title: Effects of body movement restraint on cardiac response to auditory stimulation in sleeping infants.
abstract: When exposed to an unfamiliar and sudden noise, infant rodents may show an abrupt bradycardia, as part of a "fear-paralysis response". The response is enhanced by body movements restraint. To investigate if this reaction is seen in humans, 15 normal infants with a median age of 12 weeks were studied polygraphically. They were exposed to a 100-dB (A) white noise, while sleeping in REM sleep. Each infant was studied in both "unrestrained" and "restrained" conditions. Restraint of body movement was obtained by means of sand bags and tightly-binding bed sheets. During movement restraint, the infants had a significantly greater and earlier decrease in heart rate compared with during the unrestrained condition. No infant had a minimal heart rate less than 95 beats/min. The present observation raises questions about the possible unfavorable effects of tightly wrapped bed sheets around sleeping infants.
authors.affiliation: Pediatric Sleep Unit, University Children's Hospital, Free University of Brussels, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Kahn
authors.forename: E
authors.initials: E
authors.lastname: Rebuffat
authors.forename: M
authors.initials: M
authors.lastname: Sottiaux
mesh_terms: D000161:Acoustic Stimulation; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007223:Infant; D007224:Infant Care; D008297:Male; D012149:Restraint, Physical; D012895:Sleep, REM / Q000502:physiology*