Reports of Four Cases of Hypertrophic Olivary Degeneration in King-Chulalongkorn Memorial Hospital from August 2010 to November 2011

We report four cases of hypertrophic olivary degeneration (HOD) , the first three cases after pontine hemorrhage from cavernous malformation, arteriovenous malformation (AVM) and hypertension and the latter one after surgery for removal of Non-Hodgkin lymphoma (NHL) involving dentate nucleus. The magnetic resonance (MR) features of all cases and diffuse tensor imaging (DTI) with fiber tractography findings in one case are described as well as discussion and review literature of this uncommon condition are performed.