Cerebellar Purkinje cell loss is not pathognomonic of essential tremor.

BACKGROUND: Most of the literature on pathology of essential tremor (ET) has reported no consistent abnormalities. Some recent studies however indicate that cerebellar Purkinje cell (PC) loss is the pathological basis of ET in most patients. OBJECTIVE: To compare cerebellar PC loss in ET, with normal and tremor dominant Parkinson's disease [PD] control brains. METHODS: Cerebellar PC counts were performed in seven ET, six PD and two normal control brains. Three different counting methods - sectioned through nucleolus, through nucleus and through any part of PC body, were used to count the PC. RESULTS: There were individual differences in the PC counts both in the ET and the PD cases. In all three subgroups, there was a reduction in the number of PC with advancing age. When the individuals of comparable age in the three subgroups were considered, there was no clear distinction between ET, PD and normal control subjects. There was no association between the degree of PC loss and the severity or the duration of ET. CONCLUSION: Our study militates against the hypothesis that PC loss is pathognomonic of ET.