Age / Sex : 28 / M

Bifid median nerve with persistent median artery

Discussion

Findings:  

MRI) There are two separate bundles of the median nerve at carpal tunnel. A persisent median artery is located between the two nerve bundles. The artery is beneath the transverse carpal ligament. 

Differential Diagnosis:  

Diagnosis: Bifid median nerve with persistent median artery

Discussion: Bifid median nerve (high division of median nerve proximal to the carpal tunnel) is a median nerve anomaly with an incidence rate of 2.8%. It is known to be associated with various abnormalities, such as vascular malformations (persistent median artery), aberrant muscles, and carpal tunnel syndrome. Its relatively higher cross-sectional area can cause carpal tunnel syndrome. The median artery is usually situated between the radial and ulnar trunks of the median nerve, and has a superficial course in the carpal tunnel with a close relationship to the transverse carpal ligament.

References:

1. Gassner EM et al. Persistent median artery in the carpal tunnel - Color Doppler ultrasonographic findings. J Ultrasound Med 21:455–461, 2002

2. Bayrak IK et al. Bifid median nerve in patients with carpal tunnel syndrome. J Ultrasound Med. 2008;27 (8): 1129-36

3. Bagatur AE et al. Bifid median nerve causing carpal tunnel syndrome: MRI and surgical correlation. Orthopedics. 2013 Apr; 36(4):451-6.