Cognitive dysfunction in multiple sclerosis: natural history and impact on productive living

Cognitive impairment has a strong relation to nonsomatic symptoms of depression in relapsing-remitting multiple sclerosis

It is unclear how cognitive impairment in multiple sclerosis (MS) is influenced by physical disability, fatigue, and depression. Our aim was to identify the strongest clinical predictors for cognitive impairment in relapsing-remitting MS (RRMS) patients. The clinical risk factors included in the analysis were physical disability (EDSS), fatigue (FSS), the somatic and nonsomatic components of depression (BDI), disease progression rate [Multiple Sclerosis Severity Score (MSSS)], and psychotropic medication. Cognitive impairment had a prevalence of 30.5% in patients affecting preferentially attention, executive functions, processing speed and visual perception/organization. MSSS was not associated with cognitive impairment, depression, or fatigue. In regression models, cognitive performance was best predicted by the nonsomatic symptoms of depression alone or in combination with physical disability. Exclusion of patients with any psychotropic medication did not influence the results. Our results underscore the importance of evaluating depressive symptoms when suspecting cognitive impairment in patients with RRMS.

Cognitive deficits in multiple sclerosis: a systematic review

OBJECTIVE: To present the results of prospective and retrospective studies on multiple sclerosis patients cognitive dysfunctions, as well as to discuss the batteries of neuropsy- chological tests used in these investigations. METHOD: A systematic review was performed involving 40 studies published from 1997 to 2009, in PubMed, Scopus, Ovid, ISI Web of Knowledge, Scientific Electronic Library on line (Scielo) and Latin-American and Caribbean Center of Health Sciences Informations database. Clear description of multiple sclerosis patients cognitive deficits evaluation, study design, sample size; inclusion-exclusion and discontinuation criteria; instruments for neuropsychological evaluation, diagnostic methods, evaluated functions and detailed statistical analysis had been the inclusion criteria. RESULTS: There is consensus on cognitive impairment of multiple sclerosis patients, especially on memory, speed processing, executive function, attention and concentration domains. One has identified use of 23 batteries and 74 neuropsychological tests, despite the recommendation of Consortium of Multiple Sclerosis Centers to the application of MACFIMS battery. CONSIDERATIONS: The absence of the uniformization for multiple sclerosis patients cognitive evaluation battery has precluded to achieve evidences to recommend its incorporation on diagnostic routine. Nevertheless this tendency is already outlined.

Three screening batteries to detect cognitive impairment in multiple sclerosis

To compare the sensitivities for detecting cognitive impairment in patients with multiple sclerosis (MS) and administration times of three brief batteries of neuropsychological tests, 64 patients with MS completed the Neuropsychological Screening Battery for Multiple Sclerosis (NPSBMS), the Screening Examination for Cognitive Impairment (SEFCI), and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Failure on a particular test was defined as a score below the 5th percentile for healthy controls, and the number of patients who failed at least one or two tests (out of four) was determined for each battery. Both the SEFCI and the NPSBMS identified significantly more patients with impairment than the RBANS, which was no more sensitive than the Mini-Mental State Exam (MMSE). Results were similar at both the one- and two-failed-tests criteria, but there were no significant differences between the SEFCI and the NPSBMS at either failure criterion. Mean administration time was 22.6 min for the SEFCI compared to 31.7 min for the NPSBMS (p < 0.001). Eleven (17%) of the patients refused to attempt the Paced Auditory Serial Addition Test (PASAT), one component of the NPSBMS. For screening patents on a single occasion, the SEFCI is preferred because its administration time is shorter than the NPSBMS.