Purkinje Cell Loss in Essential Tremor: Collective Data From 215 Brains Over a 21-Year Period

Area of Science:

• Neuroscience
• Neuropathology
• Movement Disorders

Background:

• Essential tremor (ET) is a common movement disorder.
• Cerebellar pathology, particularly involving Purkinje cells, is implicated in ET.
• Previous postmortem studies have yielded inconsistent findings regarding Purkinje cell counts in ET.

Purpose of the Study:

• To quantify Purkinje cell populations in a large cohort of ET brains.
• To compare Purkinje cell counts in ET with age-matched controls and spinocerebellar ataxia (SCA) cases.
• To investigate the relationship between Purkinje cell changes, aging, and other neuropathologies in ET.

Main Methods:

• Analysis of cerebellar tissue from 215 ET brains, 72 SCA brains, and 165 control brains (452 total).
• Assessment of Purkinje cell loss using linear density and empty basket percentages.
• Age-matched sub-analysis comparing 195 ET and 79 control brains.

Main Results:

• ET cerebella exhibited 15.0% lower Purkinje cell linear density and 37.8% higher empty basket percentage than controls (p < 0.0001).
• Purkinje cell numbers declined with age in controls but not in ET.
• ET was positioned on the milder end of the cerebellar neurodegenerative spectrum compared to SCAs.

Conclusions:

• This extensive dataset confirms a diminished Purkinje cell population in essential tremor.
• Purkinje cell loss in ET is not attributable to Alzheimer's disease, Lewy body pathology, or clinical confounders.
• Further histopathological research is needed to understand Purkinje cell changes in ET within the context of aging and neurodegeneration.