Hypertrophic olivary degeneration: A comprehensive review focusing on etiology

Brain Res. 2019 Sep 1;1718:53-63. doi: 10.1016/j.brainres.2019.04.024. Epub 2019 Apr 23.


Hypertrophic olivary degeneration (HOD) is a rare form of trans-synaptic degeneration characterized by hypertrophy of the inferior olivary nucleus situated in the olivary body, part of the medulla oblongata, representing a major source of input to the cerebellum. HOD typically results from focal lesions interrupting connections from the inferior olive within the dentato-rubro-olivary pathway (DROP), a region also known as the Guillain-Mollaret triangle (GMT) (red nucleus, inferior olivary nucleus, and contralateral dentate nucleus). Clinically, HOD presents classically as palatal tremor and can include dentatorubral tremor and/or ocular myoclonus. Oppenheim first described the enlargement of the ION in his post-mortem study. Since then, a limited number of cases have been reported in the literatures. Thus, we intended to describe the definition, pathophysiology, clinical features, radiological features, diagnosis, and current management of HOD. We provide a comprehensive review of HOD focusing on etiology. The present review may lead to a better understanding of HOD clinical characteristic with the goal of contributing to existing knowledge of this rare disease.

Keywords: Dentato-rubro olivary pathway; Guillain-Mollaret triangle; Hypertrophic olivary degeneration.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Cerebellar Nuclei / pathology
  • Cerebellum / pathology
  • Female
  • Humans
  • Hypertrophy / etiology
  • Hypertrophy / pathology
  • Magnetic Resonance Imaging / methods
  • Male
  • Medulla Oblongata / pathology
  • Nerve Degeneration / etiology*
  • Nerve Degeneration / pathology
  • Olivary Nucleus / metabolism*
  • Olivary Nucleus / pathology*
  • Red Nucleus / pathology
  • Tremor / pathology