title: A variation of the cords of the brachial plexus on the right and a communication between the musculocutaneous and median nerves on the left upper limb: a unique case.
abstract: During routine anatomical dissection of the upper extremity of a 64-year-old cadaver for educational purposes, we observed variations in the brachial plexus on each side. On the right an anomaly of cord formation was present and on the left there was a communication between the musculocutaneous nerve (MCN) and median nerve (MN). On the right side the brachial plexus showed two trunks, superior (C5 and C6) and inferior (C7, C8, and T1); the middle trunk was absent. The superior trunk bifurcated into anterior and posterior divisions, the anterior division continued as the lateral cord forming the MCN. The posterior division gave off the subscapular branch. The inferior trunk trifurcated into radial, median, and ulnar nerves. The radial nerve gave off the axillary and thoracodorsal nerves. The ulnar nerve gave off the median cutaneous nerves of the arm and forearm. The median nerve received a small ascending branch from the MCN. On the right side, there was a communicating branch from the MCN to the MN in the lower third of the arm region. This communicating branch also gave rise to a muscular branch to the brachialis muscle and the lateral cutaneous nerve of forearm. No additional heads of the biceps brachii muscle were observed in either upper limb. Knowledge of the variations of the brachial plexus in humans can be valuable for operations of the shoulder joint and its repair for providing an effective block or treatment for anesthetists and also for explaining otherwise incomprehensible clinical signs for neurologists.
authors: Department of Anatomy, Marmara University School of Medicine, Istanbul, Turkey.
authors: Özlem
authors: Ö
authors: Kirazlı
authors: Department of Neurosurgery, Dr. Lutfi Kirdar Kartal Education and Research Hospital, Istanbul, Turkey.
authors: Necati
authors: N
authors: Tatarlı
authors: Department of Neurosurgery, Sakarya University School of Medicine, Sakarya, Turkey.
authors: Davut
authors: D
authors: Ceylan
authors: Department of Anatomy, Marmara University, Medical Faculty, Istanbul, Turkey.
authors: Hüsniye
authors: H
authors: Hacıoğlu
authors: Department of Anatomy, Hacettepe University School of Medicine, Ankara, Turkey.
authors: Seda
authors: S
authors: Uygun
authors: Department of Neurosurgery, Marmara University School of Medicine, Institute of Neurological Sciences, Istanbul, Turkey.
authors: Aşkın
authors: A
authors: Şeker
authors: Department of Neurosurgery, Koç University School of Medicine, Istanbul, Turkey.
authors: Evren
authors: E
authors: Keleş
authors: Department of Anatomy, Koç University School of Medicine, Istanbul, Turkey.
authors: Safiye
authors: S
authors: Çavdar
mesh_terms: D001917:Brachial Plexus / Q000002:abnormalities* / Q000033:anatomy & histology; D002102:Cadaver; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000002:abnormalities* / Q000033:anatomy & histology; D008875:Middle Aged; D009138:Musculocutaneous Nerve / Q000002:abnormalities* / Q000033:anatomy & histology; D034941:Upper Extremity / Q000033:anatomy & histology / Q000294:innervation*