Different clinical features of essential tremor: a 200-patient study.

Two hundred consecutive patients affected by essential tremor (ET), referred to the Movement Disorders Center of the University of Bologna between January 1977 and December 1981, were studied to identify the different clinical features of this disorder, and its associated neurological signs. In this series, 169 patients suffered from typical essential tremor (TET); in the other 31 cases uncommon clinical features were detected: 25 presented postural, action and rest tremor (continuous tremor: CT); 5 had orthostatic tremor (OT) and 1 was affected by writing tremor (WT). Buccolinguofacial dyskinesias (BLFD) were associated with ET in 19 cases; 2 presented dystonia, and in 6 mild extrapyramidal signs were detected. Uncommon types of tremor: ET plus BLFD and ET associated with extrapyramidal signs had an higher incidence in older people. No patient developed Parkinson's disease (PD) during the follow-up period (2-5 years).