Objectives: Study objectives included the characterization of the sleep pattern in a large sample of children with chronic tic disorder (TD), as well if whether or not sleep changes and movement-related arousals are associated with tic severity.
Methods: The sleep pattern of 25 children with a chronic tic disorder and who were unmedicated at the time of and during the study was investigated by means of polysomnography and compared to that of 22 healthy children matched for age, gender and intelligence.
Results: Children with a chronic tic disorder displayed a reduced quality of sleep, as well as an increased number of movement-related arousals during sleep compared to healthy controls. Children with TD exhibited more frequent movement-related arousals the more severe the tics were during the day. The number of short arousals associated with motor phenomena correlated with lower sleep efficiency, and longer sleep onset and slow-wave sleep (SWS) latency. Moreover, lower sleep efficiency and longer SWS latency in children with TD may determine the severity of the tics during the day.
Conclusions: In children with TD, motor activity during sleep seems to be related to the severity of the tics during the day. Impaired sleep in cases of TD might worsen the tic symptoms during the day.