Hypertrophic olivary degeneration following head injury: a case report

Abstract

Hypertrophic olivary degeneration (HOD) is a unique type of neuronal degeneration presenting as hypertrophy, in contrast to atrophy as seen in most cases. It presents with classical characteristic clinical features due to involvement of dentate-rubral-olivary pathway, also described as triangle of Guillain and Mollaret formed in midbrain, pons and cerebellum. It can be idiopathic or secondary to infarction, bleeding, tumours, trauma or demyelination. However, the mechanism is still unclear. Herein, we present a case of HOD that had developed after post-traumatic pontine and midbrain haemorrhagic contusion. A young male patient presented with progressively increasing tremors of both hands, inability to walk and multiple cranial nerve palsy. Magnetic resonance imaging demonstrated bilateral inferior olivary nucleus enlargement and signal changes seen as T2 and T2-FLAIR hyperintensities and non-enhancing T1 iso-intensities. Based on these features, diagnosis of HOD was made. Patient was kept on conservative management and his condition improved. Hypertrophic olivary degeneration is a unique neuronal degeneration with typical clinical manifestations and distinct imaging features. Proper and early recognition and multidisciplinary treatment approach can result in the best outcomes for the patient.