Five common tremors. Classification, key to therapy.

Tremor is the most common movement disorder seen in clinical practice, encountered frequently by primary care physicians as well as neurologists. Most tremors can be classified as physiologic, enhanced physiologic, essential, cerebellar, or parkinsonian on the basis of careful clinical observation. Sometimes, electrophysiologic studies are helpful. With correct classification, effective treatment can usually be provided. Beta-blocking drugs are effective in both enhanced physiologic tremor and essential tremor, although at widely varying dosages, and a levodopa combination often relieves parkinsonian rest tremor.