A 65-year-old diabetic woman underwent coronary arteriogram through left elbow catheterization. Shortly afterward, she developed severe pain in the left hand and numbness in the first three digits of the left hand and was referred for evaluation 1 month later. The patient was hypertensive and had thyroid disease; she was taking medicines for these conditions.
Neurologic examination revealed normal mentation and cranial nerves. Strength was normal except for diminished flexion of the left thumb; she could not completely flex digits 2 and 3 when asked to make a fist, and she could not oppose the thumb to the index finger to perform the O sign ( Fig. 5-1 ). She also had weakness of the toe dorsiflexors bilaterally. Reflexes were normal, except in the ankles where they were absent. Sensory examination revealed decreased pain sensation in the median nerve distribution of the left hand, decreased vibration sense in the toes, and decreased pain sensation up to the ankles. The neurologic examination was otherwise normal.
What is the Differential Diagnosis?
This patient appeared to have a diabetic neuropathy and a median neuropathy at the elbow. The motor findings localized the lesion, or affected, mainly at the anterior interosseous nerve, but the sensory findings suggested that the main trunk of the median nerve was affected.
An EMG Test was Performed
