Evaluation of Cognitive Functions in Patients with Narcolepsy

기면병 환자의 인지기능 평가

  • Jin, You-Yang (Department of Neuropsychiatry, Chonnam National University Hospital) ;
  • Yoon, Jin-Sang (Department of Neuropsychiatry, Chonnam National University Medical School) ;
  • Chung, Eun-Kyung (Department of Medical Education, Chonnam National University Medical School)
  • 진유양 (전남대학교병원 정신건강의학과) ;
  • 윤진상 (전남대학교 의과대학 정신건강의학교실) ;
  • 정은경 (전남대학교 의과대학 의학교육학교실)
  • Received : 2012.11.19
  • Accepted : 2013.05.23
  • Published : 2013.06.30


Objective: This study aimed to evaluate attention, memory and executive function in patients with narcolepsy. Methods: This study included 23 narcoleptic patients whose diagnosis were confirmed by the International Classification of Sleep Disorders(ICSD) at Chonnam National University Hospital Sleep Disorders Clinic or an other hospital in Korea, from 2005 to 2008, as well as 23 normal controls. All participants were given an IQ test for Korean-Wechsler Adult Intelligence Scale and several neuropsychological function tests (the d2 test for attention function, the Rey Complex Figure Test for nonverbal memory, the Korean-California Verbal Learning Test [K-CVLT] for verbal memory, and the Wisconsin Card Sorting Test for executive function). Clinical features of narcoleptic patients, including the frequency of excessive daytime sleepiness, cataplexy, sleep paralysis and hypnagogic hallucination, were investigated by a structured clinical interview administered by a neuropsychiatist. Excessive daytime sleepiness was evaluated by the Epworth sleepiness scale. Results: Characteristic symptoms of narcolepsy observed in this study included excessive daytime sleepiness (n=23, 100.0%), cataplexy (n=19, 82.6%), hypnagogic hallucination (n=5, 21.7%) and sleep paralysis (n=12, 52.2%). In nocturnal polysomnographic findings, stage 2 sleep and REM latency were found to be significantly decreased in narcoleptic patients compared with the control group, and were accompanied by significant increases in stage 1 sleep. Narcoleptic patients had lower scores than the control group on total number, Total Number-Total Error, Concentration Performance and Fluctuation Rate on the d2 test, which measures attention. Also, there were significant differences between the performance of patient and control groups on the B list of the K-CVLT, which measures verbal memory. Conclusion: Narcoleptic patients showed decreased attention and verbal memory performance compared to the control group; however, in many areas, narcoleptic patients still demonstrated normal cognitive function.


Narcolepsy;Cognitive aspects;Attention;Memory;Executive function


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