Essential tremor pathology: neurodegeneration and reorganization of neuronal connections

Nat Rev Neurol. 2020 Feb;16(2):69-83. doi: 10.1038/s41582-019-0302-1. Epub 2020 Jan 20.

Abstract

Essential tremor (ET) is the most common tremor disorder globally and is characterized by kinetic tremor of the upper limbs, although other clinical features can also occur. Postmortem studies are a particularly important avenue for advancing our understanding of the pathogenesis of ET; however, until recently, the number of such studies has been limited. Several recent postmortem studies have made important contributions to our understanding of the pathological changes that take place in ET. These studies identified abnormalities in the cerebellum, which primarily affected Purkinje cells (PCs), basket cells and climbing fibres, in individuals with ET. We suggest that some of these pathological changes (for example, focal PC axonal swellings, swellings in and regression of the PC dendritic arbor and PC death) are likely to be primary and degenerative. By contrast, other changes, such as an increase in PC recurrent axonal collateral formation and hypertrophy of GABAergic basket cell axonal processes, could be compensatory responses to restore cerebellar GABAergic tone and cerebellar cortical inhibitory efficacy. Such compensatory responses are likely to be insufficient, enabling the disease to progress. Here, we review the results of recent postmortem studies of ET and attempt to place these findings into an anatomical-physiological disease model.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Axons / pathology
  • Essential Tremor / pathology*
  • Humans
  • Nerve Fibers / pathology
  • Neural Pathways / pathology*
  • Neurodegenerative Diseases / pathology*
  • Neurons / pathology