Search

Objective: Glutamate is the principal excitatory neurotransmitter and is involved in normal brain function. Cognitive impairment is common in multiple sclerosis (MS), and understanding its mechanisms is crucial for developing effective treatments. We used structural and metabolic brain imaging to test two hypotheses: (i) glutamate levels in grey matter regions are abnormal in MS, and (ii) patients show a relationship between glutamate concentration and memory performance., Methods: Eighteen patients with relapsing-remitting MS and 17 healthy controls were cognitively assessed and underwent (1)H-magnetic resonance spectroscopy at 3 T to assess glutamate levels in the hippocampus, thalamus, cingulate and parietal cortices. Regression models investigated the association between glutamate concentration and memory performance independently of magnetisation transfer ratio values and grey matter lesions withint he same regions, and whole-brain grey matter volume., Results: Patients had worse visual and verbal memory than controls. A positive relationship between glutamate levels in the hippocampal, thalamic and cingulate regions and visuospatial memory was detected in patients, but not in healthy controls., Conclusions: The relationship between memory and glutamate concentration, which is unique to MS patients, suggests the reliance of memory on glutamatergic systems in MS., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Objective: To measure the effects of disease-modifying drugs (DMDs) on the development of cortical lesions (CL) and cortical atrophy in patients with relapsing-remitting multiple sclerosis (RRMS)., Methods: RRMS patients (n = 165) were randomized to subcutaneous (sc) interferon (IFN) beta-1a (44 mcg three times weekly), intramuscular (im) IFN beta-1a (30 mcg weekly) or glatiramer acetate (GA; 20 mg daily). The reference population comprised 50 untreated patients. Clinical and MRI examinations were performed at baseline, 12 months and 24 months., Results: One hundred and forty-one treated patients completed the study. After 12 months, 37/50 (74%) of untreated patients developed ≥ 1 new CL (mean 1.6), compared with 30/47 (64%) of im IFN beta-1a-treated patients (mean 1.2, p = 0.021), 24/48 (50%) of GA-treated patients (mean 0.8, p = 0.001) and 12/46 (26%) of sc IFN beta-1a-treated patients (mean 0.4, p < 0.001). After 24 months, ≥ 1 new CL was observed in 41/50 (82%) of untreated (mean 3.0), 34/47 (72%) of im IFN beta-1a-treated (mean 1.6, p < 0.001), 30/48 (62%) of GA-treated (mean 1.3, p < 0.001) and 24/46 (52%) of sc IFN beta-1a-treated patients (mean 0.8, p < 0.001). Mean grey matter fraction decrease in DMD-treated patients at 24 months ranged from 0.7 to 0.8 versus 1.0 in untreated patients (p = 0.023)., Conclusions: Disease-modifying drugs significantly decreased new CL development and cortical atrophy progression compared with untreated patients, with faster and more pronounced effects seen with sc IFN beta-1a than with im IFN beta-1a or GA.

Introduction: The cause of epilepsy in multiple sclerosis (MS) has not yet been elucidated. The relevance of cortical pathology (cortical lesions and thickness) in MS patients with and without epilepsy was evaluated in a longitudinal study., Methods: 32 relapsing-remitting MS patients with epilepsy (RRMS/E) and 60 matched RRMS patients without epilepsy were included in a 3 year longitudinal study. The following clinical and MR parameters were analysed: Expanded Disability Status Scale (EDSS), cognitive score (CS), cortical lesion (CL) number and volume, grey matter fraction (GMf), global cortical thickness (CTh), T2 white matter lesion volume (T2WMLV), new CLs and new WM lesions., Results: At baseline (T0), CLs were observed in 27/32 (84.4%) RRMS/E and in 26/60 (43.3%) RRMS (p<0.001) patients, and the RRMS/E group had a higher number (10.2 ± 8.9 vs 4.5 ± 2.4; p<0.001) and total volume (2.0 ± 1.3 vs 0.7 ± 0.8 cm(3); p<0.001) of CLs compared with the RRMS group. No significant difference in T2WMLV was observed. Global CTh was lower in RRMS/E (2.12 ± 0.19 vs 2.35 ± 0.14 mm; p<0.001), and this group also showed a decline in cognition (CS 10.9 ± 6.3 vs 6.2 ± 3.5; p<0.001). After 3 years (T1), the RRMS/E group had a higher accumulation of new CLs (3.4 ± 3.2 vs 1.2 ± 1.1; p<0.001) and faster reduction of GMf (p=0.022) while the two groups did not differ in the number of new WM and new Gad+ lesions., Discussion: RRMS/E had a more severe and rapidly evolving cortical pathology (CLs and atrophy) compared with RRMS without epilepsy. The RRMS/E group was also characterised by more pronounced cognitive decline, higher EDSS and higher prevalence of men.

Background: Although neuropathological observations suggest that cerebellar cortex is a major site of demyelination in multiple sclerosis (MS), only a few MRI studies on cerebellar cortical pathology in MS are available., Objective: To analyse cerebellar cortical volume (CCV) and leucocortical lesions (CL) in MS, and their impact on clinical disability., Methods: The authors studied 125 patients divided into 38 Clinical Isolated Syndrome (CIS), 35 relapsing remitting multiple sclerosis (RRMS), 27 secondary progressive multiple sclerosis (SPMS) and 25 primary progressive multiple sclerosis, and 32 normal controls (NC). CCV and cerebellar CL number and volume were evaluated by means of Freesurfer software and Double Inversion Recovery, respectively., Results: Compared with NC (mean 113.2 + or - 2.6 cm(3)), the CCV was significantly reduced in CIS (105.4 + or - 2.2 cm(3), p=0.018), RRMS (104.0 + or - 2.0 cm(3), p=0.012), SPMS (98.8 + or - 2.0 cm(3), p<0.001) and PPMS (100.6 + or - 2.2 cm(3), p<0.001), even after age, gender and mean cortical volume correction. CL were observed in all patient groups and were an independent predictor of CCV and cerebellar dysfunction., Discussion: The authors confirm that the cerebellar cortex is severely and early affected by MS pathology. The monitoring of cerebellar cortical atrophy and CL may help to understand the mechanism underlying disability progression in MS.

Objective: We assessed the occurrence, extent, and frequency of formation of cortical lesions (CLs) in patients with relapsing-remitting (RR) and secondary progressive (SP) multiple sclerosis (MS), and their relationship with cortical atrophy and disability progression., Methods: One-hundred seven MS patients (76 RRMS and 31 SPMS), enrolled in a prospective, longitudinal magnetic resonance imaging (MRI) study, were assessed clinically and by brain MRI (including a double inversion recovery sequence) 3 years after study initiation. CL number and volume, T2 white matter (WM) lesion volume, gray matter fraction, and expanded disability status scale (EDSS) were measured., Results: At baseline, CLs were detected in 64.4% of RRMS and 74.2% of SPMS patients. During follow-up, 132 new CLs were found in 44 RRMS patients (57.9%; 0.8 new CL/patient/yr) and 61 in 15 SPMS patients (48.4%; 1.0 new CL/patient/yr). Among these patients, only 31 also showed at least 1 new WM lesion. CL number and volume increases were higher in the 52 patients with a clinical worsening compared with those without (p < 0.001). Baseline CL volume correlated with baseline EDSS (r = 0.36, p < 0.001) and EDSS changes over time (r = 0.51, p < 0.001). Baseline CL volume was an independent predictor of EDSS accumulation and GM volume change at follow-up in both patient groups. In SPMS patients, baseline T2 WM lesion volume was another independent predictor of EDSS worsening., Interpretation: In relapse-onset MS, CLs accumulate over time and are associated with disability progression. The quantification of CLs might represent an additional useful paraclinical tool to monitor MS evolution.

Background: Although cognitive dysfunction affects a relevant portion of patients with multiple sclerosis (MS), its pathologic substrate has not been clarified and it does not seem entirely explained by white matter changes., Methods: A total of 100 consecutive patients with relapsing remitting MS (RRMS) and 42 normal controls (NC) were enrolled in the study. Cognitive performance was assessed by Rao's Brief Repeatable Battery of Neuropsychological Tests (BRB). Regional cortical thickness (CTh) was evaluated by Freesurfer., Results: Thirty-one patients with RRMS failed 1 or 2 tests of BRB and were considered to have a mild cognitive impairment (mCI-RRMS), while 8 patients failed at least 3 tests and were classified as markedly impaired (sCI-RRMS). The mean CTh of mCI-RRMS and sCI-RRMS group was significantly lower than in NC (p < 0.001) and cognitively normal patients with RRMS (CN-RRMS) (p < 0.001). The regional analysis revealed significant cortical thinning in frontal and temporal regions (frontotemporal thinning) of CN-RRMS compared to NC, while a widespread pattern of cortical thinning was observed in mCI-RRMS and in sCI-RRMS compared to both CN-RRMS and NC. A correlation was observed between cognitive score (CS) and the mean CTh (r = -0.69, p < 0.001) and between CS and CTh of almost all the cortical areas analyzed (r value between -0.20 and -0.65, p < 0.01). A correlation was found between T2-WM-LV and mean CTh (r = -0.31, p = 0.004) or CS (r = 0.21, p = 0.031). The multivariate analysis confirmed a widespread cortical thinning as the best predictor of cognitive impairment., Conclusions: A widespread pattern of cortical thinning characterizes patients with cognitive dysfunction, suggesting such dysfunction as expression of a more aggressive and widespread cortical pathology.

Background: Neuropsychological deficits in patients with multiple sclerosis (MS) have been shown to be associated with the major pathological substrates of the disease, ie, inflammatory demyelination and neurodegeneration. Double inversion recovery sequences allow cortical lesions (CLs) to be detected in the brain of patients with MS. Modern postprocessing techniques allow cortical atrophy to be assessed reliably., Objective: To investigate the contribution of cortical gray matter lesions and tissue loss to cognitive impairment in patients with relapsing-remitting MS., Design: Cross-sectional survey., Setting: Referral, hospital-based MS clinic. Patients Seventy patients with relapsing-remitting MS., Main Outcome Measures: Neuropsychological performance was tested using the Rao Brief Repeatable Battery of Neuropsychological Tests, version A. Patients who scored 2 SDs below the mean normative values on at least 1 test of the Rao Brief Repeatable Battery of Neuropsychological Tests, version A, were considered to be cognitively impaired. A composite cognitive score (the cognitive impairment index) was computed. T2 hyperintense white matter lesion volume, contrast-enhancing lesion number, CL number and volume, normalized brain volume, and normalized neocortical gray matter volume were also assessed., Results: Twenty-four patients with relapsing-remitting MS (34.3%) were classified as cognitively impaired. T2 hyperintense white matter lesion volume and contrast-enhancing lesion number were not different between cognitively impaired and cognitively unimpaired patients. Cognitively impaired patients had a higher CL number (P = .01) and volume (P < .001) and decreased normalized brain volume (P = .02) and normalized neocortical gray matter volume (P = .002) when compared with cognitively unimpaired patients. Multivariate analysis revealed that age (beta = 0.228; P = .02), CL volume (beta = 0.452; P < .001), and normalized neocortical gray matter volume (beta = 0.349; P < .001) were independent predictors of the cognitive impairment index (r(2) = 0.55; F = 23.903; P < .001)., Conclusion: The burden of CLs and tissue loss are among the major structural changes associated with cognitive impairment in relapsing-remitting MS.

Background: Using double inversion recovery (DIR) MRI, cortical lesions can be seen in the brain of patients with multiple sclerosis (MS). The burden of such lesions seems to be well correlated with the severity of MS-related disability., Objective: To investigate whether the extent of cortical damage in patients with benign MS (BMS) might contribute to explain their favorable clinical status., Methods: Forty-eight patients with BMS (Expanded Disability Status Scale [EDSS] score < or =3.0 and disease duration > or =15 years) and 96 patients with non-disabling, early relapsing-remitting (RR) MS (EDSS score < or =3.0 and disease duration < or =5 years) were studied. Brain MRI, including a DIR and a fluid-attenuated inversion recovery (FLAIR) sequence, was acquired at baseline and after 12 months. On DIR images, intracortical (ICL) and cortical-subcortical lesions (CSL) were identified and their number and volume calculated. Total white matter (WM) lesion volume was quantified on FLAIR images., Results: Compared with early RRMS, patients with BMS had lower number of ICL at both study time points (P < or = 0.001 for both comparisons). At one-year follow-up, a significant increase of ICL and CSL number and total volume was observed only in early patients with RRMS. The number and volume of cortical lesions was not correlated with WM lesion volume. Total ICL number at baseline, total cortical lesion volume at baseline, and total cortical lesion volume change were independent predictors of MS phenotype., Conclusion: In patients with BMS, the selective sparing of the cortex from disease-related focal pathology might be one of the factors associated to their favorable clinical status, independently of the (possible) accrual of WM lesions.

Introduction: Increasing evidence suggests relevant cortical gray matter pathology in patients with Multiple Sclerosis (MS), but how early this pathology begins; its impact on clinical disability and which cortical areas are primarily affected needs to be further elucidated., Methods: 115 consecutive patients (10 Clinically Isolated Syndrome (CIS), 32 possible MS (p-MS), 42 Relapsing Remitting MS (RR-MS), 31 Secondary Progressive MS (SP-MS)), and 40 age/gender-matched healthy volunteers (HV) underwent a neurological examination and a 1.5 T MRI. Global and regional Cortical Thickness (CTh) measurements, brain parenchyma fraction and T2 lesion load were analyzed., Results: We found a significant global cortical thinning in p-MS (2.22 +/- 0.09 mm), RR-MS (2.16 +/- 0.10 mm) and SP-MS (1.98 +/- 0.11 mm) compared to CIS (2.51 +/- 0.11 mm) and HV (2.48 +/- 0.08 mm). The correlations between mean CTh and white matter (WM) lesion load was only moderate in MS (r = -0.393, p = 0.03) and absent in p-MS (r = -0.147, p = 0.422). Analysis of regional CTh revealed that the majority of cortical areas were involved not only in MS, but also in p-MS. The type of clinical picture at onset (in particular, pyramidal signs/symptoms and optic neuritis) correlated with atrophy in the corresponding cortical areas., Discussion: Cortical thinning is a diffuse and early phenomenon in MS already detectable at clinical onset. It correlates with clinical disability and is partially independent from WM inflammatory pathology.