National Sleep Foundation

Chapter 7: Sleep-Related Movement Disorders

A Case Study in Sleep-Related Rhythmic Movement Disorder

Jack is a 9-year-old, alert, and active boy suffering from severe body rocking behavior before sleep onset.

Patient History and Examination: Jack was small for his age.

History of Previous Illness: None relevant.

Past Medical History: None noted.

Social History: Jack performed poorly in school.

Family History: Jack has a stressful family life, stemming from the fact that his father is an alcoholic who is occasionally violent towards his family.

Review of Sleep Pattern: Jack’s mother reported that he has rocked in his bed since infancy. Recently, during a period of high stress, Jack rocked his bed so much that it moved across the entire bedroom.

Evaluation and Diagnosis: The results of a three-night polysomnographic sleep lab evaluation showed that, on the first night, Jack began to demonstrate kneeling and rocking behavior five minutes after the lights were turned out. The behavior continued for 45 minutes, and ceased about 5 minutes into stage 3 sleep. Four hours later, Jack resumed rocking for 25 minutes following a spontaneous awakening. On the second night of the evaluation, Jack started rocking before sleep onset and continued rocking for 25 minutes. On the third night of the evaluation, rocking began before sleep onset and continued for 14 minutes; no rocking occurred during a subsequent spontaneous awakening. On the basis of patient history and the polysomnograph, a Sleep-Related Rhythmic Movement Disorder (RMD) (body rocking) was diagnosed.

Treatment and Follow-up: The diagnosis was explained to Jack’s parents and the relationship between environmental stress and RMD described. Pharmacotherapy was not considered, given Jack’s young age. A five-year follow-up call revealed that Jack’s parents had divorced, which diminished the stress in Jack’s home; the body rocking decreased at the same time. Temporary stressors, such as problems with friends, temporarily incited rocking for short durations (<5 minutes).