Movement disorders in childhood.

Clinical Aspects Dyskinesias are abnormal involuntary movements. The common dyskinesias include tics, chorea, tremor, dystonia, myoclonus, and hyperactivity (Table 1). Several other less common dyskinesias also are important to recognize. The diagnosis of the type of movement disorder is clinical. When the movements are episodic and not seen by the pediatrician, obtaining a home videotape is recommended. Most patients who have movement disorders, with the exception of tic disorders, should be referred to a neurologist, but it is important for the pediatrician to be able to identify them and to be informed on issues relevant to management. THE MOST COMMON DYSKINESIAS Tic disorders include motor (myoclonic and dystonic), vocal (phonic), and sensory tics. Tics may be simple or complex (Table 2). Myoclonic tics are jerks; dystonic tics are postures. Children who have vocal tics such as throat clearing, coughing, or sniffing may be referred to allergists or ear, nose, and throat specialists before the correct diagnosis is made. Sensory tics are peculiar sensations. Tics are increased by stress, decreased by activities that require concentration, exhibit a fluctuating pattern, and are less noticeable during sleep. The patient can suppress the movements or vocalizations voluntarily for minutes or hours, but then is unable to control the movements or the vocalizations.