Brain structural damage in spinocerebellar ataxia type 2. A voxel‐based morphometry study

Voxel‐based morphometry (VBM) enables an unbiased in‐vivo whole‐brain quantitative analysis of differences in gray matter (GM), white matter (WM) and cerebro‐spinal fluid (CSF) volumes. We assessed with VBM 20 spinocerebellar ataxia Type 2 (SCA2) patients with mild or moderate cerebellar deficit and 20 age and sex‐matched healthy controls. SCA2 patients showed a significant (P < 0.05 corrected for multiple comparison) symmetric loss of GM in the cerebellar vermis and hemispheres sparing lobules I,II, Crus II,VII, and X, and of the WM in the peridentate region, middle cerebellar peduncles, dorsal pons, and cerebral peduncles. The CSF volume was increased in the posterior cranial fossa. No GM, WM or CSF volume changes were observed in the supratentorial compartment. A mild (P < 0.05, >0.01) correlation was observed between the GM and WM loss and severity of the neurological deficit. In SCA2 patients with mild to moderate cerebellar deficit, GM and WM volume loss and CSF volume increase are confined to the posterior cranial fossa. © 2008 Movement Disorder Society     

A 3-year diffusion tensor MRI study of grey matter damage progression during the earliest clinical stage of MS

Objective   To investigate the medium-term evolution of grey matter (GM) damage in patients at presentation with clinically isolated syndrome suggestive of multiple sclerosis (MS), and to assess whether it is associated with clinical disease activity during the initial stage of MS. Methods   In 30 patients enrolled within three months from the onset of a clinically isolated syndrome, conventional and diffusion tensor MRI scans of the brain were acquired at baseline and after 3 years. Percentage brain volume change between baseline and follow-up scans was computed. Histograms of mean diffusivity and fractional anisotropy for the normal-appearing white matter and histograms of mean diffusivity for the GM were produced. Results   Mean percentage brain volume change was –1.04 % (p < 0.001 vs. null change). GM mean diffusivity showed an increase at follow-up (p = 0.004), whose magnitude was greater, but not significantly, in patients who relapsed than in those who did not. There was no correlation between on-study relapse rate and GM mean diffusivity changes over time. Conclusions   In patients with clinically isolated syndrome suggestive of MS, GM damage begins to accumulate during the initial stage of the disease, possibly as a consequence of GM lesion accumulation. The magnitude of such a damage does not seem to be associated with the concomitant clinical activity.     

Quantitative magnetic resonance imaging of brain development in premature and mature newborns

Definition in the living premature infant of the anatomical and temporal characteristics of development of critical brain structures is crucial for insight into the time of greatest vulnerability of such brain structures. We used three-dimensional magnetic resonance imaging (3D MRI) and image-processing algorithms to quantitate total brain volume and total volumes of cerebral gray matter (GM), unmyelinated white matter (WM), myelinated WM, and cerebrospinal fluid (CSF) in 78 premature and mature newborns (postconceptional age, 29–41 weeks). Total brain tissue volume was shown to increase linearly at a rate of 22 ml/wk. Total GM showed a linear increase in relative intracranial volume of approxi mately 1.4% or 15 ml in absolute volume per week. The pronounced increase in total GM reflected primarily a fourfold increase in cortical GM. Unmyelinated WM was found to be the most prominent brain tissue class in the preterm infant younger than 36 weeks of postconceptional age. Although minimal myelinated WM was present in the preterm infant at 29 weeks, between 35 and 41 weeks an abrupt fivefold increase in absolute volume of myelinated WM was documented. Extracerebral and intraventricular CSF was readily quantitated by this technique and found to change minimally. The application of 3D MRI and tissue segmentation to the study of human infant brain from 29 to 41 weeks of postconceptional age has provided new insights into cerebral cortical development and myelination and has for the first time provided means of quantitative assessment in vivo of early human brain development.     

Gray matter volume reduction in obsessive-compulsive disorder with schizotypal personality trait

OBJECTIVES: Obsessive-compulsive disorder (OCD) with schizotypal personality trait (SPT) and OCD without SPT demonstrated differences in cognitive dysfunction and treatment response. This study aimed to investigate whether brain volume differs between OCD with SPT and OCD without SPT. METHODS: OCD with SPT (n=20), OCD without SPT (n=47), healthy comparison subjects (n=83) and schizophrenic patients (n=59) participated in this study. We assessed brain volume such as gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF) using magnetic resonance imaging. The imaging data sets were filtered using anisotropic diffusion methods to improve the signal to noise ratio. The semi-automated region-growing method was used to remove images of tissues exterior to the brain. The fuzzy C-means algorithm was used to segment the extracted brain images into gray matter, white matter and cerebrospinal fluid. RESULTS: OCD with SPT (p=0.048) and Schizophrenic patients (p<0.001) demonstrated a significant GM volume reduction compared to healthy controls. OCD without SPT revealed no significant GM volume reduction compared to healthy controls (p=0.504). CONCLUSION: This study suggests that OCD with SPT could be distinguished as a distinct subtype of OCD, based on observations of gray matter volume.     

Biophysical mechanisms of electroconvulsive therapy-induced volume expansion in the medial temporal lobe: A longitudinal in vivo human imaging study

BackgroundElectroconvulsive therapy (ECT) applies electric currents to the brain to induce seizures for therapeutic purposes. ECT increases gray matter (GM) volume, predominantly in the medial temporal lobe (MTL). The contribution of induced seizures to this volume change remains unclear.MethodsT1-weighted structural MRI was acquired from thirty patients with late-life depression (mean age 72.5 ± 7.9 years, 19 female), before and one week after one course of right unilateral ECT. Whole brain voxel-/deformation-/surface-based morphometry analyses were conducted to identify tissue-specific (GM, white matter: WM), and cerebrospinal fluid (CSF) and cerebral morphometry changes following ECT. Whole-brain voxel-wise electric field (EF) strength was estimated to investigate the association of EF distribution and regional brain volume change. The association between percentage volume change in the right MTL and ECT-related parameters (seizure duration, EF, and number of ECT sessions) was investigated using multiple regression.ResultsECT induced widespread GM volume expansion with corresponding contraction in adjacent CSF compartments, and limited WM change. The regional EF was strongly correlated with the distance from the electrodes, but not with regional volume change. The largest volume expansion was identified in the right MTL, and this was correlated with the total seizure duration.ConclusionsRight unilateral ECT induces widespread, bilateral regional volume expansion and contraction, with the largest change in the right MTL. This dynamic volume change cannot be explained by the effect of electrical stimulation alone and is related to the cumulative effect of ECT-induced seizures.     

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.     

Increased orbital frontal gray matter volume after cognitive behavioural therapy in paediatric obsessive compulsive disorder

Abstract

Objectives. Identify differences in regional brain volume between medication-free pediatric OCD patients and controls and examine changes after cognitive behavioural therapy. Methods. We assessed 29 medication-free paediatric OCD patients (Age: M =?13.78 years; SD =?2.58; range 8.2–19.0) and 29 controls, matched on age and gender, with T1-weighted MR scans in a repeated measures, pre-post treatment design. Voxel based morphometry (VBM) following diffeomorphic anatomical registration through exponential lie algebra (DARTEL) was used to test voxel-wise for the effects of diagnosis and treatment on regional gray matter (GM) and white matter (WM) volumes. Results. After cognitive behavioural therapy, orbitofrontal GM and capsula externa WM increased in paediatric OCD relative to controls. In patients, changes in symptom severity (delta CY-BOCS) correlated positively with GM volume in the orbitofrontal cortex after treatment. Furthermore, before treatment, paediatric OCD patients, compared to the controls, showed larger GM volume in left frontal pole and left parietal cortex and larger WM volume in cingulum and corpus callosum. Conclusions. Our findings underscore the involvement of the ventral frontal-striatal circuit in paediatric OCD and the plasticity of this circuit in response to the modulatory effects of CBT. The possible relation to brain development is discussed.     

Distinct Brain Volume Changes Correlating with Clinical Stage,Disease Progression Rate,Mutation Size,and Age at Onset Prediction as Early Biomarkers of Brain Atrophy in Huntington's Disease

Searching brain and peripheral biomarkers is a requisite to cure Huntington's disease (HD). To search for markers indicating the rate of brain neurodegenerative changes in the various disease stages, we quantified changes in brain atrophy in subjects with HD. We analyzed the cross‐sectional and longitudinal rate of brain atrophy, quantitatively measured by fully‐automated multiparametric magnetic resonance imaging, as fractional gray matter (GM, determining brain cortex volume), white matter (WM, measuring the volume of axonal fibers), and corresponding cerebral spinal fluid (CSF, a measure of global brain atrophy), in 94 gene‐positive subjects with presymptomatic to advanced HD, and age‐matched healthy controls. Each of the three brain compartments we studied (WM, GM, and CSF) had a diverse role and their time courses differed in the development of HD. GM volume decreased early in life. Its decrease was associated with decreased serum brain‐derived‐neurotrophic‐factor and started even many years before onset symptoms, then decreased slowly in a nonlinear manner during the various symptomatic HD stages. WM volume loss also began in the presymptomatic stage of HD a few years before manifest symptoms appear, rapidly decreasing near to the zone‐of‐onset. Finally, the CSF volume increase began many years before age at onset. Its volume measured in presymptomatic subjects contributed to improve the CAG‐based model of age at onset prediction. The progressive CSF increase depended on CAG mutation size and continued linearly until the last stages of HD, perhaps representing the best marker of progression rate and severity in HD (R²= 0.25, P < 0.0001).     

Peak width of skeletonized mean diffusivity (PSMD) and cognitive functions in relapsing-remitting multiple sclerosis

Peak width of skeletonized mean diffusivity (PSMD) is a new MRI marker, which has shown clinical relevance in some neurological conditions and, in preliminary data, in multiple sclerosis (MS). We aimed here to investigate, in a group of relapsing-remitting MS (RRMS) patients, the relationship between PSMD and cognitive performances, in comparison with other MRI measures. RRMS patients (n = 60) and normal controls (n = 15) underwent a 3 T MRI examination. MRI-based white matter (WM) lesion volume, microstructural integrity (assessed with Tract-Based Spatial Statistics of diffusion tensor imaging [DTI] images) and brain volumes (i.e., total brain, grey matter [GM] and WM) were computed. In addition, PSMD was calculated through “skeletonization” of WM tracts and diffusion histograms. Cognition was evaluated with Rao’s Brief Repeatable Battery (BRB), which incorporated tests of verbal and visual memory, attention, concentration, information processing speed and verbal fluency. PSMD closely correlated with symbol digit modalities test (SDMT) (r = −0.70, p < 0.001) and, to a lesser extent, with verbal and visual memory tests. Multiple regression analysis showed that PSMD explained SDMT variance (R² = 0.54, p < 0.001) more than other MRI measures. Results point out the relevance of microstructural damage, as assessed by PSMD, as a reliable marker of cognition in MS, especially in explaining dysfunction in information processing speed.

     

Increase in gray matter and decrease in white matter volumes in the cortex during treatment with atypical neuroleptics in schizophrenia

The effects of atypical antipsychotic treatment on the brain volume deficits associated with schizophrenia are poorly understood. We assessed the brain volumes of eleven healthy controls and 29 patients with schizophrenia, using magnetic resonance imaging at baseline and at follow-up after two years of treatment with atypical neuroleptics. Two groups of patients were analyzed: treatment-na?ve patients (n = 17) and chronic treatment-resistant patients (n = 12). Treatment-na?ve patients received risperidone during the follow-up period, whereas chronic patients received clozapine. Gray matter (GM) and white matter (WM) volumes in the frontal, parietal, occipital, and temporal lobes were measured. Contrary to the controls, both groups of patients presented GM increases and WM decreases in the parietal and occipital lobes (p < .005). Frontal GM also increased in the chronic group with clozapine. There was a significant (p < .001) inverse relationship between the baseline volumes (GM deficit/WM excess) and the longitudinal change. These GM and WM changes were not related to changes in weight. Thus, treatment with risperidone and clozapine in schizophrenia may have an effect on gray and white matter volume and needs further exploration.     

A longitudinal study of MRI-detected atrophy in secondary progressive multiple sclerosis

MRI measures of tissue atrophy within the central nervous system may reflect the neurodegenerative process which underpins the progressive phase of multiple sclerosis (MS). There has been limited longitudinal investigation of MRI-detected atrophy in secondary progressive MS. This study includes 56 subjects with secondary progressive MS. Subjects were followed up for 2 years and MRI analysis was conducted at 12 month intervals using the following measures: (1) whole brain (WB) volume change; (2) grey and white matter (WM) volumes; (3) central brain volume; (4) upper cervical spinal cord (SC) area; (5) T2 lesion volumes. Clinical measures included the Expanded Disability Status Scale and the MS Functional Composite. All volumetric MRI measures were assessed for sensitivity, responsiveness, reliability and correlation with disability. The mean annual atrophy rate of WB was 0.59% per year and this was the most responsive atrophy measure assessed. Grey matter (GM) atrophy (−1.18% per year) was greater and more responsive than WM atrophy (0.12% per year). The SC demonstrated the highest atrophy rate at 1.63% per year. WB, GM and SC atrophy all correlated with change in the Multiple Sclerosis Functional Composite z score (r = 0.35, 0.42, 0.34), and GM atrophy was the only correlate of change in the 9 Hole Peg Test and Paced Auditory Serial Addition Test performance. None of the MRI measures correlated with Expanded Disability Status Score progression. Measures of WB, GM and SC atrophy all have attributes for use as surrogate markers in secondary progressive MS trials and improvement in the reliability of the GM and SC volume measurements may enhance these further.     

Bariatric Surgery Induces White and Grey Matter Density Recovery in the Morbidly Obese: A Voxel‐Based Morphometric Study

Obesity is associated with lowered brain's grey (GM) and white matter (WM) density as measured by voxel‐based morphometry (VBM). Nevertheless, it remains unknown whether obesity has a causal influence on cerebral atrophy. We recruited 47 morbidly obese subjects (mean BMI = 42.2, SD = 4.0, 42 females and five males) eligible for bariatric surgery and 29 non‐obese subjects (mean BMI = 23.2, SD = 2.8, 23 females and six males) served as controls. Baseline scans were acquired with T1‐weighted magnetic resonance imaging (MRI) at 1.5 Tesla; obese participants were scanned again six months after the surgery. Local GM and WM densities were quantified using VBM. Full‐volume analyses were used for comparing baseline between‐group differences as well as the effects of surgery‐induced weight loss in the morbidly obese. Metabolic variables were used in linear models to predict WM and GM densities. Obese subjects had initially lower GM densities in widespread cortical areas including frontal, parietal, and temporal regions as well as insulae. Lower WM densities were observed throughout the WM. Bariatric surgery and concomitant weight loss resulted in global increase in WM density. Grey matter increase was limited to occipital and inferior temporal regions. Metabolic variables were associated with brain densities. We conclude that weight loss results in global recovery of WM as well as local recovery of grey matter densities. These changes likely reflect improved brain tissue integrity. Hum Brain Mapp 37:3745–3756, 2016. © 2016 Wiley Periodicals, Inc.     

Brain volumes quantification from MRI in healthy controls: Assessing correlation,agreement and robustness of a convolutional neural network-based software against FreeSurfer,CAT12 and FSL

Background and purposeThere are instances in which an estimate of the brain volume should be obtained from MRI in clinical practice. Our objective is to calculate cross-sectional robustness of a convolutional neural network (CNN) based software (Entelai Pic) for brain volume estimation and compare it to traditional software such as FreeSurfer, CAT12 and FSL in healthy controls (HC).Materials and MethodsSixteen HC were scanned four times, two different days on two different MRI scanners (1.5 T and 3 T). Volumetric T1-weighted images were acquired and post-processed with FreeSurfer v6.0.0, Entelai Pic v2, CAT12 v12.5 and FSL v5.0.9. Whole-brain, grey matter (GM), white matter (WM) and cerebrospinal fluid (CSF) volumes were calculated. Correlation and agreement between methods was assessed using intraclass correlation coefficient (ICC) and Bland Altman plots. Robustness was assessed using the coefficient of variation (CV).ResultsWhole-brain volume estimation had better correlation between FreeSurfer and Entelai Pic (ICC (95% CI) 0.96 (0.94?0.97)) than FreeSurfer and CAT12 (0.92 (0.88?0.96)) and FSL (0.87 (0.79?0.91)). WM, GM and CSF showed a similar trend. Compared to FreeSurfer, Entelai Pic provided similarly robust segmentations of brain volumes both on same-scanner (mean CV 1.07, range 0.20–3.13% vs. mean CV 1.05, range 0.21–3.20%, p = 0.86) and on different-scanner variables (mean CV 3.84, range 2.49–5.91% vs. mean CV 3.84, range 2.62–5.13%, p = 0.96). Mean post-processing times were 480, 5, 40 and 5 min for FreeSurfer, Entelai Pic, CAT12 and FSL respectively.ConclusionBased on robustness and processing times, our CNN-based model is suitable for cross-sectional volumetry on clinical practice.     

老年轻度认知功能损害的脑磁共振显像三维测量研究

目的 研究老年轻度认知功能损害者的脑形态结构变化特点。方法 于1999年1月至2000年6月用脑磁共振显像（MRI）三维测量法组织分割和体积测量分析技术,检查有轻度认知功能损害的老年人21例（MCI组）和认知功能正常的老年人29名（NC组）。结果 （1）MRI测量：与NC组相比,MCI组的颅内总体积少5．2％,灰质体积少8．8％,灰质百分比少3．9％,总脑脊液多12．3％,两组差异有显著或非显著性（P＜0．05或P＜0．01）。（2）多元逐步判别分析：脑灰质和侧脑室体积具有非常显著性判别意义（P＜0．01）,两组判别总正确率为74．5％。结论 MRI三维测量有助于了解老年轻度认知功能损害者的脑部形态结构的改变。     

Structural brain abnormalities in patients with vestibular migraine

New advances in understanding the pathophysiology of vestibular migraine (VM) have suggested a large overlap between migraine and vestibular pathways. We explored the regional distribution of gray (GM) and white matter (WM) abnormalities in VM patients in comparison to migraine patients with (MWA) and without aura (MWoA) and their correlations with patients’ clinical manifestations. Using a 3.0 Tesla scanner, brain T2-weighted and 3D T1-weighted MRI scans were acquired from 19 VM, 19 MWA, 19 MWoA and 20 age-matched controls. GM and WM volumetric abnormalities were estimated using voxel-based morphometry (SPM12). Compared to controls, migraine patients had decreased GM volume of the left cerebellum and an increased GM volume of the left temporal lobe. VM patients had a selective GM volume increase of frontal and occipital regions compared to controls and the other two groups of migraineurs and no regions with decreased GM volume. Compared to MWoA and MWA, VM had increased GM volume of the left thalamus. Regional GM abnormalities did not correlate with disease duration and attack frequency. No WM volumetric differences were detected between migraine patients and controls. These results show that GM volume abnormalities of nociceptive and multisensory vestibular brain areas occur in VM patients. Overall, our findings suggest that an abnormal brain sensitization might lead to a dismodulation of multimodal sensory integration and processing cortical areas in VM patients.     

Progression of regional atrophy in the left hemisphere contributes to clinical and cognitive deterioration in multiple sclerosis: A 5‐year study

In this longitudinal study, we investigated the regional patterns of focal lesions accumulation, and gray (GM) and white matter (WM) atrophy progression over a five‐year follow‐up (FU) in multiple sclerosis (MS) patients and their association with clinical and cognitive deterioration. Neurological, neuropsychological and brain MRI (dual‐echo and 3D T1‐weighted sequences) assessments were prospectively performed at baseline (T0) and after a median FU of 4.9 years from 66 MS patients (including relapse‐onset and primary progressive MS) and 16 matched controls. Lesion probability maps were obtained. Longitudinal changes of GM and WM volumes and their association with clinical and cognitive deterioration were assessed using tensor‐based morphometry and SPM12. At FU, 36/66 (54.5%) MS patients showed a significant disability worsening, 14/66 (21.2%) evolved to a worse clinical phenotype, and 18/63 (28.6%) developed cognitive deterioration. At T0, compared to controls, MS patients showed a widespread pattern of GM atrophy, involving cortex, deep GM and cerebellum, and atrophy of the majority of WM tracts, which further progressed at FU (P < 0.001, uncorrected). Compared to stable patients, those with clinical and cognitive worsening showed a left‐lateralized pattern of GM and WM atrophy, involving deep GM, fronto‐temporo‐parieto‐occipital regions, cerebellum, and several WM tracts (P < 0.001, uncorrected).GM and WM atrophy of relevant brain regions occur in MS after 5 years. A different vulnerability of the two brain hemispheres to irreversible structural damage may be among the factors contributing to clinical and cognitive worsening in these patients. Hum Brain Mapp 38:5648–5665, 2017. © 2017 Wiley Periodicals, Inc.     

Quantitative magnetic resonance imaging differences between Alzheimer disease with and without subcortical lacunes

Previous reports showed that patients with Alzheimer disease (AD) frequently have coexisting vascular-related pathologies, such as cerebral infarcts and white matter lesions. The aim of this study was to determine the effects of subcortical lacunar infarcts on brain structure in patients with AD. Semi-automated tissue segmentation and volumetry of magnetic resonance imaging data were performed in 38 AD patients without lacunes (AD-L), 24 AD patients with subcortical lacunes (AD+L), and 40 age-matched cognitively healthy subjects without lacunes. The following tissue volumes were quantified, expressed as percentage of total intracranial volume: ventricular cerebrospinal fluid (CSF), sulcal CSF, cortical gray matter (GM), subcortical GM, white matter (WM), white matter signal hyperintensities (WMSH), lacunes, and hippocampus. There was no difference in the Mini-Mental State Examination between the two AD groups. AD+L patients compared with AD-L subjects had significantly greater volumes of WMSH and ventricular CSF spaces (as expected) but smaller sulcal CSF spaces and no significant increase in cortical GM atrophy (both unexpected). In the AD groups, ventricular CSF correlated inversely with cortical GM but not with WM; sulcal CSF correlated inversely with cortical GM and WM. Cognitive impairment was associated with sulcal CSF volume but not with volumes of WMSH or lacunes. In conclusion, the presence of subcortical lacunes in those with AD is associated with more WM lesions and ventriculomegaly but not with cortical atrophy.     

Normal-appearing white and grey matter damage in MS

Abstract The aims of this study were to improve, using a 3.0 Tesla (T) scanner and diffusion tensor (DT) magnetic resonance imaging (MRI) with sensitivity encoding, our understanding of: 1) the possible pathological substrates of normal-appearing white matter (NAWM) and grey matter (GM) damage in multiple sclerosis (MS) and 2) the factors associated to WM and GM atrophy in this condition. Conventional and DT MRI of the brain were acquired from 32 relapsing-remitting (RR) MS patients and 16 controls. Lesion load, WM (WMV), overall GM (GMV), and neocortical GM (NCV) volumes were measured. NAWM mean diffusivity (MD) and fractional anisotropy (FA), and GM MD were calculated. GMV and NCV were lower (p ≤ 0.001) in MS patients than controls, whereas WMV did not differ significantly. MS patients had higher NAWM and GM average MD and lower NAWM average FA (p ≤ 0.001) than controls. Moderate correlations were found between intrinsic lesion and tissue damage with both GM volumetric and diffusivity changes ()0.41 ≤ r ≤ 0.42, p ≤ 0.04). DT MRI and volumetry measurements at 3.0 T confirm the presence of NAWM and GM abnormalities in RRMS patients. Although histopathology was not available, axonal and neuronal damage and consequent reactive glial proliferation are the most likely substrates of the changes observed.     

Increases in brain white matter abnormalities and subcortical gray matter are linked to CD4 recovery in HIV infection

MRI alterations in the cerebral white (WM) and gray matter (GM) are common in HIV infection, even during successful combination antiretroviral therapy (CART), and their pathophysiology and clinical significance are unclear. We evaluated the association of these alterations with recovery of CD4+ T cells. Seventy-five HIV-infected (HIV+) volunteers in the CNS HIV Anti-Retroviral Therapy Effects Research study underwent brain MRI at two visits. Multi-channel morphometry yielded volumes of total cerebral WM, abnormal WM, cortical and subcortical GM, and ventricular and sulcal CSF. Multivariable linear regressions were used to predict volumetric changes with change in current CD4 and detectable HIV RNA. On average, the cohort (79 % initially on CART) demonstrated loss of total cerebral WM alongside increases in abnormal WM and ventricular volumes. A greater extent of CD4 recovery was associated with increases in abnormal WM and subcortical GM volumes. Virologic suppression was associated with increased subcortical GM volume, independent of CD4 recovery. These findings suggest a possible link between brain alterations and immune recovery, distinct from the influence of virologic suppression. The association of increasing abnormal WM and subcortical GM volumes with CD4+ T cell recovery suggests that neuroinflammation may be one mechanism in CNS pathogenesis.