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    ABSTRACT: Narcolepsy is a rare, disabling sleep disorder, with a prevalence of 20 to 30 per 100,000. Its onset, from childhood to the fifties, peaks in the second decade. The main features are excessive daytime sleepiness and cataplexy or sudden loss of muscle tone triggered by emotional situations. Other less consistent symptoms include hypnagogic hallucinations, sleep paralysis, sleep maintenance insomnia, REM sleep behavior disorders, attention deficit and weight gain at disease onset. Narcolepsy with cataplexy remains a clinical diagnosis but nighttime and daytime polysomnography (multiple sleep latency tests) are useful to document a mean sleep latency below 8 min and at least two sleep-onset REM periods. HLA typing shows an association with HLA DQB1*0602 in more than 92% of cases but was not included in the new diagnostic criteria. In contrast, a low hypocretin levels (values below 110 pg/ml) in the cerebrospinal fluid (CSF) was highly specific for narcolepsy with cataplexy. The deficiency of the hypocretin system is well-established in animal models of narcolepsy (murine and canine narcolepsy) but also in human narcoleptics with a 90% reduction of CSF hypocretin levels in relation with an early loss of hypocretin neurons. The cause of human narcolepsy remains unknown, however an autoimmune process is most probable. The treatment of narcolepsy includes stimulants against sleepiness (modafinil, methylphenidate), anticataplectic drugs (antidepressants) and sodium oxybate. The current therapeutic target is oriented towards hypocretine agonists, histamine (an arousal system) H3 antagonists and immunosuppressants.
    Revue Neurologique 164(8-9):634-45. · 0.66 Impact Factor
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    ABSTRACT: A March peak and a September trough in the birth pattern of narcolepsy patients with clear-cut cataplexy was recently reported. The objectives of the present study were to determine whether the month-of-birth pattern would (a) vary with the presence and severity of cataplexy and (b) differ for patients positive and negative for HLA-DQB1*0602. Cross-sectional survey with data obtained from the clinical trials assessing the safety and efficacy of modafinil in the treatment of narcolepsy. Sleep clinics throughout the United States. A group of 530 narcolepsy patients diagnosed based on the International Classification of Sleep Disorders using clinical histories, nocturnal polysomnography, and Multiple Sleep Latency Tests. NA. A surplus of March births and a fall-off in September births was found in narcolepsy relative to the general population. This finding was only observed when cataplexy was moderate or severe. The month-of-birth pattern was similar for HLA-DQB1*0602 positive and negative patients. A March birth and HLA-DQB1*0602 positivity were independent risk factors in a logistic regression analysis. Environmental events during development may influence narcolepsy severity or the likelihood of developing the disease.
    Sleep 01/2005; 27(8):1471-5. · 4.59 Impact Factor
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    ABSTRACT: Sleep and wakefulness are complex behaviors that are influenced by many genetic and environmental factors, which are beginning to be discovered. The contribution of genetic components to sleep disorders is also increasingly recognized as important. Point mutations in the prion protein, period 2, and the prepro-hypocretin/orexin gene have been found as the cause of a few sleep disorders but the possibility that other gene defects may contribute to the pathophysiology of major sleep disorders is worth in-depth investigations. However, single gene disorders are rare and most common disorders are complex in terms of their genetic susceptibility, environmental effects, gene-gene, and gene-environment interactions. We review here the current progress in the genetics of normal and pathological sleep.
    Annals of Medicine 02/2005; 37(8):580-9. DOI:10.1080/07853890500372047 · 3.89 Impact Factor
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