Hypertrophic Olivary Degeneration
- Hypertrophic olivary degeneration is a unique type of transsynaptic degeneration resulting in hypertrophy of degenerated inferior olivary neurons rather than atrophy.
- It results from damage to neuronal pathways in the Guillain-Mollaret triangle between the dentate nucleus of the cerebellum, red nucleus, and inferior olivary nucleus.
- Palatal myoclonus is the classic clinical manifestation due to disruption of the central tegmental tract between the red nucleus and inferior olivary nucleus.
- Most commonly occurs following focal lesions to the brainstem, such as hemorrhage, which in this case was related to a cavernous hemangioma.
- Typically appears 4-6 months after brainstem insult and resolves by 3-4 years, though the T2 hyperintensity may persist longer.
