Sternberg working memory performance following treatment with pramipexole in patients with moderate-to-severe restless legs syndrome.
OBJECTIVE
We recently reported that the P300 amplitude related to the Sternberg working memory (WM) task was significantly lower in drug-naïve severe restless legs syndrome (RLS) patients than controls. Here, we evaluated the effects of pramipexole on the Sternberg WM task performance by event-related potential (ERP) study.


METHODS
Thirteen drug-naïve RLS patients (52.0 ± 9.48 years) were enrolled in the study. Pramipexole was administered over a period of 12 weeks every night 1 h before bedtime. Two ERP studies were carried out: the first was performed just before giving the first dose of pramipexole and the second was conducted at 12-16 weeks after commencement of pramipexole administration. P300 amplitudes and reaction times were compared before and after treatment considering brain regions and memory load as within-subject factors. Clinical and sleep-related variables were correlated with P300 amplitude.


RESULTS
After treatment with pramipexole, the International RLS Severity Scale (IRLS) score was significantly decreased. Sleep quality and depression were also significantly improved. Omission error was significantly reduced without significant change of commission error. Reaction time was significantly shortened, regardless of memory load size, following treatment with pramipexole. Parietal P300 amplitude was significantly increased after treatment with pramipexole for all memory load sizes. Increase of frontal P300 amplitude was significantly correlated with improvement of sleep duration, IRLS, Insomnia Severity Index, and Pittsburgh Sleep Quality Index score.


CONCLUSIONS
Our study suggested that pramipexole improves WM performance in patients with RLS in addition to improving RLS symptoms, sleep disturbance, and depression.
Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea. Electronic address: jungky10@gmail.com.
Ki-Young
KY
Jung
Department of Neurology, Korea University Medical Center Anam Hospital, Korea University College of Medicine, Seoul, South Korea.
Sung Min
SM
Kim
Department of Neurology, Korea University Medical Center Anam Hospital, Korea University College of Medicine, Seoul, South Korea.
Jin-Young
JY
Song
Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea.
Byeong Uk
BU
Lee
Department of Biomedical Engineering, Hanyang University, Seoul, South Korea.
Chany
C
Lee
Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea.
Sang Kun
SK
Lee
Department of Neurology, Korea University Medical Center Anam Hospital, Korea University College of Medicine, Seoul, South Korea.
Yong Seo
YS
Koo
Department of Neurology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea.
Yong Won
YW
Cho
Department of Biomedical Engineering, College of Health Science, Yonsei University, Wonju, Gangwon-do, South Korea.
Jeong Woo
JW
Choi
Department of Biomedical Engineering, College of Health Science, Yonsei University, Wonju, Gangwon-do, South Korea. Electronic address: khkim0604@yonsei.ac.kr.
Kyung Hwan
KH
Kim
D000328:Adult; D052160:Benzothiazoles / Q000009:adverse effects* / Q000627:therapeutic use*; D003863:Depression / Q000188:drug therapy / Q000523:psychology; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D018913:Event-Related Potentials, P300 / Q000187:drug effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects*; D008875:Middle Aged; D009483:Neuropsychological Tests; D000077487:Pramipexole; D011930:Reaction Time / Q000187:drug effects; D012148:Restless Legs Syndrome / Q000188:drug therapy* / Q000523:psychology
D052160:Benzothiazoles; D000077487:Pramipexole
Dopamine agonist; Event-related potential; P300; Pramipexole; Restless legs syndrome; Working memory