The role of the cerebellum in multiple sclerosis.

In multiple sclerosis (MS), cerebellar signs and symptoms as well as cognitive dysfunction are frequent and contribute to clinical disability with only poor response to symptomatic treatment. The current consensus paper highlights the broad range of clinical signs and symptoms of MS patients, which relate to cerebellar dysfunction. There is considerable evidence of cerebellar involvement in MS based on clinical, histopathological as well as structural and functional magnetic resonance imaging (MRI) studies. The review of the recent literature, however, also demonstrates a high variability of results. These discrepancies are, at least partially, caused by the use of different techniques and substantial heterogeneity among the patient cohorts in terms of disease duration, number of patients, and progressive vs. relapsing disease courses. Moreover, the majority of studies were cross-sectional, providing little insight into the dynamics of cerebellar involvement in MS. Some links between the histopathological changes, the structural and functional abnormalities as captured by MRI, cerebellar dysfunction, and the clinical consequences are starting to emerge and warrant further study. A consensus is formed that this line of research will benefit from advances in neuroimaging techniques that allow to trace cerebellar involvement at higher resolution. Using a prospective study design, multimodal high-resolution cerebellar imaging is highly promising, particularly in patients who present with radiologically or clinically isolated syndromes or newly diagnosed MS.