Ocular Myoclonus due to Hemorrhage in Right Pontine Tegment: A Case Report

• Published in: Equilibrium Research Vol. 60; no. 4; pp. 227 - 233
• Main Authors: Ochiai, Atsushi, Tokumasu, Koji, Fujino, Akito, Naganuma, Hideaki, Hashimoto, Shinichiro, Okamoto, Makito
• Format: Journal Article
• Language: English
• Published: Japan Society for Equilibrium Research 2001
• Subjects: ENG; ocular myoclonus; pseudohypertrophy of the right inferior olivary nucleus
• ISSN: 0385-5716; 1882-577X
• DOI: 10.3757/jser.60.227

We report here a fifty-one-year old male with ocular myoclonus due to hemorrhage in the right pontine tegment. The patient complained of a continual dizzy feeling after treatment for the acute stage of cerebral hemorrhage had been completed at an other hospital. Neurootological examination revealed saccadic smooth pursuit eye movement and slightly suppressed optokinetic nystagmus but no pathological spontaneous eye movement. However, one year after the onset, oscillopsia developed and an abnormal eye movement appeared. ENG study revealed pendular-like oscillatory eye movements in both vertical and horizontal directions. The vertical component was dominant and phase difference in both directions was observed. On follow-up studies over a 4-year period, the abnormal eye movement decreased and the high intensity noted at the right dorsal region of the pons in CT at the initial stage disappeared later. Pseudohypertrophy of the right inferior olivary nucleus was suspected based on CT findings at the later stage. The abnormal eye movement was diagnosed as ocular myoclonus due to a lesion in the Guillain-Mollaret's triangle.