Do isolated cognitive relapses exist? Yes.

In this 2014 retrospective study, 17 relapsing remitting MS subjects out of 99 presented a transient decline of at least 4 points at the symbol digit modalities test (SDMT) at the time of magnetic resonance imaging (MRI) compared to evaluations completed in the preceding and following 6 months. Multiple sclerosis relapse: Qualitative findings from clinician and patient interviews. A multiple sclerosis (MS) relapse is defined as a transient neurological deficit lasting more than 24 hours and not due to concomitant conditions such as fever.[1] Relapses are acknowledged to be protean in their presentation, and while motor and sensory presentations - and their clinical relevance - have been thoroughly described, the association between cognition and relapses is to date still only partially understood. [Extracted from the article]