Review Question - QID 210557

A 53-year-old woman presents to her primary care physician due to her “feet feeling painful.” She reports initially having decreased sensation in both of her feet and recently her hands. She now experiences paresthesias, numbness, and a “burning pain.” She is recovering from a recent myocardial infarction. Approximately 1.5 weeks ago, she experienced mild watery diarrhea and an atypical pneumonia. For the past 3 weeks, she has been experiencing fatigue, trouble with concentration, and mild weight gain. Beyond this, she has no other acute concerns. Her past medical history is significant for type 2 diabetes mellitus, hypertension, and coronary artery disease. She is currently taking metformin, aspirin, atorvastatin, metoprolol, and lisinopril. Her temperature is 99°F (37.2°C), blood pressure is 155/98 mmHg, pulse is 85/min, and respirations are 14/min. On physical exam, there is a loss of vibratory sensation and altered proprioception in the bilateral feet. She has impaired pain, light touch, and temperature sensation starting from her feet to mid-calf and hands. She has normal strength and muscle tone throughout her upper and lower extremities, as well as absent bilateral ankle reflexes. Which of the following is the most appropriate next step in management?