LAUSR

Background: Hypertrophic Olivary Degeneration is a rare type of trans-synaptic degeneration. It occurs secondary to lesions which disrupt any tract within the dentatoruboolivary pathway which is made up of a triangle including the dentate nucleus, red nucleus and inferior olivary body. Methods: We reviewed the clinical and radiological findings of a 62 year-old man who presented with ataxia, slurred speech and dizziness. A literature review was carried out of previous reports of Hypertrophic Olivary Degeneration, in particular previous cerebral haemorrhages, and their presentations. Results: Initially the patient presented with an episode of collapse associated with loss of consciousness. Relevant past medical history included ischaemic heart disease, previous percutaneous coronary intervention, hypertension and hypercholesterolaemia. Of note he was on aspirin. Clinical examination revealed ataxia and slurred speech. CT and MRI Brain imaging revealed a right cerebellar haemorrhage. Aspirin was restarted following repeat MRI brain at a one month confirming resolution of the haemorrhage. This MRI brain noted a lesion of high signal on T2/FLAIR, and was associated with enlargement of the left side of the medulla oblongata. Given its location and the time interval between this study and the previous MRI it was thought most likely to represent Hypertrophic Olivary Degeneration. Eight months after the original presentation the patient represented with increased ataxia, slurred speech and dizziness. Neurological examination was positive for palatal myoclonus. MRI confirmed progression of the Hypertrophic Olivary Degeneration with no acute stroke disease. Conclusion: This case highlights palatal myoclonus which is one of the rare clinical manifestations of Hypertrophic Olivary Degeneration. The case also maps MRI brain changes to the associated clinical manifestations over the proposed timeline reported in the literature. Hypertrophic olivary degeneration, although rare, remains an important condition for clinicians to be aware of due to its classical presentation and findings on imaging.