Tics and tremors.

Tics are the most common movement disorder of childhood. The single tic, or habit spasm, is benign and self-limited. Complex tic disorders include other features such a multiple tics, vocal tics, and complex stereotyped movements. Tourette syndrome represents the most-severe end of a spectrum of tic disorders. The basic features are multiple tics and vocalizations with a changing repertoire over time. Severity waxes and wanes spontaneously. Treatment with haloperidol is effective but associated with a high incidence of side effects. Some cases undergo remission in late adolescence. There is a strong genetic component. Sympathomimetic drugs may precipitate the syndrome. Tremors are less common in children. Essential tremor is a benign but troublesome condition which frequently is familial. Treatment with propranolol is effective. The majority of tremors in the pediatric age group are due to underlying metabolic, endocrine, or heredodegenerative disorders. Treatment is that of the underlying biochemical abnormality.