Clinical features of essential tremor seen in neurology practice: a study of 357 patients.

To assess the clinical features of essential tremor (ET), we studied 357 patients with diagnostic criteria for this disease who were referred to the Neurology departments of three urban hospitals. This is not a true epidemiological study, and can be biased in favour of patients with functional disability. There was a predominance of affectation of females and a peak of age at onset in the sixth and seventh decades. Family history of tremor was positive in 46.8% of patients. Females showed a a significantly higher frequency of inheritance through maternal than through paternal line, and had a higher frequency of head and voice tremor, than males. When compared with patients without family history, those with family history of tremor had lower age at onset of tremor, and lower frequency of jaw and trunk tremor in non-familial cases.