A Man With Unilateral Proximal Leg Weakness After Heart Catheterization

A 79-year-old diabetic man developed acute pain in the right hip and knee immediately after a heart catheterization. Past medical history included kidney stones, atrial fibrillation, and hypertension. He did not smoke, drink alcohol, or use illicit drugs.

Mental function and cranial nerve examination were normal. He had normal strength and sensation in the upper extremities; there was a profound weakness of the right iliopsoas and quadriceps muscles which did not overcome gravity. Adductors, hamstrings, and gluteal muscles were normal. There was a mild bilateral weakness of toe dorsiflexors. Reflexes were 2+ in the upper extremities, 1+ in the left knee, and 0 at the right knee. Adductor reflexes were 1+ bilaterally. Both ankle jerks were absent. There was absent vibration sense in the toes and decreased pinprick in a stocking distribution to the mid-leg in both sides. There was also a patchy decreased pain sensation in the anterior right thigh. Femoral stretch produced mild pain, and a straight leg raising test was negative. No masses were present in the inguinal area or pelvis. The rest of the examination was unremarkable.

What is the Most Likely Diagnosis?

This patient had unilateral weakness in the femoral-innervated muscles, with sparing of the adductors innervated by the obturator nerve. This finding is suggestive of a femoral neuropathy, rather than a lumbosacral plexopathy or an L2–L4 radiculopathy. The most likely cause of this neuropathy is trauma to the femoral nerve during catheterization. Another possibility is a hematoma compressing this nerve. The patient also had evidence of a polyneuropathy, likely from diabetes. It was not clear if the right saphenous nerve was affected by this because the sensory loss in the legs was equal in both sides.

What Tests should be Done?

A CT scan or an MRI of the pelvis and retroperitoneal area should be done, as should routine blood tests, including a complete metabolic panel (CMP), particularly glucose, a complete blood count (CBC), prothrombin time (PT), partial thromboplastin time, glycosylated hemoglobin, blood urea nitrogen, and creatinine, and an EMG.

CBC, CMP, and PT were normal, except for his blood sugar that was 242 mg/dL (normal, 70–115 mg/dL) and his glycosylated hemoglobin that was 7% (normal, <6.0%).