The child in the question is experiencing episodes of sleep terror disorder, a dyssomnia characterized by sudden partial arousal accompanied by piercing screams, motor agitation, disorientation, arid autonomic arousal. The episodes take place during the transition from deep sleep to REM sleep. Children do not report nightmares (which would be associated with REM sleep) and do not have any memory of the episodes the next day Sleep terrors occur in 3% of children and I % of adults. Although specific treatment for this disorder is seldom required, in rare cases it is necessary. Diazepam in small doses at bedtime improves the condition and sometimes completely eliminates the attacks.