• Sleep Medicine and Psychophysiology
• /
• v.8 no.2
• /
• pp.107-112
• /
• 2001

Introduction: Narcolepsy, a sleep disorder characterized by excessive daytime sleepiness and cataplexy, is known to be closely associated with the human leukocyte antigen (HLA) DQB1*0602. Several studies have suggested that HLA-DQB1*0602 is strongly linked with narcolepsy-cataplexy. However, no studies have yet been made on whether HLA DQB1*0602 is associated with Korean patients with narcolepsy. This study was designed to investigate the frequency of HLA-DQB1*0602 of Korean patients with narcolepsy. Methods: Twenty patients were selected (mean age: $28.2{\pm}3.0$, 11 men and 9 women). The patients were confirmed to have narcolepsy by the overnight polysomnography and multiple sleep latency test (MSLT) in addition to their clinical history and symptoms at St. Vincent's Hospital and Korea University Hospital Sleep Disorders Clinic. Any subjects co-morbid with other hypersomnic sleep disorders such as sleep apnea or periodic limb movements during sleep were excluded. Clinical data was collected through a semi-structured interview for narcoleptic patients. All patients and 21 control did HLA typing for the presence of DQB1*0602. Results Obtained were as Follows: 1) Mean sleep latency was 2.4 (${\pm}2.0$ minutes) and mean frequency of sleep-onset REM period was 3.0 (${\pm}1.6$) by MSLT. 2) Characteristic symptoms of narcolepsy investigated were as follows: excessive daytime sleepiness (100%), cataplexy (100%), sleep paralysis (60%), hypnagogic hallucination (70%) and disrupted nocturnal sleep (75%). 3) Strong emotional expression such as laughing (80%) and joking (70%) triggered cataplexy which affects the knee and leg region (80%) and jaw region (30%). 4) HLA-DR2 was found in 90% of patients and 35% in controls. The frequency of HLA-DQB1*0602 in patients and controls was 90%, and 24%, respectively. Conclusions: These results, which exhibit high HLA-DQB1*0602 expression in Korean patients with narcolepsy, suggest that HLADQB1*0602 could be a strong genetic marker in narcolepsy.

• Sleep Medicine and Psychophysiology
• /
• v.7 no.2
• /
• pp.115-119
• /
• 2000

Objectives Summary: A 20-year-old man was presented with a history of difficult waking for 10 years. He suffered from morning headache, chronic fatigue and mild daytime sleepiness but had no history of irresistible sleep attack, cataplexy, hypnagogic hallucination or sleep paralysis. Methods: Night polysomnography (PSG), multiple sleep latency test (MSLT) and HLA-typing were carried out. Results: The PSG showed short sleep latency (4.0 min) and REM latency (2.5 min), increased arousal index (15.7/hour), periodic limb movements during sleep (PLMS index=8.1/hr) with movement arousal index 2.1/hr and normal sleep efficiency (97.5%). The MSLT revealed normal sleep latency (15 min 21 sec) and 4 times sleep-onset REM (SOREM). HLA-typing showed DQ6- positive, that corresponded at the genomic level to the subregion DQB1*0601, which was different from the usual locus in narcolepsy patients (DQB1*0602 and DQA1*0102). Conclusion: Differential diagnosis should be made with circadian rhythm disorder and other causes of primary waking disorder. The possibility of a variant type of narcolepsy could be suggested with an unusual clinical manifestation and a new genetic marker.

• Sleep Medicine and Psychophysiology
• /
• v.18 no.1
• /
• pp.40-44
• /
• 2011

Narcolepsy is a sleep disorder, which is characterized by excessive daytime sleepiness (EDS) that is typically associated with cataplexy, sleep fragmentation and other REM sleep-related phenomenon such as sleep paralysis and hypnagogic hallucination. Narcoleptic symptoms can be developed from various medical or neurological disorders. A 17-year-old male patient admitted for the evaluation of EDS which started three-month ago. He slept more than 18 hours a day with cataplexy and hypnagogic hallucination. He was obese with body mass index (BMI) of 30.4 kg/$m^2$. After admission he was newly diagnosed to the thyrotoxicosis. T3 391.2 ng/dL (60-181), free T4 4.38 ng/dL (0.89-1.76), TSH <0.01 ${\mu}IU$/mL (0.35-5.5) were measured. His pulse rate ranged 70-90 beats per minute and blood pressure ranged 150/100-120/70 mmHg. Polysomnography revealed many fragmentations in sleep with many positional changes (81 times/h). Sleep onset latency was 33.5 min, sleep efficiency was 47.9%, and REM latency from sleep onset was delayed to 153.6 min. REM sleep percent was increased to 27.1%. Periodic limb movement index was 13.4/h. In the multiple sleep latency test (MSLT), average sleep latency was 0.4 min and there were noted 3 SOREMPs (Sleep Onset REM sleep period) on 5 trials. We couldn't discriminate the obvious sleep-wake pattern in the actigraph and his HLA DQB1 $^*0602$ type was negative. His thyroid function improved following treatment with methimazole and propranolol. Vital sign maintained within normal range. Cataplexy was controlled with venlafaxine 75 mg. Subjective night sleep continuity and PLMS were improved with clonazepam 0.5 mg, but the EDS were partially improved with modafinil 200-400 mg. Thyrotoxicosis might give confounding role when we were evaluating the EDS, though sleep fragmentation was one of the major symptoms of narcolepsy, but enormous amount of it made us think of the influence of thyroid hormone. The loss of sleep-wake cycle, limited improvement of EDS to the stimulant treatmen, and the cataplexy not supported by HLA DQB1 $^*0602$ should be answered further. We still should rule out idiopathic hypersomnia and measuring CSF hypocretin level would be helpful.

• Korean Journal of Clinical Laboratory Science
• /
• v.37 no.3
• /
• pp.216-219
• /
• 2005

We report a case of narcolepsy. A 25-year-old man has had excessive daytime sleepiness of about 10 years durations. He awakens daily feeling exhausted and continually falls asleep during the day while engaged in such situation like reading and watching television. He has exhibited cataplexy, a sudden loss of muscular tone, brought on by emotion, usually laughter. Polysomnogram revealed increased sleep stage 1, 2 and decreased deep sleep. Multiple sleep latency test (MSLT) showed that sleep latency was 1.33 minutes and there were 3 noted sleep onset rapid eye movement (SOREM) on 5 trials. The epworth sleepiness scale (ESS) was 17/24. Typing of HLA haplotype that was positive for the $DQB1^{\ast}0602$ allele, and hypocretin-1 (orexin A) could not be detected in cerebrospinal fluid (CSF). Brain MRI showed normal image. We diagnosed his case as narcolepsy based on history of cataplexy, and three occurances of SOREM, and positive of HLA haplotype.

• Sleep Medicine and Psychophysiology
• /
• v.12 no.2
• /
• pp.122-132
• /
• 2005

Objectives: The objective of this study is to assess cognitive functions and their relationship with sleep symptoms in young narcoleptic patients. Methods: Eighteen young narcolepsy patients and 18 normal controls (age: 17-35 years old) were recruited. All narcolepsy patients had HLA $DQB_1$ *0602 allele and cataplexy. Several important areas of cognition were assessed by a battery of neuropsychological tests consisting of 13 tests: executive functions (e.g. cognitive set shifting, inhibition, and selective attention) through Wisconsin card sorting test, Trail Making A/B, Stroop test, Ruff test, Digit Symbol, Controlled Oral Word Association and Boston Naming Test; alertness and sustained attention through paced auditory serial addition test; verbal/nonverbal short-term memory and working memory through Digit Span and Spatial Span; visuospatial memory through Rey-Osterrieth complex figure test; verbal learning and memory through California verbal learning test; and fine motor activity through grooved pegboard test. Sleep symptoms in narcolepsy patients were assessed with Epworth sleepiness scale, Ullanlinna narcolepsy scale, multiple sleep latency test, and nocturnal polysomnography. Relationship between cognitive functions and sleep symptoms in narcolepsy patients was also explored. Results: Compared with normal controls, narcolepsy patients showed poor performance in paced auditory serial addition (2.0 s and 2.4 s), digit symbol tests, and spatial span (forward)(t=3.86, p<0.01; t=-2.47, p=0.02; t=-3.95, p<0.01; t=-2.22, p=0.03, respectively). There were no significant between-group differences in other neuropsychological tests. In addition, results of neuropsychological test in narcolepsy patients were not correlated with Epworth sleepiness scale score, Ullanlinna narcolepsy scale score and sleep variables in multiple sleep latency test or nocturnal polysomnography. Conclusion: The current findings suggest that young narcolepsy patients have impaired attention. In addition, impairment of attention in narcolepsy might not be solely due to sleep symptoms such as excessive daytime sleepiness.