Spinal infection and abscess Quiz: Ace Your Exams

A 77-year-old man is brought to the emergency department from an assisted living facility with shooting pain down his legs. His caregiver states that for the past three weeks, he has had pain at rest and with movement which the patient describes as a jolt of pain down his legs. The patient has also felt feverish in the last three weeks but has not had chills or weight loss. He has a history of Parkinson disease and has a peripherally inserted central catheter (PICC) for total parenteral nutrition (TPN). He has a remote history of intravenous (IV) drug use 20 years ago, but none since. His HbA1c is 5.4%, last checked two months ago. Temperature is 38.3°C (101.0°F), pulse is 102/min, respiratory rate is 18/min, blood pressure is 132/82 mmHg and oxygen saturation is 99% on room air. The patient has a PICC line in place with surrounding erythema, without drainage or fluctuance. Midline lumbar tenderness to palpation and 4/5 weakness in the lower extremities bilaterally. Contrast-enhanced magnetic resonance imaging shows a fluid collection in the lumbar epidural space with rim enhancement and a hypointense center. Which of the following most likely led to this patient’s current condition?