A BRACHIAL PLEXUS VARIATION CHARACTERIZED BY THE ABSENCE OF THE SUPERIOR TRUNK

JAMES VILLAMERE SHANNON GOODWIN MAXWELL HINCKE ALIREZA JALALI

Neuroanatomy - 2009;8(1):4-6

Faculty of Medicine, University of Ottawa, Ottawa, CANADA

 

During routine dissection of a 55-year-old female cadaver, a variation of the brachial plexus characterized by the absence of the superior trunk on the left side was observed. The ventral rami of the C5 and C6 nerve roots, without joining to form the superior trunk, independently divided into anterior and posterior divisions, which joined the lateral and posterior cords, respectively. Additionally, the suprascapular nerve that normally originates from the superior trunk initiated exclusively from the C5 nerve root in this variation. Similar variations in the brachial plexus were not observed on the contralateral side. The details of this variation and its clinical significance are discussed herein.