A Formation Variation of the Median Nerve in the Arm

Öz

The variation of the median nerve was observed incidentally during dissection of a 67 year-old male formalin-fixed Turkish cadaver assigned to the preclinical medical students at the Human Anatomy Laboratory of the Faculty of Meram Medicine, Selcuk University, Konya, Turkey. The median nerve was originating normally from the brachial plexus on proximal arm, but it received a communicating branch originated from the lateral cord on the middle arm. After lateral root of the median nerve leaved, the lateral cord bifurcated (lateral and medial branches) and both of them pierced the coracobrachial muscle. In previous studies, there were different definitions about connections. Knowledge of anatomic variations of the peripheral nervous system is helpful in explaining unusual clinical signs and permits correct interpretation of clinical neurophysiology.

Anahtar Kelimeler

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Kolda Nervus Medianus'un Bir Oluşum Varyasyonu

Öz

Selçuk Üniversitesi Meram Tıp Fakültesi Anatomi Anabilim Dalı'nda rutin öğrenci diseksiyonları sırasında, 67 yaşındaki erkek kadavrada n. medianus varyasyonuna rastlandı. N. medianus kolun proksimalinde plexus brachialis'ten gelen dallarla normal olarak oluşmaktaydı. Kolun ortasında sinire fasciculus lateralis'ten gelen bir bağlantı dalının katıldığı tespit edildi. Radix lateralis nervi mediani ayrıldıktan sonra fasciculus lateralis'in ikiye ayrıldığı ve her iki dalın da musculus coracobrachialis'i deldiği gözlendi. Periferik sinir sisteminin anatomik varyasyonlarının bilinmesinin klinik nörofizyolojinin doğru yorumlanmasında ve farklı klinik bulguların açıklanmasında yararlı olacağı düşüncesindeyiz.

Anahtar Kelimeler

• Nervus musculocutaneus, Nervus medianus, Kadavra, Varyasyon

Kaynakça

1. İçke Ç, Temizkan-Kizanoğlu H. Olgu sunumu: Nervus medianus'un oluşum varyasyonu. Dokuz Eylül Ü Tıp Fak Der 2006; 20: 103–107.
2. Kabak Ş, Ekinci N, Halıcı M ve ark. Median sinirin oluşum varyasyonlarının incelenmesi. J Arthroplasty 2001; 12: 183–185.
3. Moore KL. Clinic Oriented Anatomy. 3th ed. Baltimore: Williams & Wilkins 1992: 553.
4. Arıncı K, Elhan A. Anatomi. 4. Basım. Cilt 2. Ankara: Güneş Kitabevi 2006: 166-167.
5. Arora J, Kapur V, Suri RK, Khan RQ. Inter-Communications between median and musculocutaneous nerves with dual innervation of brachialis muscle-a case report. J Anat Soc India 2003; 52: 66–68.
6. Choi D, Rodriguez- Nieddenführ M, Vazaquez T, Parkin I, Sanudo JR. Patterns of connections between the musculocutaneus and median nerves in the axilla and arm. Clin Anat 2002; 15: 11–17.
7. Venieratos D, Anagnostopoulou S. Classification of communications between the musculocutaneus and median nerves. Clin Anat 1998; 11: 327–331.
8. Loukas M, Aqueelah H. Musculocutaneous and median nerve connections within, proximal and distal to the coracobrachialis muscle. Folia Morphol 2005; 2: 101–108.

9. Le Minor JM. A rare variation of the median and musculocutaneous nerves in man. Arch Anat Histol Embryol 1990; 73: 33-42.
10. Uysal İİ, Karabulut AH, Büyükmumcu M, Unver Dogan N, Salbacak A. The course and variations of the branches of the musculocutaneous nerve in human fetuses. Clin Anat 2009; 22: 337-345.
11. Saeed M, Rufai AA. Median and musculocutaneus nerves: variant formation and distribution. Clin Anat 2003; 16: 453– 457.
12. Chauhan R, Roy TS. Communication between the median and musculocutaneous nerve- a case report. J Anat Soc India 2002; 51: 72–75.
13. Uzun A, Seelig LL Jr. A variation in the formation of the median nerve: communicating branch between the musculocutaneous and median nerves in man. Folia Morphol 2001; 60: 99-101.
14. Buch-Hansen K. Variations of the median nerve and the musculocutaneous nerve and their connections. Anat Anz 1955; 102: 187–203.
15. Beheiry EE. Anatomical variations of the median nerve distribution and communication in the arm. Folia Morphol 2004; 63: 313–318.