Short-term brain atrophy changes in relapsing–remitting multiple sclerosis

Magnetic Resonance Imaging Correlates of Multiple Sclerosis Immunopathological Patterns

OBJECTIVE

Histology reveals that early active multiple sclerosis lesions can be classified into 3 main interindividually heterogeneous but intraindividually stable immunopathological patterns of active demyelination (patterns I-III). In patterns I and II, a T-cell- and macrophage-associated demyelination is suggested, with pattern II only showing signs of a humoral immune response. Pattern III is characterized by inflammatory lesions with an oligodendrocyte degeneration. Patterns suggest pathogenic heterogeneity, and we postulated that they have distinct magnetic resonance imaging (MRI) correlates that may serve as biomarkers.

METHODS

We evaluated in an international collaborative retrospective cohort study the MRI lesion characteristics of 789 conventional prebiopsy and follow-up MRIs in relation to their histopathologically classified immunopathological patterns (n = 161 subjects) and lesion edge features (n = 112).

RESULTS

A strong association of a ringlike enhancement and a hypointense T2-weighted (T2w) rim with patterns I and II, but not pattern III, was observed. Only a fraction of pattern III patients showed a ringlike enhancement, and this was always atypical. Ringlike enhancement and T2w rims colocalized, and ringlike enhancement showed a strong association with macrophage rims as shown by histology. A strong concordance of MRI lesion characteristics, meaning that different lesions showed the same features, was found when comparing biopsied and nonbiopsied lesions at a given time point, indicating lesion homogeneity within individual patients.

INTERPRETATION

We provide robust evidence that MRI characteristics reflect specific morphological features of multiple sclerosis immunopatterns and that ringlike enhancement and T2w hypointense rims might serve as a valuable noninvasive biomarker to differentiate pathological patterns of demyelination. ANN NEUROL 2021.

Double Filtration Plasmapheresis Treatment of Refractory Multiple Sclerosis Relapsed on Fingolimod: A Case Report

Double filtration plasmapheresis (DFPP) is an emerging semi-selective apheretic method for treating immuno-mediated neurological diseases. Here we report the first case of steroid-refractory relapsed multiple sclerosis (MS) on Fingolimod (FTY), treated effectively by this technique, in a 37-year-old woman. This condition is thought to be caused by soluble inflammatory species, but its demyelinating pattern is unknown; moreover, despite megadoses of intravenous 6-methyl prednisolone, it induces severe neurological deterioration, but dramatically responded to DFPP in our patient. The clinical improvement was driven by a strong DFPP-induced anti-inflammatory effect, with significant reduction of C3/C4 components, total gamma globulin concentrations (IgG), and gamma-fibrinogen (FGG), resulting in a brain pseudoatrophy phenomenon. Our findings are: first, the steroid-refractory relapsed MS on FTY, however serious, can be treated with DFPP; second, given the good clinical improvement due to the DFPP-induced neuroinflammatory components removal, this clinical condition can be associated with a Lucchinetti pattern II of demyelination.

Methods on Skull Stripping of MRI Head Scan Images-a Review

The high resolution magnetic resonance (MR) brain images contain some non-brain tissues such as skin, fat, muscle, neck, and eye balls compared to the functional images namely positron emission tomography (PET), single photon emission computed tomography (SPECT), and functional magnetic resonance imaging (fMRI) which usually contain relatively less non-brain tissues. The presence of these non-brain tissues is considered as a major obstacle for automatic brain image segmentation and analysis techniques. Therefore, quantitative morphometric studies of MR brain images often require a preliminary processing to isolate the brain from extra-cranial or non-brain tissues, commonly referred to as skull stripping. This paper describes the available methods on skull stripping and an exploratory review of recent literature on the existing skull stripping methods.

Immunological and short-term brain volume changes in relapsing forms of multiple sclerosis treated with interferon beta-1a subcutaneously three times weekly: an open-label two-arm trial

Background

Brain volume atrophy is observed in relapsing–remitting multiple sclerosis (RRMS).

Methods

Brain volume changes were evaluated in 23 patients with RRMS treated with interferon β-1a 44 μg given subcutaneously (SC) three times a week (tiw) and 15 healthy controls. Percentages of whole brain and tissue-specific volume change were measured from baseline (0 months) to 3 months, from 3 to 6 months, and from baseline to 6 months using SIENAX Multi Time Point (SX-MTP) algorithms. Immunological status of patients was also determined and correlations between subsets of T cells and changes in brain volume were assessed.

Results

Interferon β-1a 44 μg SC tiw in 23 patients with RRMS resulted in significant reductions in whole brain and gray matter tissue volume early in the treatment course (baseline to 3 months; mean change; –0.95 %; P = 0.030, –1.52 %; P = 0.004, respectively), suggesting a short-term treatment-induced pseudoatrophy effect. From baseline to 6 months, there were significant correlations observed between decreased T- cell expression of IL-17 F and decreased whole brain and brain tissue-specific volume.

Conclusions

These findings are consistent with the interpretation of the pseudoatrophy effect as resolution of inflammation following treatment initiation with interferon β-1a 44 μg SC tiw, rather than disease-related tissue loss.

Trial registration

ClinicalTrials.gov; NCT01085318

Dramatic recovery of steroid-refractory relapsed multiple sclerosis following Fingolimod discontinuation using selective immune adsorption

BACKGROUND

Selective immune adsorption (SIA) is an emerging method for treating immune-mediated neurological diseases, given its superior safety profile compared to plasma exchange (PEX). However, the available literature concerning Multiple Sclerosis includes no cases of SIA applied to steroid-refractory rebound after Fingolimod discontinuation.

CASE PRESENTATION

Here we report the case of a 32-year-old woman suffering from multiple sclerosis treated with Fingolimod and admitted to a Multiple Sclerosis Centre after drug discontinuation due to the occurrence of lymphopenia. During the few weeks preceding admission, the patient experienced progressive and severe neurological deterioration that did not respond to an initial cycle of pulsed high doses of intravenous 6-methyl prednisolone (IVMP). Given the ineffectiveness of a second cycle of IVMP, the patient was treated with plasma immunoadsorption, leading to dramatic functional recovery. The patient then started a neuro-rehabilitation program. About one month after the final SIA procedure the patient started Natalizumab-based therapy, while maintaining a stable neurological condition. We noted significant modification of C3/C4 complement components and total gamma globulin concentrations (IgG) during SIA.

CONCLUSIONS

Our observations show that however serious, steroid-refractory neurological deterioration occurring after Fingolimod discontinuation in multiple sclerosis can be treated with selective immune-adsorption therapy which thus represents a good alternative in these cases. It could be speculated that this clinical condition was associated with pattern II of demyelination, given the good response to a form of treatment that acts on autoantibodies. Thus, SIA represented an effective therapeutic strategy for this case of relapsed MS as steroid-resistent rebound post Fingolimod cessation.

Longitudinal Mixed-Effect Model Analysis of the Association between Global and Tissue-Specific Brain Atrophy and Lesion Accumulation in Patients with Clinically Isolated Syndrome

BACKGROUND AND PURPOSE

The relationship between lesion formation and brain atrophy development in the early phase of multiple sclerosis is unclear. We investigated the association between new lesion accumulation and brain atrophy progression in patients with clinically isolated syndrome over 48 months.

MATERIALS AND METHODS

Patients with clinically isolated syndrome (n = 210) were evaluated with 1.5T MR imaging at baseline and at 6, 12, 24, 36, and 48 months as part of a multicenter observational study of early administration of intramuscular interferon β-1a. Mixed-effect model analyses, adjusted for age, sex, and treatment status, investigated the association between accumulation of contrast-enhancing and T2 lesions and brain-volume percent changes in a 48-month period.

RESULTS

In patients with clinically isolated syndrome, the average whole-brain volume decreased 2.5%, the mean lateral ventricle volume increased 16.9%, and a mean of 7.7 new/enlarging T2 lesions accumulated over the follow-up period. Patients with clinically isolated syndrome who showed greater percentages of change in whole-brain, white and gray matter, cortical, and lateral ventricle volumes over the follow-up period had more severe lesion outcomes at baseline (all P < .007). There were significant associations between decreased individual brain-volume measures at baseline and greater percentages of change during follow-up (P < .05). We found a significant association between the total cumulative number of new/enlarging T2 lesions and the evolution of whole-brain (P < .001), lateral ventricle (P = .007), gray matter and thalamic (P = .013), subcortical deep gray matter (P = .015), and cortical (P = .036) volumes over the follow-up period.

CONCLUSIONS

Lesion accumulation and brain-volume changes occur simultaneously in the early phase of clinically isolated syndrome. More severe lesion and brain-volume outcomes at baseline were associated with greater development of brain atrophy over the follow-up period in patients with clinically isolated syndrome.

Update on the relationships between neuropsychological dysfunction and structural MRI in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS, characterized by demyelination and neurodegeneration. Besides the sensory and motor deficits that are the hallmark of this disease, approximately 50% of MS patients are cognitively impaired. Over the years, structural neuroimaging has been used widely in MS patients for both diagnostic and research purposes. Various conventional and nonconventional magnetic resonance imaging (MRI) measures have provided important information about the degree and mechanisms of cerebral pathology, and these measures correlate with cognitive and affective disturbances. In this article, recent contributions to the literature regarding the correlation between MRI and neuropsychological function in MS are reviewed.

Clinical and imaging metrics for monitoring disease progression in patients with multiple sclerosis

Multiple sclerosis (MS) is an autoimmune disease of the CNS leading to clinical disability in 250,000-350,000 young adults in the USA and Europe. The disease affects both white matter (WM) and gray matter (GM) tissues of the brain and spinal cord. While WM disease is easily quantified using currently available magnetic resonance imaging (MRI) techniques, identification and quantification of GM disease present a daily challenge. Nonconventional brain and spinal cord MRI techniques, including magnetization transfer, MRI spectroscopy and diffusion tensor imaging, have improved our understanding of MS pathology in the deep GM. The sensitivity of high-resolution MRI obtained at a high magnetic field will improve the detection of spinal cord and brain cortical GM disease. The appropriate use of the above-mentioned techniques has the potential to more accurately explain the level of disability in MS patients.

Effect of MRI coregistration on serial short-term brain volume changes in multiple sclerosis

OBJECTIVE

To test the effect of serial magnetic resonance (MR) coregistration on short-term brain volume changes using different semiautomated and automated brain volume techniques in patients with relapsing-remitting (RR) multiple sclerosis (MS). Coregistration is frequently used to increase precision in serial MR imaging (MRI) analyses. However, the effect of coregistration on measurement of whole brain volume changes from serial scans in the short term has not been tested in MS patients.

METHODS

Twenty-eight patients with RR MS [mean disease duration: 4.9 years, mean age: 34.4 years and mean expanded disability status scale (EDSS): 1.4] were scanned at baseline and monthly for a period of 3 months with 2D spin-echo T1-weighted sequences obtained with nongapped 3 mm axial slices. Percent brain parenchymal fraction change (PBPFC) was calculated by a semiautomated (Buffalo) and, separately, by two automated (Buffalo automated and SIENAX) techniques, whereas percent brain volume change (PBVC) was calculated by the SIENA technique. For coregistration of serial images we used a robust, fully automated linear image coregistration tool. PBPFC and PBVC were calculated before and after coregistration, comparing scans from the following time periods: (1) baseline to month 3; (2) baseline to month 1; (3) month 1 to 2 and (4) month 2 to 3.

RESULTS

The highest median PBPFCs measured on non-coregistered images were detected for the baseline-to-month-3 time period and ranged from -0.11% for Buffalo semiautomated to -0.45% for Buffalo automated (p = ns). On coregistered images, the highest PBPFCs were detected for the baseline-to-month-3 time period and ranged from 0.3% for Buffalo semiautomated, -0.3% for Buffalo automated, 0.02% for SIENAX and -0.02% for SIENA (PBVC). At all time points of the study, no significant differences of median volume changes were measured on coregistered and non-coregistered images when comparing the results among the segmentation algorithms.

CONCLUSIONS

Over a 3 month period we did not detect short-term changes in normalized brain volumes using different measurement techniques. A longer observation period is needed to assess whether coregistration can affect the measurement of long-term brain volume changes.

Voxel-wise magnetization transfer imaging study of effects of natalizumab and IFNβ-1a in multiple sclerosis

Objective:

To determine the effects of intravenous natalizumab and intramuscular interferon beta-1a (IFNβ-1a) on the volume of white-matter (WM) lesions and normal appearing brain tissue (NABT) undergoing voxel-wise (VW) increases in magnetization transfer ratio (MTR) suggestive of remyelination in patients with relapsing multiple sclerosis.

Methods:

This prospective, open-label, single-blinded study enrolled patients with relapsing–remitting multiple sclerosis (RRMS) and relapsing secondary progressive multiple sclerosis (RSPMS) as well as a group of age/sex-matched healthy controls ( n=22). Patients with multiple sclerosis were assigned to receive natalizumab monotherapy ( n=77; RRMS/RSPMS) or intramuscular IFNβ-1a ( n=26) as either monotherapy (RRMS) or combined with pulsed i.v. methylprednisolone, as needed (RSPMS). The primary endpoint was the two-year change in volume of NABT VWMTR, by quantifying the number of voxels that increased (suggesting remyelination) or decreased (suggesting demyelination) in their MTR value.

Results:

The volume of tissue undergoing increases in VWMTR was significantly larger in natalizumab compared with IFNβ-1a-treated patients (year 1: p=0.001 in NABT and p<0.006 in WM lesions; year 2: p=0.008 in NABT) and compared with healthy control subjects (year 1: p=0.05 and year 2: p=0.007 in NABT). The larger volume within NABT undergoing decreases in VWMTR was detected in multiple sclerosis patients compared with healthy controls ( p<0.001), and in the IFNβ-1a group compared with the natalizumab group (year 1: p=0.05; year 2: p=0.002). One patient on natalizumab died from progressive multifocal leukoencephalopathy eight months after completing the study.

Conclusion:

Natalizumab may promote remyelination and stabilize demyelination in lesions and NABT in relapsing multiple sclerosis, compared with intramuscular IFNβ-1a.

Comparison of standard 1.5 T vs. 3 T optimized protocols in patients treated with glatiramer acetate. A serial MRI pilot study

This study explored the effect of glatiramer acetate (GA, 20 mg) on lesion activity using the 1.5 T standard MRI protocol (single dose gadolinium [Gd] and 5-min delay) or optimized 3 T protocol (triple dose of Gd, 20-min delay and application of an off-resonance saturated magnetization transfer pulse). A 15-month, phase IV, open-label, single-blinded, prospective, observational study included 12 patients with relapsing-remitting multiple sclerosis who underwent serial MRI scans (Days -45, -20, 0; the minus ign indicates the number of days before GA treatment; and on Days 30, 60, 90, 120, 150, 180, 270 and 360 during GA treatment) on 1.5 T and 3 T protocols. Cumulative number and volume of Gd enhancing (Gd-E) and T2 lesions were calculated. At Days -45 and 0, there were higher number (p < 0.01) and volume (p < 0.05) of Gd-E lesions on 3 T optimized compared to 1.5 T standard protocol. However, at 180 and 360 days of the study, no significant differences in total and cumulative number of new Gd-E and T 2 lesions were found between the two protocols. Compared to pre-treatment period, at Days 180 and 360 a significantly greater decrease in the cumulative number of Gd-E lesions (p = 0.03 and 0.021, respectively) was found using the 3 T vs. the 1.5 T protocol (p = NS for both time points). This MRI mechanistic study suggests that GA may exert a greater effect on decreasing lesion activity as measured on 3 T optimized compared to 1.5 T standard protocol.

A randomized, blinded, parallel-group, pilot trial of mycophenolate mofetil (CellCept) compared with interferon beta-1a (Avonex) in patients with relapsing-remitting multiple sclerosis

BACKGROUND

Mycophenolate mofetil (MMF, CellCept®) has been utilized as an antirejection agent in transplant recipients and in patients with myriad autoimmune disorders including multiple sclerosis (MS).

OBJECTIVE

To investigate radiographic and clinical safety involving monotherapy use of daily oral MMF (1 g b.i.d.) versus weekly intramuscular interferon beta 1a (Avonex® at 30 mcg) in relapsing-remitting MS (RRMS).

METHODS

We organized a randomized, serial, 6-monthly, MRI-blinded, parallel-group multicenter pilot study to determine the safety of MMF versus interferon beta monotherapy in 35 untreated patients with RRMS, all of whom exhibited evidence of gadolinium (Gd) enhancement on a screening MRI of the brain. The primary outcome was the reduction in the cumulative mean number of combined active lesions (CAL), new Gd-enhancing lesions, and new T2 lesions on MRI analyses.

RESULTS

Both interferon beta and MMF appeared safe and well tolerated in the majority of patients. There was no difference between MMF therapy and the standard regimen of interferon beta therapy on the primary safety MRI endpoints of the study. However, the MMF group showed a trend toward a lower accumulation of combined active lesions, CAL, Gd and T2 lesions when compared with interferon beta treated patients.

CONCLUSIONS

The results from this pilot study suggest that the application of MMF monotherapy in MS deserves further exploration.

T2 hypointense rims and ring-enhancing lesions in MS

BACKGROUND

Hypointense rims peripherally on T2-weighted MRI (rim lesions) have been associated with gadolinium ring-enhancing lesions in multiple sclerosis (MS) in pathological studies. However, little is known about their frequency, we analyzed clinical significance in a cohort of MS sufferers according to routine clinical practice.

METHODS

We retrospectively reviewed all available MRI scans performed on our MS patients between 2000 and 2009. A total of 580 MRI scans from 257 patients were analyzed. The presence of rim lesions and ring enhancement was assessed and counted blind. Furthermore, the correlation between both patterns, and with clinical characteristics, was evaluated.

RESULTS

Thirty-five rim lesions were identified and 9% (24/257) of the patients showed at least one of these lesions. Forty ring-enhancing lesions were counted and 12% (29/245) of the patients who had undergone gadolinium MRI presented at least one such lesion. Thirteen lesions co-localized both patterns (40% of the rim lesions and 33% of the ring-enhancing lesions). Rim lesions and ring-enhancing lesions were observed in patients with clinically isolated syndrome (7%, 7%), relapsing-remitting (11%, 15%) and secondary progressive (13%, 9%) but none with primary progressive MS. Presence of ring-enhancing lesions was significantly associated with a shorter time to reach EDSS (Expanded Disability Status Scale) 4.0 and 6.0 (hazard ratio 7.6, 95% confidence interval 2.3-24.6).

CONCLUSIONS

Rim lesions and ring-enhancing lesions are present in close to 10% of patients with MS, and frequently both lesions appear independently one to the other. The association of ring enhancement with worst prognosis needs to be confirmed in prospective studies.

Ring and nodular multiple sclerosis lesions: a retrospective natural history study

BACKGROUND

In patients with multiple sclerosis (MS), contrast-enhancing lesions (CELs) on postcontrast MRI are considered markers of the inflammatory responses associated with blood-brain barrier breakdown. Based upon shape, CELs may be defined as nodular (nCEL) or ring (rCEL) lesions. Several short-term studies pointed towards the assumption that rCELs represent areas of a more aggressive inflammatory process.

METHODS

In the present long-term (i.e., 2 years) retrospective natural history study, we used monthly imaging to follow rCEL and nCELs evolution in 16 patients with MS during the natural history. New CELs were identified monthly on month 4-9 MRIs, using month 1-3 MRIs to ensure that all CELs were not previously enhancing. Chronic black holes (cBHs) were counted monthly upon CEL disappearance up to the 24th MRI. Generalized estimating equation methods investigated within-patient differences between rCELs and nCELs in volume and likelihood to convert into cBHs. Kaplan-Meier survival curves estimated differences in the length of persistence between cBHs originating from nCELs and cBHs deriving from rCELs.

RESULTS

Fifty-two new rCELs and 281 nCELs were identified. rCELs had larger mean (z = 5.06, p < or = 0.0001) volumes than nCELs. The proportion of cBHs from rCELs was similar (z = 1.81, p = 0.0710) to the proportion of cBHs from nCELs. Likewise, the length of persistence of cBHs deriving from rCELs was similar (chi(1)(2) = 2.339, p = 0.1262) to the duration of cBHs from nCELs.

CONCLUSIONS

Our data suggest that worse radiologic characteristics associated with the acute phase of ring contrast-enhancing lesions and nodular contrast-enhancing lesions do not necessarily reflect a poorer lesion outcome over time.

Cerebral atrophy as outcome measure in short-term phase 2 clinical trials in multiple sclerosis

Introduction

Cerebral atrophy is a compound measure of the neurodegenerative component of multiple sclerosis (MS) and a conceivable outcome measure for clinical trials monitoring the effect of neuroprotective agents. In this study, we evaluate the rate of cerebral atrophy in a 6-month period, investigate the predictive and explanatory value of other magnetic resonance imaging (MRI) measures in relation to cerebral atrophy, and determine sample sizes for future short-term clinical trials using cerebral atrophy as primary outcome measure.

Methods

One hundred thirty-five relapsing–remitting multiple sclerosis patients underwent six monthly MRI scans from which the percentage brain volume change (PBVC) and the number and volume of gadolinium (Gd)-enhancing lesions, T2 lesions, and persistent black holes (PBH) were determined. By means of multiple linear regression analysis, the relationship between focal MRI variables and PBVC was assessed. Sample size calculations were performed for all patients and subgroups selected for enhancement or a high T2 lesion load at baseline.

Results

A significant atrophy occurred over 6 months (PBVC = −0.33%, SE = 0.061, p < 0.0001). The number of baseline T2 lesions (p = 0.024), the on-study Gd-enhancing lesion volume (p = 0.044), and the number of on-study PBHs (p = 0.003) were associated with an increased rate of atrophy. For a 50% decrease in rate of atrophy, the sample size calculations showed that approximately 283 patients per arm are required in an unselected sampled population and 185 patients per arm are required in a selected population.

Conclusion

Within a 6-month period, significant atrophy can be detected and on-study associations of PBVC and PBHs emphasizes axonal loss to be a driving mechanism. Application as primary outcome measure in short-term clinical trials with feasible sample size requires a potent drug to obtain sufficient power.

A sensitive, noise-resistant method for identifying focal demyelination and remyelination in patients with multiple sclerosis via voxel-wise changes in magnetization transfer ratio

Magnetization transfer imaging (MTI) provides a reliable and histopathologically validated means for identifying important tissue changes in multiple sclerosis (MS), including demyelination and remyelination. However, most approaches to date have been based on a priori regions of interest (ROIs) and have been relatively insensitive to small focal changes or competing processes. More recent techniques have sought to address this through a voxel-wise approach, but have been limited in their detection capabilities by the amount of noise in standard MTR images. To address this issue while remaining sensitive to local changes, we propose the use of the recently introduced threshold-free cluster enhancement (TFCE) technique in combination with a Monte Carlo estimation approach. TFCE is first applied to enhance individual voxels based on their level of local cluster support, and then Monte Carlo estimation is performed to allow meaningful statistical interpretation of the resulting TFCE values. We validated this technique in three complementary ways: healthy control scan-rescan analysis, analysis of a "gold standard" simulated dataset, and analysis of a group of MS patients and healthy volunteers with 1-year longitudinal MRI scans. Scan-rescan analysis demonstrated a very low false-positive rate (1.44 mL increasing and 1.48 mL decreasing at the optimal detection threshold). Simulated dataset analysis yielded an area under receiver-operating characteristic curve of 0.942 (compared to 0.801 for a more conventional voxel-wise thresholding analysis). Finally, analysis of the real subject population showed highly significant differences (p<0.001) in volume of decreasing MTR between patients and controls. The proposed method provides a valuable means for quantifying MS-related tissue changes, particularly demyelination and remyelination, in vivo and without the use of highly complex or experimental MRI acquisition techniques. It improves on the sensitivity of other approaches, and may increase the statistical power of studies investigating the effects of therapy on MRI outcomes in MS.

Gender-related differences in MS: a study of conventional and nonconventional MRI measures

Background

Studies showed gender-associated differences in multiple sclerosis (MS) disease evolution and in the evolution of conventional magnetic resonance imaging (MRI) findings.

Objective

The aim of this study was to investigate gender differences according to a number of conventional and nonconventional MRI measures in patients with MS.

Methods

We examined 763 consecutive patients with MS [499 (19.2% men) relapsing-remitting (RR), 230 (24.8% men) secondary-progressive, and 34 (44.1% men) primary-progressive], 32 (21.9% men) patients with clinically isolated syndrome (CIS), and 101 (30.7% men) normal controls (NC). Patients were assessed using conventional and nonconventional MRI measures. Gender-related MRI differences were investigated using general linear model analysis, corrected for MS disease type.

Results

In the total MS group, male patients showed lower normalized peripheral gray matter (GM) ( P < 0.001) and normalized GM ( P = 0.011) volumes than female patients. Female patients presented lower normalized white matter (WM) volumes ( P = 0.011). These gender effects were not observed in NC. Male patients also showed more advanced central atrophy ( P = 0.022). In RRMS male patients, there was also a higher lateral ventricle volume ( P = 0.001). The GM-WM normalized ratio was lower for male patients with MS compared with male NC (0.97 vs. 1.09, P < 0.001) but not in patients with CIS compared with NC.

Conclusions

There were no significant gender-related differences regarding nonconventional MRI measures. GM and central atrophy are more advanced in male patients, whereas WM atrophy is more advanced in female patients. These gender-related MRI differences may be explained by the effect of sex hormones on brain damage and repair mechanisms.

Brain atrophy evolution and lesion load accrual in multiple sclerosis: a 2-year follow-up study

Background

To investigate in a large cohort of patients with multiple sclerosis (MS), lesion load and atrophy evolution, and the relationship between clinical and magnetic resonance imaging (MRI) correlates of disease progression.

Methods

Two hundred and sixty-seven patients with MS were studied at baseline and two years later using the same MRI protocol. Abnormal white matter fraction, normal appearing white matter fraction, global white matter fraction, gray matter fraction and whole brain fraction, T2-hyperintense, and T1-hypointense lesions were measured at both time points.

Results

The majority of patients were clinically stable, whereas MRI-derived brain tissue fractions were significantly different after 2 years. The correlation between MRI data at baseline and their variation during the follow-up showed that lower basal gray matter atrophy was significantly related with higher progression of gray matter atrophy during follow-up. The correlation between MRI parameters and disease duration showed that gray matter atrophy rate decreased with increasing disease duration, whereas the rate of white matter atrophy had a constant pattern. Lower basal gray matter atrophy was associated with increased probability of developing gray matter atrophy at follow-up, whereas gray matter atrophy progression over 2 years and new T2 lesion load were risk factors for whole brain atrophy progression.

Conclusions

In MS, brain atrophy occurs even after a relatively short period of time and in patients with limited progression of disability. Short-term brain atrophy progression rates differ across tissue compartments, as gray matter atrophy results more pronounced than white matter atrophy and appears to be a early phenomenon in the MS-related disease progression.

A voxel-based morphometry study of grey matter loss in MS patients with different clinical phenotypes

To assess regional grey matter (GM) changes in a large cohort of multiple sclerosis (MS) patients with different clinical phenotypes, using voxel-based morphometry (VBM) and their correlation with the extent of global and regional T2 lesion volumes (LV), we acquired conventional MRI scans from 71 MS patients with different clinical phenotypes (26 with relapsing-remitting [RR] MS, 27 with secondary progressive [SP] MS and 18 with primary progressive [PP] MS), 28 patients with a clinically isolated syndrome (CIS) suggestive of MS, and 21 controls. No GM loss was found in CIS patients. Compared to CIS patients, those with RRMS had a significant GM loss in the right pre and postcentral gyri. Compared to RRMS, SPMS patients had a significant GM loss in several regions of the fronto-parieto-temporo-occipital lobes, the cerebellum and superior and inferior colliculus, bilaterally, and deep GM structures. Compared to PPMS, SPMS patients had a significant GM loss in the postcentral gyrus, the cuneus, the middle occipital gyrus, the thalamus, the cerebellum, and the superior and inferior colliculus. In all MS groups, regional GM loss was strongly/moderately correlated with brain T2 LV. In SPMS and PPMS patients, a correlation was found between cortical regional GM loss and T2 LV of the corresponding or adjacent lobes. In MS patients, GM volume loss follows different patterns of regional distribution according to the clinical phenotype of the disease, is likely secondary to the presence and topography of focal WM inflammatory-demyelinating lesions, and is more evident in the progressive forms of the disease.

Independent contributions of cortical gray matter atrophy and ventricle enlargement for predicting neuropsychological impairment in multiple sclerosis

The primary goal of this study was to investigate associations between regional gray matter (GM) atrophy and neuropsychological function in multiple sclerosis (MS), while accounting for the influence of central brain atrophy (i.e. third ventricle enlargement). Using a cross-sectional design, we studied 59 MS patients with brain MRI and neuropsychological testing. Regional gray matter fractions (rGMFs) were calculated from MRI images for 11 homologous brain areas using the semiautomatic brain region extraction (SABRE) technique. Neuropsychological testing followed consensus panel guidelines and included tests emphasizing episodic memory, working memory and processing speed. The analytic approach was stepwise linear regression, with forward selection and p<0.05 threshold for significance. Consistent with previous research, there were significant correlations between third ventricle width and neuropsychological tests. Stepwise linear regression analyses controlling for third ventricle width retained rGMFs obtained from specific regions within the prefrontal cortex. Left frontal atrophy was associated with tests emphasizing auditory/verbal memory. Right frontal atrophy was associated with impairment in visual episodic and working memory. For the first time, we show an independent relationship between cortical atrophy and cognitive impairment after accounting for the effects of central atrophy.

I nterferon beta-1a slows progression of brain atrophy in relapsing-remitting multiple sclerosis predominantly by reducing gray matter atrophy

Background Brain atrophy, as assessed by magnetic resonance imaging (MRI), has been correlated with disability in patients with multiple sclerosis (MS). Recent evidence indicates that both white matter (WM) and gray matter (GM) are subject to atrophy in patients with MS. Although neurological deficiencies in MS are primarily due to loss of WM, the clinical significance of GM atrophy has not been fully explored in MS.

Methods We have undertaken a three-year, open-label study, comparing 26 patients who elected to receive intramuscular interferon beta-1a (IFN β-1a) therapy, with 28 patients who elected not to receive therapy. Both groups had quantitative cranial MRI scans at study entry and after three years, and standardized clinical assessments every six months. Brain parenchymal fraction (BPF), GM fraction (GMF), and WM fraction (WMF) percent changes were calculated, and T2- and T1-lesion volumes (LVs) assessed.

Results After three years, mean percent (%) change in BPF favored the IFN β-1a treatment group (IFN β-1a —1.3% versus the control group —2.5%, P=0.009), as did the mean percent change in GMF (+0.2 versus —1.4%, P=0.014), and the mean percent change in T1-LV (—9.3 versus +91.6%, P=0.011). At the end of the study, there was a significant within-patient decrease in BPF for both groups (P=0.02 for the IFN β-1a treatment group, and P<0.001 for the control group), a significant within-patient decrease in WMF for the IFN β-1a treatment group (P=0.01), and a significant decrease in GMF for the control group (P=0.013) when compared with baseline.

Conclusion Over a three-year period, treatment with IFN β-1a significantly slowed the progression of whole-brain and GM atrophy, and of T1-hypointense LV accumulation, when compared with the control group. Multiple Sclerosis 2007; 13: 490-501. http://msj.sagepub.com

Neuroimaging in multiple sclerosis

Conventional magnetic resonance imaging (MRI) has routinely been used to improve the accuracy of multiple sclerosis (MS) diagnosis and prognosis. Metrics derived from conventional MRI are now routinely used to detect therapeutic effects and extend clinical observations. However, conventional MRI measures, such as the use of lesion volume and count of gadolinium-enhancing and T2 lesions, have insufficient sensitivity and specificity to reveal the true degree of pathological changes occurring in MS. They cannot distinguish between inflammation, edema, demyelination, Wallerian degeneration, and axonal loss. In addition, they do not show a reliable correlation with clinical measures of disability and do not provide a complete assessment of therapeutic outcomes. Recent neuropathologic studies of typical chronic MS brains reveal macroscopic demyelination in cortical and deep gray matter (GM) that cannot be detected by currently available MRI techniques. Therefore, there is a pressing need for the development of newer MRI techniques to detect these lesions. Newer metrics of MRI analysis, including T1-weighted hypointense lesions, central nervous system atrophy measures, magnetization transfer imaging, magnetic resonance spectroscopy, and diffusion tensor imaging, are able to capture a more global picture of the range of tissue alterations caused by inflammation and neurodegeneration. At this time, they provide the only proof--albeit indirect--that important occult pathology is occurring in the GM. However, evidence is increasing that these nonconventional MRI measures correlate better with both existing and developing neurological impairment and disability when compared to conventional metrics.

Pharmacogenetics of MXA SNPs in interferon-beta treated multiple sclerosis patients

The myxovirus resistance A (MXA) mRNA has been extensively investigated for assessing the biologic responses of multiple sclerosis (MS) patients to interferon-beta (IFN-beta) therapy. The objective of this study was to evaluate the associations between two MXA promoter region single nucleotide polymorphisms (rs2071430 and rs17000900) and the gene expression responses, clinical and MRI phenotypes in IFN-beta treated MS patients. The rs2071430 and rs17000900 SNPs, which are located in or near an interferon-stimulated response element (ISRE), were genotyped in 179 relapsing MS patients. Quantitative MRI measurements were available for 101 patients on IFN-beta monotherapy. Gene expression was assessed in 22 anti-interferon-beta neutralizing antibody negative patients. No significant association was found between the MXA genotype at these two SNPs and clinical, MRI and MXA gene expression in MS patients treated with IFN-beta therapy.

Skull-stripping magnetic resonance brain images using a model-based level set

The segmentation of brain tissue from nonbrain tissue in magnetic resonance (MR) images, commonly referred to as skull stripping, is an important image processing step in many neuroimage studies. A new mathematical algorithm, a model-based level set (MLS), was developed for controlling the evolution of the zero level curve that is implicitly embedded in the level set function. The evolution of the curve was controlled using two terms in the level set equation, whose values represented the forces that determined the speed of the evolving curve. The first force was derived from the mean curvature of the curve, and the second was designed to model the intensity characteristics of the cortex in MR images. The combination of these forces in a level set framework pushed or pulled the curve toward the brain surface. Quantitative evaluation of the MLS algorithm was performed by comparing the results of the MLS algorithm to those obtained using expert segmentation in 29 sets of pediatric brain MR images and 20 sets of young adult MR images. Another 48 sets of elderly adult MR images were used for qualitatively evaluating the algorithm. The MLS algorithm was also compared to two existing methods, the brain extraction tool (BET) and the brain surface extractor (BSE), using the data from the Internet brain segmentation repository (IBSR). The MLS algorithm provides robust skull-stripping results, making it a promising tool for use in large, multi-institutional, population-based neuroimaging studies.

Magnetic resonance imaging measures of brain atrophy in multiple sclerosis

Magnetic resonance imaging (MRI) has been widely used to diagnose and monitor multiple sclerosis (MS). Although MRI-visible lesions are a key feature of MS, they are thought to correlate poorly with clinical progression. Neurodegeneration is increasingly being recognized as an important factor in the pathogenesis of MS, and MRI measures of brain atrophy have been suggested as surrogate markers of neuroaxonal loss and disease progression. This pathology may be more relevant to the progression of disability than focal inflammation. A number of MRI-based methods have been developed for the measurement of global and regional brain atrophy. Natural-history studies of MS and clinically isolated syndromes suggestive of MS have observed atrophy in these subjects above that seen in controls, over periods ranging from three months to years. Brain atrophy has also been incorporated as an outcome measure in therapeutic trials of disease-modifying treatments. This paper considers neuroaxonal loss and the pathological basis of brain atrophy, methods developed to quantify brain atrophy, the findings of natural-history and therapeutic studies, the relationship of brain atrophy to disability and cognition, and the future research directions and clinical applications of brain atrophy measurements.

Granzyme B mediates neurotoxicity through a G-protein-coupled receptor

Neuroinflammatory diseases such as multiple sclerosis (MS) are characterized by focal regions of demyelination and axonal loss associated with infiltrating T cells. However, the role of activated T cells in causing neuronal injury remains unclear. CD4 and CD8 T cells were isolated from normal donors and polyclonally activated using plate-bound anti-CD3 and soluble anti-CD28. The conditioned T cell supernatants caused toxicity to cultured human fetal neurons, which could be blocked by immunodepleting the supernatants of granzyme B (GrB). Recombinant GrB also caused toxicity in neurons by caspase-dependent pathways but no toxicity was seen in astrocytes. The neurotoxicity was independent of perforin and could not be blocked by mannose-6-phosphate. However, GrB-induced neurotoxicity was sensitive to pertussis toxin, implicating the stimulation of Gialpha protein-coupled receptors. GrB caused a decrease in cAMP levels but only modest increases in intracellular calcium. The effect on intracellular calcium could be markedly potentiated by stromal-derived factor 1alpha. GrB-induced neurotoxicity could also be blocked by vitamin E and a neuroimmunophilin ligand. In conclusion, GrB may be an important mediator of neuronal injury in T cell-mediated neuroinflammatory disorders.

Clinical-magnetic resonance imaging correlations in multiple sclerosis

Conventional magnetic resonance imaging (MRI) has routinely been used to improve the accuracy of multiple sclerosis (MS) diagnosis and monitoring, detect the effects of disease-modifying therapy, and refine the utility of clinical assessments. However, conventional MRI measures, such as the use of lesion volume and count of gadolinium-enhancing and T2 lesions, have insufficient sensitivity and specificity to reveal the true degree of pathological changes occurring in MS. Newer metrics of MRI analysis, including T1-weighted hypointense lesions (black holes) and central nervous system (CNS) atrophy measures, are able to capture a more global picture of the range of tissue alterations caused by inflammation, demyelination, axonal loss, and neurodegeneration. There is mounting evidence that these MRI measures correlate well with existing and developing neurological impairment and disability. In so doing, these MRI techniques can help elucidate the mechanisms underlying the pathophysiology and natural history of MS. The current understanding is that T1 black holes and CNS atrophy more accurately reflect the neurodegenerative and destructive components of the MS disease process. Therefore, the short and long-term studies that aim to measure the degree and severity of the neurodegenerative MS disease process should incorporate these MRI metrics as part of their standard routine MRI protocols.

The measurement and clinical relevance of brain atrophy in multiple sclerosis

Brain atrophy has emerged as a clinically relevant component of disease progression in multiple sclerosis. Progressive loss of brain tissue bulk can be detected in vivo in a sensitive and reproducible manner by MRI. Clinical studies have shown that brain atrophy begins early in the disease course. The increasing amount of data linking brain atrophy to clinical impairments suggest that irreversible tissue destruction is an important determinant of disease progression to a greater extent than can be explained by conventional lesion assessments. In this review, we will summarise the proposed mechanisms contributing to brain atrophy in patients with multiple sclerosis. We will critically discuss the wide range of MRI-based methods used to quantify regional and whole-brain-volume loss. Based on a review of current information, we will summarise the rate of atrophy among phenotypes for multiple sclerosis, the clinical relevance of brain atrophy, and the effect of disease-modifying treatments on its progression.

Semi-automatic brain region extraction (SABRE) reveals superior cortical and deep gray matter atrophy in MS

In multiple sclerosis (MS), atrophy occurs in various cortical and subcortical regions. However, it is unclear whether this is mostly due to gray (GM) or white matter (WM) loss. Recently, a new semi-automatic brain region extraction (SABRE) technique was developed to quantify parenchyma volume in 13 hemispheric regions. This study utilized SABRE and tissue segmentation to examine whether regional brain atrophy in MS is mostly due to GM or WM loss, correlated with disease duration, and moderated by disease course. We studied 68 MS patients and 39 normal controls with 1.5 T brain MRI. As expected, MS diagnosis was associated with significantly lower (P < 0.001) regional brain parenchymal fractions (RBPFs). While significant findings emerged in 11 GM comparisons, only four WM comparisons were significant. The largest mean RBPF percent differences between groups (MS < NC) were in the posterior basal ganglia/thalamus region (-19.3%), superior frontal (-15.7%), and superior parietal (-14.3%) regions. Logistic regression analyses showed GM regions were more predictive of MS diagnosis than WM regions. Eight GM RBPFs were significantly correlated (P < 0.001) with disease duration compared to only one WM region. Significant trends emerged for differences in GM, but not WM between secondary progressive (SP) and relapsing-remitting MS patients. Percent differences in GM between the two groups were largest in superior frontal (-9.9%), medial superior frontal (-6.5%), and superior parietal (-6.1%) regions, with SP patients having lower volumes. Overall, atrophy in MS is diffuse and mostly related to GM loss particularly in deep GM and superior frontal-parietal regions.