THE RELATIONSHIP OF ESSENTIAL TREMOR TO OTHER MOVEMENT-DISORDERS - REPORT ON 678 PATIENTS

We examined 678 essential tremor patients in specialty, university, an d private practice clinics. The mean age of patients was 65.2 years wi th a similar number of men and women. Six percent of patients were lef t-handed. A positive family history of tremor was reported in more tha n 60% of patients. Alcohol ingestion was reported to decrease tremor i n 74% of patients who were cognizant of the effect of alcohol on tremo r. Mean age at tremor onset was 45.3 years. An earlier onset of tremor was observed in those patients having a positive family history of tr emor. Tremor affected the hands in 90% of patients, head in 50%, voice in 30%, and legs and chin in 15%. Functional disability was common an d impairment at work occurred in 18%. Propranolol and primidone were t he most frequently used drugs and were effective in 40% of patients. S ix and one-tenth percent of essential tremor patients had concomitant Parkinsons disease, 6.9% had a coexisting dystonia, and 1.8% had myocl onus. It is concluded that the frequency of Parkinson's disease in ess ential tremor is more than would be reported in the general population and that other movement disorders are infrequently observed in essent ial tremor.