Basal Ganglia Research Articles

Protocol for a randomised controlled unblinded feasibility trial of HD-DRUM: a rhythmic movement training application for cognitive and motor symptoms in people with Huntington’s disease

IntroductionHuntington’s disease (HD) is an inherited neurodegenerative disease causing progressive cognitive and motor decline, largely due to basal ganglia (BG) atrophy. Rhythmic training offers promise as therapy to counteract BG-regulated...

Stress in Musicians with and Without Focal Dystonia Is Not Reflected in Limbic Circuit Activation.

Musicians' dystonia (MD) is a movement disorder with several established risk factors, but the exact pathophysiology remains unknown. Recent research suggests dysfunction in sensory-motor, basal ganglia, cerebellar, and limbic loops as potential causes. Adverse childhood experiences are also considered risk factors. This study aimed to investigate whether MD patients have experienced more childhood trauma, leading to increased stress reactivity and neural vulnerability to movement disorders. Using functional magnetic resonance imaging and the Montreal Imaging Stress Task, 40 MD patients were compared with 39 healthy musicians (HMs). Whole-brain analysis and regions of interest analysis were performed. Parameter estimates and subjective stress levels were compared between groups and correlated with the Childhood Trauma Questionnaire. MD patients reported significantly higher childhood trauma scores than healthy control subjects, but they did not differ in their subjective stress experiences. Stress-related activity of limbic areas was neither found in the whole sample nor between the two groups. Instead, increased activity of visual association and temporal areas was observed, but this activation did not differ between patients and HMs. However, patients showed a tendency toward reduced precuneus activity under stress. Adverse childhood experiences were negatively correlated with precuneus, thalamus, and substantia nigra activity across all participants. Overall, MD patients and HMs had similar subjective and neurological reactions to stress but differed in childhood trauma experiences and precuneus activity under stress. Further research about the functional connectivity between precuneus, cerebellum, thalamus, and basal ganglia in musicians is needed. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Effects of growth hormone and sex steroid therapy on brain structure and pituitary function in turner syndrome

Introduction: Turner syndrome (TS) is a chromosomal disorder affecting approximately 1 in 2,500 live female births, characterized by the partial or complete absence of one X chromosome. This genetic anomaly leads to physical, cognitive, and endocrine abnormalities, including short stature, gonadal dysgenesis, and structural brain anomalies. Cognitive deficits in TS involve visuospatial processing, memory, and executive function, often linked to structural brain changes. Magnetic resonance imaging (MRI) has revealed significant alterations in gray and white matter volumes in various brain regions. Growth hormone (GH) and sex steroid therapies, such as estrogen and progesterone, are used to address growth and developmental delays in TS. However, their impact on brain structure and pituitary function remains an area of active research. Aim of the Review: To systematically review and synthesize findings on the effects of GH and sex steroid therapy on brain structure and pituitary function in patients with Turner syndrome. Methods: A comprehensive literature review was conducted to identify studies examining the effects of GH and sex steroid therapy on brain structure and pituitary function in TS. Data from various sources were compiled, focusing on MRI-based structural brain changes. Key parameters analyzed included sample size, findings from MRI and fMRI studies, and clinical associations. Studies were summarized and presented in a structured table format. Results: Estrogen-progesterone treatment was found to suppress pituitary gonadotropin release more effectively than estrogen alone, indicating a feedback interaction between pituitary gonadotropin release and sex steroids. MRI studies showed that TS patients exhibit smaller volumes in the hippocampus, caudate, lenticular, thalamic nuclei, and parieto-occipital brain matter, correlating with cognitive deficits. GH-IGF axis abnormalities are modulated by body composition and physical fitness, with sex hormone replacement normalizing the GH-IGF axis and improving body composition. Although GH therapy alone did not significantly improve cognitive functions, the combination of GH with oxandrolone improved working memory. Estrogen deficiency and TS are associated with slower growth in parieto-occipital regions and enhanced volume growth in basal ganglia and cerebellar areas during adolescence, underscoring the importance of estrogen replacement in brain development. Discussion: GH and sex steroid therapies significantly impact brain structure, pituitary function, and clinical outcomes in TS. GH therapy, often combined with sex steroids, improves growth and cognitive functions, particularly working memory. However, GH alone does not significantly impact overall cognitive function. The timing and combination of these therapies are crucial for optimizing outcomes. Regular monitoring and individualized treatment plans are essential to address the complex needs of TS patients. Further research is needed to explore the long-term impacts of these therapies and develop optimal treatment regimens. Conclusion: GH and sex steroid therapies are vital in managing TS contributing to improved growth, body composition, and cognitive enhancements. A multifaceted therapeutic approach and regular monitoring are crucial for optimizing treatment outcomes and quality of life for TS patients.

Quantitative assessment of enlarged perivascular spaces via deep-learning in community-based older adults reveals independent associations with vascular neuropathologies, vascular risk factors, and cognition

Abstract Enlarged perivascular spaces (EPVS) are common in older adults, but their neuropathologic correlates are unclear mainly because most work to date has relied on visual rating scales and/or clinical cohorts. The present study first developed a deep learning model for automatic segmentation, localization and quantification of EPVS in ex-vivo brain MRI, and then used this model to investigate the neuropathologic, clinical, and cognitive correlates of EPVS in 817 community-based older adults that underwent autopsy. The new method exhibited high sensitivity in detecting EPVS as small as 3 mm3, good segmentation accuracy and consistency. Most EPVS were located in the frontal lobe, but the highest density was observed in the basal ganglia. EPVS in the cerebrum and specifically in the frontal lobe were associated with infarcts independent of other neuropathologies, while temporal and occipital EPVS were associated with cerebral amyloid angiopathy. EPVS in most brain lobes were also associated with diabetes mellitus independently of neuropathologies, while basal ganglia EPVS were independently associated with hypertension, supporting the notion of independent pathways from diabetes and hypertension to EPVS. Finally, EPVS were associated with lower cognitive performance independently of neuropathologies and clinical variables, suggesting that EPVS represent additional abnormalities contributing to lower cognition.

Neuroimaging Findings in Children with Cerebral Palsy – Risk Assessment for Symptomatic Epilepsy

Neuroimaging plays a key role in the diagnosis of cerebral palsy (CP), as it helps to understand the etiology and pathogenesis of neurological impairment. The aim of the study is to demonstrate the role of neuroimaging in assessing the risk for epilepsy in children with CP with various lesions in CT and MRI with a focus on neuroimaging findings in full-term and premature children and their risk for epilepsy. The study includes 521 children with CP, diagnosed in the Clinic of Child Neurology, UMHATNP “St. Naum” between 2008 and 2018. Two hundred and twenty children underwent MRI of the brain, 464 of the cases had CT, and 127 had both MRI and CT. Various pathological lesions in MRI (brain malformations, lesions in the white or gray matter, lesions in the basal ganglia, cystic lesions, cortical atrophy, ventriculomegaly) were found in all patients with CP and symptomatic epilepsy, while 5.8% of those children with CP without epilepsy had normal MRI. Normal findings were observed in CT in 7.5% of the children with CP and epilepsy, while this result reached 12.1% when children did not have epilepsy. Among the abnormal findings in MRI with the highest relative risk for symptomatic epilepsy were ventriculomegaly RR – 1.296 (95% CI 1.149–1.463), cortical atrophy RR – 1.235 (95% CI 1.082–1.410) and lesions in the gray matter RR – 1.210 (95% CI 1.056–1.387). When comparing the types of the lesions in MRI in full-term and premature children with CP, we observed that white matter lesions predominated in premature children, while grey matter lesions in full-term children, which explains the higher incidence of epilepsy in full-term children. We found a higher incidence of pathological lesions in neuroimaging studies in patients with CP and concomitant epilepsy compared to those without epilepsy, as well as a high relative risk for epilepsy in patients with ventriculomegaly, cortical atrophy, and gray matter lesions.

A detailed survey of the murine limbus, its stem cell distribution, and its boundaries with the cornea and conjunctiva.

The narrow intersection between the cornea and conjunctiva, otherwise known as the limbus, is purported to harbor stem cells (SCs) that replenish the ocular surface epithelium throughout life. Damage to this site or depletion of its SCs can have dire consequences for eye health and vision. To date, various SC and keratin proteins have been used to identify the limbus, however, none could definitively mark its boundaries. Herein, we use the mouse as a model system to investigate whether structural and phenotypic features can be used to define the limbus and its boundaries with adjacent tissues. We demonstrate that differentially aligned blood and lymphatic vessels, intraepithelial nerves, and basal epithelial cellular and nuclei dimensions can be used as structural landmarks of the limbus. Identification of these features enabled approximation of the limbal expanse, which varied across distinct ocular surface quadrants, with the superior nasal and inferior temporal limbus being the widest and narrowest, respectively. Moreover, label-retaining SCs were unevenly distributed across the ocular circumference, with increased numbers in the superior temporal and inferior temporal moieties. These findings will heighten our current understanding of the SC niche, be beneficial for accurately predicting SC distribution to improve their isolation and devising efficacious cell therapies, and importantly, aid the ongoing search for novel SC markers.

Efficacy of intra-arterial carboplatin and bevacizumab in the C6 rat glioma model of glioblastoma multiforme

BackgroundUtilizing an endovascular rat glioma model, this study aimed to analyze the efficacy of intra-arterial (IA) carboplatin and bevacizumab delivery with blood-brain barrier breakdown (BBBB) for glioblastoma treatment.MethodsC6-glioma cells were...

Analyzing the topological properties of resting-state brain function network connectivity based on graph theoretical methods in patients with high myopia

AimRecent imaging studies have found significant abnormalities in the brain’s functional or structural connectivity among patients with high myopia (HM), indicating a heightened risk of cognitive impairment and other behavioral changes. However, there is a lack of research on the topological characteristics and connectivity changes of the functional networks in HM patients. In this study, we employed graph theoretical analysis to investigate the topological structure and regional connectivity of the brain function network in HM patients.MethodsWe conducted rs-fMRI scans on 82 individuals with HM and 59 healthy controls (HC), ensuring that the two groups were matched for age and education level. Through graph theoretical analysis, we studied the topological structure of whole-brain functional networks among participants, exploring the topological properties and differences between the two groups.ResultsIn the range of 0.05 to 0.50 of sparsity, both groups demonstrated a small-world architecture of the brain network. Compared to the control group, HM patients showed significantly lower values of normalized clustering coefficient (γ) (P = 0.0101) and small-worldness (σ) (P = 0.0168). Additionally, the HM group showed lower nodal centrality in the right Amygdala (P < 0.001, Bonferroni-corrected). Notably, there is an increase in functional connectivity (FC) between the saliency network (SN) and Sensorimotor Network (SMN) in the HM group, while the strength of FC between the basal ganglia is relatively weaker (P < 0.01).ConclusionHM Patients exhibit reduced small-world characteristics in their brain networks, with significant drops in γ and σ values indicating weakened global interregional information transfer ability. Not only that, the topological properties of the amygdala nodes in HM patients significantly decline, indicating dysfunction within the brain network. In addition, there are abnormalities in the FC between the SN, SMN, and basal ganglia networks in HM patients, which is related to attention regulation, motor impairment, emotions, and cognitive performance. These findings may provide a new mechanism for central pathology in HM patients.

Cranial and spinal nerve enhancement in SURF1-associated Leigh syndrome.

A 23-month-old boy with poor growth, developmental delay, and hypotonia presented with acute onset of ataxia and fatigue. Magnetic resonance imaging (MRI) of the brain and spinal cord was performed as part of diagnostic work-up. MRI showed bilateral symmetrical lesions in basal ganglia, midbrain, and brainstem consistent with Leigh syndrome. Signal abnormalities were also present within the cervical cord, with enhancement of multiple cranial, spinal, and cauda equina nerve roots. Genetic testing confirmed compound heterozygosity for two pathogenic variants in SURF1 implicated in Leigh syndrome. Whilst nerve root enhancement has been described in other mitochondrial disorders, we believe this is the first published case of both cranial and spinal nerve root enhancement in Leigh syndrome.

Differences in gray matter atrophy and functional connectivity between motor subtypes of Parkinson's disease.

Parkinson's disease (PD) patients with postural gait abnormalities exhibit poorer motor function scores, more severe non-motor symptoms, faster cognitive function deterioration, and a less favorable response to drugs and surgery compared to PD patients with tremor. This discrepancy is believed to be associated with more pronounced gray matter atrophy and abnormal functional connectivity. To investigate the distinctive pathological mechanisms between PD subtypes, we examined gray matter volume (GMV) and functional connectivity in patients with Parkinson's disease presenting with postural instability/gait difficulty (PD-PIGD), patients with tremor-dominant Parkinson's disease (PD-TD), and healthy controls. Voxel-based morphometry (VBM) of T1-weighted images was conducted to compare GMV among 64 PD-PIGD patients, 44 PD-TD patients, and 32 controls. Subsequently, functional connectivity within regions showing reduced GMV was compared across the groups. We analyzed whether differences among the groups were associated with clinical characteristics and neuroimaging biomarkers using partial correlation and binary logistic regression. Our comparison between PD-PIGD and PD-TD patients revealed a link between PD-PIGD and more extensive frontotemporal atrophy, potentially indicating increased basal ganglia activity accompanied by decreased cerebellum activity. Furthermore, in addition to the smaller GMV in the left middle temporal gyrus, the increased functional connectivity between this brain region and the right caudate was also the independent risk factor for PD-PIGD. In addition, we compared brain network connectivity between the PIGD and TD subtypes, using an independent component analysis (ICA). We found that Compared to PD-TD, PD-PIGD patients showed an enhanced sensorimotor network (SMN) around the left supplementary motor area. These findings suggest that severe gray matter atrophy and abnormal functional connectivity and brain networks may serve as pathophysiological mechanisms distinguishing PD-PIGD patients from other subtypes.

The efficacy of robot-assisted surgery on minor basal ganglia cerebral hemorrhage with neurological dysfunction.

This study aims to compare the outcomes of robot-assisted drainage and conservative treatment in minor basal ganglia hemorrhage (10ml< hemorrhage volume ≤ 30ml) patients with neurological dysfunction, and analyze patients treated with robot-assisted drainage in order to optimize this treatment strategy. In a retrospective study conducted in December 2021 to December 2023, minor basal ganglia cerebral hemorrhage patients with neurological dysfunction were enrolled from the Department of Neurosurgery, Shanghai Ninth People's Hospital. The patients included both the surgical (robot-assisted drainage) and conservative groups. The efficacy of robot-assisted drainage compared with conservative treatment in patients with minor cerebral hemorrhage and neurological dysfunction was evaluated by modified Rankin Scale (mRS) score after 3 months, muscle strength (grade 1 to 5) and cost of hospitalization. Of the patients included, 23 received robot-assisted drainage and 20 received conservative treatment. There were no significant differences in gender, age, history of hypertension and diabetes, muscle strength and mRS score at admission. Female patients accounted for 32.6%, and male patients accounted for 67.4%. About 90% of the patients enrolled had a pre-existing hypertension history. The mRS score after 3 months indicated that prognosis of the patients was significantly better in the surgical treatment group than the conservative treatment group (favorable prognosis 69.57% VS. 35%, P = 0.034) while the patients underwent surgery paid higher hospital bills than patients treated conservatively. Compared with traditional conservative treatment, robot-assisted drainage surgery is more helpful to improve the prognosis of patients with minor basal ganglia hemorrhage (volume ≤ 30mL) accompanied by neurological dysfunction. Robot assisted surgery can safely and effectively remove the hematoma of minor basal ganglia hemorrhage, and there were 69.6% of surgery group patients had a good prognosis in this study.

Beta and theta oscillations track effort and previous reward in the human basal ganglia and prefrontal cortex during decision making

Choosing whether to exert effort to obtain rewards is fundamental to human motivated behavior. However, the neural dynamics underlying the evaluation of reward and effort in humans is poorly understood. Here, we report an exploratory investigation into this with chronic intracranial recordings from the prefrontal cortex (PFC) and basal ganglia (BG; subthalamic nuclei and globus pallidus) in people with Parkinson's disease performing a decision-making task with offers that varied in levels of reward and physical effort required. This revealed dissociable neural signatures of reward and effort, with BG beta (12 to 20 Hz) oscillations tracking effort on a single-trial basis and PFC theta (4 to 7 Hz) signaling previous trial reward, with no effects of net subjective value. Stimulation of PFC increased overall acceptance of offers and sensitivity to reward while decreasing the impact of effort on choices. This work uncovers oscillatory mechanisms that guide fundamental decisions to exert effort for reward across BG and PFC, supports a causal role of PFC for such choices, and seeds hypotheses for future studies.

Motor Cortical Neuronal Hyperexcitability Associated with α-Synuclein Aggregation.

Dysfunction of the cerebral cortex is thought to underlie motor and cognitive impairments in Parkinson disease (PD). While cortical function is known to be suppressed by abnormal basal ganglia output following dopaminergic degeneration, it remains to be determined how the deposition of Lewy pathology disrupts cortical circuit integrity and function. Moreover, it is also unknown whether cortical Lewy pathology and midbrain dopaminergic degeneration interact to disrupt cortical function in late-stage. To begin to address these questions, we injected α-synuclein (αSyn) preformed fibrils (PFFs) into the dorsolateral striatum of mice to seed αSyn pathology in the cortical cortex and induce degeneration of midbrain dopaminergic neurons. Using this model system, we reported that αSyn aggregates accumulate in the motor cortex in a layer- and cell-subtype-specific pattern. Particularly, intratelencephalic neurons (ITNs) showed earlier accumulation and greater extent of αSyn aggregates relative to corticospinal neurons (CSNs). Moreover, we demonstrated that the intrinsic excitability and inputs resistance of αSyn aggregates-bearing ITNs in the secondary motor cortex (M2) are increased, along with a noticeable shrinkage of cell bodies and loss of dendritic spines. Last, neither the intrinsic excitability of CSNs nor their thalamocortical input was altered by a partial striatal dopamine depletion associated with αSyn pathology. Our results documented motor cortical neuronal hyperexcitability associated with αSyn aggregation and provided a novel mechanistic understanding of cortical circuit dysfunction in PD.

Association of plasma metals with resting-state functional connectivity in ischemic stroke

BackgroundMetal exposure has long been considered a significant risk factor for ischemic stroke. However, existing data on the effects of metal exposure on brain function in ischemic stroke are limited. Therefore, this study aimed to explore the correlation between exposure to various metals and changes in resting-state functional connectivity (rs-FC) in ischemic stroke patients. MethodsThis study included 28 acute ischemic stroke patients with hemiplegia and 28 matched healthy controls (HCs). All participants underwent T1-weighted MRI and 3.0T resting-state functional magnetic resonance imaging (fMRI). After MRI acquisition, the rs-FC between 137 cortical and subcortical regions was extracted and preprocessed. Plasma levels of 19 metals were measured using inductively coupled plasma mass spectrometry (ICP-MS). The Bayesian kernel machine regression (BKMR) model and the weighted quantile sum regression (WQS) model were used to assess the overall effect of metal mixture exposure. The severity of neurological deficits in each acute ischemic stroke patient was evaluated using the National Institutes of Health Stroke Scale (NIHSS). Additionally, the associations between exposure to various metals and modifications in brain functional connectivity were determined using Pearson or Spearman correlation analysis. ResultsBilateral brain connectivity was significantly decreased compared to controls and was associated with neurological impairment in ischemic stroke. In patients with ischemic stroke, the plasma concentrations of Cr (p < 0.001), Cu (p = 0.004), As (p = 0.010), Cs (p = 0.046), Rb (p = 0.041), and Sb (p = 0.001) were significantly higher than those in the HCs, whereas the plasma Tl concentrations (p = 0.022) were significantly lower. The results of the BKMR and WQS models showed that combined exposure to metal mixtures was linked to a higher risk of ischemic stroke. Cr was positively correlated with the rs-FC between the left Rolandic_Oper and the left Supp_Motor_Area (r = 0.414, p = 0.029), while negatively correlated with the rs-FC between the right Parietal_Inf and the left supramarginal (r = -0.398, p = 0.037). Cu was negatively correlated with the rs-FC between the left paracentral lobule and the left thalamus (r = -0.409, p = 0.031). Tl was positively correlated with the rs-FC between the right Parietal_Inf and the left supramarginal cortex (r = 0.590, p = 0.001). A negative correlation was observed between Cs and rs-FC between the right Cingulate_Mid and left Occipital_Sup (r = -0.429, p = 0.024). Sb was negatively correlated with the rs-FC between the left Parietal_Inf and the right SupraMarginal (r = -0.384, p = 0.044), the right Parietal_Inf and the left SupraMarginal (r = -0.583, p = 0.001), and the left SupraMarginal and the right SupraMarginal (r = -0.377, p = 0.048). ConclusionPlasma levels of Cr, Cu, Tl, Cs, and Sb were associated with altered rs-FC in brain regions related to motor control, sensory integration, executive function, language processing, and emotional regulation in ischemic stroke patients with basal ganglia infarction.

Association of sarcopenia with regional brain atrophy and white matter lesions in a general older population: the Hisayama Study.

Sarcopenia has been reported to be associated with cognitive decline and the risk of dementia. However, few studies have addressed the association between sarcopenia and brain morphological changes in the general population. A total of 1373 community-dwelling participants aged ≥ 65years underwent brain MRI. Sarcopenia was defined based on the Asian Working Group for Sarcopenia's criteria. The pattern of regional gray matter volume loss associated with sarcopenia were assessed using a voxel-based morphometry (VBM) analysis. Regional brain volumes, intracranial volumes (ICV), and white matter lesions volumes (WMLV) were also measured using FreeSurfer. An analysis of covariance was used to examine the associations of sarcopenia with regional brain volumes in proportion to ICV. Of the participants, 112 had sarcopenia. The participants with sarcopenia had significantly lower total brain volume/ICV and total gray matter volume/ICV and higher WMLV/ICV than those without sarcopenia after adjusting for confounders. In VBM, sarcopenia was associated with lower gray matter volume in the frontal lobe, insula, cingulate gyrus, hippocampus, amygdala, and basal ganglia. Using FreeSurfer, we confirmed that the participants with sarcopenia had significantly lower frontal, insular, cingulate, and hippocampal volumes than those without sarcopenia. The current study showed that participants with sarcopenia had significantly lower volume in the frontal lobe, insula, cingulate, and hippocampus and higher WMLV than participants without sarcopenia. As these brain regions are likely to play an important role in cognitive function, these changes may suggest a shared underlying mechanism for the progression of sarcopenia and cognitive decline.

A quantitative MRI comparative study of imaging markers for cerebral small vessel disease in the middle-aged and elderly patients with and without hypertension

Objective: To explore the difference of MRI markers of small cerebral vascular disease in middle-aged and elderly patients with hypertension and non-hypertension. Methods: A cross-sectional study. The clinical data of 316 patients who underwent head MRI with susceptibility weighted imaging scans at the Affiliated Zhongda Hospital of Southeast University from November 2013 to August 2022 were retrospectively analyzed, including 190 males and 126 females, with the age of (71.6±8.9)years. According to the history of hypertension, the patients were divided into hypertension group(n=259) and the non-hypertension group(n=57). The patients in the non-hypertension group were further divided into abnormal blood pressure group on admission (n=19) and normal blood pressure group on admission (n=38). The imaging features of different CSVD dimensions in the patient's images were quantified or graded and compared between hypertensive and non-hypertensive patient groups. Deep learning methods were employed to segment white matter lesions, and voxel-wise analysis was conducted to investigate the differences in whole-brain white matter lesion probability between patients in both groups. Spearman correlation analysis was used to analyze the correlation between hypertension and small cerebral vascular disease. Results: Compared with the non-hypertensive group, the cerebral microhemorrhage count, deep microhemorrhage count, basal ganglia level lacunae count, perivascular space (EPVS) grade of hemioval center level and EPVS grade of basal ganglia level were higher in the hypertensive group (all P<0.05). The cerebral microhemorrhage count [3.0(1.0, 15.0) vs 1.0 (0, 4.2)], deep microhemorrhage count [1.0 (0, 7.0) vs 1.0 (0, 4.2)] and EPVS classification at basal ganglium level [2.0(1.0, 3.0) vs 1.0(1.0, 2.0)] in the group with history of hypertension were higher than those in the group with normal blood pressure at admission (all P<0.05). The EPVS grade at the central level of the semiovale in the hypertension group was higher than that of the group with normal blood pressure at admission [2.0(1.0, 2.0) vs 1.0 (1.0, 2.0)], and also higher than that of the group with abnormal blood pressure at admission [2.0(1.0, 2.0) vs 1.0(1.0, 2.0)](both P<0.05). Voxel-by-voxel analysis showed no significant difference in the probability of white matter lesions in the whole brain between patients with and without a history of hypertension, but patients with a history of hypertension showed more extensive para-ventricular white matter hypersignaling than those without a history of hypertension. Spearman correlation analysis showed that hypertension grade was correlated with the number of microbleeding lesions in depth (r=0.149), the number of lacunae lesions in the center of the hemioval (r=0.209), and the number of lacunae lesions in the basal ganglia (r=0.204) (all P<0.05). Conclusions: Chronic hypertension can affect different dimensions of small vessel disease imaging, primarily manifested in the increases of deep microbleed counts and the EPVS grade.

CHANTER syndrome in the context of pain medication: a case report

BackgroundCHANTER (Cerebellar Hippocampal and Basal Nuclei Transient Edema with Restricted diffusion) is a recently described syndrome occurring in the context of drug abuse. While clinical findings are rather unspecific (disorientation, unresponsiveness), MR imaging (MRI) discloses a characteristic pattern (restricted diffusion in the basal ganglia and hippocampi, cerebellar oedema and haemorrhage), allowing for timely diagnosis before complications such as cerebellar swelling and herniation do occur. Here we report a case of CHANTER primarily based on imaging findings, as there was no evidence of drug abuse on admission.Case presentationA 62-year-old Patient was admitted to our hospital after being unresponsive at home. Prehospital intubation was performed, which limited neurological assessment. Under these circumstances no obvious symptoms could be determined, i.e. pupils were isocoric and responsive, and there were no signs of seizures. While the initial CT scan was unremarkable, the subsequent MRI scan showed a distinct imaging pattern: moderately enhancing areas in the basal ganglia and hippocampi with diffusion restriction, accompanied by cerebellar haemorrhage and oedema (Figs. 1 and 2). A comprehensive clinical and laboratory work-up was performed, including drug screening, spinal tap, Holter ECG, echocardiography and EEG. The only conspicuous anamnestic finding was a chronic pain syndrome whose medication had been supplemented with opioids two months previously. The opioid medication was discontinued, which led to a rapid improvement in the patient’s clinical condition without any further measures. The patient was able to leave the intensive care unit and was discharged 10 days after admission without persistent neurological deficits.ConclusionFamiliarity with typical MRI patterns of toxic encephalopathy in patients from high-risk groups, such as drug abusers, is crucial in emergency neuroradiology. In the presence of typical MRI findings, CHANTER syndrome should be included in the differential diagnosis, even if there is no history of drug abuse, to avoid delay in diagnosis and treatment.

Dopamine-mediated interactions between short- and long-term memory dynamics.

In dynamic environments, animals make behavioral decisions based on the innate valences of sensory cues and information learnt about these cues across multiple timescales1-3. However, it remains unclear how the innate valence of a sensory stimulus affects acquisition of learnt valence information and subsequent memory dynamics. Here we show that in the Drosophila brain, interconnected short- and long-term memory units of the mushroom body jointly regulate memory via dopamine signals that encode innate and learnt sensory valences. Through time-lapse, in vivo voltage-imaging studies of neural spiking in >500 flies undergoing olfactory associative conditioning, we found that protocerebral posterior lateral 1 dopamine neurons (PPL1-DANs)4 heterogeneously and bi-directionally encode innate and learnt valences of punishment, reward, and odor cues. During learning, these valence signals regulate memory storage and extinction in mushroom body output neurons (MBONs)5. In initial conditioning bouts, PPL1-γ1pedc and PPL1-γ2α'1 neurons control short-term memory formation, which weakens inhibitory feedback from MBON-γ1pedc>α/β to PPL1-α'2α2 and PPL1-α3. During further conditioning, this diminished feedback allows these two PPL1-DANs to encode the net innate plus learnt valence of the conditioned odor cue, which gates long-term memory formation. A computational model constrained by the fly connectome6,7 and our spiking data explains how dopamine signals mediate the circuit interactions between short- and long-term memory traces, yielding predictions that our experiments confirm. Overall, the mushroom body achieves flexible learning via the integration of innate and learnt valences within parallel learning units sharing feedback interconnections. This hybrid physiologic-anatomic mechanism may be a general means by which dopamine regulates memory dynamics in other species and brain structures, including the vertebrate basal ganglia.

Risk Factors for Postoperative Delirium Severity After Deep Brain Stimulation Surgery in Parkinson's Disease.

Postoperative delirium (POD) is a serious complication following deep brain stimulation (DBS) but only received little attention. Its main risk factors are higher age and preoperative cognitive deficits. These are also main risk factors for long-term cognitive decline after DBS in Parkinson's disease (PD). To identify risk factors for POD severity after DBS surgery in PD. 57 patients underwent DBS (21 female; age 60.2±8.2; disease duration 10.5±5.9 years). Preoperatively, general, PD- and surgery-specific predictors were recorded. Montreal Cognitive Assessment and the neuropsychological test battery CANTAB ConnectTM were used to test domain-specific cognition. Volumes of the cholinergic basal forebrain were calculated with voxel-based morphometry. POD severity was recorded with the delirium scales Confusion Assessment Method for Intensive Care Unit (CAM-ICU) and Nursing Delirium Scale (NU-DESC). Spearman correlations were calculated for univariate analysis of predictors and POD severity and linear regression with elastic net regularization and leave-one-out cross-validation was performed to fit a multivariable model. 21 patients (36.8%) showed mainly mild courses of POD following DBS. Correlation between predicted and true POD severity was significant (spearman rho = 0.365, p = 0.001). Influential predictors were age (p < 0.001), deficits in attention and motor speed (p = 0.002), visual learning (p = 0.036) as well as working memory (p < 0.001), Nucleus basalis of Meynert volumes (p = 0.003) and burst suppression (p = 0.005). General but also PD- and surgery-specific factors were predictive of POD severity. These findings underline the multifaceted etiology of POD after DBS in PD. Valid predictive models must therefore consider general, PD- and surgery-specific factors.

Radiation-induced cavernoma in pediatric CNS tumors: a systematic review and treatment paradigm.

This retrospective systematic literature review aimed to summarize available data regarding epidemiology, etiology, presentation, investigations, differentials, treatment, prevention, monitoring, complications, and prognosis for radiation-induced cavernous malformations (RICMs) in pediatric patients. Review conducted per PRISMA guidelines. Google Scholar, PubMed, Trip Medical Database, and Cochrane Library searched utilizing a keyphrase, articles filtered per inclusion/exclusion criteria, duplicates excluded. Based on criteria, 25 articles identified, 7 further excluded from the systematic data but included in discussion (5 × insufficient data, 2 × other systematic reviews). Many studies did not contain all explored data. 2487 patients reviewed, 325 later found to have RICM (143 male, 92 female). Mean age at irradiation 7.6years (range 1.5-19). Mean total radiation dose 56Gy (12-112). Most common indications for radiation-medulloblastoma 133x, astrocytoma 23x, ependymoma 21x, germinoma 19x. Mean age at RICM diagnosis 18years (3.6-57). Mean latency to RICM 9.9years (0.25-41). Most common anatomic locations-temporal 36, frontal 36, parietal 13, basal ganglia 16, infratentorial 20. Clinical presentation-incidental 270, seizures 19, headache 11, focal neurological deficit 7, other 13. 264 patients observed, 34 undergone surgery. RICM bled in 28 patients. Mean follow-up 11.7years (0.5-50.3). Prognostic reporting highly variable. From our data, pediatric RICMs appear to display slight male predominance, present about 10years after initial irradiation in late teen years, and present incidentally in majority of cases. They are mostly operated on when they bleed, with incidental lesions mostly being observed over time. Further prospective detailed studies needed to draw stronger conclusions.