[A deep palmar muscle as a cause for carpal tunnel syndrome].

In young patients with bilateral carpal tunnel syndrome and a negative history of synovialitis, trauma, and metabolic disease one has to consider rare muscle variations as a cause of the syndrome. Besides variations of the lumbrical muscles and the superficial flexor digitorum muscles, variations of the palmaris longus muscle can be the causative anomalous structure. A case of carpal tunnel syndrome caused by a palmaris profundus muscle in presence of a normal palmaris longus muscle is reported.