Introduction: To determine the frequency of sleep disorders in multiple sclerosis (MS) patients and their relation with other manifestations of the disease.
Methods: Selected patients had clinically definite MS (relapsing-remitting and secondary progressive forms) and duration of the disease over two years. They were serially evaluated at the unit of demyelinating diseases of a third level hospital. The following scales were applied: the Pittsburgh Sleep Quality Index, the Hamilton Depression Rating Scale, EDSS, ISS and ESS. Statistical analysis by means of non parametric test and logistic regression was carried out.
Results: One hundred patients were included (72% women and 28% males). Mean age was 39 years. Eighty eight were relapsing-remitting forms and the rest secondary progressive forms. Mean EDSS was: 2.5. Mean duration of evolution: 11.2 years. The prevalence of sleep disorders was 36%. Age, sex, evolutionary form, degree of disability and chronic fatigue did not relate with the sleep disorders in these patients. In the multivariant analysis by means of logistic regression, we found that every point more in Hamilton's scale multiplies the probability of presenting sleep disorders by 1.2.
Conclusions: Depression is the only variable that independently relates, with the presence of sleep disorders in MS patients.