title: Association between pupillometric sleepiness measures and sleep latency derived by MSLT in clinically sleepy patients.
abstract: OBJECTIVE
  The multiple sleep latency test (MSLT) has been employed extensively in clinical and research settings as a gold standard for objectively measuring sleepiness. In a general population or in a variety of work settings, however, a more convenient, rapidly administered measuring method is preferable. We examined the potential utility of pupillometry by comparing its objective measures, pupillary unrest index (PUI) and relative pupillary unrest index (RPUI), with MSLT-derived sleep latency (SL).
  
  
  METHODS
  The study cohort comprised 45 patients (39 males, 6 females, mean age 38.9 ± 11.3 years) referred to the Sleep Disorders Center for the two-nap SL test. SL was measured twice before noon, and pupillometric measurement was performed immediately before each SL test. Subjective sleepiness was measured by using the Epworth Sleepiness Scale (ESS).
  
  
  RESULTS
  The association between PUI and SL was significant and far closer than that between RPUI and SL. A significant difference was observed between the two groups, based on each subject's experience of drowsy driving accidents over the past 3 years in the PUI and RPUI, as well as in SL. The subjective sleepiness measure, ESS, did not relate to any other physiological sleepiness measures.
  
  
  CONCLUSIONS
  In our study cohort, the pupillometric sleepiness measure, PUI, was significantly correlated with, and behaved in a manner equivalent to, MSLT-derived SL in clinically sleepy patients. However, several points remain to be carefully examined before applying pupillometry for screening sleepiness in a general population, or in occupational settings.
authors: Department of Health and Psychosocial Medicine, School of Medicine, Aichi Medical University, 1-1 Yazako Karimata, Nagakute, Aichi, 480-1195, Japan.
authors: Keiko
authors: K
authors: Yamamoto
authors: Fumio
authors: F
authors: Kobayashi
authors: Reiko
authors: R
authors: Hori
authors: Aki
authors: A
authors: Arita
authors: Ryujiro
authors: R
authors: Sasanabe
authors: Toshiaki
authors: T
authors: Shiomi
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D009887:Ophthalmoscopy / Q000379:methods*; D010775:Photic Stimulation; D017286:Polysomnography / Q000379:methods; D012025:Reflex, Pupillary; D012890:Sleep; D020919:Sleep Disorders, Intrinsic / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*