Alcohol-sensitive hereditary essential myoclonus with dystonia: a study of 6 Brazilian patients.

We present the clinical profile of a group of patients with myoclonus and dystonia sensitive to alcohol and address these cases in the context of essential myoclonus. Six patients from 4 families were selected: 4 men and 2 women with myoclonus affecting predominantly the arms. Active movements of these segments elicited the dystonic and myoclonic movements. A marked improvement with alcohol intake was seen. Laboratory findings including EEG, SSEP, and cranial CT and MRI were normal. Surface EMG recording showed bursts with duration of 30-112 ms in 3 patients. One patient showed a triphasic recording pattern (agonist-antagonist-agonist) of ballistic type. Our findings suggest that the myoclonus-dystonia disorder is present in Brazilian patients.