OVERVIEW
Key Points:
• Examination of this specific nerve involves testing a small patch of skin on the ulnar aspect of the palm. Injury to this nerve is not commonly encountered.
Sensory Innervation:
• Provides sensation to the medial/ulnar palmar aspect of the hand.
• Originates from roots C8 and branches from the ulnar nerve.
EXAMINATION
Sensory examination includes testing the medial palmar aspect of the hand innervated by the palmar cutaneous branch of the ulnar nerve.
Sensory Examination:
• Ask patients to draw area of diminished sensation/numbness on a hand diagram.
• Testing the skin along the medial palmar aspect of the hand for reduced/absent sensation by use of light touch or other sensory examination modalities.
Clinical Relevance:
• Provides sensation to the medial palmar aspect of the hand.
• Unlike the palmar cutaneous branch of the median nerve, this nerve is not encounter in many scenarios.
Adjacent Sensory Distribution:
PROXIMAL – Medial antebrachial cutaneous.
LATERAL – Palmar and digital cutaneous branches of the ulnar nerve.
DORSAL – Dorsal cutaneous branch of the ulnar nerve.
• This palmar sensory territory overlaps the ulnar nerve sensory of the hand territory which is innervated by the digital branches of the ulnar nerve.
Relevant Anatomy:
Innervation
• Roots: C8.
• Nerve: Ulnar nerve.
• Sensory Territory: Medial palmar aspect of the hand.
• Innervation Route: C8 → ulnar nerve → palmar cutaneous branch of ulnar nerve.
Course: The palmar cutaneous branch of the ulnar nerve can branch as an individual branch from the medial aspect of the ulnar nerve at the wrist just proximal to Guyon’s canal. The nerve continues distally and superficially to innervate the medial palmar aspect of the hand.