Physiologic and pathologic tremors. Diagnosis, mechanism, and management.

Tremor, the commonest of the involuntary movement disorders, is characterized by rhythmical oscillatory movement that occurs at rest or during activity; all tremors cease during sleep. Physiologic tremor is present in normal persons and is asymptomatic. Tremor is considered pathologic when it impairs a patient's function. Clinically, the pathologic tremors may be classified as accentuated physiologic, parkinsonian, essential, and cerebellar. We review here the basic mechanisms and clinical features of various tremors and emphasize recent advances in pathophysiology and management.