L Fisniku

Gray matter atrophy is related to long‐term disability in multiple sclerosis

To determine the relation of gray matter (GM) and white matter (WM) brain volumes, and WM lesion load, with clinical outcomes 20 years after first presentation with clinically isolated syndrome suggestive of multiple sclerosis (MS).

Humoral immune response to EBV in multiple sclerosis is associated with disease activity on MRI

Background: Evidence suggests that Epstein-Barr virus (EBV) plays a role in triggering or perpetuating disease activity in multiple sclerosis (MS). Methods: We investigated 100 subjects (50 clinically isolated syndrome [CIS], 25 relapsing-remitting [RR] MS, 25 primary progressive [PP] MS) for 1) evidence of EBV reactivation and 2) disease activity as indicated by serial gadolinium (Gd)-enhanced MRIs over a 5-year period. EBV DNA in blood was quantified by real-time quantitative PCR and EBV serology for anti-Epstein-Barr virus nuclear antigen 1 (EBNA-1) immunoglobulin G (IgG), anti-viral capsid antigen (VCA) IgG, and anti-EBV IgM. Data were analyzed using repeated measures analysis, analysis of variance, and logistic regression analysis. Results: All subjects had serologic evidence of previous EBV infection, but no lytic reactivation was detected. Significant differences in EBNA-1 IgG titers were found between subgroups, highest in the RRMS cohort compared with PPMS (p < 0.001) and CIS (p < 0.001). Gd-enhancing lesions on MRI correlated with EBNA-1 IgG (r = 0.33, p < 0.001) and EBNA-1:VCA IgG ratio (r = 0.36, p < 0.001). EBNA-1 IgG also correlated with change in T2 lesion volume (r = 0.27, p = 0.044) and Expanded Disability Status Scale score (r = 0.3, p = 0.035). Conclusions: The correlation between elevated Epstein-Barr virus nuclear antigen 1 (EBNA-1) immunoglobulin G (IgG) and gadolinium-enhancing lesions suggests an association between Epstein-Barr virus (EBV) infection and multiple sclerosis (MS) disease activity. The heightened immune response to EBV in MS is specifically related to EBNA-1 IgG, a marker of the latent phase of the virus. The lack of association between acute viral reactivation in the peripheral blood and Gd+ lesions suggests a limited role of the former in driving disease activity.

Cognitive impairment in relapsing—remitting multiple sclerosis can be predicted by imaging performed several years earlier

Cognitive deficits in multiple sclerosis (MS) are common and correlate with contemporary MRI brain abnormalities, particularly atrophy, but the ability of imaging early in the disease to predict later cognitive impairment remains to be determined. Thirty relapsing—remitting MS patients recruited within three years of the onset of the disease, and in whom MRI had been performed at baseline and a year later, were assessed neuropsychologically five years later. Imaging parameters accounting for significant variance in cognitive performance were identified using multiple regressions, once confounding variables were controlled. Patients performed significantly worse than expected on tests of attention/speed of information processing and half of them had experienced some decline in IQ in relation to premorbid estimates. The rate of global brain atrophy in the first year of the study accounted for significant variance in the overall cognitive performance, and in memory and attention/speed of information processing. Poor performance on attention tests was associated with high T1-weighted lesion volume and reduced magnetization transfer ratio (MTR) in normal-appearing white matter (NAWM). These results suggest that neuroaxonal loss was identified early in the disease, and its rate of progression, predicted cognitive impairment later in the disease. Neuroaxonal loss is likely to affect commissural and association fibres that subserve the cognitive processes impaired in MS. Multiple Sclerosis 2008; 14: 197—204. http://msj.sagepub.com

MRI measures show significant cerebellar gray matter volume loss in multiple sclerosis and are associated with cerebellar dysfunction

Background Regional atrophy measures may offer useful information about the causes of specific clinical deficits in multiple sclerosis (MS). Objective To determine the magnitude of cerebellar gray and white matter (GM and WM) atrophy in patients with clinically isolated syndromes (CIS) and MS, and their role in clinical manifestations of cerebellar damage. Methods T1-weighted volumetric magnetic resonance imaging (MRI) of 73 patients [29 CIS, 33 relapsing–remitting MS (RRMS), 11 secondary progressive MS (SPMS)] was compared with 25 controls. GM and WM regions were generated using SPM5 and cerebellar regions delineated. Linear regression was used to investigate differences in tissue-specific cerebellar volumes between groups and the association with clinical measures. Results Mean cerebellar GM volume (CGMV) was 100.1 cm3 in controls, 96.4 cm3 in CIS patients, 91.8 cm3 in RRMS patients, and 88.8 cm3 in SPMS patients. Mean cerebellar WM volumes (CWMV) were 21.3 cm3, 20.4 cm3, 19.9 cm3, and 18.8 cm3, respectively. CGMV was reduced by 4.8 cm3 (P = 0.054) in RRMS patients, and 8.5 cm3 (P = 0.012) in SPMS patients, relative to controls. Only patients with SPMS showed a borderline significant reduction in CWMV compared with controls (mean 2.1 cm3, P = 0.053). CGMV was significantly smaller in patients assessed as having cerebellar dysfunction compared with patients who had normal cerebellar function. Significant associations of CGMV and CWMV with performance on the nine-hole peg test were also observed. Conclusion Clinically relevant GM atrophy occurs in the cerebellum of MS patients and is more prominent than WM atrophy. As such, it may provide complementary data to other regional atrophy and intrinsic tissue measures.

Detecting treatment effects on brain atrophy in relapsing remitting multiple sclerosis: Sample size estimates

Brain atrophy, thought to reflect neuroaxonal degeneration, may be considered an objective marker of disease progression in multiple sclerosis (MS). Our objective was to estimate sample sizes required for parallel group placebo-controlled trials of disease-modifying treatments in relapsing remitting MS (RRMS), using brain atrophy on MRI as the outcome measure. In addition, we investigated how brain atrophy measurement method and trial duration affect sample sizes. Thirtythree patients with RRMS and 16 controls had T1-weighted volumetric MR imaging acquired at baseline and up to six repeat timepoints (six monthly intervals). Brain atrophy was quantified between baseline and each repeat image using four methods: segmented brain volume difference, BBSI, SIENA and ventricular enlargement. Linear mixed models were fitted to data from each subject group and method. Sample size calculations were performed using mean and variance estimates from these models. For a 2 year trial, a treatment slowing atrophy rate by 30% required 123 subjects in each treatment arm if using SIENA to measure atrophy, 157 for the BBSI, 140 for ventricular enlargement and 763 for segmented brain volume difference. For a given effect size and method, sample sizes were statistically significantly reduced the longer the trial duration. Our estimations suggest that brain atrophy could provide an additional outcome measure to clinical assessment for monitoring treatment effects in RRMS although the relationship between atrophy and subsequent disability, and potential confounding factors to atrophy measurement must be further investigated.

Voxel-based analysis of grey matter magnetization transfer ratio maps in early relapsing remitting multiple sclerosis

Previous studies using magnetization transfer ratio (MTR) histogram analysis have demonstrated the existence of global grey matter (GM) abnormalities in patients with early relapsing-remitting multiple sclerosis (RRMS). However, MTR histogram analysis does not provide any information on the localization of the morphological changes within the GM. The aim of this study was to investigate the localization of GM injury in early RRMS, performing voxel-based analysis of GM MTR maps. Statistical mapping analysis of GM MTR maps was performed in a group of 38 patients with early RRMS and 45 healthy controls. Between-group comparisons (P<0.05, corrected for multiple comparisons) demonstrated significant GM MTR decrease in patients located in the bilateral lenticular nuclei, the bilateral insula, the left posterior cingulate cortex, and the right orbitofrontal cortex. To limit the potential confounding effect of regional GM atrophy, the percentages of GM were assessed in the regions showing significant MTR decrease, and no GM atrophy was evidenced in these regions. This study demonstrates that several GM regions are commonly affected in patients with early RRMS. Predominant involvement of these structures may be partly related to their vulnerability to anterograde or retrograde degeneration from transected axons in the white matter and/or to the predominant localization of GM demyelinating lesions in such regions. Multiple Sclerosis 2007; 13: 483-489. http://msj.sagepub.com

Hippocampal atrophy in relapsing-remitting and primary progressive MS: a comparative study

Background: In multiple sclerosis (MS), demyelination and neuroaxonal damage are seen in the hippocampus, and MRI has revealed hippocampal atrophy. Objectives: To investigate and compare hippocampal volume loss in patients with relapsing—remitting MS (RRMS) and primary progressive MS (PPMS) using manual volumetry, and explore its association with memory dysfunction. Methods: Hippocampi were manually delineated on volumetric MRI of 34 patients with RRMS, 23 patients with PPMS and 18 controls. Patients underwent neuropsychological tests of verbal and visuospatial recall memory. Linear regression was used to compare hippocampal volumes between subject groups, and to assess the association with memory function. Results: Hippocampal volumes were smaller in MS patients compared with controls, and were similar in patients with RRMS and PPMS. The mean decrease in hippocampal volume in MS patients was 317 mm3 (9.4%; 95% CI 86 to 549; p = 0.008) on the right and 284 mm3 (8.9%; 95% CI 61 to 508; p = 0.013) on the left. A borderline association of hippocampal volume with memory performance was observed only in patients with PPMS. Conclusion: Hippocampal atrophy occurs in patients with RRMS and PPMS. Factors additional to hippocampal atrophy may impact on memory performance.

TI-relaxation time changes over five years in relapsing-remitting multiple sclerosis

The pathological effects of multiple sclerosis are not confined to lesions; tissues that appear normal on conventional magnetic resonance imaging scans are also affected, albeit subtly. One imaging technique that has proven sensitive to such effects is T1-relaxation time measurement, with previous work demonstrating abnormalities in normal-appearing white matter and grey matter. In this work we investigated the evolution of T1-relaxation time changes in normal-appearing white matter and grey matter in relapsing—remitting multiple sclerosis. Three- and five-year follow-up data from 35 people with clinically early (a mean of 1.6 years from first clinical event) relapsing—remitting multiple sclerosis and 15 healthy controls were analysed. T1-relaxation time histograms were extracted from normal-appearing white matter and grey matter, and mean, peak height and peak location values were estimated. T1-relaxation time peak height declined in the multiple sclerosis normal-appearing white matter and grey matter, but not the control group (rate difference p = 0.024 in normal-appearing white matter, in normal-appearing grey matter p = 0.038); other T1-relaxation time changes were not significantly different between groups. Changes in T1-relaxation time measures did not correlate with increases in brain T2-weighted lesion loads or Expanded Disability Status Scale scores. These results suggest that the processes underlying changes in normal-appearing white matter and grey matter T1-relaxation times are not immediately linked to white matter lesion formation, and may represent more diffuse but progressive sub-clinical pathology in relapsing—remitting multiple sclerosis.

Relationship between brain MRI lesion load and short-term disease evolution in non-disabling MS: a large-scale, multicentre study

Background and Objectives: We evaluated clinical and conventional MRI features of a large population of patients with non-disabling MS to identify potential markers of a benign disease course. Methods: In seven MAGNIMS centres we retrospectively identified 182 patients with benign (B) MS (EDSS score ≤3.0, disease duration ≥15 years) and 187 patients with non-disabling relapsing–remitting MS (NDRRMS) (Expanded Disability Status Scale score ≤3.0, disease duration between 5 and 14 years), in whom clinical data were collected within two weeks from a brain T2-weighted scan. Brain T2 lesion volume (LV) was measured in all patients. In 146 BMS and 146 NDRRMS patients, clinical data were also available after a median follow up of 29 months (range: 7–104 months). Results: Mean LV was higher in BMS than in NDRRMS patients (p < 0.001), but the mean ratio between LV and disease duration was higher in NDRRMS than in BMS patients (1.1 vs. 0.6 ml/year, p < 0.001). In BMS patients, brain LV was correlated with EDSS score increase at follow up (r = 0.18, p = 0.03). Conclusions: An overall low rate of brain LV increase during a long-lasting disease course might be a feature of BMS. In BMS patients, a high brain LV might be associated with worsening of locomotor disability at short-term follow up.

Po120 CMT1A and co-existing primary progressive multiple sclerosis

A 56-year-old lady presented with a 3 year history of slowly worsening mobility and balance, spasms, and sphincter dysfunction. At 46 she received a genetically confirmed diagnosis of Charcot-Marie-Tooth (CMT) Type-1A with a positive family history, having presented with minimal distal sensory and motor involvement and electrophysiologically confirmed carpel tunnel syndrome successfully treated neurosurgically. Examination now revealed optic disc pallor, left upper and lower limb spasticity, pyramidal weakness and gait ataxia. Whole neuroaxis contrast Magnetic Resonance Imaging showed scattered periventricular, temporal and right cerebellar lesions suggestive of demyelination without enhancement. CSF showed intrathecal oligoclonal band synthesis and raised IgG index. The supplementary diagnosis of primary progressive multiple sclerosis (PP-MS) was made. A relapsing-remitting MS or PP-MS phenotype is only very rarely described in patients with co-existent genetically confirmed CMT, including Type 1, Type 2 and X-linked cases. Although an inflammatory component is felt to be superimposed upon the dysmyelinative neuropathy in some patients, involvement of the central nervous system reported in cases of CMT more commonly comprises asymptomatic white matter lesions. Hypotheses exist proposing a shared pathological basis to the co-existence of MS and CMT through dysregulated immune tolerance to myelin however such co-occurrence could plausibly be explained by chance alone.