TREMOR DISORDERS - DIAGNOSIS AND MANAGEMENT

Tremor is commonly encountered in medical practice, but can be difficu lt to diagnose and manage. It is an involuntary rhythmic oscillation o f a body part produced by reciprocally innervated antagonist muscles. Tremors vary in frequency and amplitude and are influenced by physiolo gic and psychological factors and drugs. Categorization is based on po sition, posture, and the movement necessary to elicit the tremor. A re sting tremor occurs when the body part is in repose. A postural tremor occurs with maintained posture and kinetic tremor with movement. Vari ous pathologic conditions are associated with tremors. Essential tremo r, which is the most common, is postural and kinetic, with a frequency between 4 and 8 Hz, and involves mainly the upper extremities and hea d. Essential tremor responds to treatment with primidone, p-blockers, and benzodiazepines. Parkinson's disease causes a 4- to 6-Hz resting t remor in the arms and legs that responds to the use of anticholinergic s and a combination of carbidopa and levodopa. Tremor can also be a ma nifestation of Wilson's disease, lesions of the cerebellum and midbrai n, peripheral neuropathy, trauma, alcohol, and conversion disorders. T reatment should be directed to the underlying condition. Stereotactic thalamotomy or thalamic stimulation is a last resort.