• In carpal tunnel release surgery, an incision at the radial aspect of the carpal tunnel puts this nerve at risk; therefore we recommend making the incision at the ulnar-most aspect of the carpal tunnel. Patients with injury to this nerve may have neuropathic pain in the distribution of this nerve territory.
• Provides sensation to the radial/lateral palmar aspect of the hand at the base of the thumb.
• Originates from roots C6, C7 and branches from the median nerve.
Sensory examination includes testing the lateral palmar aspect of the hand innervated by the palmar cutaneous branch of the median nerve.
• Ask patients to draw the area of diminished sensation/numbness on a body diagram.
• Test the skin along the radial/lateral palmar aspect of the hand for reduced/absent sensation by use of light touch or other sensory examination modalities.
• Provides sensation to the radial/lateral palmar aspect of the hand.
• The palmar cutaneous nerve travels superficial to the flexor retinaculum of the hand while the median nerve travels deep. Therefore in patients with carpal tunnel syndrome, the palmar cutaneous nerve will be functioning normally and patients generally do not exhibit deficits in this territory.
Adjacent Sensory Distribution:
PROXIMAL/MEDIAL – Medial antebrachial cutaneous nerve, ulnar palmar cutaneous nerve.
PROXIMAL/LATERAL – Lateral antebrachial cutaneous nerve.
MEDIAL – Palmar and digital cutaneous branches of the ulnar nerve.
DORSAL – Superficial branch of the radial nerve.
• This palmar sensory territory overlaps the median nerve sensory of the hand territory which is innervated by the digital branches of the median nerve.
• Roots: C6, C7.
• Nerve: Median nerve.
• Sensory Territory: Lateral palmar aspect of the hand.
• Innervation Route: C6, C7 → median nerve → palmar cutaneous branch of median nerve.
Course: The palmar cutaneous branch of the median nerve branches from lateral/radial aspect of the median nerve within the distal compartment of the forearm. The nerve continues distally and separates from the main median nerve just proximal to the wrist crease where it travels superficial to the flexor retinaculum. Afterwards, the nerve continues distally and can pierce the thenar musculature to innervate the cutaneous territory at the lateral/radial palmar aspect of the hand.