Sleep-related rhythmic movements and sleep terrors: A possible common neurophysiological background in a preschool boy

We report the case of a 3-year-old boy with a history of frequent and injurious sleep-related rhythmicmovements and sleep terrors.We documented six episodes of body rocking and head banging via video polysomnography. No epileptic seizures were observed. In addition to the association between a sleep movement disorder and a disorder of arousal, our case shows that sleep-related rhythmic movements can arise not only during relaxed wakefulness or during a stable sleep stage, but also during a less clearly defined sleep stage during which it is difficult to further subtype non-rapid eye movement sleep. On the contrary, the portion of sleep without rhythmic movement episodes were clearly depicted with their physiological features. These findings might be of relevance for understanding the pathophysiology of both sleep-related rhythmic movements and sleep terrors and emphasize the importance to assess sleep using polysomnography, especially when episodes are frequent and injurious. The neurophysiological information obtained from this assessment might be helpful and guide an eventual treatment option.