Cognition and its relation to brain health in patients with MS

Dear Editor,

We would like to refer to the recently published paper on quality standards for brain health in people with multiple sclerosis (MS) by Hobart and colleagues. ¹ The authors comprehensively describe the core, achievable and aspirational care aspects that are most relevant for people with MS, specifically when it comes to preserving brain health. In this regard, time is of the essence and it can be hypothesized that adequate and timely care will substantially improve MS-related outcomes.

Surprisingly, monitoring of cognitive functioning in people with MS only reached the status of aspirational care. According to the author panel, composed of 21 MS neurologists, this is a consequence of not knowing how to measure and monitor cognitive status over time as well as a lack of agreement among the MS community. In their view, agreement on which test or screening battery to use for this particular purpose would encourage acceptance of cognitive screening as a standard of MS care.

Luckily, we have good news in that regard. Just around the same period as the acceptance of the Hobart paper, recommendations on how to measure and monitor cognitive decline were published in Multiple Sclerosis Journal. ² These recommendations were endorsed by the International Multiple Sclerosis Cognition Society (IMSOCGS) and the Consortium of Multiple Sclerosis Centers (CMSC). Based on a large body of literature, a selection of appropriate neuropsychological tests for cognitive screening in MS was provided (see Table 3 of the article). ²

Following these international recommendations, a minimal cognitive assessment was determined as consisting of a baseline screening with a test for information processing speed (in clinically stable patients) and annual re-assessment with the same instrument. A good example is the Symbol Digit Modalities Test (SDMT), which has been demonstrated to have limited learning effects and to be able to detect clinically meaningful change. ³ In our opinion, this recommendation could have been incorporated as core care within the brain health consensus guidelines. ¹ Next to cognitive functioning, patient-reported outcomes on mood, anxiety, fatigue, and subjective cognitive complaints should also be part of the core care.

A more elaborate neuropsychological evaluation may be incorporated as achievable care and for this, one could use the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) ⁴ or other more detailed neuropsychological test measures. ²

With regard to cognitive decline and (response to) cognitive rehabilitation, brain health, cognitive reserve and time are of utmost importance. Recently, it has been demonstrated that functional training is most effective in improving cognitive functioning in patients with a relapsing remitting disease course and patients with higher grey matter volume, for example, patients that are most likely to be relatively early in their disease course. ⁵ Components of a brain-healthy lifestyle (e.g. exercise) might have positive effects on cognitive functioning as well. Timely identification of patients that are worsening in cognitive functioning is therefore key, allowing them the opportunity to benefit most from psychological care or lifestyle advice.