Cognitive deterioration in patients with early multiple sclerosis: a 5-year study.

Area of Science:

• Neuroscience
• Clinical Neurology

Background:

• Multiple sclerosis (MS) is a chronic neurological disease affecting cognitive function.
• Longitudinal studies in early MS are crucial for understanding disease progression and developing effective interventions.
• Methodological challenges like practice effects and participant drop-out can impact the reliability of cognitive assessments.

Purpose of the Study:

• To investigate cognitive functioning changes in early multiple sclerosis (MS) over a 5-year period.
• To examine methodological issues, including practice effects and drop-out rates, in longitudinal cognitive research for MS.

Main Methods:

• Ninety participants with clinically isolated syndrome or MS (disease duration ≤ 6 years) were enrolled.
• The Brief Repeatable Battery of Neuropsychological Tests in MS was administered annually for up to 5 years.
• To mitigate practice effects, tests were administered 1-2 weeks apart at baseline and then yearly.

Main Results:

• Significant deterioration was observed in working memory and speed of information processing.
• Immediate and delayed visual spatial memory also showed significant decline.
• Verbal memory remained stable, while improvements were noted in a secondary measure of processing speed and verbal fluency.
• The drop-out rate was 30%, with no significant differences in baseline or early cognitive changes between completers and drop-outs.

Conclusions:

• Early MS is associated with cognitive deterioration in working memory and visual spatial memory over 5 years.
• Despite practice effects influencing some cognitive measures, the Symbol Digit Modality Test is a potentially valuable tool for longitudinal cognitive assessment in MS.