Sleep disturbance, depression, and lesion site in patients with multiple sclerosis.

We examined the prevalence of sleep problems in a sample of patients with mild but clinically definite multiple sclerosis (n = 143) and sought to determine whether there was a relationship between the presence of sleep complaints and the level of depression. As magnetic resonance imaging scans were available for a subsample of the patients with multiple sclerosis (n = 117), we also wanted to determine whether there was a relationship between the site of the lesion and the presence of sleep difficulties. The prevalence of sleep difficulties was three times higher in the patients with multiple sclerosis than the control group (25.2% vs 8.2%). Moreover, the presence of sleep complaints was associated with higher levels of depression. Three lesion sites that subserve supplemental motor areas were significantly related to the presence of sleep complaints. These findings suggest that, for some patients with MS, sleep disturbance and accompanying increases in depression may be a function of the lesion site resulting in nocturnal spasms.