In addition to night waking and sleep onset problems, children may also experience a range of undesirable behaviours occurring during their sleep or sleep - wake transitions, including sleepwalking, sleep talking, bedwetting, bruxism (i.e., grinding or clenching the teeth during sleep), sleep terrors, and
rhythmic movement disorders (rocking the entire body from one side to another, rolling the head against the pillow).
Essential tremor is the most common neurological
movement disorder, and it causes uncontrollable
rhythmic motion, often of the upper extremities, which can make it difficult for people with the disease to perform everyday tasks.