the initial workup. These examinations' sensitivity and specificity were calculated on the basis of the final diagnosis after 2 years, along with the added value of advanced workup (MRI and LT‐EEG) over routine workup (routine EEG and CT). Results: Of the 1010 patients presenting with FSE in the ED, a definite diagnosis of NOE was obtained for 501 patients (49.6%). Sensitivity of LT‐EEG was higher than that of routine EEG (54.39% vs. 25.5%, p <.001). Similarly, sensitivity of MRI was higher than that of CT (67.98% vs. 54.72%, p =.009). Brain MRI showed epileptogenic lesions in an additional 32% compared to brain CT. If only MRI and LT‐EEG were considered, five would have been incorrectly diagnosed as nonepileptic (5/100, 5%) compared to patients with routine EEG and MRI (25/100, 25%, p =.0001). In patients with all four examinations, advanced workup provided an overall additional yield of 50% compared to routine workup. Significance: Our results demonstrate the remarkable added value of the advanced workup launched already in the ED for the diagnosis of NOE versus nonepileptic causes of seizure mimickers. Our findings suggest the benefit of first‐seizure tracks or even units with overnight EEG, similar to stroke units, activated upon admission in the ED. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the frequency and significance of brain imaging findings in methanol poisoning patients and to propose a criterion for prioritizing brain imaging. Methods: We retrospectively reviewed the data of 306 patients (286 men and 34 women, mean age 32.10 ± 9.9 years) with confirmed methanol poisoning who were admitted to two hospitals in Iran during the COVID‐19 pandemic. We analyzed their demographic, clinical, laboratory, and brain imaging data. Results: The main brain computed tomography (CT) scan findings were hypodensity in the putamen (11.1%), cerebellar nuclei (8.2%), diffuse cerebral edema (7.5%), and intracranial hemorrhage (ICH; 1.6%). These findings were associated with blood pH, Glasgow Coma Scale (GCS), renal failure, bicarbonate, oxygen, carbon dioxide, potassium, and glucose levels (p < 0.05). Poor prognosis was related to blindness, opium addiction, chronic alcohol use, hyperglycemia, and abnormal CT scans (p < 0.001 for all). The most predictive brain imaging findings for poor prognosis were hypodensity in the cerebellar nuclei, diffuse cerebral edema, and ICH. Conclusion: Brain imaging can provide valuable information for the diagnosis and management of methanol poisoning patients. We suggest that patients with severe acidosis, low GCS, low pH, low oxygen saturation, and high glucose levels should undergo brain CT scan as a priority. [ABSTRACT FROM AUTHOR]

Introduction: Emergency department management of transient ischaemic attack varies from admission for all to outpatient referral. We studied the short-term outcomes of transient ischaemic attack managed with an agreed protocol. Predictors of stroke can be different for Asians and non-Asians. ABCD2 as initial triage of transient ischaemic attack is debatable. The predictive ability of ABCD2 score was studied as well. Methods: This was a prospective observational study with consecutive subject recruitment in Emergency department. All transient ischaemic attacks were admitted, hard and e-records of Emergency department, transient ischaemic attack clinic, Medical and Neurosurgical department and general follow-ups in Hospital Authority hospitals were studied up to 1 year. Stroke-day was measured from symptom-onset to time-of-stroke. Results: In 18-month period, 124 patients were recruited. The median onset-to-door time was 3.5 h. All computed tomography brain positive findings, except one subdural haematoma, were ischaemic in origin. Six strokes, all disabling, recurred within 90 days, three on day 1–3, two died in 6 months. The stroke risks at 2, 7, 90 days and 1 year were 1.61%, 3.23%, 4.84% and 4.84%, respectively. No significant trend was observed in stroke risk across ABCD2 scores (p = 0.783) with area under the curve of 0.537 (95% confidence interval = 0.380–0.694; p = 0.762). The short-term stroke risk was associated with atrial fibrillation (p = 0.002). The median Emergency Medicine ward length of stay was 1.33 days. Conclusion: In our Emergency department–based management, the short-term stroke risk of transient ischaemic attack is low, and the predictivity of ABCD2 score in risk stratification cannot be validated. Stroke recurrences were associated with atrial fibrillation. A low ABCD2 could be falsely reassuring. As half of the strokes recurred very early, we recommend admission in the hyperacute phase. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Infective endocarditis should be considered in any febrile individual with acute onset neurological symptoms. If suspicion is high, a negative brain computed tomography does not virtually exclude embolism, and magnetic resonance imaging is warranted. A diagnosis of infective endocarditis (IE) is often delayed, particularly in those infected with unusual organisms. Hereby, we report a case of a female patient presented with dysarthria, confusion, and altered mental status after being treated for Escherichia coli bacteremia. Computed tomography of the brain was unrevealing; however, scattered embolic phenomena were visualized on magnetic resonance imaging (MRI). The case underscores the importance of clinical awareness, particularly in the setting of unusual microorganisms, and the role of brain MRI in the diagnosis of IE. [ABSTRACT FROM AUTHOR]

Mirror visual feedback (MVF) technique consists in placing a mirror in a person's body midline to induce the illusion of bilateral synchronous movements of the limbs during actual unilateral movements. A recent electroencephalographical (EEG) study demonstrated that MVF‐induced illusion was related to the event‐related desynchronization (ERD) of alpha (8–12 Hz) rhythms (cortical activation) at the central and parietal scalp electrodes ipsilateral to the unilateral right finger movements. In the present study, we re‐analyzed those data to localize the cortical sources of alpha ERD during the anticipation and experience of the MVF‐induced illusion of index finger movements. To this aim, the exact Low‐Resolution Brain Electromagnetic Tomography freeware was used for the estimation of the cortical sources of the alpha ERD. Results showed that as compared to the condition without MVF, the MVF condition was characterized by greater (p <.01, uncorrected) alpha ERD sources in right frontopolar areas during the anticipation of the MVF‐induced illusion of left movements. The MVF condition was also characterized by greater (p <.05, corrected) alpha ERD sources in right premotor, primary somatomotor, and posterior inferior parietal areas during both the anticipation and experience of that MVF‐induced illusion. These findings suggest that the MVF‐induced illusory experience of left finger movements may be due to dynamic changes in alpha ERD in associative, premotor, somatomotor, and visuomotor frontal–parietal areas located in the hemisphere contralateral to the mirrored motor acts. This study investigates the electroencephalographic (EEG) cortical sources during the Mirror Visual Feedback (MVF) illusory experience. The analysis of the EEG alpha desynchronization showed as the polar frontal cortex pre‐activates the somatomotor set (anticipation). The experience of the MVF is related to a strong activity of the premotor, somatomotor, and posterior parietal areas ipsilateral to the real movement (execution). These findings support the use of MVF‐based therapies and EEG‐based technologies for motor recovery. [ABSTRACT FROM AUTHOR]

The cognitive system automatically develops predictions on the basis of regularities of event sequences and reacts to the violation of these predictions. In the visual modality, the electrophysiological signature of this process is an event‐related potential component, the visual mismatch negativity (vMMN). So far, we have no data, whether the system underlying vMMN is capable of dealing with more than one event sequence simultaneously. To disclose this aspect of the capacity of the system, in a passive oddball paradigm, we presented two interwoven sequences. The stimuli were objects (diamond patterns with their diagonals), one of the sequences was presented to the left side and the other to the right side of the visual field. From time to time, two parallel lines of the diamonds disappeared (OFF event) and then reappeared (ON event). The frequently vanishing pair of lines on the left side (standard) was identical to the rarely vanishing lines of the objects on the right side (deviant) and vice versa. We found that deviant ON events elicited vMMN only for left‐side deviants and deviant OFF events elicited vMMN only for right‐side deviants. The standardized low resolution brain electromagnetic tomography (sLORETA) source localization showed vMMN sources both in posterior visual structures and in anterior locations, and activity was stronger in the hemisphere contralateral to the deviant event. According to the results, the system underlying vMMN is capable of dealing with two sequences, but within a sequence, it detected only one type (either OFF or ON) of deviancy. [ABSTRACT FROM AUTHOR]

Background and purpose: Non‐traumatic subarachnoid hemorrhage (SAH) is a devastating disease associated with high morbidity and mortality. A higher blood burden and the presence of intraparenchymal extension of the bleeding (intracerebral hemorrhage [ICH]) are well known predictors of poor outcome. Only few studies have addressed the role of hematoma location on patient's functional outcome. The main aims were to compare clinical and radiographic characteristics between SAH patients with and without ICH and to compare different ICH localizations in relation to long‐term functional outcome. Methods: We prospectively collected data on 280 consecutive SAH patients (aneurysmal and non‐aneurysmal) admitted to a tertiary care hospital between 2010 and 2017 and assessed the initial computed tomography scans of the brain acquired after intensive care unit admission. Poor functional outcome was defined as a modified Rankin Scale score >2, 3 months after SAH. We used multivariable logistic linear regression to investigate associations between ICH location and clinical variables as well as functional outcome. Results: Intraparenchymal extension of the hemorrhage was observed in 59/280 patients (21%). The median (interquartile range) ICH volume was 11.3 (4.9–16.2) ml and the location was supratentorial in 55/59 patients (93%). Most parenchymal hemorrhages were located in the frontal (n = 24.41%) and temporal lobes (n = 12.21%), followed by insular ICH (n = 7.12%), corpus callosum (n = 6.10%), parietal (n = 2.3%) and occipital locations (n = 2.3%). Among SAH patients with ICH, those with lesions located in the corpus callosum (n = 6/59) had a significantly higher risk of 3‐month poor functional outcome in comparison to all other ICH locations, even after adjusting for Hunt and Hess grade and age (adjusted odds ratio [adjOR] 50.5, 95% confidence interval [CI] 1.3–2004.2, p = 0.034). These results remained robust when comparing the whole SAH cohort (adjOR 21.7, 95% CI 1.4–347.8, p = 0.030). Conclusions: Intraparenchymal bleeding in patients with non‐traumatic SAH, in particular that involving the corpus callosum, strongly predicts functional outcome. [ABSTRACT FROM AUTHOR]

Background and Purpose: Precise evaluation of brain computerized tomography (CT) is a crucial step in acute ischemic stroke evaluation. Electronic Alberta Stroke Program Early CT Score (E‐ASPECTS) helps in the selection of patients who may be eligible for thrombolysis. This paper seeks to assess the performance of emergency physicians (EPs) in the evaluation of ASPECTS scores with and without the use of E‐ASPECTS and to compare their results with neuroradiologists. Methods: A total of 116 patients were selected. Initially, two EPs and two neuroradiologists evaluated the admission nonenhanced CT without E‐ASPECTS. Then, after 30 days, they re‐evaluated the images using E‐ASPECTS. Sensitivity, specificity, Matthew's correlation coefficients (MCC), and receiver operating characteristic curves were generated for analysis before and after the software use. Results: Eps' performances improved when they used E‐ASPECTS, with their results closer to those obtained by neuroradiologists. In the initial evaluation, MCC values for the two EPs were –0.01 and 0.04, respectively. After the software assistance, they obtained 0.38 and 0.43, respectively, which was closer to the scores obtained by the neuroradiologists (0.53 and 0.39, respectively). Discussion: This is the first study that has specifically compared neuroradiologists' and EPs' performances before and after using E‐ASPECTS. E‐ASPECTS assisted and improved the evaluation of the images of patients with acute ischemic stroke. Conclusion: Artificial intelligence in the emergency room may increase the number of patients treated with tissue‐type plasminogen activators. [ABSTRACT FROM AUTHOR]

Introduction: Arterial calcification is an integral component of active atherosclerosis and is an independent risk factor for cardiovascular disease. Atherosclerosis is a systemic, life‐threating disease that may occur at different sites and in various clinical presentations. Intracranial and valvular calcifications are common among dialysis patients and have been associated with poor cardiovascular outcomes. The aim of this study was to assess the clinical impact of valvular and intracranial arterial calcifications on mortality among chronic hemodialysis patients. Methods: A blinded neuroradiologist graded intracranial calcifications (ICC) of all hemodialysis patients who underwent brain computerized tomography (CT) from 2015 to 2017 in our institution. Valvular calcifications were assessed by echocardiography. Only hemodialysis patients with available echocardiography and brain CT were included. Findings: This study included 119 patients (mean age 70.6 ± 12.6 years, 57.1% men, and mean dialysis vintage 25.8 ± 42.6 months). Among the cohort, 19 (16%) had no cardiac or brain calcifications and 65 (54.6%) had both valvular and intracranial calcifications. Considering the patients with no calcification as the reference group yielded adjusted odds ratios for all‐cause mortality of 3.68 (95%CI 1.55–8.75) among patients with any brain calcifications, p = 0.002. While valvular calcifications alone did not increase the 1‐year mortality rate, ICC was the most important predictor of all‐cause 1‐year mortality in the study cohort. Discussion: We found an independent association between ICC and the risk of death among hemodialysis patients. Assessing ICC may contribute to the risk stratification of hemodialysis patients. These calcifications are no less important than valvular calcifications. [ABSTRACT FROM AUTHOR]

This article discusses a case of a 72-year-old female who presented with constipation and altered sensorium. The patient was diagnosed with cirrhosis of the liver and a congenital portosystemic shunt (Abernathy type 2). The etiology of the liver cirrhosis was unknown, but it was likely nonalcoholic steatohepatitis (NASH). The patient was treated with oral lactulose and showed improvement. Congenital portosystemic shunts are rare vascular anomalies that can lead to complications such as hepatic encephalopathy. The patient's symptoms were likely precipitated by constipation. [Extracted from the article]

Key Clinical Message: Marchiafava‐Bignami disease, a rare condition often associated with alcoholism, shows myelin degeneration with tissue necrosis specifically in the corpus callosum. Urgent application of magnetic resonance imaging could lead to prompt diagnosis. A 66‐year‐old male with habitual alcohol drink complained acute deterioration of left‐side muscle weakness as initial presentation. On the arrival, the patient was confused, with stable vital sign and unremarkable pyramidal sign. Although several potential diagnoses could be considered, brain computed tomography did not provide diagnostic information, and subsequently‐performed magnetic resonance imaging revealed hyperintense lesions on T2‐flair images in corpus callosum, suggesting MBD as clinical diagnosis. Prompt diagnosis enabled us to introduce thiamine administration with subsequent favorable neurological outcome. [ABSTRACT FROM AUTHOR]

The relationship between posttraumatic stress disorder (PTSD) and focal epilepsy is poorly understood. It has been hypothesized that there is a complex and reciprocal potential reinforcement of the symptoms of each condition. In this study, we investigated whether there are PTSD‐specific brain changes in temporal lobe epilepsy (TLE). Brain fluorodeoxyglucose positron emission tomography (PET) metabolism was compared between controls and two groups of TLE patients: one group of 15 patients fulfilling the criteria for a potential diagnosis of PTSD (TLE‐PTSD+), another group of 24 patients without a diagnosis of PTSD (TLE‐PTSD‐), and a group of 30 healthy control participants. We compared the differences in brain PET metabolism among these three groups, and we studied their correlations with interictal and peri‐ictal scales of PTSD symptoms. TLE‐PTSD+ patients showed more significant hypometabolism involving right temporal and right orbitofrontal cortex in comparison to TLE‐PTSD‐ patients and healthy subjects. Moreover, degree of reduced metabolism in these brain areas correlated with interictal and peri‐ictal PTSD questionnaire scores. PTSD in temporal epilepsy is associated with specific changes in neural networks, affecting limbic and paralimbic structures. This illustrates the close intertwining of epileptogenic and psychogenic processes in these patients. [ABSTRACT FROM AUTHOR]

Diffuse optical tomography is a non‐invasive and non‐irradiating medical imaging technique that is particularly suitable for cerebral monitoring of newborns since it can be used at the bedside of the patient. Here, a new model for optical tomography in the neonatal brain is presented that takes into account the presence of arachnoid trabeculæ in the cerebrospinal fluid (CSF). It is known that the classical diffusion approximation (DA) for light propagation is at the limit of validity in the CSF layer due to the low values of the absorption and scattering coefficients. The new model is obtained by the DA of the homogenized radiative transfer equation and is rigorously justified. Numerical results in two and three dimensions attest for the improved sensitivity of the new model to the presence of perturbations in the brain layer. [ABSTRACT FROM AUTHOR]

Background: Small vessel disease (SVD), and most specifically hereditary forms like CADASIL and cerebral amyloid angiopathy (hCAA), are conditions of increasing clinical importance. We report a rare case of hCAA in a Greek family that presented with a CADASIL clinical and neuroimaging phenotype. Methods: A 65‐year‐old man was admitted with recurrent transient episodes of right leg numbness. The patient's medical history started at the age of 50 years with depression and behavioral disorders. His family history was positive for stroke (father), dementia (father and brother), migraine (daughter) and depression (father and daughter). Results: Neurological examination disclosed anomic aphasia with severely impaired cognitive status, and brisk reflexes. Brain computed tomography and magnetic resonance imaging showed CADASIL‐like leukoencephalopathy (hyperintense lesions in bilateral temporopolar area, external capsule, thalami, centrum semiovale and superior frontal regions) with occipital calcifications and cerebral microbleeds. Screen for variants in NOTCH3 gene was negative. Exome sequencing revealed a novel pathogenic mutation for hCAA. Conclusions: We report a novel amyloid precursor protein mutation which results in a CADASIL‐like clinical phenotype (progressive cognitive and motor decline, stroke, migraine and behavioral disorders) and CADASIL‐leukoencephalopathy coupled with occipital calcifications. Earlier recognition and swift hCAA diagnosis may prompt rational preventive and potential disease‐modifying interventions. [ABSTRACT FROM AUTHOR]

Pain arises from the integration of sensory and cognitive processes in the brain, resulting in specific patterns of neural oscillations that can be characterized by measuring electrical brain activity. Current source density (CSD) estimation from low‐resolution brain electromagnetic tomography (LORETA) and its standardized (sLORETA) and exact (eLORETA) variants, is a common approach to identify the spatiotemporal dynamics of the brain sources in physiological and pathological pain‐related conditions. However, there is no consensus on the magnitude and variability of clinically or experimentally relevant effects for CSD estimations. Here, we systematically examined reports of sample size calculations and effect size estimations in all studies that included the keywords pain, and LORETA, sLORETA, or eLORETA in Scopus and PubMed. We also assessed the reliability of LORETA CSD estimations during non‐painful and painful conditions to estimate hypothetical sample sizes for future experiments using CSD estimations. We found that none of the studies included in the systematic review reported sample size calculations, and less than 20% reported measures of central tendency and dispersion, which are necessary to estimate effect sizes. Based on these data and our experimental results, we determined that sample sizes commonly used in pain studies using CSD estimations are suitable to detect medium and large effect sizes in crossover designs and only large effects in parallel designs. These results provide a comprehensive summary of the effect sizes observed using LORETA in pain research, and this information can be used by clinicians and researchers to improve settings and designs of future pain studies. [ABSTRACT FROM AUTHOR]

Background: Functional neurological disorders (FND) represent a significant proportion of presentations to outpatient adult neurology services. There is little information relating to patients presenting to acute inpatient care. Methods: We identified patients presenting as acute admissions with FND to Christchurch Hospital, Christchurch, New Zealand, from 2016 to 2018. We analyzed relevant demographic and clinical data from electronic records and measured incidence of presentation to secondary care and healthcare utilization. Results: One hundred sixty‐two patients presented on 173 occasions with FND, representing 9% of all admissions to the neurology service during the 3‐year study period. The mean age was 40 (SD 17) years, 111 (69%) patients were female and the median length of stay was 3 (IQR 2–4) days. A total of 92 computed tomography brain scans, 77 magnetic resonance imaging brain scans and 42 electroencephalograms were carried out. On 22 (13%) occasions, patients were referred for outpatient psychological therapy. In the 3 years prior to each patient's last presentation in the study period, these 162 patients had a total of 671 presentations to the emergency department. Healthcare demand did not decrease after the index admission. The rate of acute inpatient admission for FND was 10 per 100,000 per year for the total Christchurch Hospital catchment, 6/100,000/year in rural areas, and 11/100,000/year in urban areas. Conclusion: FND represented almost 1 in 10 acute neurology admissions with significant inpatient healthcare resource utilization. [ABSTRACT FROM AUTHOR]

Objectives: The utility of brain metastasis screening in asymptomatic metastatic renal cell carcinoma is controversial. Our study evaluated the utility of routine head computed tomography during systemic therapy. Methods: We retrospectively investigated 152 metastatic renal cell carcinoma patients who did not initially have brain metastasis at Yamagata University Hospital from January 2008 to July 2019. Patients who routinely received head computed tomography scan together with routine contrast‐enhanced chest/abdominal/pelvic computed tomography scan every 2–4 months during systemic therapy ("Routine head computed tomography" group, n = 95) and patients without routine head computed tomography ("No routine head computed tomography" group, n = 57) were compared. Results: Brain metastasis occurred in 16 patients in the "Routine head computed tomography" group and six patients in the "No routine head computed tomography" group. There was no statistical difference in overall survival after metastatic renal cell carcinoma diagnosis between groups (53.4 vs 37.3 months, respectively, P = 0.357) and neurological symptom‐free survival after metastatic renal cell carcinoma diagnosis (53.4 vs 36.6 months, P = 0.336). Although there was no statistical difference on incidence of unrecovered neurological symptom (25.0% vs 50.0%, P = 0.334), fewer patients in the "Routine head computed tomography" group required craniotomy (0% vs 66.7%, P = 0.002). In the "No routine head computed tomography" group, the neurological symptom resolved for all patients without craniotomy. Conclusions: Routine head computed tomography during systemic therapy for metastatic renal cell carcinoma is not significantly associated with improved brain metastasis prognosis. However, routine head computed tomography enables brain metastasis diagnosis in the asymptomatic phase, which can avoid craniotomy. [ABSTRACT FROM AUTHOR]

Key points: Individuals with cerebral palsy (CP) have a reduced somatosensory cortical responseSomatosensory cortical response strength decreases from adolescence to early adulthoodSomatosensory cortical responses in youth with CP are similar to adult controlsIndividuals with CP may have aberrant maturation of the somatosensory system Numerous studies have documented tactile and proprioceptive deficits in children with cerebral palsy (CP) and linked these with weaker somatosensory cortical activity. However, whether such aberrations in somatosensory processing extend and/or progress into adulthood remains poorly understood. In the current study, we used magnetoencephalography (MEG) to investigate the primary somatosensory responses in a sample of individuals with CP (N = 42; age = 9–28 years) and a cohort of healthy controls (N = 23; age range = 11–23 years). Briefly, transient electrical stimulation was applied to the right tibial nerve, and standardized low‐resolution brain electromagnetic tomography (sLORETA) was used to image the dynamic somatosensory cortical response. We found that the strength of somatosensory cortical activity within the 112–252 ms time window was significantly reduced in the individuals with CP compared with the healthy controls (HC = 286.53 ± 30.51, 95% CI [226.74, 346.32]; CP = 208.30 ± 19.66,CI [169.77, 246.83], P = 0.0126). These results corroborate previous findings of aberrant somatosensory cortical activity in individuals with CP. Our results also suggest that the somatosensory cortical activity tends to become weaker with age, with a similar rate of neurophysiological change in individuals with CP and healthy controls (P = 0.8790). Visualization of regression models fitted to the data imply that youth with CP may have somatosensory cortical activity similar to adult controls. These findings suggest that some individuals with CP exhibit an aberrant developmental trajectory of their somatosensory system. Key points: Individuals with cerebral palsy (CP) have a reduced somatosensory cortical responseSomatosensory cortical response strength decreases from adolescence to early adulthoodSomatosensory cortical responses in youth with CP are similar to adult controlsIndividuals with CP may have aberrant maturation of the somatosensory system [ABSTRACT FROM AUTHOR]

This review describes the development of single‐photon emission tomography (SPECT) in the Copenhagen area under the leadership of the internationally renown scientist, Niels A. Lassen, and the history leading up to construction of the tomograph. Measurements of global cerebral blood flow (CBF) in the 1940s and 1950s were performed by Kety & Schmidt and Lassen & Munck. Determination of regional cerebral blood flow (rCBF) by intra‐arterial injection of 133Xe and measurement with a 254‐multicrystal scintillation detector and a computer system was a major step forward in the study of physiology and pathophysiology of cortical cerebral blood flow. Tomography with radioisotope ligands, including non‐invasive administration, was advanced in different centres during the 1970s. An emission tomograph, the Tomomatic 64, was developed as a result of a multidisciplinary Danish and international collaboration. It was the first emission tomograph to provide dynamic data that could produce cross‐sectional rCBF images. The present description of the construction and function of the Tomomatic 64 includes comparison with other contemporary and later brain‐dedicated SPECT systems. Basic and clinical application of the Tomomatic 64 in Copenhagen resulted in several hundred important scientific publications and improved diagnostics for patients with a variety of neurological disorders. It is concluded that the development of the Tomomatic 64 was a major step forward in the study and examination of rCBF and brain function related to several brain disorders, in addition to vascular diseases. [ABSTRACT FROM AUTHOR]

Medical images are obtained with computer‐aided diagnosis using electronic devices such as CT scanners and MRI machines. The captured computed tomography (CT)/magnetic resonance imaging (MRI) images typically have limited spatial resolution, low contrast, noise and nonuniform variability in intensity due to environmental effects. Therefore, the distinctions of the objects are blurred, distorted and the meanings of the objects are not quite precise. Fuzzy sets and fuzzy logic are best suited for addressing vagueness and ambiguity. Fuzzy clustering technique has been commonly used for segmentation of images throughout the last decade. This study presents a comparative study of 14 fuzzy‐clustered image segmentation algorithms used in the CT scan and MRI brain image segments. This study used 17 data sets including 4 synthetic data sets, namely, Bensaid, Diamond, Square, and its noisy version, 5 real‐world digital images, and 8 CT scan/MRI brain images to analyze the algorithms. Ground truth images are used for qualitative analysis. Apart from the qualitative analysis, the study also quantitatively evaluated the methods using three validity metrics, namely, partition coefficient, partition entropy, and Fukuyama‐Sugeno. After a thorough and careful review of the results, it is observed that extension of the fuzzy C‐means (EFCM) outperformed every other image segmentation algorithm, even in a noisy environment, followed by kernel‐based FCM σ, the output of which is also very good after EFCM. [ABSTRACT FROM AUTHOR]

We localize the sources of brain activity of children with epilepsy based on electroencephalograph (EEG) recordings acquired during a visual discrimination working memory task. For the numerical solution of the inverse problem, with the aid of age‐specific MRI scans processed from a publicly available database, we use and compare three regularization numerical methods, namely the standardized low resolution brain electromagnetic tomography (sLORETA), the weighted minimum norm estimation (wMNE) and the dynamic statistical parametric mapping (dSPM). We show that all three methods provide the same spatio‐temporal patterns of differences between the groups of epileptic and control children. In particular, our analysis reveals statistically significant differences between the two groups in regions of the parietal cortex indicating that these may serve as "biomarkers" for diagnostic purposes and ultimately localized treatment. [ABSTRACT FROM AUTHOR]

Aim: The aim of this paper is to describe the clinical features of COVID‐19‐related encephalopathy and their metabolic correlates using brain 2‐desoxy‐2‐fluoro‐D‐glucose (FDG)‐positron‐emission tomography (PET)/computed tomography (CT) imaging. Background and purpose: A variety of neurological manifestations have been reported in association with COVID‐19. COVID‐19‐related encephalopathy has seldom been reported and studied. Methods: We report four cases of COVID‐19‐related encephalopathy. The diagnosis was made in patients with confirmed COVID‐19 who presented with new‐onset cognitive disturbances, central focal neurological signs, or seizures. All patients underwent cognitive screening, brain magnetic resonance imaging (MRI), lumbar puncture, and brain 2‐desoxy‐2‐fluoro‐D‐glucose (FDG)‐positron‐emission tomography (PET)/computed tomography (CT) (FDG‐PET/CT). Results: The four patients were aged 60 years or older, and presented with various degrees of cognitive impairment, with predominant frontal lobe impairment. Two patients presented with cerebellar syndrome, one patient had myoclonus, one had psychiatric manifestations, and one had status epilepticus. The delay between first COVID‐19 symptoms and onset of neurological symptoms was between 0 and 12 days. None of the patients had MRI features of encephalitis nor significant cerebrospinal fluid (CSF) abnormalities. SARS‐CoV‐2 RT‐PCR in the CSF was negative for all patients. All patients presented with a consistent brain FDG‐PET/CT pattern of abnormalities, namely frontal hypometabolism and cerebellar hypermetabolism. All patients improved after immunotherapy. Conclusions: Despite varied clinical presentations, all patients presented with a consistent FDG‐PET pattern, which may reflect an immune mechanism. [ABSTRACT FROM AUTHOR]

Indexing of medical images for efficient management is gaining importance with its continuously growing database size. The popular text‐based image indexing method is time‐consuming. Content‐based labeling uses mathematical models for automatic indexing, offers higher speed and unbiased performance. Widely used image features are computed from pixel intensity and its distribution pattern. Pixel intensity depends on imaging modality. It introduces differences in the content of the same image when acquired using different modalities. In this article, we have proposed an intensity independent descriptor, Information Count and Distribution Matrix (ICDM). It is formulated to eliminate modality dependency and decrease the mathematical load. ICDM is formed using the foreground information of an image. Three primary (and two auxiliary) features are extracted from this matrix and used for brain image indexing. Brain computed tomography images are indexed by more than 96% accuracy using the proposed features. The formation of ICDM is proposed to reduce the semantic gaps between human and computer vision. [ABSTRACT FROM AUTHOR]

A 45‐year‐old man presented with an acute pontine infarction with dolichoectasia of the basilar artery. Four days after initiation of antithrombotic therapy, the occurrence of symptomatic subarachnoid hemorrhage was confirmed by brain computed tomography (MRI), with a remarkable shrinkage of dolichoectasia of the basilar artery. Despite the discontinuation of antithrombotic therapy, subsequent multiple ruptures occurred with re‐expanded DBA and the patient died of respiratory insufficiency. Since DBA has an anatomical structural abnormality in a vessel wall, a shape of vessel could dramatically be changed. Because a transformation of DBA diameter could occur in the course of ischemic and hemorrhagic stroke, we need to pay attention to change of DBA diameter. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: The neuronal ceroid lipofuscinoses (NCLs; Batten disease) are a group of fatal neurodegenerative lysosomal storage diseases of children caused by various mutations in a range of genes. Forms associated with mutations in two of these, CLN5 and CLN6, are being investigated in well‐established sheep models. Brain atrophy leading to psychomotor degeneration is among the defining features, as is regional progressive ossification of the inner cranium. Ongoing viral‐mediated gene therapy trials in these sheep are yielding encouraging results. In vivo assessment of brain atrophy is integral to the longitudinal monitoring of individual animals and provides robust data for translation to treatments for humans. Methods: Computed tomography (CT)‐based three‐dimensional reconstruction of the intracranial volume (ICV) over time reflects the progression of cortical brain atrophy, verifying the use of ICV measurements as a surrogate measure for brain size in ovine NCL. Results: ICVs of NCL‐affected sheep increase for the first few months, but then decline progressively between 5 and 13 months in CLN5−/− sheep and 11–15 months in CLN6−/− sheep. Cerebral ventricular volumes are also increased in affected animals. To facilitate ICV measures, the radiodensities of ovine brain tissue and cerebrospinal fluid were identified. Ovine brain tissue exhibited a Hounsfield unit (HU) range of (24; 56) and cerebrospinal fluid a HU range of (−12; 23). Conclusions: Computed tomography scanning and reconstruction verify that brain atrophy ovine CLN5 NCL originates in the occipital lobes with subsequent propagation throughout the whole cortex and these regional differences are reflected in the ICV loss. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To clarify the relationship of clinical factors with isolated vertigo or dizziness of cerebrovascular origin. Methods: Clinical data of patients admitted in East Hospital from Jan. 2015 to Apr. 2016, whose complaint were acute vertigo or dizziness were retrospectively collected. All patients arrived at the emergency department within 24 hr of symptom onset, had no acute ischemic lesion first CT and NIHSS score of 0. Patients were divided into cerebral infarction group and noncerebral infarction group according to subsequent cerebral imaging results and clinical and laboratory factors related to cerebral infarction were analyzed. Result: 51.6% of patients were female (n = 141). 46 patients (16.8%) were diagnosed with acute cerebral infarction. Baseline demographic data of the two groups was not significantly different. Univariate analysis found that history of smoking (p = 0.009), headache (p = 0.028), unsteadiness (p = 0.009), neuron specific enolase (p = 0.001), and vertebral artery abnormalities found on imaging (p = 0.009) were the significant difference between two groups. Increased neuron specific enolase (p = 0.005) and an abnormal vertebral artery (p = 0.044) were significant on multivariate analysis. Conclusions: 16.8% of acute isolated vertigo or dizziness presentations were diagnosed with acute cerebral infarction. Increased serum neuron specific enolase and vertebral artery abnormalities were the strongest indicators of acute cerebral infarction. [ABSTRACT FROM AUTHOR]

Abstract: Background and Purpose: Mechanical thrombectomy (MT) is indicated for the treatment of large vessel occlusion (LVO) stroke. MT should be provided as quickly as possible; therefore, a test identifying suspected LVO in the prehospitalization stage is needed to ensure direct transport to a comprehensive stroke center (CSC). We assume that patients with clinically severe hemiparesis have a high probability of LVO stroke. We modified the FAST test into the FAST PLUS test: The first part is the FAST test and the second part evaluates the presence of severe arm or leg motor deficit. This prospective multicenter study evaluates the specificity and sensitivity of the FAST PLUS test in detecting LVO stroke. Methods: Paramedics were trained through e‐learning to conduct the FAST PLUS test. All prehospital suspected stroke patients who were administered the FAST PLUS test were included. Demographics, National Institutes of Health Stroke Scale (NIHSS) score, brain computed tomography (CT), and CT angiography (CTA) were recorded. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and receiver operating curve (ROC) area for LVO were calculated. Results: The study included 435 patients. LVO were found in 124 patients (28%). Sensitivity was 93%, specificity was 47%, PPV was 41%, NPV was 94%, and ROC area for ICA/MCA occlusion was 0.65. Intracerebral hemorrhage (ICH) was identified in 48 patients (11%). Conclusion: We found that the FAST PLUS test had a high sensitivity for LVO stroke. Of the 435 patients, 41% were all directly transported to a CSC based on positive FAST PLUS test scores and were potential candidates for MT. [ABSTRACT FROM AUTHOR]

Purpose: While MR‐only treatment planning using synthetic CTs (synCTs) offers potential for streamlining clinical workflow, a need exists for an efficient and automated synCT generation in the brain to facilitate near real‐time MR‐only planning. This work describes a novel method for generating brain synCTs based on generative adversarial networks (GANs), a deep learning model that trains two competing networks simultaneously, and compares it to a deep convolutional neural network (CNN). Methods: Post‐Gadolinium T1‐Weighted and CT‐SIM images from fifteen brain cancer patients were retrospectively analyzed. The GAN model was developed to generate synCTs using T1‐weighted MRI images as the input using a residual network (ResNet) as the generator. The discriminator is a CNN with five convolutional layers that classified the input image as real or synthetic. Fivefold cross‐validation was performed to validate our model. GAN performance was compared to CNN based on mean absolute error (MAE), structural similarity index (SSIM), and peak signal‐to‐noise ratio (PSNR) metrics between the synCT and CT images. Results: GAN training took ~11 h with a new case testing time of 5.7 ± 0.6 s. For GAN, MAEs between synCT and CT‐SIM were 89.3 ± 10.3 Hounsfield units (HU) and 41.9 ± 8.6 HU across the entire FOV and tissues, respectively. However, MAE in the bone and air was, on average, ~240–255 HU. By comparison, the CNN model had an average full FOV MAE of 102.4 ± 11.1 HU. For GAN, the mean PSNR was 26.6 ± 1.2 and SSIM was 0.83 ± 0.03. GAN synCTs preserved details better than CNN, and regions of abnormal anatomy were well represented on GAN synCTs. Conclusions: We developed and validated a GAN model using a single T1‐weighted MR image as the input that generates robust, high quality synCTs in seconds. Our method offers strong potential for supporting near real‐time MR‐only treatment planning in the brain. [ABSTRACT FROM AUTHOR]

Converging preclinical evidence links extrastriatal dopamine release and glutamatergic transmission via the metabotropic glutamate receptor 5 (mGluR5) to the rewarding properties of alcohol. To date, human evidence is lacking on how and where in the brain these processes occur. Mesocorticolimbic dopamine release upon intravenous alcohol administration and mGluR5 availability were measured in 11 moderate social drinkers by single-session [18 F]fallypride and [18 F]FPEB positron emission tomography, respectively. Additionally, baseline and postalcohol glutamate and glutamine levels in the anterior cingulate cortex (ACC) were measured by using proton-magnetic resonance spectroscopy. To investigate differences in reward domains linked to both neurotransmitters, regional imaging data were related to subjective alcohol responses. Alcohol induced significant [18 F]fallypride displacement in the prefrontal cortex (PFC), temporal and parietal cortices and thalamus (P < 0.05, corrected for multiple comparisons). Dopamine release in the ACC and orbitofrontal and ventromedial PFCs were correlated with subjective 'liking' and 'wanting' effects (P < 0.05). In contrast, baseline mGluR5 availability was positively correlated with the 'high' effect of alcohol in dorsolateral, ventrolateral and ventromedial PFCs and in the medial temporal lobe, thalamus and caudate nucleus (P < 0.05). Although neither proton-magnetic resonance spectroscopy glutamate nor glutamine levels were affected by alcohol, baseline ACC glutamate levels were negatively associated with the alcohol 'liking' effect (P < 0.003). These data reveal new mechanistic understanding and differential neurobiological underpinnings of the effects of acute alcohol consumption on human behavior. Specifically, prefrontal dopamine release may encode alcohol 'liking' and 'wanting' effects in specific areas underlying value processing and motivation, whereas mGluR5 availability in distinct prefrontal-temporal-subcortical regions is more related to the alcohol 'high' effect. [ABSTRACT FROM AUTHOR]

Abstract: Many discrepancies are found in the literature regarding the damage and constitutive models for head tissues as well as the values of the constants involved in the constitutive equations. Their proper definition is required for consistent numerical model performance when predicting human head behaviour, and hence skull fracture and brain damage. The objective of this research is to perform a critical review of constitutive models and damage indicators describing human head tissue response under impact loading. A 3D finite element human head model has been generated by using computed tomography images, which has been validated through the comparison to experimental data in the literature. The threshold values of the skull and the scalp that lead to fracture have been analysed. We conclude that (1) compact bone properties are critical in skull fracture, (2) the elastic constants of the cerebrospinal fluid affect the intracranial pressure distribution, and (3) the consideration of brain tissue as a nearly incompressible solid with a high (but not complete) water content offers pressure responses consistent with the experimental data. [ABSTRACT FROM AUTHOR]

Summary: The aim of this study was to evaluate the impact of cerebral blood flow (CBF) recovery obtained from brain single‐photon emission computed tomography (SPECT) images on postoperative outcome after aneurysmal subarachnoid haemorrhage (SAH). Twenty‐nine patients who had undergone surgical clipping for ruptured anterior communicating artery aneurysms were analyzed prospectively. Routine measurements of CBF were performed using technetium‐99 m hexamethyl propyleneamine oxine SPECT on days 4 and 14 after SAH. Regional voxel data analyzed by three dimensional stereotactic surface projection (3D‐SSP) were compared between patients and age‐matched normal database (NDB). In 3D‐SSP analysis of all patients, cortical hypoperfusion around the surgical site in bilateral frontal lobes was evident on day 4 (P < .05 vs NDB), which was improved significantly on day 14. However, the recovery was less complete in patients with poor clinical grades (P < .05) and presenting symptoms attributable to delayed cerebral ischaemia (DCI) (P < .05) than those without. Multivariate analysis showed that patients with mild to moderate CBF recovery (relative Z‐score differences of <4) (P = .014; odds ratio, 2.5; 95% confidence interval, 1.93–3.31) was independently associated with poor functional outcome at 3 months. We conclude that reduced CBF recovery detected by serial 3D‐SSP SPECT image analyses can be a potential predictor of poor prognosis in postoperative patients after SAH. [ABSTRACT FROM AUTHOR]

Summary: Aims: Deep brain stimulation of the subthalamic nucleus (STN‐DBS) has become an effective treatment strategy for patients with Parkinson's disease. However, the biological mechanism underlying DBS treatment remains poorly understood. Method: In this study, we investigated how STN‐DBS modulated the brain network using a bimodal positron emission tomography (PET)/functional magnetic resonance imaging (fMRI) dataset. We first performed an activation likelihood estimation meta‐analysis of 13 PET/SPECT studies concerning STN‐DBS effects on resting‐state brain activity in Parkinson's disease. Additionally, using a functional connectivity analysis in resting‐state fMRI, we investigated whether these STN‐DBS‐affected regions were functionally connected to constitute an effective network. Results: The results revealed that STN‐DBS reduced brain activity in the right thalamus, bilateral caudal supplementary area, and the left primary motor cortex, and it increased brain activity in the left thalamus during rest. Second, these STN‐DBS‐affected areas were functionally connected within an STN‐DBS effective network. Conclusion: Deep brain stimulation of the subthalamic nucleus (STN‐DBS) may deactivate the motor cortex as a remote and network effect, affecting the target and the neighboring subcortical areas. These areas may constitute an effective network of STN‐DBS modulation. Our results shed light on the mechanisms of STN‐DBS treatment from a network perspective and highlight the potential therapeutic benefits of targeted network modulation. [ABSTRACT FROM AUTHOR]

Aim: To study specific vascular anatomy of dural arteriovenous fistulae (DAVFs) locating at the foramen magnum in patients admitted to our centre in the past year (2019–2020), and to evaluate effectiveness of microsurgical disconnection of DAVFs alone. Patients and Methods: Two male patients were included. Neuroimaging results obtained on admission, including computer tomography, digital subtraction angiography and magnetic resonance imaging of the brain, were studied and compared. Digital subtraction angiography with selective injection to the external carotid artery was particularly explored to trace main feeding arteries and draining veins of DAVFs. Results: Both patients had diffuse subarachnoid haemorrhage (SAH), particularly anterior to the medulla on initial computer tomography of the brain. Branches of the ascending pharyngeal artery were identified as main feeding arteries. Draining veins included anterior/posterior spinal veins and pterygopalatine venous plexus. Magnetic resonance imaging confirmed DAVFs at the level of foramen magnum to C1 vertebra. Complete occlusion was achieved with far‐lateral microsurgical approach, with intra‐operative indocyanine green injection confirming no filling of venous pouch. Post‐operative follow‐up digital subtraction angiography demonstrated no angiographic evidence of residual DAVFs or new haemorrhages. Conclusion: DAVFs at the foramen magnum could present as SAH. A combination of neuroimaging methods aid diagnosis and identification of underlying vascular anatomy. Satisfactory outcomes with complete occlusion were achieved with microsurgical approach alone. [ABSTRACT FROM AUTHOR]

Objectives To explore the association, if any, between the relationship between cardiac troponin and cerebral herniation after intracerebral hemorrhage ( ICH). Methods Six hundred and eighty-seven consecutive ICH patients admitted to West China Hospital from May 1, 2014 to September 1, 2015 were retrospectively reviewed. Data on demographics, etiology, laboratory examinations at admission including serum cardiac troponin, computed tomography ( CT) scans at admission and follow-up, and clinical outcomes were obtained. Using multiple logistic regression to identify the relationship of troponin and herniation. The association between troponin and hematoma volume was assessed using bivariate correlation and linear regression. Results Among 188 (27.4%) patients who underwent the test of serum cardiac troponin at admission, 16 (8.5%) demonstrated cerebral herniation. The median time from symptom onset to CT at admission and follow-up was 4 and 30.25 hr, respectively. In multivariate analysis, elevated troponin was independently associated with cerebral herniation (adjusted odds ratio [ OR] 5.19; 95% confidence interval [ CI], 1.08-24.93). And those with elevated troponin had larger hematoma volume at follow-up in bivariate correlation (correlation coefficient, .375, p = .003) and linear regression (β, .370, 95% CI, 0.062-0.320, p = .005), higher National Institutes of Health Stroke Scale score (adjusted OR 2.06; 95% CI, 1.06-4.01, p = .033) and lower Glasgow Coma Scale score (adjusted OR 2.34; 95% CI, 1.17-4.68, p = .016) than those without. Conclusions Elevated cardiac troponin was associated with an almost five-fold increased risk of cerebral herniation, but not in-hospital mortality. The possibility of cerebral herniation should be considered when ICH patients with large hematoma volume and elevated troponin. [ABSTRACT FROM AUTHOR]

Neuroimaging offers a wide range of opportunities to obtain information about neuronal activity, brain inflammation, blood-brain barrier alterations, and various molecular alterations during epileptogenesis or for the prediction of pharmacoresponsiveness as well as postoperative outcome. Imaging biomarkers were examined during the XIII Workshop on Neurobiology of Epilepsy ( XIII WONOEP) organized in 2015 by the Neurobiology Commission of the International League Against Epilepsy (ILAE). Here we present an extended summary of the discussed issues and provide an overview of the current state of knowledge regarding the biomarker potential of different neuroimaging approaches for epilepsy. [ABSTRACT FROM AUTHOR]

Purpose Early identification of ischemic stroke plays a significant role in treatment and potential recovery of damaged brain tissue. In noncontrast CT (ncCT), the differences between ischemic changes and healthy tissue are usually very subtle during the hyperacute phase (< 8 h from the stroke onset). Therefore, visual comparison of both hemispheres is an important step in clinical assessment. A quantitative symmetry-based analysis of texture features of ischemic lesions in noncontrast CT images may provide an important information for differentiation of ischemic and healthy brain tissue in this phase. Methods One hundred thirty-nine (139) ncCT scans of hyperacute ischemic stroke with follow-up magnetic resonance diffusion-weighted (MR-DW) images were collected. The regions of stroke were identified in the MR-DW images, which were spatially aligned to corresponding ncCT images. A state-of-the-art symmetric diffeomorphic image registration was utilized for the alignment of CT and MR-DW, for identification of individual brain hemispheres, and for localization of the region representing healthy tissue contralateral to the stroke cores. Texture analysis included extraction and classification of co-occurrence and run-length texture-based image features in the regions of ischemic stroke and their contralateral regions. Results The classification schemes achieved area under the receiver operating characteristic [Az] ≈ 0.82 for the whole dataset. There was no statistically significant difference in the performance of classifiers for the data sets with time between 2 and 8 hours from symptom onset. The performance of the classifiers did not depend on the size of the stroke regions. Conclusions The results provide a set of optimal texture features which are suitable for distinguishing between hyperacute ischemic lesions and their corresponding contralateral brain tissue in noncontrast CT. This work is an initial step toward development of an automated decision support system for detection of hyperacute ischemic stroke lesions on noncontrast CT of the brain. [ABSTRACT FROM AUTHOR]

Purpose Dynamic [18F]fluoro-ethyl-L-tyrosine positron emission tomography ([18F] FET- PET) is used to identify tumor lesions for radiotherapy treatment planning, to differentiate glioma recurrence from radiation necrosis and to classify gliomas grading. To segment different regions in the brain k-means cluster analysis can be used. The main disadvantage of k-means is that the number of clusters must be pre-defined. In this study, we therefore compared different cluster validity indices for automated and reproducible determination of the optimal number of clusters based on the dynamic PET data. Methods The k-means algorithm was applied to dynamic [18F] FET- PET images of 8 patients. Akaike information criterion ( AIC), WB, I, modified Dunn's and Silhouette indices were compared on their ability to determine the optimal number of clusters based on requirements for an adequate cluster validity index. To check the reproducibility of k-means, the coefficients of variation CVs of the objective function values OFVs (sum of squared Euclidean distances within each cluster) were calculated using 100 random centroid initialization replications RCI100 for 2 to 50 clusters. k-means was performed independently on three neighboring slices containing tumor for each patient to investigate the stability of the optimal number of clusters within them. To check the independence of the validity indices on the number of voxels, cluster analysis was applied after duplication of a slice selected from each patient. CVs of index values were calculated at the optimal number of clusters using RCI100 to investigate the reproducibility of the validity indices. To check if the indices have a single extremum, visual inspection was performed on the replication with minimum OFV from RCI100. Results The maximum CV of OFVs was 2.7 × 10−2 from all patients. The optimal number of clusters given by modified Dunn's and Silhouette indices was 2 or 3 leading to a very poor segmentation. WB and I indices suggested in median 5, [range 4-6] and 4, [range 3-6] clusters, respectively. For WB, I, modified Dunn's and Silhouette validity indices the suggested optimal number of clusters was not affected by the number of the voxels. The maximum coefficient of variation of WB, I, modified Dunn's, and Silhouette validity indices were 3 × 10−2, 1, 2 × 10−1 and 3 × 10−3, respectively. WB-index showed a single global maximum, whereas the other indices showed also local extrema. Conclusion From the investigated cluster validity indices, the WB-index is best suited for automated determination of the optimal number of clusters for [18F] FET- PET brain images for the investigated image reconstruction algorithm and the used scanner: it yields meaningful results allowing better differentiation of tissues with higher number of clusters, it is simple, reproducible and has an unique global minimum. [ABSTRACT FROM AUTHOR]

Purpose A brain sized radio frequency ( RF)-penetrable PET insert has been designed for simultaneous operation with MRI systems. This system takes advantage of electro-optical coupling and battery power to electrically float the PET insert relative to the MRI ground, permitting RF signals to be transmitted through small gaps between the modules that form the PET ring. This design facilitates the use of the built-in body coil for RF transmission and thus could be inserted into any existing MR site wishing to achieve simultaneous PET/ MR imaging. The PET detectors employ nonmagnetic silicon photomultipliers in conjunction with a compressed sensing signal multiplexing scheme, and optical fibers to transmit analog PET detector signals out of the MRI room for decoding, processing, and image reconstruction. Methods The PET insert was first constructed and tested in a laboratory benchtop setting, where tomographic images of a custom resolution phantom were successfully acquired. The PET insert was then placed within a 3T body MRI system, and tomographic resolution/contrast phantom images were acquired both with only the B0 field present, and under continuous pulsing from different MR imaging sequences. Results The resulting PET images have comparable contrast-to-noise ratios ( CNR) under all MR pulsing conditions: The maximum percent CNR relative difference for each rod type among all four PET images acquired in the MRI system has a mean of 14.0 ± 7.7%. MR images were successfully acquired through the RF-penetrable PET shielding using only the built-in MR body coil, suggesting that simultaneous imaging is possible without significant mutual interference. Conclusions These results show promise for this technology as an alternative to costly integrated PET/ MR scanners; a PET insert that is compatible with any existing clinical MRI system could greatly increase the availability, accessibility, and dissemination of PET/ MR. [ABSTRACT FROM AUTHOR]

The density of a hematoma on a non-contrast computed tomography of the brain is determined by the degree of clot retraction, hematocrit and globin content. Classically, the appearance of an intracranial haemorrhage on a computed tomography correlates with the temporal evolution of hematoma. However, this case illustrates there are circumstances that this classical temporal appearance may not hold true. [ABSTRACT FROM AUTHOR]

Purpose: Transcranial focused ultrasound (FUS) shows great promise for a range of therapeutic applications in the brain. Current clinical investigations rely on the use of magnetic resonance imaging (MRI) to monitor treatments and for the registration of preoperative computed tomography (CT)-data to the MR images at the time of treatment to correct the sound aberrations caused by the skull. For some applications, MRI is not an appropriate choice for therapy monitoring and its cost may limit the accessibility of these treatments. An alternative approach, using high frequency ultrasound measurements to localize the skull surface and register CT data to the ultrasound treatment space, for the purposes of skull-related phase aberration correction and treatment targeting, has been developed. Methods: A prototype high frequency, hemispherical sparse array was fabricated. Pulse-echo measurements of the surface of five ex vivo human skulls were made, and the CT datasets of each skull were obtained. The acoustic data were used to rigidly register the CT-derived skull surface to the treatment space. The ultrasound-based registrations of the CT datasets were compared to the gold-standard landmark-based registrations. Results: The results show on an average sub-millimeter (0.9±0.2 mm) displacement and subdegree (0.8°±0.4°) rotation registration errors. Numerical simulations predict that registration errors on this scale will result in a mean targeting error of 1.0±0.2 mm and reduction in focal pressure of 1.0%±0.6% when targeting a midbrain structure (e.g., hippocampus) using a commercially available low-frequency brain prototype device (InSightec, 230 kHz brain system). Conclusions: If combined with ultrasound-based treatment monitoring techniques, this registration method could allow for the development of a low-cost transcranial FUS treatment platform to make this technology more widely available. [ABSTRACT FROM AUTHOR]

Glycogen synthase kinase-3 (GSK-3) regulates multiple cellular processes in diabetes, oncology, and neurology. N-(3-(1H-1,2,4-triazol-1-yl)propyl)-5-(3-chloro-4-methoxyphenyl)oxazole-4-carboxamide (PF-04802367 or PF-367) has been identified as a highly potent inhibitor, which is among the most selective antagonists of GSK-3 to date. Its efficacy was demonstrated in modulation of tau phosphorylation in vitro and in vivo. Whereas the kinetics of PF-367 binding in brain tissues are too fast for an effective therapeutic agent, the pharmacokinetic profile of PF-367 is ideal for discovery of radiopharmaceuticals for GSK-3 in the central nervous system. A 11C-isotopologue of PF-367 was synthesized and preliminary PET imaging studies in non-human primates confirmed that we have overcome the two major obstacles for imaging GSK-3, namely, reasonable brain permeability and displaceable binding. [ABSTRACT FROM AUTHOR]

Frontotemporal dementia (FTD) is a clinically and neuroanatomically heterogeneous neurodegenerative disorder with multiple underlying genetic and pathological causes. Whilst initial neuroimaging studies highlighted the presence of frontal and temporal lobe atrophy or hypometabolism as the unifying feature in patients with FTD, more detailed studies have revealed diverse patterns across individuals, with variable frontal or temporal predominance, differing degrees of asymmetry, and the involvement of other cortical areas including the insula and cingulate, as well as subcortical structures such as the basal ganglia and thalamus. Recent advances in novel imaging modalities including diffusion tensor imaging, resting-state functional magnetic resonance imaging and molecular positron emission tomography imaging allow the possibility of investigating alterations in structural and functional connectivity and the visualisation of pathological protein deposition. This review will cover the major imaging modalities currently used in research and clinical practice, focusing on the key insights they have provided into FTD, including the onset and evolution of pathological changes and also importantly their utility as biomarkers for disease detection and staging, differential diagnosis and measurement of disease progression. Validating neuroimaging biomarkers that are able to accomplish these tasks will be crucial for the ultimate goal of powering upcoming clinical trials by correctly stratifying patient enrolment and providing sensitive markers for evaluating the effects and efficacy of disease-modifying therapies. [ABSTRACT FROM AUTHOR]