Cognition 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: +82-2-2072-6649 Fax: +82-2-2072-2474 E-mail: jungky@snu.ac.kr Cognition is the mental abilities related to knowledge which includes attention, memory, language, judgment, and decision making. Cognitive function can be affected by several factors including attention, emotion, and sleep. In restless legs syndrome (RLS), cognitive dysfunction may ensue due to sleep disturbance, emotional disorders, and attention deficit which are common in RLS. However, it remains unclear whether cognitive performance is decreased in patients with RLS. To date, there are ten published articles which studied cognition in RLS. Five studies reported cognitive dysfunction of RLS, particularly decreased performance in the attention, frontal executive function, and mental flexibility function. Three reported no significant differences in cognitive performance between RLS patients and control subjects. Two studies reported even better performance in patients with RLS compared with control subjects. Dopamine agonist may improve cognitive performance in RLS. However, it remains unclear whether this is direct effect on RLS symptoms or indirect effect including improved sleep duration, daytime sleepiness and depression, or both. Event-related potential studies demonstrated reduced P300 amplitude either oddball task or Sternberg working memory task. Larger sample and studies using functional neuroimaging study are needed to confirm whether cognition is impaired or not in RLS. J Sleep Med 2015;12(1):1-6