Following a difficult intravenous cannulation on the medial side of the mid-arm, a 30-year-old woman develops burning pain and numbness along the medial half of her forearm extending toward the wrist. Elbow movements, grip and finger sensation over the little finger are all normal. Which structure was injured?

• A Ulnar nerve
• B Intercostobrachial nerve
• C Medial cutaneous nerve of the forearm ✓
• D Medial cutaneous nerve of the arm

Explanation

The medial cutaneous nerve of the forearm arises from the medial cord and runs alongside the basilic vein in the arm, making it vulnerable during venepuncture or cannulation. It is purely sensory to the medial forearm. The ulnar nerve is excluded because motor function and sensation in the little finger are intact, and the intercostobrachial nerve supplies the axilla and medial upper arm, not the forearm.

Reference: Moore's Clinically Oriented Anatomy, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.