CAP variables and arousals as sleep electroencephalogram markers for primary insomnia.
OBJECTIVE
Polysomnographic (PSG) measures consistently reflect poor sleep quality and effective treatment in insomniac patients.


METHODS
The PSG findings of 47 patients (18 M and 29 F, 42.5+/-10 years) meeting the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for a diagnosis of primary insomnia were compared with those of 25 age- and gender-balanced healthy subjects (controls) without sleep complaints. After one adaptation night to the sleep lab, each patient underwent two randomized double-blind PSG recordings. Twenty-four patients followed a placebo-drug sequence and 23 a drug-placebo succession. Active treatment consisted of widely used hypnotic drugs, i.e. zolpidem, triazolam, zopiclone, brotizolam. Conventional PSG measures, electroencephalogram (EEG) arousals and CAP variables (including phase A subtypes) were quantified and statistically analyzed.


RESULTS
Compared to controls, insomniac patients under placebo showed a significant increase of CAP rate, subtypes A1 and A2, EEG arousals, nocturnal wakefulness and stage 1, associated with reduced values of total sleep time and slow wave sleep (stages 3 and 4). In insomniac patients, sleep quality was significantly improved by hypnotic treatment. Compared to placebo, active medication significantly reduced CAP rate, subtypes A1 and A2, but had only marginal effects on subtypes A3 and on EEG arousals. Under hypnotic treatment total sleep time, nocturnal awakenings, stage 1 and slow wave sleep recuperated normal values. The most significant correlation between sleep quality and PSG variables was found for CAP rate (P<0.0001).


CONCLUSIONS
PSG investigation extended to CAP variables and EEG arousals can be an important procedure for the diagnosis of primary insomnia and evaluation of treatment efficacy.
Terzano
Mario Giovanni
MG
Sleep Disorders Center, Department of Neurology, University of Parma, Via del Quartiere, 4, 43100 Parma, Italy. mterzano@unipr.it
Parrino
Liborio
L
Spaggiari
Maria Cristina
MC
Palomba
Vincenzo
V
Rossi
Mariano
M
Smerieri
Arianna
A
D000328:Adult; D001143:Arousal / Q000187:drug effects / Q000502:physiology*; D015415:Biomarkers; D016022:Case-Control Studies; D004569:Electroencephalography; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010507:Periodicity; D015990:Placebo Effect; D017286:Polysomnography; D011930:Reaction Time / Q000187:drug effects; D012680:Sensitivity and Specificity; D007319:Sleep Initiation and Maintenance Disorders / Q000188:drug therapy / Q000503:physiopathology*; D012894:Sleep Stages / Q000187:drug effects; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology
D015415:Biomarkers; D006993:Hypnotics and Sedatives