Effects of safinamide on REM sleep behavior disorder in Parkinson disease: A randomized, longitudinal, cross-over pilot study

Background: Rapid Eye Movement sleep behavior disorder (RBD) is characterized by dream enactment and loss of muscle atonia during REM-sleep. RBD as a premotor feature occurred souvent in patients who develop Parkinson's disease. The glutamatergic, glycinergic, and GABA-ergic systems appear to play a crucial role in the pathogenesis of RBD.

Methods: The present exploratory longitudinal cross-over study aimed to observe the effect of safinamide on RBD symptoms. Thirty patients with PD and RBD were randomized into two groups (15 subjects each), those that received for a period of 3-months safinamide (50 mg/die) in addition (Group A + ) or in absence (Group B - ) to the usual antiparkinsonian therapy. Patients exploring the clinical and video-polysomnographic changes occurred during this pharmacological therapy.

Results: Twenty-two of 30 patients reported clear improvement in symptoms during safinamide treatment, and 16 were absolutely free from clinical RBD-symptoms at the end of the treatment. Eight patients reported slight improvement in RBD-symptoms. In 6/30 patients no substantial improvement was recorded about clinical RBD-symptoms had frightening dreams or from the bed after 1-week of treatment. In addition, after safinamide, the mean UPDRS-II and III scores decreased, while PDSS-2 score indicating an improvement in both motor symptoms and nocturnal sleep features. A significant reduction of sleep behavior disorder by questionnaire-Hong Kong-score (RBDQ-HS), mainly for two individual RBDQ-HK-items (dream related movements and failing out of bed) was registered.

Conclusions: This pilot study indicated that safinamide is well tolerated and improves RBD-symptom in parkinsonian.