Mapping cognitive dysfunction in relapsing multiple sclerosis with mild disability: A cross-sectional study from South India.

BACKGROUND

Cognitive dysfunction in multiple sclerosis (MS) occurs early. Locally adapted neuropsychological data from India in MS is scarce.

OBJECTIVES

We aimed to identify the pattern of cognitive impairment in relapsing MS (RMS) with mild disability using a regionally-adapted MS-specific cognitive battery.

METHODOLOGY

The study included 59 persons with MS (pwMS) with expanded disability status scale (EDSS)≤ 4 and 62 controls. The battery had 8 neuropsychological tests (Paced Auditory Serial Addition Test [PASAT], Symbol Digit Modalities Test [SDMT], Rey Auditory Verbal Learning Test [RAVLT], Brief Visuospatial Memory Test-Revised [BVMT-R], verbal fluency [VF], Judgement of Line Orientation Test [JOLOT], Wisconsin Card Sorting Test [WCST] and Trail Making Test-B [TMT-B]) with 11 measures. The scores were compared between the groups for pattern and associations of cognitive impairment.

RESULTS

The pwMS cohort had 39 (66.1%) females; mean age of 32.56 (±8.17) years. Scores were significantly worse for pwMS in 10 of 11 tests (except JOLOT). Cohen's-d test showed the largest effect sizes for PASAT, SDMT, VF and TMT-B. Cognitive impairment (defined as ≥2 abnormal tests) were noted in 41 (69.5%) pwMS. Male sex was associated with cognitive impairment ( = 0.002).

CONCLUSIONS

In pwMS with mild disability, nearly two-thirds had cognitive abnormalities, predominantly involving processing speed, working memory, executive function, and VF.