White Matter Involvement Research Articles

Hierarchical cluster analysis of multimodal imaging data identifies brain atrophy and cognitive patterns in Parkinson’s disease

BackgroundParkinson's disease (PD) is a heterogeneous condition. Cluster analysis based on cortical thickness has been used to define distinct patterns of brain atrophy in PD. However, the potential of other neuroimaging modalities, such as white matter (WM) fractional anisotropy (FA), which has also been demonstrated to be altered in PD, has not been investigated. ObjectiveWe aim to characterize PD subtypes using a multimodal clustering approach based on cortical and subcortical gray matter (GM) volumes and FA measures. MethodsWe included T1-weighted and diffusion-weighted MRI data from 62 PD patients and 33 healthy controls. We extracted mean GM volumes from 48 cortical and 17 subcortical regions using FSL-VBM, and the mean FA from 20 WM tracts using Tract-Based Spatial Statistics (TBSS). Hierarchical cluster analysis was performed with the PD sample using Ward's linkage method. Whole-brain voxel-wise intergroup comparisons of VBM and TBSS data were also performed using FSL. Neuropsychological and demographic statistical analyses were conducted using IBM SPSS Statistics 25.0. ResultsWe identified three PD subtypes, with prominent differences in GM patterns and little WM involvement. One group (n = 15) with widespread cortical and subcortical GM volume and WM FA reductions and pronounced cognitive deficits; a second group (n = 21) with only cortical atrophy limited to frontal and temporal regions and more specific neuropsychological impairment, and a third group (n = 26) without detectable atrophy or cognition impairment. ConclusionMultimodal MRI data allows classifying PD patients into groups according to GM and WM patterns, which in turn are associated with the cognitive profile.

In vivo microstructural white matter changes in early spinocerebellar ataxia 2.

White matter (WM) integrity of Spinocerebellar ataxia 2 (SCA2) is poorly understood, more so in the early stages of SCA2. In this study, we evaluated the microstructural integrity of the WM tracts with an emphasis on the nature of in vivo pathological involvement in early SCA2. We evaluated the MRI images of 26 genetically proven SCA2 patients with disease duration <5years and 24 age- and gender-matched healthy controls using tract-based spatial statistics (TBSS) to identify the WM tract changes and their clinico-genetic correlates (age at onset, duration of disease, ataxia severity and CAG repeat length) using standard methodology. The mean age at onset and duration of disease were 28.7±8.51years and 3.5±0.69months, respectively. The mean CAG repeat length was 42.5±4.6, and the ataxia severity score was 16.1±4.9. Altered DTI scalars signifying degeneration was present in the bilateral anterior thalamic radiation (ATR), corticospinal tract (CST), inferior fronto-occipital fasciculus (IFOF), superior and inferior longitudinal fasciculus (SLF and ILF), uncinate fasciculus (UF), cingulum, corpus callosum (CC), forceps major and forceps minor (corrected p<.05). DTI scalars representing demyelination was seen in the superior cerebellar peduncle (SCP) and cerebellar WM. There was a significant correlation of SARA score with axial diffusivity of the bilateral cingulum, ATR, CST, forceps minor, IFOF, ILF, SLF and SCP on the right side (corrected p<.05). Extensive WM involvement is present in early SCA2. The DTI scalars indicate degeneration and demyelination and may have clinical implications.

The Spastic Weakness of the Lower Extremities Fol-lowing Methadone Poisoning: A Case Report

BackgroundDelayed Post-Hypoxic Leukoencephalopathy (DPHL) is a demyelinating syndrome that typically occurs in the form of progressive acute encephalopathy from a few days to weeks after apparent recovery from a coma due to prolonged cerebral hypoxia.Case Report:In this article, we present a disease case that developed spastic weakness of the lower extremities 3 months after hypoxic coma. The reported patient was eventually treated following a diagnosis of DPHL. A 28-year-old patient presented with a history of hypoxic coma following methadone overdose 3 months prior to referral with progressive lower limb weakness. Neurological examination presented weakness of 4.5 lower limbs with hyperreflexia, clonus, and Babinski reflex. Imaging data indicated a broad symmetrical involvement of the logical hemisphere white matter with delayed leukoencephalopathy after hypoxia. Furthermore, all the tests requested for the patient provided data in the healthy range.ConclusionDPHL is a unique clinical syndrome that requires high diagnostic suspicion along with additional laboratory and imaging findings. An essential point in the present report is the presentation of the spastic weakness of the lower extremities as a rare manifestation of DPHL

Clinical and Radiologic Findings of Acute Necrotizing Encephalopathy in Young Adults.

Acute necrotizing encephalopathy after an acute febrile illness, although initially described exclusively in the pediatric age group, has been recently shown to have an adult onset as well. In this study, we describe 10 patients (16 years of age or older) with acute necrotizing encephalopathy. In our study, bilateral thalamic involvement with the trilaminar pattern of diffusion restriction on MR imaging was the predominant finding seen in all of the patients reviewed. Ancillary findings of cerebral white matter, brain stem, and cerebellum involvement with sparing of the basal ganglia were also noted. A poorer outcome was observed in patients with a higher degree of thalamic involvement. The cause of an underlying infection was identified in 4 patients (dengue in 3 and influenza in 1). Overall, a sizeable portion of young adults with acute necrotizing encephalopathy have shown a poorer outcome, with dengue being an important underlying trigger in an endemic region.

Plasma neurofilament light protein correlates with diffusion tensor imaging metrics in frontotemporal dementia.

Neurofilaments are structural components of neurons and are particularly abundant in highly myelinated axons. The levels of neurofilament light chain (NfL) in both cerebrospinal fluid (CSF) and plasma have been related to degeneration in several neurodegenerative conditions including frontotemporal dementia (FTD) and NfL is currently considered as the most promising diagnostic and prognostic fluid biomarker in FTD. Although the location and function of filaments in the healthy nervous system suggests a link between increased NfL and white matter degeneration, such a claim has not been fully elucidated in vivo, especially in the context of FTD. The present study provides evidence of an association between the plasma levels of NfL and white matter involvement in behavioral variant FTD (bvFTD) by relating plasma concentration of NfL to diffusion tensor imaging (DTI) metrics in a group of 20 bvFTD patients. The results of both voxel-wise and tract specific analysis showed that increased plasma NfL concentration is associated with a reduction in fractional anisotropy (FA) in a widespread set of white matter tracts including the superior longitudinal fasciculus, the fronto-occipital fasciculus the anterior thalamic radiation and the dorsal cingulum bundle. Plasma NfL concentration also correlated with cortical thinning in a portion of the right medial prefrontal cortex and of the right lateral orbitofrontal cortex. These results support the hypothesis that blood NfL levels reflect the global level of neurodegeneration in bvFTD and help to advance our understanding of the association between this blood biomarker for FTD and the disease process.

Genetic disorders with central nervous system white matter abnormalities: An update.

Several genetic disorders have variable degree of central nervous system white matter abnormalities. We retrieved and reviewed 422 genetic conditions with prominent and consistent involvement of white matter from the literature. We herein describe the current definitions, classification systems, clinical spectrum, neuroimaging findings, genomics, and molecular mechanisms of these conditions. Though diagnosis for most of these disorders relies mainly on genomic tests, specifically exome sequencing, we collate several clinical and neuroimaging findings still relevant in diagnosis of clinically recognizable disorders. We also review the current understanding of pathophysiology and therapeutics of these disorders.

Characteristic imaging features of neurovascular involvement in primary Sneddon's syndrome: an analysis of 12 cases.

Sneddon's syndrome is a cerebrocutaneous non-inflammatory progressive distal arteriopathy, characterized by livedo racemosa, stroke, and neuropsychiatric symptoms. Our aim was to highlight the characteristic neuroimaging features of Sneddon's syndrome that might be helpful to clinicians in timely diagnosis of this entity. Twelve patients (median age 49years, 11 female) with primary Sneddon's syndrome, diagnosed in last 10years, were analyzed from the perspective of magnetic resonance imaging (MRI) features. In addition, a novel pseudoangiomatosis score was defined for grading angiographic abnormalities (range: 0 to 6). Median interval from the onset of neurological symptoms to diagnosis was 6years. Presentation was with acute stroke in 5, seizures in 3, dementia/speech problems in 2, seizures plus cognitive dysfunction in 1, and chronic progressive hemiparesis in 1. All patients had a typical lesion pattern on MRI. This included multiple (median 3) cortical-subcortical supratentorial and cerebellar non-territorial infarcts, accompanied by multifocal cerebral atrophy. Of note, large territorial infarcts due to cerebral parent artery occlusion, an embolic pattern with multi-territorial involvement on diffusion-weighted imaging, small vessel disease features like severe white matter involvement or lacunar infarcts, and cerebral hemorrhage in the absence of anticoagulation were not observed. MRI lesion severity was not correlated with angiographic arteriopathy severity, clinical stage, or presentation symptoms. Sneddon's syndrome is characterized by highly typical clinico-radiological features. Brain MRI has diagnostic value. By knowing the characteristics of the syndrome, misdiagnosis and potentially harmful treatment can be prevented in this entity that might pose a diagnostic challenge.

Degeneration of gray and white matter differs between hypometabolic and hypermetabolic brain regions in a patient with ALS-FTD: a longitudinal MRI − PET multimodal study

Objective [18F]-fluoro-2-deoxy-d-glucose positron emission tomography (18F-FDG PET) imaging and magnetic resonance imaging (MRI) of brain in ALS patients with frontotemporal lobe dementia (ALS-FTD) reveal hypometabolism and hypermetabolism, as well as gray matter (GM) and white matter (WM) abnormalities in different brain regions, respectively. Hypometabolism arising from neuronal dysfunction or loss is the most recognized pathophysiologic change in neurodegeneration, whereas mechanisms underlying hypermetabolism remain unclear. We hypothesize that hypometabolic and hypermetabolic brain regions in ALS-FTD represent differential degeneration of GM and WM structures, as revealed by co-registered MRI in a two time-point longitudinal multimodal study. Methods: A 69-year-old female with ALS-FTD underwent 18F-FDG PET, diffusion tensor imaging (DTI), and T1-weighted MRI at baseline (15 months after symptom onset), and 20.4 months later. Cerebral glucose metabolism rate, cortical thickness, cortical area, and WM network changes were measured longitudinally. Results and conclusion: The patient had symptoms and signs of bulbar-onset upper motor neuron (UMN)-predominant ALS with language and behavioral dysfunction. Evaluation at baseline showed bulbar dysfunction, and impaired language and executive function. At follow-up, worsened bulbar and other motor functions, and prominent FTD both reflected significant progression. Cortical thickness and surface area showed differential involvement in the hypometabolic and hypermetabolic regions. WM connections from frontal regions to other brain regions were completely absent by graph theory-based network analysis when compared to temporal regions indicating prominent frontal lobe degeneration. Structural neuroimaging reveals different patterns of GM and WM involvement in the hypometabolic and hypermetabolic brain regions in a patient with ALS-FTD.

Natural history of Krabbe disease \u2013 a nationwide study in Germany using clinical and MRI data

BackgroundKrabbe disease or globoid cell leukodystrophy is a severe neurodegenerative disorder caused by a defect in the GALC gene leading to a deficiency of the enzyme ß-galactocerebrosidase. The aim of this work was to describe the natural disease course covering the whole spectrum of the disease.MethodsNatural history data were collected with a standardized questionnaire, supplemented by medical record data. We defined different forms of the disease according to Abdelhalim et al. (2014). Developmental and disease trajectories were described based on the acquisition and loss of milestones as well as the time of first clearly identifiable symptoms and needs such as spasticity, seizures and tube feeding. MRI was assessed using the scoring system by Loes et al. (1999) and in addition a pattern recognition approach, based on Abdelhalim et al. (2014).ResultsThirty-eight patients were identified, from 27 of these patients 40 MRIs were available; 30 (79%) had an infantile onset, showing first symptoms in their first year of life, almost all (27 out of 30) starting in the first six months. A later onset after the first year of life was observed in 8 patients (21%, range 18 months to 60 years). Irritability, abnormalities in movement pattern as well as general developmental regression were the first symptoms in the infantile group; disease course was severe with rapid progression, e.g. loss of visual fixation, need for tube feeding and then an early death. Gait disorders were the first symptoms in all patients of the later onset groups; progression was variable. The different forms of the disease were characterized by different MRI patterns (infantile: diffuse white matter involvement and cerebellar structures specifically affected, later onset: parieto-occipital white matter and splenium affected, adult: motor tracts specifically affected).ConclusionThis is the first description of the natural history of Krabbe disease in a larger European cohort using developmental, clinical and MRI data. We would like to highlight the very different clinical and MRI characteristics of the later onset forms. These data are important for counselling affected patients and families and may serve as a basis for future treatment trials.

Distinctive diffusion-weighted imaging features in late-onset genetic leukoencephalopathies.

Genetic leukoencephalopathies are inherited disorders characterized by progressive white matter involvement. Although most are paediatric conditions, late-onset adult leukoencephalopathies are being increasingly recognized. Adult leukoencephalopathies may present as neurodegenerative diseases with cognitive decline and motor symptoms. Similar to their paediatric counterparts, different adult leukoencephalopathies often have distinctive MRI appearances. In particular, DWI has been recently shown to demonstrate specific patterns of persistent diffusion restriction in several adult-onset leukoencephalopathies. As such, DWI may provide important clues to the diagnosis of adult-onset leukoencephalopathy. The purpose of this review is to discuss characteristic DWI features in some late-onset leukoencephalopathies.

Imaging and clinical data indicate considerable disease burden in 'probable' PLS: Patients with UMN symptoms for 2-4 years.

Primary lateral sclerosis (PLS) is an adult-onset upper motor neuron disease manifesting in progressive spasticity and gradually resulting in considerably motor disability. In the absence of early disease-specific diagnostic indicators, the majority of patients with PLS face a circuitous diagnostic journey. Until the recent publication of consensus diagnostic criteria, 4-year symptom duration was required to establish the diagnosis. The new diagnostic criteria introduced the category of ‘probable PLS’ for patients with a symptom duration of 2–4 years. “Evolving diagnostic criteria in primary lateral sclerosis: The clinical and radiological basis of "probable PLS" [1]. This dataset provides radiological metrics in a cohort of ‘probable PLS’ patients, ‘definite PLS’ patients and age-matched healthy controls. Region-of-interest radiological data include diffusivity metrics in the corticospinal tracts and corpus callosum as well as mean cortical thickness values in the pre- and para-central gyri in each hemisphere. Our data indicate considerable grey matter and relatively limited white matter involvement in ‘probable PLS’ which supports the rationale for this diagnostic category as a clinically useful entity. The introduction of this diagnostic category will likely facilitate the timely recruitment of PLS patients into research studies and pharmacological trials before widespread neurodegenerative change ensues.

Clinical characteristics of Alexander disease.

Alexander disease (ALXDRD) is a primary astrocyte disease caused by GFAPgene mutation. The clinical features of ALXDRD vary from infantile-onset cerebral white matter involvement to adult-onset brainstem involvement. Several studies revealed that the level of GFAP overexpression is correlated with disease severity, and basic research on therapies to reduce abnormal GFAP accumulation has recently been published. Therefore, the accumulation of clinical data to advance understanding of the natural history is essential for clinical trials expected in the future. This review focuses on the clinical characteristics of ALXDRD including the clinical symptoms, imaging findings and genetics to provide diagnostic information useful in daily clinical practice.

The Spectrum of MR Imaging Patterns Suggestive of Pediatric Posterior Reversible Encephalopathy Syndrome in Children With Cerebral X-Linked Adrenoleukodystrophy.

Children receiving chemotherapy, or immunosuppression have an increased risk for pediatric posterior reversible encephalopathy syndrome (pPRES); pPRES is scantly described in cerebral X-linked adrenoleukodystrophy (cALD) patients, for which hematopoietic stem cell transplantation improves outcomes. This study aimed to describe distinctive lesion patterns, distribution, and evolution of neuroimaging findings in PRES in a single-center pediatric cohort of cALD. We retrospectively identified all clinically acquired brain MRIs of children with cALD at a tertiary care university hospital between 1995 and 2020. We reviewed clinical features, conventional MRI, and diffusion-weighted imaging findings of patients with gray matter and white matter (WM) changes suggestive of concurrent PRES-cALD. Associations between the distinctive anatomic features, distribution, and abnormal signal intensity on MRI were examined with regard to the etiology and clinical outcome. Our search revealed a series of eight pediatric cALD patients presenting with seizures, headache, or altered mental status with MRI findings suggestive of both PRES and cALD simultaneously. In each, the cortical-subcortical vasogenic edema on fluid-attenuated inversion recovery was consistent with pPRES, overlying the periventricular WM (PVWM) involvement typical of cALD. Of these 8 patients, the cortical-subcortical lesions on FLAIR were completely reversible on follow-up MRI in 7, but only partially reversible in 1. It is crucial to recognize that pPRES can occur in cALD, notably, the cortical edema and leptomeningeal enhancement can accelerate the diagnosis of superimposed pPRES, while the PVWM lesions of cALD remain following the resolution of pPRES.

Global Brain Involvement in Posterior Cortical Atrophy: Multimodal MR Imaging Investigation.

Posterior cortical atrophy (PCA), considered a visual variant of Alzheimer's disease, has similar pathological characteristics yet shows a selective visual manifestation with relative preservation of other cortical areas, at least at early stages of disease. Using a gamut of imaging methods, we aim to evaluate the global aspect of this relatively local disease and describe the interplay of the involvement of the different brain components. Ten PCA patients and 14 age-matched controls underwent MRI scans. Cortical thickness was examined to identify areas of cortical thinning. Hippocampal volume was assessed using voxel-based morphometry. The integrity of 20 fiber tracts was assessed by Diffusion Tensor Imaging. Regions of difference in global functional connectivity were identified by resting-state fMRI, using multi-variant pattern analysis. Correlations were examined to evaluate the connection between grey matter atrophy, the network changes and the disease load. The patients presented bilateral cortical thinning, primarily in their brains' posterior segments. Impaired segments of white matter integrity were evident only within three fiber tracts in the left hemisphere. Four areas were identified as different in their global connectivity pattern. The visual network-related areas showed reduced connectivity and was correlated to atrophy. Right Broadman area 39 showed in addition increased connectivity to the frontal areas. Global structural and functional imaging pointed to the highly localized nature of PCA. Functional connectivity followed grey matter atrophy in visual regions. White matter involvement seemed less prominent, however damage is directly related to presence of disease and not mediated only by grey matter damage.

Disrupted white matter connectivity and organization of brain structural connectomes in tuberous sclerosis complex patients with neuropsychiatric disorders using diffusion tensor imaging.

Tuberous sclerosis complex (TSC) is a genetic neurocutaneous syndrome with variable and unpredictable neurological comorbidity that includes epilepsy, intellectual disability (ID), autism spectrum disorder, and neurobehavioral abnormalities. The degree of white matter involvement is believed to be associated with the severity of neurological impairment. The goal of the present study was to evaluate diffusion characteristics of tubers, white matter lesions, and brain structural network alterations in TSC patients using diffusion tensor imaging (DTI), graph theoretical analysis (GTA), and network-based statistical (NBS) analysis. Forty-two patients with a definitive diagnosis of TSC were recruited for this study. All patients underwent brain DTI examination using a 3T magnetic resonance imaging system. Mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD) values, and fractional anisotropy (FA) mapping in 52 tubers and white matter lesions were measured and compared with those of contralateral normal regions. GTA was performed on the inter-regional connectivity matrix, and NBS analysis was used to identify the significance of any connected subnetworks evident in the set of altered connections. For neurological severity subgrouping, a neurological severity score was assigned to TSC patients including those with ID, seizure, autism, and other neuropsychiatric disorders (NPDs). Significantly higher MD, AD, and RD, and lower FA values, were found in TSC lesions compared with those measured in contralateral normal regions for tubers (P < 0.05). GTA and NBS analysis provided better local segregation but worse global integration of the structural network (regular-like network) in TSC patients with ID, seizure, and higher Neurological Severity Score. Disrupted subnetworks in TSC patients with severe status included connections from the frontal lobe to the parietal lobe, temporal lobe to the caudate, and temporal lobe to the insula. DTI has the potential to provide valuable information about cytoarchitectural changes in TSC lesions beyond morphological MRI findings alone. Using GTA and NBS, current results provide the information of disrupted white matter connectivity and organization in TSC patients with different neuropsychological impairments.

CD4 Deficiency Causes Poliomyelitis and Axonal Blebbing in Murine Coronavirus-Induced Neuroinflammation.

Mouse hepatitis virus (MHV) is a murine betacoronavirus (m-CoV) that causes a wide range of diseases in mice and rats, including hepatitis, enteritis, respiratory diseases, and encephalomyelitis in the central nervous system (CNS). MHV infection in mice provides an efficient cause-effect experimental model to understand the mechanisms of direct virus-induced neural-cell damage leading to demyelination and axonal loss, which are pathological features of multiple sclerosis (MS), the most common disabling neurological disease in young adults. Infiltration of T lymphocytes, activation of microglia, and their interplay are the primary pathophysiological events leading to disruption of the myelin sheath in MS. However, there is emerging evidence supporting gray matter involvement and degeneration in MS. The investigation of T cell function in the pathogenesis of deep gray matter damage is necessary. Here, we employed RSA59 (an isogenic recombinant strain of MHV-A59)-induced experimental neuroinflammation model to compare the disease in CD4-/- mice with that in CD4+/+ mice at days 5, 10, 15, and 30 postinfection (p.i.). Viral titer estimation, nucleocapsid gene amplification, and viral antinucleocapsid staining confirmed enhanced replication of the virions in the absence of functional CD4+ T cells in the brain. Histopathological analyses showed elevated susceptibility of CD4-/- mice to axonal degeneration in the CNS, with augmented progression of acute poliomyelitis and dorsal root ganglionic inflammation rarely observed in CD4+/+ mice. Depletion of CD4+ T cells showed unique pathological bulbar vacuolation in the brain parenchyma of infected mice with persistent CD11b+ microglia/macrophages in the inflamed regions on day 30 p.i. In summary, the current study suggests that CD4+ T cells are critical for controlling acute-stage poliomyelitis (gray matter inflammation), chronic axonal degeneration, and inflammatory demyelination due to loss of protective antiviral host immunity.IMPORTANCE The current trend in CNS disease biology is to attempt to understand the neural-cell-immune interaction to investigate the underlying mechanism of neuroinflammation, rather than focusing on peripheral immune activation. Most studies in MS are targeted toward understanding the involvement of CNS white matter. However, the importance of gray matter damage has become critical in understanding the long-term progressive neurological disorder. Our study highlights the importance of CD4+ T cells in safeguarding neurons against axonal blebbing and poliomyelitis from murine betacoronavirus-induced neuroinflammation. Current knowledge of the mechanisms that lead to gray matter damage in MS is limited, because the most widely used animal model, experimental autoimmune encephalomyelitis (EAE), does not present this aspect of the disease. Our results, therefore, add to the existing limited knowledge in the field. We also show that the microglia, though important for the initiation of neuroinflammation, cannot establish a protective host immune response without the help of CD4+ T cells.

Van Der Knaap Disease in a 3-year-old Male Child: A Case Report

Van der Knaap disease or megalencephalic leukoencephalopathy with subcortical cysts is a leukodystrophy with autosomal-recessive inheritance caused by mutation in the gene MLC1 which is localized on chromosome 22q. It is characterized by macrocephaly, motor developmental delay, seizures, spasticity, ataxia, and mild mental deterioration. On neuroimaging, involvement of cerebral white matter along with subcortical cysts in frontal and temporal lobes are hallmarks of the disease. There is no definite treatment of this disease. We report a case of Van Der Knaap disease in a 3-year-old male child who presented with seizures and delayed developmental milestones.

Differences in the preferential location and invasiveness of diffuse low‐grade gliomas and their impact on outcome

BackgroundLow‐grade gliomas (LGGs) are primary diffuse slow‐growing brain tumors derived from glial cells. The management of these tumors is dependent on their location, which often harbors eloquent areas. We retrospectively recorded the location of diffuse gliomas to identify whether specific differences exist between the histological types.MethodsWe analyzed 102 patients with previous histological diagnosis of WHO‐II astrocytomas (62) and WHO‐II oligodendrogliomas (40) according to WHO‐2016 classification. MRI sequences (T2‐FLAIR) were used for tumor volume segmentation and to create a frequency map of their locations within the Montreal Neurological Institute (MNI) space. The Brain‐Grid (BG) system (standardized radiological tool of intersected lines according to anatomical landmarks) was created and merged with a tractography atlas for infiltration analysis.ResultsAstrocytomas frequently infiltrated association and projection white matter pathways within fronto‐temporo‐insular regions on the left side. Oligodendrogliomas infiltrated larger white matter networks (association‐commissural‐projection) of the frontal lobe bilaterally. A critical number of infiltrated BG voxels (7 for astrocytomas, 10 for oligodendrogliomas) significantly predicted shorter overall survival (OS) in both groups. Bilateral tumor extension in astrocytomas and preoperative tumor volume in oligodendrogliomas were independent prognostic factors for shorter OS.ConclusionsAstrocytomas and oligodendrogliomas differ in preferential location, and this has an impact on the type and the extent of white matter involvement. The number of BG voxels infiltrated reflected different tumor invasiveness and its impact on OS in both groups. All this new information may be valuable in neurosurgical oncology to classify and plan treatment for patients with diffuse gliomas.

Multimodal MRI Longitudinal Assessment of White and Gray Matter in Different SPG Types of Hereditary Spastic Paraparesis.

Hereditary spastic paraplegias (HSP) are a group of genetically and clinically heterogeneous neurologic disorders. Hereby we describe a relatively large group of patients (pts) affected by HSP studied at baseline (31 pts) and at follow-up (mean period 28.9 ± 8.4 months; 23 pts) with multimodal advanced MRI: high-resolution T1 images for voxel-based morphometry (VBM) analysis, magnetic resonance spectroscopy (MRS), and diffusion tensor imaging (DTI). An age-matched healthy control (HC) group underwent the same neuroimaging protocol in a time schedule matched with the HSP patients. At baseline, VBM showed gray matter (GM) reduction in HSP in the right pre-frontal cortex and bilaterally in the thalami. MRS at baseline depicted in HSP patients compared to the HC group reduction of NAA/Cr ratio in the right pre-frontal region, increase of Cho/Cr ratio in the right pre-central regions, and increase of mI/Cr ratio on the left pre-central area. At cross-sectional follow-up analysis and longitudinal evaluation, no VBM and MRS statistically significant results were obtained. Tract-based spatial statistics (TBSS) analysis showed widespread DTI brain white matter (WM) alterations in patients compared to HC at baseline, which are characterized by reduction of fractional anisotropy (FA) and increase of mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity, as confirmed on cross-analysis of the follow-up dataset. A longitudinal analysis with TBSS in HSP patients did not show significant variations, while upon applying region-based analysis we found increased FA and decreased MD and AD in specific brain WM fiber complex during follow-up. The changes were not correlated with the clinical presentation (pure vs complicated HSP), motor function, and motility indexes or history of specific treatments (botulinum toxin). In conclusion, the cross-sectional analysis of the multiparametric MRI data in our HSP patients confirmed the non-prominent involvement of the cortex in the primary motor regions but rather of other more associative areas. On the contrary, DTI demonstrated a widespread involvement of the brain WM, including the primary motor regions, which was confirmed at follow-up. The longitudinal analysis revealed an apparent inversion of tendency when considering the expected evolution of a neurodegenerative process: we detected an increase of FA and a decrease of MD and AD. These time-related modifications may suggest a repair attempt by the residual central WM fibers, which requires confirmation with a larger group of patients and with a longer time interval.

Coronavirus 2019 (COVID-19)–Associated Encephalopathies and Cerebrovascular Disease: The New Orleans Experience

BackgroundThe coronavirus 2019 (COVID-19) pandemic has had a dramatic impact on health care systems and a variable disease course. Emerging evidence demonstrates that severe acute respiratory syndrome coronavirus 2 is associated with central nervous system disease. We describe central nervous system manifestations in critical patients with COVID-19 at our tertiary center.MethodsWe conducted a single-center retrospective analysis of all actively critical patients with COVID-19 admitted to our tertiary care academic center in New Orleans, Louisiana, on April 22, 2020, with new onset of neurologic disease. Patients were grouped into 1 of 3 categories according to imaging and clinical features; encephalopathy, acute necrotizing encephalopathy, and vasculopathy.ResultsA total of 27 of 76 (35.5%) critical patients with COVID-19 met inclusion criteria. Twenty patients (74%) were designated with COVID-19–associated encephalopathy, 2 (7%) with COVID-19–associated acute necrotizing encephalopathy, and 5 (19%) with COVID-19–associated vasculopathy. Sixty-three percent of neurologic findings were demonstrated on computed tomography, 30% on magnetic resonance imaging, and 44% on electroencephalography. Findings most often included ischemic strokes, diffuse hypoattenuation, subcortical parenchymal hemorrhages, and focal hypodensities within deep structures. Magnetic resonance imaging findings included diffuse involvement of deep white matter, the corpus callosum, and the basal ganglia. For patients with large-territory ischemic stroke, all but one displayed irregular proximal focal stenosis of the supraclinoid internal carotid artery.ConclusionsAnalysis of active critical COVID-19 admissions at our revealed a high percentage of patients with new neurologic disease. Although variable, presentations followed 1 of 3 broad categories. A better understanding of the neurologic sequalae and radiographic findings will help clinicians mitigate the impact of this disease.