Analysis of error profiles occurring during the OSLER test: a sensitive mean of detecting fluctuations in vigilance in patients with obstructive sleep apnea syndrome.
The OSLER test represents a simple alternative to the maintenance of wakefulness test. Standard analysis of OSLER test results yields a mean sleep latency (MSL). The aim of this study was to use both MSL and errors (nonresponses to stimulations) to characterize daytime sleepiness in apneic patients. OSLER test results at 9:00 A.M., 11:00 A.M. and 1:30 P.M. were compared in 27 obstructive sleep apnea syndrome patients (50.4 +/- 10.4 years; apnea-hypopnea index: 43.05 +/- 25.08) and 20 control subjects (C). Not only did obstructive sleep apnea syndrome patients demonstrate earlier sleep onset than control subjects (MSL: 1,788 seconds +/- 511 versus 2,335 seconds +/- 139, p < 0.001), but they also spent a greater percentage of time making errors than control subjects (5.4% +/- 4.7 of total test time versus 0.4% +/- 0.4, p < 0.001) with specific error profiles (high prevalence of three to six consecutive errors). When error profile analysis was added to standard sleep latency assessment, up to 40% of patients with normal sleep latency were exhibiting abnormal fluctuation in vigilance. A single 9:00 A.M. OSLER session appeared as sensitive as three consecutive sessions in its use as a means of identifying patients with significant daytime sleepiness. On the other hand, the 1:30 P.M. OSLER test session was least specific to distinguish apneic subjects from normal subjects, suggesting that the OSLER test can identify the afternoon peak in physiologic somnolence.
Sleep Laboratory and Neuropsychological Unit, PRETA Laboratory TIMC CNRS 5525, University Hospital, 38043 Grenoble cedex 9, France.
Stephanie
S
Mazza
Jean-Louis
JL
Pepin
Chrystele
C
Deschaux
Bernadette
B
Naegele
Patrick
P
Levy
D001143:Arousal / Q000502:physiology*; D015982:Bias; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000592:standards*; D017286:Polysomnography; D011597:Psychomotor Performance; D011930:Reaction Time / Q000502:physiology; D012680:Sensitivity and Specificity; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000503:physiopathology*; D012894:Sleep Stages / Q000502:physiology*; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology*