False perception of visual verticality in multiple sclerosis.

We wanted to investigate to what extent patients with multiple sclerosis (MS), not complaining of dizziness or disequilibrium, may have problems with the estimation of gravidity. Therefore, we studied the static 'subjective visual vertical' (SVV), a test that is thought to reflect mainly otolith function. Further, we correlated SVV measures with the degree of disease disability. A group of outpatients was compared with a group of age- and sex-matched healthy volunteers. The deviations of SVV in patients were significantly larger than in controls. Overall, SVV was abnormal in 48% of individual patients. There was a significant correlation between SVV and the global disability score. The same held true for correlation with the subscores of brainstem and cerebellar complaints. The SVV test proved to be a simple method that was well tolerated by the patients. It can be considered a complementary otoneurological tool for evaluating MS patients. Further, these findings suggest that misperception of the verticality parallels the disability in MS patients.