Sleep in multiple sclerosis patients treated with interferon beta: an actigraphic study

Sleep disorders in multiple sclerosis (MS) patients are common and complex. Some evidences suggest that interferon beta (IFN-β), a first line disease modifying therapy can be involved in the induction of sleep architecture changes. The aim of this study was to evaluate and characterize actigraphic patterns in MS patients treated with IFN-β.

Ten relapsing remitting MS patients with low to mild disability (Expanded Disability Status Scale<2.5), aged 20-50y treated with IFN-β for more than 6 months were enrolled. Actigraphy was used to study sleep pattern. Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI). Ten sex-and age-matched healthy subjects served as controls. In patients, a comparison between drug free nights and nights following drug administration was made.

Patients had significantly higher PSQI (p = 0.006), sleep onset latency (p = 0.029), sleep efficiency percentage (p = 0.001) and number of wake episodes (p = 0,0001) values, when compared with controls. When comparing the actigraphic results acquired in the nights after treatment with those acquired in the free-drug nights, the only significant difference (p = 0.038) was detected for time in bed that was higher after IFN-β administration.

Our results, besides confirming the presence of alterations in sleep patterns in MS patients, suggest that IFN-β may contribute to promote alteration in sleep architecture. Actigraphy is a simple diagnostic tool, able to support an objective measure of sleep parameters. The relative simplicity of application and low costs may allow considering its use for an adequate screening of sleep disorders in MS patients.