Frontal lobe dysfunction in essential tremor: a preliminary study.

27 patients with essential tremor (ET) were studied to determine the cognitive feature of this condition. 15 familial cases and 12 cases with a family history Parkinson's disease (PD) were identified. Performances on frontal lobe tasks of ET patients were compared with those of 15 patients with PD and 15 healthy control subjects. The ET patients showed significant impairments both in attentional and conceptual thinking tasks, similar to those observed in the PD group. Despite the nosographic independence of the two conditions, data showed that the frontal lobe feature of ET was similar to those of PD, thus possibly suggesting a common dysregulation of dopamine pathways.