Entrapment neuropathy of the palmar cutaneous branch of the median nerve by the fascia of flexor digitorum superficialis

A case of thenar numbness, with concomitant carpal tunnel syndrome is presented. Physical findings and the result of injection of a local anesthetic into two different sites of tenderness suggested coexistence of entrapment and/or compression of the palmar cutaneous branch of the median nerve and the main trunk of the median nerve at the carpal tunnel. At operation, constriction of the palmar cutaneous branch of the median nerve by the fascia of seemingly normal flexor digitorum superficialis was observed beneath the site of maximum tenderness. After decompression of this nerve, combined with carpal tunnel release, the patient lost all pain and numbness; there was no recurrence at 5 months follow-up.