ackground: Hypertrophic olivary degeneration (HOD) is usually caused by a disruption of the dentato-rubro-olivary pathway, also known as the triangle of Guillain-Mollaret. HOD is a unique form of degeneration because it results in enlargement of the affected structure rather than atrophy. We present a case of unilateral atrophic olivary degeneration secondary to brainstem cavernous angioma.

Case:  A 55-year-old man was admitted to gastrointestinal department due to a acute gastric ulcer. He also complained of constant symptoms of dysarthria and clumsiness of the right hand over the past 12 years. He had a history of hypertension and smoking. Neurologic examination showed moderate dysarthria and mild clumsiness of fine finger movements in the right hand. There was no palatal myoclonus on the 8 days follow up period. The first brain MRI was performed 4 years after the onset of symptoms, and MRI showed a 2.5 x 2cm,  multinodular mass lesion on the right side of the midbrain and pons tegmentum. T2 weighted images showed papcorn-like central area of mixed signal intensity with peripheral rim of decreased signal intensity. A Follow-up MRI obtained 8 years later showed no significant interval changes of cavernous angioma of the brainstem except a tiny T2 weighted low signal lesion in the right inferior olivary nucleus. He was treated with choline alfoscerate and proton pump inhibitors.

Conclusion: We report a case of unilateral olivary degeneration secondary to cavernous angioma of the brainstem. We suggest that HOD might be changed to atrophy of the olivay in chronic stage.

Unilateral Olivary Degeneration Secondary to Brainstem Cavernous Angioma