A 20-year-old man is evaluated due to weakness in the left hand. The patient has a motor vehicle collision, where he injured his left arm. Since that day, he has been complaining of numbness in the left hand and weakness. On examination, there is a loss of sensation over the 5th digit and hypothenar muscles atrophy. Triceps reflexes are 2+ and symmetric bilaterally. This patient's nerve injury is most likely at which of the following levels?

Question

Quizplus · Accepted Answer

Eductional Objective: The ulnar nerve injury could occur at either two levels, the medial epicondyle of the humerus or the Guyon's canal close to the hook of the hamate and pisiform bone in the wrist. Ulnar nerve injury causes diminished sensation over the medial 1 1/2 digits and the hypothenar eminence. Patients will experience weakness of wrist flexion or adduction, finger abduction and adduction, and flexion of the 4th and 5th digits. Hypothenar muscles atrophy will result also.

A 20-Year-Old Man Is Evaluated Due to Weakness in the Left