title: Sleep-disordered breathing and periodic limb movements in narcolepsy with cataplexy: a systematic analysis of 35 consecutive patients.
abstract: BACKGROUND
  Disturbed sleep is a core feature of narcolepsy with cataplexy (NC). Few studies have independently assessed sleep-disordered breathing (SDB) and periodic limb movements (PLMs) in non-homogeneous series of patients with and without cataplexy. We systematically assessed both SDB and PLMs in well-defined NC patients.
  
  
  METHODS
  We analyzed the clinical and polysomnographic features of 35 consecutive NC patients (mean age 40 ± 16 years, 51% males, 23/23 hypocretin-deficient) to assess the prevalence of SDB (apnea-hypopnea index >5) and PLMs (periodic leg movements in sleep (PLMI) >15) together with their impact on nocturnal sleep and daytime sleepiness using the multiple sleep latency test.
  
  
  RESULTS
  11 (31%) and 14 (40%) patients had SDB and PLMs, respectively. SDB was associated with older age (49 ± 16 vs. 35 ± 13 years, p = 0.02), higher BMI (30 ± 5 vs. 27 ± 6, p = 0.05), and a trend towards higher PLMI (25 ± 20 vs. 12 ± 23, p = 0.052), whereas PLMs with older age (50 ± 16 vs. 33 ± 11 years, p = 0.002) and reduced and fragmented sleep (e.g. sleep efficiency of 82 ± 12% vs. 91 ± 6%, p = 0.015; sleep time of 353 ± 66 vs. 395 ± 28, p = 0.010). SDB and PLMs were also mutually associated (p = 0.007), but not correlated to daytime sleepiness.
  
  
  CONCLUSIONS
  SDB and PLMs are highly prevalent and associated in NC. Nevertheless, SDB and PLMs are rarely severe, suggesting an overall limited effect on clinical manifestations.
authors.affiliation: Department of Neurology, University Hospital Zürich, Zürich, Switzerland.
authors.forename: Fabio
authors.initials: F
authors.lastname: Pizza
authors.forename: Sonja
authors.initials: S
authors.lastname: Tartarotti
authors.forename: Rositsa
authors.initials: R
authors.lastname: Poryazova
authors.forename: Christian R
authors.initials: CR
authors.lastname: Baumann
authors.forename: Claudio L
authors.initials: CL
authors.lastname: Bassetti
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009290:Narcolepsy / Q000150:complications*; D020189:Nocturnal Myoclonus Syndrome / Q000150:complications* / Q000453:epidemiology; D017286:Polysomnography; D015995:Prevalence; D012891:Sleep Apnea Syndromes / Q000150:complications* / Q000453:epidemiology