33 - Sleep disorders

Sleep disorders

© SPMM Course Sleep disorders ICD-10 chapter V (mental health) recognises only non-organic sleep disorders in which emotional causes are considered to be a primary factor. These are conditions that include dyssomnias (abnormalities in amount, quality, or timing of sleep) and parasomnias (abnormal episodic events occurring during sleep). Various chapters where sleep disorders are described in ICD-10 Hypersomnia, sleep-walking, sleep-terrors, nightmares, nonorganic sleep-wake disorder ICD-10 Chapter V, F51 Kleine-Levin syndrome, Narcolepsy, Disorders of the sleep - wake schedule, Sleep apnoea Chapter VI of ICD-10 Episodic movement disorders which include nocturnal myoclonus Chapter II Enuresis Chapter V, F98 (Childhood disorders) Primary nocturnal enuresis (considered to be due to delay in bladder development) Chapter XVIII

Sleep walking and sleep terrors are mostly childhood disorders and if adult onset or adult persistence is seen then significant psychological disturbance must be suspected; these are sometimes seen in early stages of dementia especially REM disorders in Lewy body dementia. In sleep terrors, several minutes of disorientation is noted on waking, and some perseverative behaviour may also be noted; recall if at all possible may be limited to fragmentary mental images. In contrast nightmares are well recalled; they may be associated with benzodiazepine, tricyclic or thioridazine use. Kleine-Levin syndrome is characterised by periodic episodes of hypersomnolence and hyperphagia. Associated features include a lack of concentration, mood changes, sometimes hypersexuality and anxiety. Laboratory tests may show some nonspecific changes in the electroencephalogram. However, clinical presentation and laboratory tests are normal during asymptomatic intervals. It most often presents in adolescent males, with complete recovery by the 3rd to 4th decade of life. Possible precipitating factors include excessive workload, febrile illness, and respiratory infections. Narcolepsy is characterised by excessive daytime drowsiness accompanied by a sudden onset of REM sleep (sleep seizure or narco lepsy) and sudden loss of muscle tone, provoked by strong emotions (cataplexy). Sleep paralysis and hynagogic hallucinations may also occur (between wakefulness and sleep) but are less common. Sleep paralysis is an episode of inability to move occuring between wakefulness and sleep. These attacks usually occur during adolescence and persist through life. Hypnagogic hallucinations are usually auditory in nature but may be visual or tactile, occur in about 25% of patients. Narcolepsy is virtually always familial, and 99.5 % of patients have the HLA Antigen DR-2 (DR15/DQ6). There is usually no structural brain lesion present in these patients.