A 60-Year-Old Man Comes to the Office for Evaluation of Gait

question 1325

Multiple Choice

A 60-year-old man comes to the office for evaluation of gait imbalance, which he has had for the past 3 days.  The patient was hospitalized 2 weeks ago for a complicated enterococcal diabetic infection of the left foot.  He was prescribed ampicillin and gentamicin, which he has continued via home intravenous antibiotic therapy.  The patient subsequently developed a constant sensation of objects moving around in his visual field when looking in any direction, which has caused him to feel unsteady.  He has no associated nausea or vomiting.  The patient has a history of poorly controlled type 2 diabetes mellitus and hypertension.  His other medications include lisinopril and basal-bolus insulin therapy.  Temperature is 36.7 C (98 F) , blood pressure is 140/96 mm Hg, pulse is 80/min, and respirations are 16/min.  BMI is 34 kg/m².  The left foot wound is healing without discharge or surrounding erythema.  Neurologic examination shows 5/5 muscle strength and 2+ reflexes in all extremities.  Hearing is decreased in the right ear on whisper test.  Rapid head movement away from a fixed target causes eye movement away from the target followed by a horizontal saccade back toward it.  Which of the following is the most likely cause of this patient's current symptoms?

• A)Benign paroxysmal positional vertigo
• B)Cerebellar infarction
• C)Diabetic autonomic dysfunction
• D)Drug toxicity
• E)Ménière disease
• F)Vertebrobasilar insufficiency