Complete microvascular 6th nerve palsy with slow abducting saccade
Daniel R. Gold, DO, Departments of Neurology, Ophthalmology, Neurosurgery, Otolaryngology - Head & Neck Surgery, Emergency Medicine, and Medicine, The Johns Hopkins School of Medicine
This is a 90-year-man with HTN, HLD, DM who woke up with horizontal diplopia. Two years prior, he was diagnosed with a microvascular right 6th nerve palsy that resolved over several months. There was little concern for giant cell arteritis, myasthenia gravis, or a mass lesion in the absence of typical symptoms or accompanying signs, and a new microvascular left 6th nerve palsy was diagnosed. With saccades to the left, not only was abduction severely limited OS, but there was significant slowing of the leftward abducting saccades even when looking from the right to center, which is typical of a paretic process. In contrast, if an abducting saccade were made from the right to center with normal/near normal speed and it stopped abruptly (due to an abduction deficit OS), this should raise suspicion for a restrictive process.
Spencer S. Eccles Health Sciences Library, University of Utah