A 64-year-old man with coronary artery disease and an 80 pack-year smoking habit presented with 2 weeks of gait instability leading to frequent falls and 8 weeks of vertigo and double vision. He reported unintentional weight loss without fevers or decreased appetite. He denied any history of alcohol abuse. Medications included metoprolol and aspirin. On examination, he was alert and oriented and vital signs were normal; body mass index was 24. Neurologic examination revealed right eye heterotropia and nasal upshoot indicative of a fourth cranial nerve palsy (Figure 1A), left ptosis, flattening of the right nasolabial fold (Figure 1B), and bilateral restricted upgaze and ataxia (Video). Strength and reflexes were preserved. Results of a basic metabolic panel and complete blood cell count were normal. Screening for human immunodeficiency virus, Lyme disease, and drug use was negative. Contrast-enhanced magnetic resonance imaging (MRI) of the brain was unremarkable. Cerebrospinal fluid (CSF) sampling revealed elevated protein (75 mg/dL [reference range, 10-42]), lymphocyte predominant pleocytosis (21-66 cells/uL [reference range, 0-11]), and oligoclonal bands (OCBs). Pleural thickening was seen on routine chest radiography; chest computed tomography (CT) revealed mediastinal lymphadenopathy, subcentimeter pulmonary nodules, and calcified pleural plaques.
Yang Y, Haigentz M, Welch M. Diplopia and Ataxia in a Heavy Smoker. JAMA. 2015;314(9):942-943. doi:10.1001/jama.2015.8617