Essential tremor is not associated with cerebellar Purkinje cell loss

There has been controversy as to whether there is an underlying neurodegenerative process of the cerebellum in essential tremor (ET). The aim of this study was to examine whether ET is associated with Purkinje cell (PC) loss. Prospectively categorized ET and control subjects who were longitudinally examined in the Arizona Study for Aging and Neurodegenerative Disorders and came to autopsy between 1998 and 2013 underwent standardized neuropathological assessment of the brain. PC linear density of the cerebellar hemisphere was calculated in a blinded manner. There were 56 ET cases and 62 age-matched controls free of dementia and other neurodegenerative disorders included in the study. Mean PC linear density was 3.80±0.81 cells per mm for tremor cases and 3.82±0.91 cells per mm for controls (Δ 0.02; 95% confidence interval [CI]: -0.30-0.34). PC counts were not associated with tremor duration (r=0.06; 95% CI: -0.21-0.32). These data demonstrate that ET is not associated with cerebellar PC loss.