Grafting the C5 root to the musculocutaneous nerve partially restores hand sensation in complete palsies of the brachial plexus.

Background: In complete brachial plexus palsy, we have hypothesized that grafting to the musculocutaneous nerve should restore some hand sensation because the musculocutaneous nerve can drive hand sensation directly or via communication with the radial and median nerves.

Objective: To investigate sensory recovery in the hand and forearm after C5 root grafting to the musculocutaneous nerve in patients with a total brachial plexus injury.

Methods: Eleven patients who had recovered elbow flexion after musculocutaneous nerve grafting from a preserved C5 root and who had been followed for a minimum of 3 years were screened for sensory recovery in the hand and forearm. Six matched patients who had not undergone surgery served as controls. Methods of assessment included testing for pain sensation using Adson forceps, cutaneous pressure threshold measurements using Semmes-Weinstein monofilaments, and the static 2-point discrimination test. Deep sensation was evaluated by squeezing the first web space, and thermal sensation was assessed using warm and cold water.

Results: All grafted patients recovered sensation in a variable territory extending from just over the thenar eminence to the entire lateral forearm and hand. Seven patients were capable of perceiving 2-0 monofilament pressure on the thenar eminence, palm, and dorsoradial aspect of the hand. All could differentiate warm and cold water. None recovered 2-point discrimination. None of the patients in the control group recovered any kind of sensation in the affected limb.

Conclusion: Grafting the musculocutaneous nerve can restore nociceptive sensation on the radial side of the hand.