Effect of Pramipexole on Cognitive Functions in Restless Legs Syndrome

Abstract

Address for correspondence Ki-Young Jung, MD, PhD Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Korea Tel: +82-2-2072-4988 Fax: +82-2-2072-7424 E-mail: jungky10@gmail.com Objectives: Neuropsychological evaluations have revealed cognitive dysfunction in restless legs syndrome (RLS) patients, especially frontal lobe functions. Although dopamine agonists improve RLS sensory symptoms and periodic leg movements during sleep, there was no study regarding the effects of dopamine agonist on cognition in patients with RLS. Methods: Sixteen drug-naive RLS patients were enrolled. They underwent sleep questionnaires, Beck Depression Inventory, and neuropsychological evaluation, consisting of Rey Complex Figure Test and recognition trial (RCFT), Korean-California Verbal Learning Test, Controlled Oral Word Association Test (COWAT) before and after treatment with pramipexole (PMP). PMP was administered over a period of 12 weeks every night 1 h before bedtime. Paired Student’s t-test and Spearman’s correlation analysis were used for analyses. Results: After treatment with PMP, the International RLS Severity Scale score was significantly decreased. Sleep quality and depression also significantly improved after the treatment. RCFT immediate recall, COWAT phoneme word frequency, and digit symbol coding scores significantly improved compared to those before the treatment (17.72±7.84 vs. 20.13±7.33, p=0.05; 36.50±12.62 vs. 41.50±12.58, p=0.03; 68.19±21.11 vs. 73.81±21.11, p=0.02, respectively). There were no significant correlations between changes in clinical variables and in cognitive functions before and after the treatment. Conclusions: This study suggests that treatment with PMP in RLS patients improves not only RLS sensory symptoms, but also cognitive functions. J Korean Sleep Res Soc 2014;11(1):16-20