Clinicopathologic observations in essential tremor: report of six cases.

Essential tremor (ET) is the most common pathologic tremor, but only eight cases have been studied pathologically. We report detailed clinical and neuropathologic studies of six additional patients. We did not find any neuropathologic lesions that might be specific for ET. Moreover, there were no abnormalities of the substantia nigra consistent with Parkinson's disease. The neuropathologic substrate of ET remains unknown.