Value of Eye Movement Examination in Aiding Precise Localization in Stroke

A 69-year-old black man with vascular risk factors, including hypertension, hyperlipidemia, and poorly controlled diabetes mellitus, who was treated with the vascular endothelial growth factor inhibitor, bevacizumab, for macular degeneration, experienced sudden onset horizontal diplopia associated with fatigue. His deficits did not prevent him from driving. The next morning he noticed right eye ptosis obscuring his vision. Because of worsening symptoms, the patient presented to the emergency department where he was found to have bilateral ptosis, right greater than left, and left internuclear ophthalmoplegia (INO). Pupils were equal and reactive to light. General neurological examination revealed peripheral neuropathy with decreased pinprick/light touch and vibration/joint position sense distally in the lower extremities with associated difficulty with tandem walk and positive Romberg sign. Initial National Institutes of Health Stroke Scale was 2 for partial gaze palsy and sensory deficits. He did not qualify for thrombolysis because of minor deficits and symptoms lasting longer than 4.5 hours.The patient was admitted to the neurology service with suspected stroke. MRI of the brain revealed a midbrain midline diffusion restriction with apparent diffusion coefficient correlate just ventral to the aqueduct of Sylvius slightly more extended to the right consistent with subacute ischemic stroke involving the nucleus of oculomotor nerve and adjacent medial longitudinal fasciculus (MLF) likely secondary to small-vessel disease. MR angiography of the head and neck did not show significant intracranial or extracranial vascular disease. Transthoracic echocardiogram revealed normal heart function and no patent foramen ovale.The patient was started on aspirin and a statin and provided an eye patch for comfort. His diplopia improved, and he was eventually discharged with follow-up with ophthalmology, balance rehabilitation clinic, and his primary care physician for management of his risk factors.This patient presented with acute onset painless horizontal diplopia and was found on examination to have …