MSRA-1362

MSRA-1362

As a doctor in the emergency department, you encounter a 42-year-old man who complains of new left leg tingling and weakness. He reports that three days ago he was independent and walking normally. The patient has a medical history of type 2 diabetes mellitus and takes insulin.

Upon examination, the patient has a heart rate of 121 beats per minute, a blood pressure of 101/72 mmHg, and a temperature of 38.3ºC. The right leg has 4/5 power throughout, while sensation is altered over the right anterior thigh and knee. The left leg has 4/5 power in hip flexion and extension, 3/5 power in knee flexion, knee extension, and ankle dorsiflexion, and 0/5 power in great toe extension and plantarflexion. Sensation is altered on the left over the thigh and knee, but absent to both light touch and pin prick in the left foot.

What is the most likely diagnosis for this patient?