[Essential tremor: clinical characterization in a sample of 176 patients]

We reviewed the clinical records of 176 patients with essential tremor (ET) according to sex, age of onset, family history, tremor characteristics and body distribution. The patients were divided into two groups: familial (F) and non familial (NF). A positive family history for tremor was observed in 47.2% of the patients. Action and postural tremor were the most frequent characteristic (49.4%), postural alone in 26.7% and action alone in 9.1%. Rest tremor was recorded in 10.2%, always associated with other characteristics. There were no clinical differences between the F and NF groups. Hands were involved in 94.9% and the head in 26.5%. Isolated tremor of the hands was the most frequent form of presentation with some greater frequency in males. Sixty per cent of the patients who presented head tremor either isolated or not, were females. The presence or absence of family history did not show difference in this proportion. The age of onset ranged between 4 and 85 years. In the F group a lower mean of onset (36.5 years) was seen in males with statistical significance. In male patients with combined action and postural tremor a lower age of onset was found. The fact of a patient having either parent affected by ET produced no difference in the age of onset. Familial or non familial ET bearing some differences, may not be considered as distinct entities.