High levels of nocturnal activity in children with attention-deficit hyperactivity disorder: a video analysis.

Sleep disturbances can lead to symptoms of attention-deficit hyperactivity disorder (ADHD) in children. In the present study, we compared the sleep patterns of 30 children with ADHD, with those of 19 controls matched for age (5-10 years) and sex. Sleep patterns were recorded during one night, using polysomnography (PSG) and a video system in the sleep laboratory. Both ADHD children and controls were medication free and showed no clinical signs of sleep and alertness problems. An infrared camera was used to record all types of movement, which were scored and analyzed using specific software (Observer(R) 3.0; Noldus International, The Netherlands). No significant differences in sleep variables were found between ADHD children and controls. Polysomnography data showed no significant difference between the two groups. Attention-deficit hyperactivity disorder children moved more often than controls (upper limbs, P < 0.04; lower limbs, P < 0.03; all types, P < 0.003). The duration of movements was significantly longer in ADHD children (upper limbs, P < 0.03; all types, P < 0.02). The results of the video analysis were consistent with previous findings that ADHD children have higher levels of nocturnal activity than controls. This activity concerned mostly upper and lower limb movements. Futher studies are required to determine why noctural activity does not affect sleep continuity in a more significant way and whether it should be treated specifically.