Massimiliano Calabrese

Cortical lesions and atrophy associated with cognitive impairment in relapsing-remitting multiple sclerosis.

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.

Assessing brain atrophy rates in a large population of untreated multiple sclerosis subtypes

Objective: To assess the time course of brain atrophy and the difference across clinical subtypes in multiple sclerosis (MS). Methods: The percent brain volume change (PBVC) was computed on existing longitudinal (2 time points) T1-weighted MRI from untreated (trial and nontrial) patients with MS. Patients (n = 963) were classified as clinically isolated syndromes suggestive of MS (CIS, 16%), relapsing-remitting (RR, 60%), secondary progressive (SP, 15%), and primary progressive (9%) MS. The median length of follow-up was 14 months (range 12–68). Results: There was marked heterogeneity of the annualized PBVC (PBVC/y) across MS subtypes (p = 0.003), with higher PBVC/y in SP than in CIS (p = 0.003). However, this heterogeneity disappeared when data were corrected for the baseline normalized brain volume. When the MS population was divided into trial and nontrial subjects, the heterogeneity of PBVC/y across MS subtypes was present only in the second group, due to the higher PBVC/y values found in trial data in CIS (p = 0.01) and RR (p < 0.001). The estimation of the sample sizes required for demonstrating a reduction of brain atrophy in patients in a placebo-controlled trial showed that this was larger in patients with early MS than in those with the progressive forms of the disease. Conclusions: This first large study in untreated patients with multiple sclerosis (MS) with different disease subtypes shows that brain atrophy proceeds relentlessly throughout the course of MS, with a rate that seems largely independent of the MS subtype, when adjusting for baseline brain volume.

Consensus recommendations for MS cortical lesion scoring using double inversion recovery MRI

Background: Different double inversion recovery (DIR) sequences are currently used in multiple sclerosis (MS) research centers to visualize cortical lesions, making it difficult to compare published data. This study aimed to formulate consensus recommendations for scoring cortical lesions in patients with MS, using DIR images acquired in 6 European centers according to local protocols. Methods: Consensus recommendations were formulated and tested in a multinational meeting. Results: Cortical lesions were defined as focal abnormalities on DIR, hyperintense compared to adjacent normal-appearing gray matter, and were not scored unless ≥3 pixels in size, based on at least 1.0 mm2 in-plane resolution. Besides these 2 obligatory criteria, additional, supportive recommendations concerned a priori artifact definition on DIR, use of additional MRI contrasts to verify suspected lesions, and a constant level of displayed image contrast. Robustness of the recommendations was tested in a small dataset of available, heterogeneous DIR images, provided by the different participating centers. An overall moderate agreement was reached when using the proposed recommendations: more than half of the readers agreed on slightly more than half (54%) of the cortical lesions scored, whereas complete agreement was reached in 19.4% of the lesions (usually larger, mixed white matter/gray matter lesions). Conclusions: Although not designed as a formal interobserver study, the current study suggests that comparing available literature data on cortical lesions may be problematic, and increased consistency in acquisition protocols may improve scoring agreement. Sensitivity and specificity of the proposed recommendations should now be studied in a more formal, prospective, multicenter setting using similar DIR protocols.

Cortical atrophy is relevant in multiple sclerosis at clinical onset

IntroductionIncreasing 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.Methods115 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.ResultsWe 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.DiscussionCortical 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.

Measurement and clinical effect of grey matter pathology in multiple sclerosis

During the past 10 years, the intense involvement of the grey matter of the CNS in the pathology of multiple sclerosis has become evident. On gross inspection, demyelination in the grey matter is rather inconspicuous, and lesions in the grey matter are mostly undetectable with traditional MRI sequences. However, the results of immunohistochemical studies have shown extensive involvement of grey matter, and researchers have developed and applied new MRI acquisition methods as a result. Imaging techniques specifically developed to visualise grey matter lesions indicate early involvement, and image analysis techniques designed to measure the volume of grey matter show progressive loss. Together, these techniques have shown that grey matter pathology is associated with neurological and neuropsychological disability, and the strength of this association exceeds that related to white matter lesions or whole brain atrophy. By focusing on the latest insights into the in-vivo measurement of grey matter lesions and atrophy, we can assess their clinical effects.

No evidence of chronic cerebrospinal venous insufficiency at multiple sclerosis onset.

An impaired cerebrospinal venous drainage, defined as chronic cerebrospinal venous insufficiency (CCSVI), has been recently hypothesized to be the possible cause of multiple sclerosis (MS). We investigated this hypothesis by studying the occurrence of CCSVI in clinically isolated syndromes (CISs) suggestive of MS.

A 3-year magnetic resonance imaging study of cortical lesions in relapse-onset multiple sclerosis.

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.

The predictive value of gray matter atrophy in clinically isolated syndromes

Background: Although gray matter (GM) atrophy is recognized as a common feature of multiple sclerosis (MS), conflicting results have been obtained in patients with clinically isolated syndromes (CIS). Methodologic and clinical constraints may take account for literature discrepancies. Methods: A total of 105 patients presenting with CIS and 42 normal controls (NC) were studied. At baseline, 65/105 patients with CIS met the criterion of dissemination in space of lesions (DIS+). All patients were clinically assessed by means of the Expanded Disability Status Scale every 6 months and underwent MRI evaluation at study entry and then annually for 4 years. Global and regional cortical thickness and deep GM atrophy were assessed using Freesurfer. Results: No significant reduction in GM atrophy was observed between the entire CIS group and the NC, excepting for the cerebellum cortical volume. When the 59 patients with CIS (46 DIS+, 13 DIS−) who converted to MS during the follow-up were compared to the NC, a significant atrophy in the precentral gyrus, superior frontal gyrus, thalamus, and putamen was observed (p ranging from 0.05 to 0.001). The multivariate analysis identified the atrophy of superior frontal gyrus, thalamus, and cerebellum as independent predictors of conversion to MS. CIS with atrophy of such areas had a double risk of conversion compared to DIS+ (odds ratio 9.6 vs 5.0). Conclusion: Selective GM atrophy is relevant in patients with CIS who convert early to MS. The inclusion of GM analysis in the MS diagnostic workup is worthy of further investigation.

Intracortical lesions Relevance for new MRI diagnostic criteria for multiple sclerosis

Objective: To generate and validate new MRI diagnostic criteria for multiple sclerosis (MS) taking into account not only white matter lesions but also intracortical lesions (ICLs). Methods: Brain double inversion recovery and brain and cord T2- and postcontrast T1-weighted scans were acquired in a training (80 patients with clinically isolated syndromes [CIS], median follow-up = 55.3 months) and a validation (39 patients with CIS, median follow-up = 28.0 months) sample. In the training sample, regression analysis and Cox proportional hazard model were used to identify MRI variables independently predicting the evolution to clinically definite (CD) MS. The best criterion selected was then validated. The performance of the new and previously available MRI criteria for disease dissemination in space (DIS) and time (DIT) were tested. Results: The final multivariate model showed that ≥1 ICL (p < 0.001), ≥1 infratentorial (p = 0.03), and ≥ 1 gadolinium-enhancing or ≥1 spinal cord lesion (p = 0.004) were independent predictors of CDMS. The presence of at least 2 of these variables was the best DIS criterion in both samples. New ICLs had a poor sensitivity for DIT. The combination of the new DIS criterion with the MAGNIMS criteria for DIT yielded to an accuracy of 81%, which was higher than those of the other available criteria. Conclusions: The accuracy of MRI diagnostic criteria for MS is increased when considering the presence of ICLs on baseline scans from patients at presentation with CIS suggestive of MS. If confirmed by other studies, ICL detection might be considered in future diagnostic algorithms for MS.

Exploring the origins of grey matter damage in multiple sclerosis

Multiple sclerosis is characterized at the gross pathological level by the presence of widespread focal demyelinating lesions of the myelin-rich white matter. However, it is becoming clear that grey matter is not spared, even during the earliest phases of the disease. Furthermore, grey matter damage may have an important role both in physical and cognitive disability. Grey matter pathology involves both inflammatory and neurodegenerative mechanisms, but the relationship between the two is unclear. Histological, immunological and neuroimaging studies have provided new insight in this rapidly expanding field, and form the basis of the most recent hypotheses on the pathogenesis of grey matter damage.