Isolated oculomotor nerve palsy caused by midbrain infarct: A case report

A 70-year-old man with hypertension and diabetes mellitus was admitted to the hospital two days after the onset of acute diplopia. His neurological examination revealed a disconjugate gaze at rest and limited inward gaze in the left eye, as well as an impaired convergence test. There was no ptosis of the upper eyelid, and the rest of the eye movements were normal. The pupils on both sides were equal in size and round, with normal light reflexes. The rest of the neurological examination was normal. High-resolution magnetic resonance imaging showed restricted diffusion in the periaqueductal gray matter of the lower midbrain. Acute stroke patients with visual symptoms may be misdiagnosed and do not receive the appropriate treatment. This is particularly important because potential acute stroke treatments such as intravenous thrombolysis or thrombectomy should be timely administered. We reported an isolated oculomotor nerve palsy caused by central cerebral infarction, which is seldom reported previously.