Evaluation of cognition and fatigue in multiple sclerosis: daily practice and future directions.

The so-called hidden symptoms or soft signs of multiple sclerosis comprise cognitive dysfunction, fatigue, depression and anxiety. From a patient's perspective, these symptoms are rated as exerting much more negative impact on quality of life and daily functioning than their physical symptoms. Despite this knowledge, the symptoms remain disregarded by many neurologists in clinical practice. This missing awareness can be attributed to several reasons. First, the underlying pathophysiological mechanisms determining occurrence and severity of the different symptoms are still unclear. Second, there is uncertainty in how to reliably assess them. It is undeniable that assessment can be difficult as the hidden symptoms seldom appear isolated but more often highly interact. Third, if standardized, fast and cost-effective assessment to quantify and monitor the evolution of the hidden symptoms would be feasible, the question still remains how to treat these aspects. The present article will give an overview on symptom background and assessment strategies for clinical practice.