Bilateral Horizontal Gaze Palsy and Oculopalatal Tremor Due to Pontine Hemorrhage

This 70-yo-woman experienced headache and diplopia and was found to have a hemorrhage centrally within the dorsal pons. Months after the onset, the patient was seen in clinic and had no horizontal eye movements (pursuit, saccades, VOR) in either eye, suggestive of bilateral nuclear 6th nerve palsies. She could overcome her adduction deficits mildly with convergence. Months after the onset, oscillopsia was also experienced and vertical pendular nystagmus was appreciated (seen in the video). Her MRI showed bilateral inferior olive hypertrophy in the medulla (i.e., T2 hyperintensity of the inferior olives), which is seen with oculopalatal tremor. Depending on which inferior olive cell populations are preferentially involved or spared, either palatal tremor or pendular nystagmus may be seen individually or in combination. In this patient's case, there was nystagmus without palatal tremor, due to involvement of the central tegmental tract involvement in the dorsal pons.