Unusually high bifurcation of the median nerve resulting in two separate cylindrical compartments within the transverse carpal ligament: a case report

Introduction The median nerve courses through the carpal tunnel before entering the hand. Numerous descriptions of this pathway exist [1, 2], which state that the terminal branches of the median nerve bifurcate into radial and ulnar divisions, at the distal border of the transverse carpal ligament. Several variants exist and have been documented. Some variations describe the course of the thenar branch, the accessory branches at the distal carpal tunnel, high division of the median nerve and accessory branches proximal to the carpal tunnel [3, 4]. We report a case of an unusually high bifurcation of the median nerve into radial and ulnar branches proximal to the transverse carpal ligament. Another factor that makes our case unique is that both the branches were encapsulated by fibers arising from the transverse carpal ligament and were separated into two separate compartments within this ligament.