Our aim is to expand on the existing knowledge of palatal myoclonus and injury to the Guillain-Mollaret Triangle, with a focus on the evolution of magnetic resonance imaging characteristics.

Case 1:

A 65 year old male presented with a clicking sensation in his throat. Palatal myoclonus was observed on exam, which was otherwise normal. Initial MRI brain was normal and this case was thought to be idiopathic; however, repeat imaging revealed medullary infarcts involving the inferior olivary nuclei. Subsequent MRI years later showed interval development of cystic changes in the same territory, consistent with HIOD. Of note, workup revealed evidence of autoimmunity including possible Sjogren’s Disease, which raises the possibility of vasculitis on the differential diagnosis.

Case 2:

A 70 year old male presented with voice change and a perceived pulsatile whistling sound. Palatal myoclonus was observed on exam. MRI brain showed non-lesional HIOD, which is not typically seen in the absence of identifiable brainstem injury.

Here we present cases of palatal myoclonus, each with atypical features. These cases highlight the growing spectrum of both imaging and clinical manifestations of palatal myoclonus/HIOD.  

(Note: a video demonstrating palatal myoclonus in one of our patients will be exhibited at the time of presentation)