title: From the brachial plexus to the hand, multiple connections between the median and ulnar nerves may serve as bypass routes for nerve fibres.
abstract: Axons from the median and ulnar nerves can pass to each other through aberrant connections between them. Multiple interconnections between the nerves may provide a detour route for nerve fibres going to the hand. We investigated the incidence of variations and the associations between them in 90 cadaveric upper limbs. In 91% of upper limbs, one to five variations were found, with several statistically significant associations. The contribution of the C8 nerve to the lateral cord was positively associated with an accessory contribution of the lateral cord to the ulnar nerve. The latter variation showed positive association with the occurrence of any of the variations in the hand itself. Ulnar innervation of the superficial head of the flexor pollicis brevis was positively associated with the Riche-Cannieu communication. The co-existence of the variations and their associations may be the explanation for unusual clinical findings related to median and ulnar conduction, which appear contrary to anatomical knowledge.
authors.affiliation: Department of Anatomy, Gachon University School of Medicine, Incheon, Korea.
authors.forename: H
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Anatomy, Kon-Kuk University College of Medicine, Seoul, Korea.
authors.forename: Y
authors.initials: Y
authors.lastname: Gil
authors.affiliation: Department of Anatomy, Gachon University School of Medicine, Incheon, Korea.
authors.forename: S
authors.initials: S
authors.lastname: Kim
authors.affiliation: Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, Korea.
authors.forename: J
authors.initials: J
authors.lastname: Bang
authors.affiliation: Yonsei University Graduate School, Seoul, Korea.
authors.forename: H
authors.initials: H
authors.lastname: Choi
authors.affiliation: Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea leehy@yuhs.ac.
authors.forename: H Y
authors.initials: HY
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001917:Brachial Plexus / Q000473:pathology*; D002102:Cadaver; D005260:Female; D006225:Hand / Q000294:innervation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009431:Neural Conduction
keywords: Anatomy; Berrettini branch; Marinacci communication; Martin-Gruber communication; variation