Isolated cognitive relapses in multiple sclerosis
ABSTRACT While cognition can be affected during sensorimotor multiple sclerosis (MS) relapses, the relevance of isolated cognitive relapses (ICRs ie, those occurring in absence of new sensorimotor symptoms) remain poorly characterised. Here, we decided to explore the relationship between ICR, subjective evaluation of cognitive performance and long-term cognitive decline in a group of subjects with relapsing-remitting MS.
We analysed the cognitive performance of 99 clinically stable relapsing-remitting MS for whom data from four consequent clinical and cognitive evaluations were available, that is, a baseline evaluation (t0), followed in the subsequent 6 months by a second evaluation performed not later than 2 weeks after a routine brain scan positive for at least one area of gadolinium enhancement (t1) and two gadolinium enhancement-negative follow-up evaluations after 6 months (t2) and 1 year (t3) from t1. Based on published literature, we defined as a meaningful change in cognition a transient reduction of Symbol Digit Modalities Test score of at least four points at t1 compared with t0 and t2.
ICRs were found in 17 patients and were not associated with subjective cognitive deficits or depression. Subjects who presented with an ICR at t1 presented with a significantly reduced cognitive performance at the follow-up evaluations compared with patients without ICR.
We showed that ICRs were not associated with changes in mood, fatigue levels or cognitive performance self-evaluations. Our study introduces an operational definition of ICRs and suggests to their role as a factor for cognitive decline in MS.
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ABSTRACT: Cognitive deficits occur in 40%-70% of people with multiple sclerosis (MS); they occur early in the clinical course of the disease, and may substantially reduce day-to-day functioning, affecting employment, instrumental activities of daily living, and adherence to medications.(1) There are currently no treatments proven to slow cognitive decline in MS, and as such it is unsurprising that cognition is not usually assessed as part of a routine clinical review. However, given the substantial difficulties that cognitive dysfunction causes people with MS, it represents a highly clinically relevant target of further research and major unmet need. Increasingly, neuropsychological testing is considered in the development of new neurologic disability metrics for clinical trials(2) and as measures of MS disease activity.(3</SUP)Neurology 01/2015; 84(8). DOI:10.1212/WNL.0000000000001293 · 8.30 Impact Factor
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ABSTRACT: The pathological mechanisms underlying cognitive dysfunction in multiple sclerosis (MS) are not yet fully understood and, in addition to demyelinating lesions and gray-matter atrophy, subclinical disease activity may play a role. To evaluate the contribution of asymptomatic gadolinium-enhancing lesions to cognitive dysfunction along with gray-matter damage and callosal atrophy in relapsing-remitting MS (RRMS) patients. Forty-two treated RRMS and 30 controls were evaluated. MRI (3T) variables of interest were brain white-matter and cortical lesion load, cortical and deep gray-matter volumes, corpus callosum volume and presence of gadolinium-enhancing lesions. Outcome variables included EDSS, MS Functional Composite (MSFC) subtests and the Brief Repeatable Battery of Neuropsychological tests. Cognitive dysfunction was classified as deficits in two or more cognitive subtests. Multivariate regression analyses assessed the contribution of MRI metrics to outcomes. Patients with cognitive impairment (45.2%) had more cortical lesions and lower gray-matter and callosal volumes. Patients with subclinical MRI activity (15%) had worse cognitive performance. Clinical disability on MSFC was mainly associated with putaminal atrophy. The main independent predictors for cognitive deficits were high burden of cortical lesions and number of gadolinium-enhancing lesions. Cognitive dysfunction was especially related to high burden of cortical lesions and subclinical disease activity. Cognitive studies in MS should look over subclinical disease activity as a potential contributor to cognitive impairment. Copyright © 2015 Elsevier B.V. All rights reserved.01/2015; 4(2). DOI:10.1016/j.msard.2015.01.006