BACKGROUND: Narcolepsy usually starts around adolescence; however, there is great variability in the clinical presentation of narcolepsy. OBJECTIVE: To determine the age at onset in conjunction with severity of narcoleptic symptoms in two large populations of narcoleptic patients with a similar genetic background. METHODS: Information on age at onset and severity of the condition was obtained in 317 patients with well-defined narcolepsy-cataplexy from Montpellier (France) and in 202 from Montreal (Canada). RESULTS: The mean age at onset was 23.4 years in Montpellier and 24.4 in Montreal. The age at onset was bimodal in two independent patient populations: a first peak occurring at 14.7 years, and a second peak occurring at 35. Age at onset clearly differentiates patients with a positive family history of narcolepsy (early onset) from those without a family history. Other clinical and polygraphic findings may indicate that young age at onset is associated with increased severity of the condition (higher frequency of cataplexy and decreased mean sleep latency on the Multiple Sleep Latency Test). CONCLUSION: Bimodal distribution of age at onset of narcolepsy was found in two independent patient populations. Our data suggest that age at onset is genetically determined.
BACKGROUND:Narcolepsy usually starts around adolescence; however, there is great variability in the clinical presentation of narcolepsy. OBJECTIVE: To determine the age at onset in conjunction with severity of narcoleptic symptoms in two large populations of narcolepticpatients with a similar genetic background. METHODS: Information on age at onset and severity of the condition was obtained in 317 patients with well-defined narcolepsy-cataplexy from Montpellier (France) and in 202 from Montreal (Canada). RESULTS: The mean age at onset was 23.4 years in Montpellier and 24.4 in Montreal. The age at onset was bimodal in two independent patient populations: a first peak occurring at 14.7 years, and a second peak occurring at 35. Age at onset clearly differentiates patients with a positive family history of narcolepsy (early onset) from those without a family history. Other clinical and polygraphic findings may indicate that young age at onset is associated with increased severity of the condition (higher frequency of cataplexy and decreased mean sleep latency on the Multiple Sleep Latency Test). CONCLUSION: Bimodal distribution of age at onset of narcolepsy was found in two independent patient populations. Our data suggest that age at onset is genetically determined.
Authors: Yves Dauvilliers; Jacques Montplaisir; Valéerie Cochen; Alex Desautels; Mali Einen; Ling Lin; Minae Kawashima; Sophie Bayard; Christelle Monaca; Michel Tiberge; Daniel Filipini; Asit Tripathy; Bich Hong Nguyen; Suresh Kotagal; Emmanuel Mignot Journal: Sleep Date: 2010-11 Impact factor: 5.849
Authors: Fang Han; Ling Lin; Jing Li; Adi Aran; Song X Dong; Pei An; Long Zhao; Ming Li; Qian Y Li; Han Yan; Jie S Wang; Hui Y Gao; Mei Li; Zhan C Gao; Kingman P Strohl; Emmanuel Mignot Journal: Sleep Date: 2011-05-01 Impact factor: 5.849