title: [A marked decrease of orexin in the cerebrospinal fluid in a patient with myotonic dystrophy type 1 showing an excessive daytime sleepiness].
abstract: Excessive daytime somnolence is one of the common complaints in patients with myotonic dystrophy. Here we report a 60-year-old female case of myotonic dystrophy type 1 with narcolepsy due to medical condition. The size of the CTG repeat in the 3' untranslated region of the DMPK gene was 1,800-2,400 repeats. Brain MRI was normal. Polysomnography revealed sleep apnea and chronic alveolar hypoventilation. Multiple sleep latency tests revealed normal sleep latencies and sleep onset REM was not observed. Orexin/hypocretin in the cerebrospinal fluid was markedly decreased to an undetectable level. Such sleep-related disorders may worsen the quality of life and possibly cause sudden death in patients with myotonic dystrophy. Narcolepsy associated with myotonic dystrophy should be evaluated appropriately.
authors.affiliation: Department of Neurology, Tohoku University School of Medicine.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Iwata
authors.forename: Naoki
authors.initials: N
authors.lastname: Suzuki
authors.forename: Hideki
authors.initials: H
authors.lastname: Mizuno
authors.forename: Ichiro
authors.initials: I
authors.lastname: Nakashima
authors.forename: Takashi
authors.initials: T
authors.lastname: Kanbayashi
authors.forename: Yasuto
authors.initials: Y
authors.lastname: Itoyama
mesh_terms: D005260:Female; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000134:cerebrospinal fluid*; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000134:cerebrospinal fluid* / Q000150:complications*; D009290:Narcolepsy / Q000209:etiology*; D009479:Neuropeptides / Q000134:cerebrospinal fluid*; D000068797:Orexins
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins