Post-traumatic Hypertrophic Olivary Degeneration with Palatal Myoclonus-A Case Report.

This is a case report of a 7-year-old boy with a medical history of a motor vehicle accident (MVA) 2 years previously. Two years post-MVA, he developed quivering and twitching of the right side of his lip, palate, and neck. Multiple antiseizure medications were attempted with no effect. However, carbamazepine was started with marked improvement. The most recent brain magnetic resonance imaging showed findings suggestive of hypertrophic olivary degeneration (HOD). Electroencephalography captured the abnormal facial twitching with audible palatal clicking, but was not associated with electrographic changes. This case demonstrates the anatomic importance of the Guillain-Mollaret triangle, as traumatic disruption of this pathway resulted in palatal myoclonus. HOD occurring due to trauma is an incredibly rare etiology, with only 1 other case reported in the literature in a 27-year-old man, with no previous reports of posttraumatic HOD occurring in an individual under 18 discovered during our literature review.