open access

Vol 80, No 4 (2021)
Case report
Submitted: 2020-08-20
Accepted: 2020-09-07
Published online: 2020-10-12
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Unusual formation of the musculocutaneous and median nerves: a case report refined by intraneural dissection and literature review

E. Clarke1, R. S. Tubbs234, M. Radek5, R. Haładaj1, M. Tomaszewski1, G. Wysiadecki1
DOI: 10.5603/FM.a2020.0121
·
Pubmed: 33084011
·
Folia Morphol 2021;80(4):1020-1026.
Affiliations
  1. Department of Normal and Clinical Anatomy, Chair of Anatomy and Histology, Medical University of Lodz, Poland
  2. Department of Neurosurgery, Tulane University School of Medicine, New Orleans, LA, United States
  3. Department of Neurosurgery and Ochsner Neuroscience Institute, Ochsner Health System, New Orleans, LA, United States
  4. Department of Anatomical Sciences, St. George’s University, Grenada
  5. Department of Neurosurgery, Spine and Peripheral Nerve Surgery, Medical University of Lodz, University Hospital WAM-CSW, Lodz, Poland

open access

Vol 80, No 4 (2021)
CASE REPORTS
Submitted: 2020-08-20
Accepted: 2020-09-07
Published online: 2020-10-12

Abstract

This report presents a detailed anatomical investigation of an upper limb specimen showing an atypical formation of the musculocutaneous nerve (MCN) and median nerve (MN). The study was refined by intraneural dissection, which supplements earlier descriptions of similar anatomical variations and allows for revision of the accepted classification.
The case described in this report was an incidental finding during routine dissection of a fixed isolated upper limb. Intraneural dissection revealed partial fusion between the MCN and aberrant bundles of the MN. Those aberrant bundles joined the main steam of the MN at the level at which the MCN branched off as an independent nerve. The procedure allowed the aberrant fibres of the MN to be differentiated from the MCN. The presence of separate bundles in a territory corresponding to the MCN was confirmed, although those bundles and the aberrant MN bundles were covered by a common epineurium. The aberrant MN bundles running within the MCN did not contribute to innervation of the forearm muscles. They rejoined the main nerve trunk in the arm.
A comprehensive understanding of the diverse anatomical variations of the upper limb nerves could be crucial for the safety and success of surgical procedures, especially procedures for reconstructing the brachial plexus or its branches.

Abstract

This report presents a detailed anatomical investigation of an upper limb specimen showing an atypical formation of the musculocutaneous nerve (MCN) and median nerve (MN). The study was refined by intraneural dissection, which supplements earlier descriptions of similar anatomical variations and allows for revision of the accepted classification.
The case described in this report was an incidental finding during routine dissection of a fixed isolated upper limb. Intraneural dissection revealed partial fusion between the MCN and aberrant bundles of the MN. Those aberrant bundles joined the main steam of the MN at the level at which the MCN branched off as an independent nerve. The procedure allowed the aberrant fibres of the MN to be differentiated from the MCN. The presence of separate bundles in a territory corresponding to the MCN was confirmed, although those bundles and the aberrant MN bundles were covered by a common epineurium. The aberrant MN bundles running within the MCN did not contribute to innervation of the forearm muscles. They rejoined the main nerve trunk in the arm.
A comprehensive understanding of the diverse anatomical variations of the upper limb nerves could be crucial for the safety and success of surgical procedures, especially procedures for reconstructing the brachial plexus or its branches.

Get Citation

Keywords

anatomical variation, brachial plexus, median nerve, musculocutaneous nerve, peripheral nerves

About this article
Title

Unusual formation of the musculocutaneous and median nerves: a case report refined by intraneural dissection and literature review

Journal

Folia Morphologica

Issue

Vol 80, No 4 (2021)

Article type

Case report

Pages

1020-1026

Published online

2020-10-12

Page views

2510

Article views/downloads

628

DOI

10.5603/FM.a2020.0121

Pubmed

33084011

Bibliographic record

Folia Morphol 2021;80(4):1020-1026.

Keywords

anatomical variation
brachial plexus
median nerve
musculocutaneous nerve
peripheral nerves

Authors

E. Clarke
R. S. Tubbs
M. Radek
R. Haładaj
M. Tomaszewski
G. Wysiadecki

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