Basal Ganglia Regions Research Articles

Gray-White Matter Ratio at the Level of the Basal Ganglia as a Predictor of Neurologic Outcomes in Cardiac Arrest Survivors: A Literature Review.

Loss of gray-white matter discrimination is the primary early imaging finding within of cranial computed tomography in cardiac arrest survivors, and this has been also regarded as a novel predictor for evaluating neurologic outcome. As displayed clearly on computed tomography and based on sensitivity to hypoxia, the gray-white matter ratio at basal ganglia (GWR-BG) region was frequently detected to assess the neurologic outcome by several studies. The specificity of GWR-BG is 72.4 to 100%, while the sensitivity is significantly different. Herein we review the mechanisms mediating cerebral edema following cardiac arrest, demonstrate the determination procedures with respect to GWR-BG, summarize the related researches regarding GWR-BG in predicting neurologic outcomes within cardiac arrest survivors, and discuss factors associated with predicting the accuracy of this methodology. Finally, we describe the effective measurements to increase the sensitivity of GWR-BG in predicting neurologic outcome.

Genetic mutation spectrum of pantothenate kinase-associated neurodegeneration expanded by breakpoint sequencing in pantothenate kinase 2 gene

BackgroundNeurodegeneration with brain iron accumulation describes a group of rare heterogeneous progressive neurodegenerative disorders characterized by excessive iron accumulation in the basal ganglia region. Pantothenate kinase-associated neurodegeneration (PKAN) is a major form of this disease.ResultsA total of 7 unrelated patients were diagnosed with PKAN in a single tertiary center from August 2009 to February 2018. Ten variants in PANK2 including three novel sequence variants and one large exonic deletion were detected. Sequencing of the breakpoint was performed to predict the mechanism of large deletion and AluSx3 and AluSz6 were found with approximately 97.3% sequence homology.ConclusionThe findings support the disease-causing role of PANK2 and indicate the possibility that exonic deletion of PANK2 found in PKAN is mediated through Alu-mediated homologous recombination.

A Newborn with an Incidental Finding on Cranial Ultrasonography.

A Newborn with an Incidental Finding on Cranial Ultrasonography.

Exercise Intensity and Brain Plasticity: What's the Difference of Brain Structural and Functional Plasticity Characteristics Between Elite Aerobic and Anaerobic Athletes?

This study investigated the differences in morphometry and functional plasticity characteristics of the brain after long-term training of different intensities. Results showed that an aerobic group demonstrated higher gray matter volume in the cerebellum and temporal lobe, while an anaerobic group demonstrated higher gray matter volume in the region of basal ganglia. In addition, the aerobic group also showed significantly higher fractional amplitude of low-frequency fluctuation (fALFF) and degree centrality (DC) in the motor area of the frontal lobe and parietal lobe, and the frontal gyrus, respectively. At the same time, the anaerobic group demonstrated higher fALFF and DC in the cerebellum posterior lobe (family-wise error corrected, p < 0.01). These findings may further prove that different brain activation modes respond to different intensities of physical activity and may help to reveal the neural mechanisms that can classify athletes from different intensity sports.

Characterization of the GfaABC1D promoter to selectively target astrocytes in the rhesus macaque brain

BackgroundThe study of astrocytic functions in non-human primates (NHPs) has been hampered by the lack of genetic tools to selectively target astrocytes. Viral vectors with selective and efficient transduction of astrocytes could be a potent tool to express marker proteins, modulators, or sensors in NHP astrocytes, but the availability of thoroughly characterized astrocytic selective promoter sequences to use in these species remains extremely limited. New MethodWe describe the specificity and efficiency of an astrocyte-specific promoter, GfaABC1D in the brain of the rhesus macaque, with emphasis in basal ganglia regions. AAV5-pZac2.1-GfaABC1D-tdTomato was locally injected into the globus pallidus external segment (GPe) and putamen. The extent, efficiency, and specificity of transduction was analyzed with immunohistochemistry at the light and electron microscope levels. ResultsThe GfaABC1D promoter directed the expression of tdTomato in an astrocyte-specific manner in directly or indirectly targeted regions (including both segments of the globus pallidus, putamen, subthalamic nucleus and cortex). Comparison with Existing MethodsDue to its small size, the GfaABC1D promoter is advantageous over other previously used glial fibrillary acidic protein-based promoter sequences, facilitating its use to drive expression of various transgenes in adeno-associated viruses (AAV) or other viral vectors. ConclusionGfaABC1D is an efficient promoter that selectively targets astrocytes in the monkey basal ganglia and expands the viral vector toolbox to study astrocytic functions in non-human primates.

Roles of the Cannabinoid System in the Basal Ganglia in Parkinson's Disease.

Parkinson’s disease (PD) is a neurodegenerative disease usually caused by neuroinflammation, oxidative stress and other etiologies. Recent studies have found that the cannabinoid system present in the basal ganglia has a strong influence on the progression of PD. Altering the cannabinoid receptor activation status by modulating endogenous cannabinoid (eCB) levels can exert an anti-movement disorder effect. Therefore, the development of drugs that modulate the endocannabinoid system may be a novel strategy for the treatment of PD. However, eCB regulation is complex, with diverse cannabinoid receptor functions and the presence of dopaminergic, glutamatergic, and γ-aminobutyric signals interacting with cannabinoid signaling in the basal ganglia region. Therefore, the study of eCB is challenging. Here, we have described the function of the cannabinoid system in the basal ganglia and its association with PD in three parts (eCBs, cannabinoid receptors, and factors regulating the cannabinoid metabolism) and summarized the mechanisms of action related to the cannabinoid analogs currently aimed at treating PD. The shortcomings identified from previous studies and the directions that should be explored in the future will provide insights into new approaches and ideas for the future development of cannabinoid-based drugs and the treatment of PD.

Complex functional brain network properties in anorexia nervosa

BackgroundAnorexia nervosa (AN) is a disorder characterized by an incapacitating fear of weight gain and by a disturbance in the way the body is experienced, facets that motivate dangerous weight loss behaviors. Multimodal neuroimaging studies highlight atypical neural activity in brain networks involved in interoceptive awareness and reward processing.MethodsThe current study used resting-state neuroimaging to model the architecture of large-scale functional brain networks and characterize network properties of individual brain regions to clinical measures. Resting-state neuroimaging was conducted in 62 adolescents, 22 (21 female) with a history of AN and 40 (39 female) healthy controls (HCs). Sensorimotor and basal ganglia regions, as part of a 165-region whole-brain network, were investigated. Subject-specific functional brain networks were computed to index centrality. A contrast analysis within the general linear model covarying for age was performed. Correlations between network properties and behavioral measures were conducted (significance q < .05).ResultsCompared to HCs, AN had lower connectivity from sensorimotor regions, and greater connectivity from the left caudate nucleus to the right postcentral gyrus. AN demonstrated lower sensorimotor centrality, but higher basal ganglia centrality. Sensorimotor connectivity dyads and centrality exhibited negative correlations with body dissatisfaction and drive for thinness, two essential features of AN.ConclusionsThese findings suggest that AN is associated with greater communication from the basal ganglia, and lower information propagation in sensorimotor cortices. This is consistent with the clinical presentation of AN, where individuals exhibit patterns of rigid habitual behavior that is not responsive to bodily needs, and seem “disconnected” from their bodies.

Abstinence from Chronic Methylphenidate Exposure Modifies Cannabinoid Receptor 1 Levels in the Brain in a Dose-dependent Manner.

Methylphenidate (MP) is a widely used psychostimulant prescribed for Attention Deficit Hyperactivity Disorder and is also used illicitly by healthy individuals. Chronic exposure to MP has been shown to affect physiology, behavior measures, and neurochemistry. The present study examined its effect on the endocannabinoid system. Adolescent rats had daily oral access to either water (control), low dose MP (4/10 mg/kg), or high dose MP (30/60 mg/kg). After 13 weeks of exposure, half of the rats in each group were euthanized, with the remaining rats underwent a four-week- long abstinence period. Cannabinoid receptor 1 binding (CB1) was measured with in vitro autoradiography using [3H] SR141716A. Rats who underwent a 4-week abstinence period after exposure to chronic HD MP showed increased CB1 binding in several cortical and basal ganglia regions of the brain compared to rats with no abstinence period. In contrast to this, rats who underwent a 4-week abstinence period after exposure to chronic LD MP showed lower CB1 binding mainly in the basal ganglia regions and the hindlimb region of the somatosensory cortex compared to rats with no abstinence period. Following 4 weeks of drug abstinence, rats who were previously given HD MP showed higher [3H] SR141716A binding in many of the cortical and basal ganglia regions examined than rats given LD MP. These results highlight the biphasic effects of MP treatment on cannabinoid receptor levels. Abstinence from HD MP seemed to increase CB1 receptor levels, while abstinence from LD MP seemed to decrease CB1 levels. Given the prolific expression of cannabinoid receptors throughout the brain, many types of behaviors may be affected as a result of MP abstinence. Further research will be needed to help identify these behavioral changes.

Comparison of quantitative susceptibility mapping methods on evaluating radiation-induced cerebral microbleeds and basal ganglia at 3T and 7T.

Quantitative susceptibility mapping (QSM) has the potential for being a biomarker for various diseases because of its ability to measure tissue susceptibility related to iron deposition, myelin, and hemorrhage from the phase signal of a T2 *-weighted MRI. Despite its promise as a quantitative marker, QSM is faced with many challenges, including its dependence on preprocessing of the raw phase data, the relatively weak tissue signal, and the inherently ill posed relationship between the magnetic dipole and measured phase. The goal of this study was to evaluate the effects of background field removal and dipole inversion algorithms on noise characteristics, image uniformity, and structural contrast for cerebral microbleed (CMB) quantification at both 3T and 7T. We selected four widely used background phase removal and five dipole field inversion algorithms for QSM and applied them to volunteers and patients with CMBs, who were scanned at two different field strengths, with ground truth QSM reference calculated using multiple orientation scans. 7T MRI provided QSM images with lower noise than did 3T MRI. QSIP and VSHARP + iLSQR achieved the highest white matter homogeneity and vein contrast, with QSIP also providing the highest CMB contrast. Compared with ground truth COSMOS QSM images, overall good correlations between susceptibility values of dipole inversion algorithms and the COSMOS reference were observed in basal ganglia regions, with VSHARP + iLSQR achieving the susceptibility values most similar to COSMOS across all regions. This study can provide guidance for selecting the most appropriate QSM processing pipeline based on the application of interest and scanner field strength.

Depression, anxiety and health-related quality of life in paediatric intracranial germ cell tumor survivors

BackgroundLittle is known about depression and anxiety among paediatric intracranial germ cell tumour (iGCT) survivors. We aimed to evaluate the risk factors associated with depression, anxiety and health-related quality of life (HRQoL) in paediatric iGCT survivors.MethodsWe recruited 200 iGCT patients (and their parents) from Beijing Tiantan Hospital and assessed their HRQoL using the Paediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core Scales. The Children’s Depression Inventory, Screen for Child Anxiety Related Emotional Disorders, and Symptom Checklist 90 were used to evaluate depression and anxiety. The results were analysed based on disease recurrence, tumour location and treatment strategies.ResultsSurvivors with recurrent tumours had worse HRQoL scores than those with non-recurrent tumours. Patients with tumours involving both the suprasellar and basal ganglia regions had the worst HRQoL scores. A large proportion of survivors had depression or anxiety. Both depression and anxiety scores were highly correlated with the HRQoL emotional functioning scores. The parent proxy-reports (PPR) and child self-reports were highly correlated in all domains.ConclusionsThis study demonstrated the clinical factors affecting paediatric iGCT survivors’ depression, anxiety, and HRQoL. Therefore, psychological interventions should be implemented. It also suggests that the PedsQL PPR would be helpful for routine screening.

Cerebral Blood Perfusion is Improved Regionally After Shunt Surgery in the High-Pressure Hydrocephalic Brain.

To show the abnormal cerebral hemodynamics, in high-pressure hydrocephalic patients, could be restored by shunt surgery, and the tympanic membrane temperature (TMT) could be used to non-invasively monitor this recovery process. One-hundred-and-four patients, with high-pressure hydrocephalus (spinal tap opening pressure > 180 mmH2O), were prospectively enrolled in our study. The computed tomography perfusion (CTP) was scheduled for 7-10 days preand post-shunt surgery. The TMT and Glasgow Coma Scale (GCS) scores were collected during the same session. The CTP after the shunt surgery revealed a significant increase in cerebral blood volume (CBV) in both hemispheres (p < 0.05). More specifically, this CBV increase was observed in the midbrain, cerebellum, basal ganglion, temporal lobe, and frontal lobe regions (all p < 0.05). Simultaneously, patients' post-surgical TMT and GCS scores also increased compared to their pre-surgical scores since the first post-shunt follow-up (p < 0.01). Notably, while the GCS scores continued to increase during the post-shunt follow-up, the TMT exhibited a fluctuation period after the shunt and required seven days to reach a steady state. Our study revealed that a shunt could significantly increase cerebral perfusion in high-pressure hydrocephalic patients in a region-specific manner. During the perioperative period of hydrocephalus, TMT can be used to monitor cerebral hemodynamic changes.

The Value of Arterial Spin Labeling Imaging in the Classification and Prognostic Evaluation of Neonatal Hypoxic-ischemic Encephalopathy.

This study aims to investigate the correlation between cerebral blood flow (CBF) values and neonatal behavioral neurological assessment (NBNA) in hypoxic-ischemic encephalopathy (HIE), the relationship between early CBF value changes and the prognosis of neonatal HIE, and the consistency between the clinical grading and magnetic resonance (MR) grading of HIE. Forty neonates with HIE were scanned using the three-dimensional arterial spin labeling (ASL) sequencing of the cranial Magnetic Resonance Imaging (MRI). These newborns were classified as having mild, moderate and severe HIE, according to the clinical grading, and as being normal or having mild, moderate, or severe HIE, according to the MRI grading. Then, the consistency of these two grading systems was compared. Afterwards, the differences in the CBF values of neonates in groups with mild, moderate and severe HIE were compared. In addition, these neonates were grouped according to their NBNA scores. A score of ≥35 was considered a good prognosis, while a score of ≤35 was considered a poor prognosis. The differences in CBF values between these two groups were compared, and the correlation between the CBF values and NBNA scores was determined. There was a strong consistency between the evaluation results for the clinical grading and MR grading (kappa value = 0.672, P<0.001). The differences in CBF values for the basal ganglia (BG) area and thalamus, and the differences in NBNA scores for groups with mild, moderate, or severe HIE were statistically significant (P<0.05). The differences between the poor prognosis group and the good prognosis group, in terms of the CBF values for the BG area and thalamus, and the NBNA scores were statistically significant (P<0.05). The CBF values in the BG region and thalamus were closely and negatively correlated with the NBNA scores. Early CBF values in the BG area and thalamus can objectively and visually reflect the severity of the HIE, and be used to predict the outcome of functional brain damage, allowing early neuroprotective treatment to be initiated. The higher the perfusion in the BG region and thalamus, the lower the NBNA score, and the worse the prognosis would likely be. ASL combined with the NBNA score provides a more comprehensive classification for HIE and a more accurate assessment of the clinical prognosis, providing more medical imaging information for early clinical treatment.

Resting-State Functional Connectivity in Frontostriatal and Posterior Cortical Subtypes in Parkinson's Disease-Mild Cognitive Impairment.

The "dual syndrome hypothesis" distinguished two subtypes in mild cognitive impairment (MCI) in Parkinson's disease: frontostriatal, characterized by attentional and executive deficits; and posterior cortical, characterized by visuospatial, memory, and language deficits. The aim was to identify resting-state functional modifications associated with these subtypes. Ninety-five nondemented patients categorized as having normal cognition (n=31), frontostriatal (n=14), posterior cortical (n=20), or mixed (n=30) cognitive subtype had a 3 T resting-state functional magnetic resonance imaging scan. Twenty-four age-matched healthy controls (HCs) were also included. A group-level independent component analysis was performed to identify resting-state networks, and the selected components were subdivided into 564 cortical regions in addition to 26 basal ganglia regions. Global intra- and inter-network connectivity along with global and local efficiencies was compared between groups. The network-based statistics approach was used to identify connections significantly different between groups. Patients with posterior cortical deficits had increased intra-network functional connectivity (FC) within the basal ganglia network compared with patients with frontostriatal deficits. Patients with frontostriatal deficits had reduced inter-network FC between several networks, including the visual, default-mode, sensorimotor, salience, dorsal attentional, basal ganglia, and frontoparietal networks, compared with HCs, patients with normal cognition, and patients with a posterior cortical subtype. Similar results were also found between patients with a mixed subtype and HCs. MCI subtypes are associated with specific changes in resting-state FC. Longitudinal studies are needed to determine the predictive potential of these markers regarding the risk of developing dementia. © 2021 International Parkinson and Movement Disorder Society.

Deep brain stimulation for movement disorder treatment: exploring frequency-dependent efficacy in a computational network model

A large-scale computational model of the basal ganglia network and thalamus is proposed to describe movement disorders and treatment effects of deep brain stimulation (DBS). The model of this complex network considers three areas of the basal ganglia region: the subthalamic nucleus (STN) as target area of DBS, the globus pallidus, both pars externa and pars interna (GPe-GPi), and the thalamus. Parkinsonian conditions are simulated by assuming reduced dopaminergic input and corresponding pronounced inhibitory or disinhibited projections to GPe and GPi. Macroscopic quantities are derived which correlate closely to thalamic responses and hence motor programme fidelity. It can be demonstrated that depending on different levels of striatal projections to the GPe and GPi, the dynamics of these macroscopic quantities (synchronisation index, mean synaptic activity and response efficacy) switch from normal to Parkinsonian conditions. Simulating DBS of the STN affects the dynamics of the entire network, increasing the thalamic activity to levels close to normal, while differing from both normal and Parkinsonian dynamics. Using the mentioned macroscopic quantities, the model proposes optimal DBS frequency ranges above 130 Hz.

Exploring brain glucose metabolic patterns in cognitively normal adults at risk of Alzheimer’s disease: A cross-validation study with Chinese and ADNI cohorts

ObjectiveDisease-related metabolic brain patterns have been verified for a variety of neurodegenerative diseases including Alzheimer’s disease (AD). This study aimed to explore and validate the pattern derived from cognitively normal controls (NCs) in the Alzheimer’s continuum. MethodsThis study was based on two cohorts; one from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) and the other from the Sino Longitudinal Study on Cognitive Decline (SILCODE). Each subject underwent [18F]fluoro-2-deoxyglucose positron emission tomography (PET) and [18F]florbetapir-PET imaging. Participants were binary-grouped based on β-amyloid (Aβ) status, and the positivity was defined as Aβ+. Voxel-based scaled subprofile model/principal component analysis (SSM/PCA) was used to generate the “at-risk AD-related metabolic pattern (ARADRP)” for NCs. The pattern expression score was obtained and compared between the groups, and receiver operating characteristic curves were drawn. Notably, we conducted cross-validation to verify the robustness and correlation analyses to explore the relationships between the score and AD-related pathological biomarkers. ResultsForty-eight Aβ+ NCs and 48 Aβ- NCs were included in the ADNI cohort, and 25 Aβ+ NCs and 30 Aβ- NCs were included in the SILCODE cohort. The ARADRPs were identified from the combined cohorts and the two separate cohorts, characterized by relatively lower regional loadings in the posterior parts of the precuneus, posterior cingulate, and regions of the temporal gyrus, as well as relatively higher values in the superior/middle frontal gyrus and other areas. Patterns identified from the two separate cohorts showed some regional differences, including the temporal gyrus, basal ganglia regions, anterior parts of the precuneus, and middle cingulate. Cross-validation suggested that the pattern expression score was significantly higher in the Aβ+ group of both cohorts (p < 0.01), and contributed to the diagnosis of Aβ+ NCs (with area under the curve values of 0.696–0.815). The correlation analysis revealed that the score was related to tau pathology measured in cerebrospinal fluid (p-tau: p < 0.02; t-tau: p < 0.03), but not Aβ pathology assessed with [18F]florbetapir-PET (p > 0.23). ConclusionsARADRP exists for NCs, and the acquired pattern expression score shows a certain ability to discriminate Aβ+ NCs from Aβ- NCs. The SSM/PCA method is expected to be helpful in the ultra-early diagnosis of AD in clinical practice.

Factors associated with motor severity in vascular parkinsonism with normal dopamine transporter imaging

IntroductionTo delineate the determinants of motor severity in vascular parkinsonism (VaP), we investigated the impact of regional white matter intensity (WMH) burden and co-morbidities on the motor score in the patients with VaP and normal dopamine transporter (DAT) imaging. MethodsIn this multicenter, retrospective study, we reviewed the records of 63 patients diagnosed with VaP and normal DAT imaging on 18F-FP-CIT PET. Signal hyperintensities in deep white matter (DWMH), periventricular (PVH), basal ganglia (BG) regions, and infratentorial foci (ITF) were rated according to Scheltens scale, a semi-quantitative visual rating system. Motor severity was assessed with Unified Parkinson's Disease Rating Scale (UPDRS) motor score. Regional hyperintensity scores, patients' demographics, and co-morbidities such as type 2 diabetes, hypertension, dyslipidemia, and previous stroke history were used as starting variables, and stepwise regression analysis was performed to select independent predictors of motor severity. ResultsPVH (R = 0.33, p = 0.008) and DWMH score (R = 0.31, p = 0.015) correlated with the motor severity, while BG and ITF scores did not. Diabetic patients had significantly higher motor scores compared with non-diabetics (34.7 (13.0) vs. 27.5 (12.4), p = 0.008). Other factors such as sex, BMI, hypertension, dyslipidemia, and previous history of stroke did not impact motor severity. In multivariate analysis, PVH scores and diabetes significantly correlated with motor severity. ConclusionPVH burden and diabetes were independent factors associated with motor severity in VaP with normal DAT imaging. Our results suggest that diabetes, along with white matter hyperintensities, may have a significant role in the development of motor symptoms in VaP.

Automated delineation of enlarged perivascular spaces (EPVS)

AbstractBackgroundEnlarged Perivascular Spaces (EPVS) are associated with small vessel disease. The objective of this study was to develop semi‐automated techniques for the quantification of EPVS burden.MethodAn intensity‐based threshold was used to identify EPVS. A threshold of maximum plus two standard deviations of intensities of normal‐appearing white matter in the supratentorial region was used to identify EPVS. To compare the performance of the semi‐automatic approach for EPVS segmentation to visually rated EPVS scores, two regions of interest were outlined in the basal ganglia (BG) region and the centrum semiovale (CS). For both these regions, a score was generated by an experienced neurologist by visually counting the number of EPVS with a score of zero representing the absence of any EPVS, a score of 1 representing 1‐10 EPVS, a score of 2 representing 11‐20 EPVS, a score of 3 representing 21‐40 EPVS, and a score of 4 representing &gt;40 EPVS. The semi‐automatic approach provided a count of the number of EPVS that were converted to grade using the same scaling as the visual approach. Spearman Rank Order Correlation Coefficient was calculated to estimate the correlation between the two methods. Mann‐Whitney U tests of ranks are employed to determine if any group differences are present. Finally, Cohen’s kappa was used to compare the concordance between measures between the two different methods.ResultFigure 2 shows the results of the segmentation in subjects with differing EPVS burden. Spearman Rank Order Correlation analysis showed a significant correlation between the EPVS scores determined visually and those obtained semi‐automatically in 60 subjects (Table 1). Results of the Mann‐Whitney U tests showed that there was no statistically significant (p &gt; 0.05) difference between the EPVS scores obtained visually and using the semi‐automatic approach (Table 2). Cohen's κ test showed that there was moderate agreement between the two estimation methods in the BG (κ = .522, p &lt; .0001) and CS regions (κ = .571, p &lt; .0001).ConclusionThe developed method showed good concordance with expert visual read and can provide quantitative measures of EPVS burden (counts and volume) for evaluation of vascular risk.

Perivascular spaces are associated with tau pathophysiology and synaptic dysfunction in early Alzheimer’s continuum

AbstractBackgroundPerivascular spaces (PVS) have an important role in the elimination of metabolic waste from the brain. However, the relationship between enlarged PVS (ePVS) and risk factors or pathophysiological mechanisms involved in Alzheimer’s disease (AD) remains unknown. The aim of this study was to investigate the association between the ePVS, demographic and cardiovascular risk factors, cognitive performance and CSF biomarkers of several pathophysiological mechanisms for AD.MethodThe study included 322 middle‐aged cognitively unimpaired participants from the ALFA+ study, many within the Alzheimer’s continuum. The exploratory Roche NeuroToolKit assays, a panel of automated robust prototype assays, and Elecsys® immunoassays were used to measure CSF Aβ42, Aβ40, p‐tau and t‐tau, NfL, neurogranin, TREM2, YKL40, GFAP, IL6, S100, and α‐synuclein. Cognitive performance was measured using a Preclinical Alzheimer Cognitive Composite (PACC) score. PVS in the basal ganglia (BG) and centrum semiovale (CS) were assessed based on a validated 4‐point visual rating scale [Figure 1]. Odds ratios were calculated for associations of cognitive performance, cardiovascular and AD risk factors with ePVS using logistic and multinomial models adjusted for relevant confounders. Models were stratified by Aβ status (positivity defined as Aβ42/40 &lt; 0.071).ResultThe degree of PVS enlargement significantly increased with age in both BG and CS regions independently of cardiovascular risk factors. Higher levels of p‐tau, t‐tau, and neurogranin were significantly associated with ePVS in the CS of Aβ‐positive individuals, after accounting for relevant confounders [Figure 2], but no other significant associations were found.ConclusionOur results support that ePVS in the CS are associated with tau pathophysiology, and synaptic dysfunction in asymptomatic stages of the Alzheimer’s continuum.

Basal ganglia correlates of wellbeing in early adolescence

It has been suggested that biological markers that define mental health are different to those that define mental illness. The basal ganglia changes dramatically over adolescence and has been linked to wellbeing and mental health disorders in young people. However, there remains a paucity of research on wellbeing and brain structure in early adolescence. This cross-sectional study examined relationships between grey matter volume (GMV) of basal ganglia regions (caudate, putamen, pallidum and nucleus accumbens) and self-reported wellbeing (COMPAS-W), in a sample of Australian adolescents aged 12 years (N = 49, M = 12.6, 46.9% female). Significant negative associations were found between left hemisphere caudate GMV and scores on ‘total wellbeing’, ‘composure’ and ‘positivity’. The results of this study indicate that smaller caudate GMV at age 12 is linked to increased subjective wellbeing. While seemingly counter-intuitive, our finding is consistent with previous research of decreased GMV in the pons and increased COMPAS-W scores in adults. Our results suggest that protective neurobiological factors may be identifiable early in adolescence and be linked to specific types of wellbeing (such as positive affect and optimism). This has implications for interventions targeted at building resilience against mental health disorders in young people.

Hemichorea in a patient with ipsilateral cortical infarction: a case report

BackgroundHemichorea is usually caused by contralateral deep structures of brain. It rarely results from acute cortical ischemic stroke and that caused by ipsilateral brain lesions is even rarer.Case presentationA 64-year-old female presented with acute obtuseness and left-sided hemichorea. She had a history of right frontal lobe surgery and radiotherapy due to brain metastasis from lung cancer 8 years ago. MRI revealed acute left frontal lobe infarction in addition to an old right frontal lobe lesion. 18FDG PET-CT showed hypometabolism in the left frontal lobe and hypermetabolism in the right basal ganglia region and central sulcus. The choreatic movement remitted after antipsychotic treatment.ConclusionThe mechanism of hemichorea after ipsilateral cortical infarction is poorly understood. We assume both previous contralateral brain lesion and recent ipsilateral ischemic stroke contributed to the strange manifestation in this case.