Trifid Median Nerve Associated With Persistent Median Artery

Mario Alfredo Chávez-López, Adolfo Tello-Esparza
2015 Journal of clinical rheumatology  
Y alcin et al 1 have recently described the sonographic appearance of the trifid median nerve in an asymptomatic 54-yearold man. In this patient, no arterial anomaly was present. Another recent report describes the coexistence of the bifurcation and trifurcation (without median artery) of the median nerve in right and left wrists, respectively, in a patient with bilateral carpal tunnel syndrome. 2 Bifid median nerve and persistent median artery have been reported to have an incidence up to 19%
more » ... nd 11%, respectively, in a recent magnetic resonance imaging study. 3 We present the case of a 49-year-old woman with a diagnosis of rheumatoid arthritis referred for an ultrasound examination of the left wrist. Her complaints were pain and swelling of the ulnar side of the wrist and tingling in the hand. Ultrasound revealed tenosynovitis of the extensor carpi ulnaris. The transverse sonographic view of the wrist showed 3 structures with the same sonographic appearance as the median nerve (Fig. A) . From radial to ulnar side (right to left in the image), it was possible to identify the first bundle, a smaller round shape image with positive power Doppler signal, and other 2 small bundles (Fig. B) . To the best of our knowledge, a trifid median nerve with persistent median artery has not been previously described. As is demonstrated in this case, musculoskeletal ultrasound is positioned as 1 of the first-line diagnostic methods for the study, follow-up, and treatment of peripheral nerve pathologies. It is a fast cost-effective and dynamic study. 4 There is increasing consensus about the necessity for ultrasonographic studies before surgical procedures of the carpal tunnel. Because some of these patients are considered for ultrasoundguided injections or referred for surgical procedures, rheumatologists and orthopedic surgeons should be aware of the existence of this particular anatomic variant to avoid any iatrogenic injuries. 5 REFERENCES 1. Yalcin E, Onder B, Akyuz M. Trifid median nerve. J Hand Surg Eur Vol. 2011;36:812-13. 2. Duymus M, Yilmaz O, Ulasli AM, et al. Coexistence of trifid and bifid median nerve in a patient with bilateral carpal tunnel syndrome. Turk Neurosurg. 2013;23:685-7. 3. Pierre-Jerome C, Smitson RD Jr, Shah RK, et al. MRI of the median nerve and median artery in the carpal tunnel: prevalence of their anatomical variations and clinical significance. Surg Radiol Anat. 2010;32:315-22. 4. Kara M, Özçakar L, De Muynck M, et al. Musculoskeletal ultrasound for peripheral nerve lesions. Eur J Phys Rehabil Med. 2012;48:665-74. 5. Checa A, Manohar J, Russell E, et al. Persistent median artery in the wrist: from a medical curiosity to a common anatomic variant with therapeutic implications.
doi:10.1097/rhu.0000000000000221 pmid:25710863 fatcat:2hnmzfpwxzfwxeoidk5a5yrbe4