![]() 24 Unemployment because of narcolepsy was reported to occur in 20–43% of patients with narcolepsy. 22-24,28 In one study, nearly half of patients reported decreased earnings and fear of job loss, and more than one-third reported lost promotions as a result of their disorder. 24 The ES and unwanted sleep episodes associated with narcolepsy can result in substantial impairments with work and life activities. 24 Patients with narcolepsy are at substantial risk for automobile accidents, with nearly one-third of patients reporting accidents compared with 5% of non-narcolepsy controls. Impaired memory 1,24 and impaired performance related to vigilance and cognition 24-27 are common complaints that affect more than half of all patients with narcolepsy. Patients with narcolepsy have considerably diminished quality of life, 22,23 and the majority of these effects are directly related to ES23. Cerebrospinal fluid hypocretin-1 levels less than one-third of mean normal values may be used rather than the MSLT/SOREMP criteria in patients with cataplexy. 1 Diagnosis of narcolepsy with cataplexy also requires a history of cataplexy. The nocturnal PSG is followed by an MSLT, in which a mean sleep latency of (eight minutes and SOREMPs on (two occasions is required for diagnosis. 1 Polysomnography (PSG) is performed to rule out other sleep disorders such as obstructive sleep apnea. Narcolepsy with or without narcolepsy is primarily diagnosed by a clinical history of excessive daytime sleepiness that occurs daily for three months. 16-20 Reports of hypocretin-1 levels in patients with noncataplectic narcolepsy have shown variable results across studies, 16-18 and the HLA DQB1*0602 allele is present in only 41% of patients without cataplexy. In patients with cataplectic narcolepsy, 78–100% exhibit abnormally low circulating levels of the hypothalamic neuropeptide hypocretin- 1,15-18 perhaps due to an autoimmune process, since a strong concordance between low hypocretin-1 levels and the DQB1*0602 subtype has also been shown. 14 ES typically appears as the first symptom, with the first occurrence of cataplexy delayed by five years. 11 These data, along with others reporting the presence of SOREMPs in non-narcolepsy patients, 12,13 have led some authors to suggest that SOREMPs may be more closely related to ES than narcolepsy, and that re-evaluation of the International Classification of Sleep Disorders diagnostic criteria may be warranted.10 The age at onset of narcolepsy follows a bimodal relationship, with a first major peak at 15 years and a second smaller peak in the mid 30s. 10 Singh and colleagues have shown that in a random sample of 333 adults who had an MSLT of (five minutes, 9.5% had two or more SOREMPs. 1 These criteria, however, have been observed in the general population of the Wisconsin Sleep Cohort Study9 in 5.9% of men and 1.1% of women. 1,5 The true prevalence of narcolepsy without cataplexy is unknown and has been reported to range from 1%6 to 36%7 of narcolepsy cases, but may be as high as 50% of all narcolepsy cases.1 Diagnostic criteria for narcolepsy with or without cataplexy are a mean sleep latency (eight minutes and (two SOREMPs on the Multiple Sleep Latency Test (MSLT),8 according to the International Classification of Sleep Disorders. The prevalence of narcolepsy with cataplexy occurs with high variability, depending on the study population, and is thought to affect approximately 0.02–0.18% of the general population in Western nations. 2-4 Sleep paralysis, memory lapses, automatic behavior (continuing an activity without consciousness or memory), disrupted night-time sleep, and hypnogognic hallucinations are also characteristic symptoms associated with both types of narcolepsy. 1 Interestingly, cataplexy associated with narcolepsy is similar to the muscle atonia observed during rapid eye movement (REM) sleep however, consciousness is maintained at the onset of cataplectic episodes, and sleepiness, hallucinations, and multiple sleep onset REM sleep periods (SOREMPs) may be present as the episode proceeds. Cataplexy is a sudden loss of postural muscle tone that is frequently localized to certain areas of the body such as the head and neck. 1 There are two major variants of narcolepsy: narcolepsy with cataplexy, and narcolepsy without cataplexy. Narcolepsy is a chronic neurological sleep disorder characterized by symptoms of excessive sleepiness (ES) during the day.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |