Complex Variation Of Median Nerve: A Case Report

Abstract

During routine dissections we saw complex variation of median nerve in the right arm of anadult male cadaver. Lateral cord continued as lateral root of median nerve without giving offmusculocutaneous nerve and it formed median nerve joining with medial root of median nervewhich arises from medial cord. There was a communicating accessory branch 2.5 cm longrunning obliquely between the cords which formed the median nerve. Coracobrachialis musclewas innervated by a thin branch arising from lateral cord. Median nerve given two branches ata point 9 cm distal to its formation. First branch supplied to biceps brachii, the second branchcontinued as brachial muscle’s nerve and lateral antebrachial cutaneous nerve. Main trunk passedthrough the cubital fossa and ran along the forearm following the normal course of mediannerve. We think it is important that clinicians performing surgical procedures or nerve blocksin this region should consider this variation in order to avoid failures and complications

Keywords

• Median nerve,musculocutaneous nerve,variation,dissection

Median Sinirin Kompleks Varyasyonu: Olgu Sunumu

Abstract

Rutin diseksiyon sırasında yetişkin erkek kadavranın sağ kolunda kompleks bir median sinirvaryasyonu gördük. Lateral fasikül muskulokutanöz sinir terminal dalını vermeden mediansinirin lateral kökü olarak devam etmekte ve medial fasikülden gelen median sinirin medialkökü ile birleşerek median siniri oluşturmaktaydı. Median siniri oluşturan bu iki fasikül arasındaoblik olarak seyreden 2,5 cm uzunluğunda birleştirici aksesuar bir dal mevcuttu. Korakobrakialkas lateral fasikülden gelen ince bir dal tarafından innerve edilmişti. Median sinir oluşumunun9 cm distalinde iki dal vermişti. İlk dal biseps braki kasını innerve etmişti, ikinci dal ise brakialiskasının siniri ve lateral antebrakial kutanöz sinir olarak devam etmişti. Ana gövde ise kubitalfossa içinden geçip median sinirin normal seyrini izleyerek önkol boyunca uzanmıştı.Klinisyenlerin bu bölgedeki cerrahi işlemleri ve sinir bloklarını yaparken bu varyasyonu gözönünde bulundurmasının başarısız girişimleri ve komplikasyonları önlemek için önemliolduğunu düşünmekteyiz

Keywords

• Median sinir,muskulokutanöz sinir,varyasyon,diseksiyon

References

1. Moore KL, Dalley AF: Clinically Oriented Anatomy. 4rd ed. Baltimore. Lippincott Williams & Wilkins. 1999.
2. Songur A, Uygur R, Akcer S, Toktas M: Fenestrated brachial vein perforated by the lateral root of median nerve: a case report. Anatomy 2009, 3:65-68.
3. Drake RK, Vogl W, Mitchell AWM: Gray's Anatomy. 39th ed. Edinburgh. Churchill Livingstone. 2005.
4. Sadler TW: Langman’s Medical Embryology. 8th ed. Lippincott Williams & Wilkins. 2000.
5. Aggarwal A, Harjeet K, Sahni D, Aggarwal A: Bilateral multiple complex variations in the formation and branching pattern of brachial plexus. Surg Radiol Anat. 2009, 31:723- 731.
6. Goyal N, Harjeet, Gupta M: Bilateral variant contributions in the formation of median nerve. Surg Radiol Anat. 2005, 27:562-565.
7. 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. (Warsz) 2001, 60:99-101.
8. Villamere J, Goodwin S, Hincke M, Jalalı A: A brachial plexus variation characterized by the absence of the superior trunk. Neuroanatomy 2009, 8:4-6.

9. Loukas M, Aqueelah H: Musculocutaneous and median nerve connections coracobrachialis muscle. Folia Morphol. (Warsz) 2005, 64:101-108. and distal to the
10. Bergmann R, Thompson SA, Afifi AK, Saadeh FA: Compendium of human anatomic variation. Baltimore, Munich, Urban and Schwarzenberg. 1988.
11. Gümüsburun E, Adigüzel E: A variation of the brachial plexus characterized by the absence of the musculocutaneous nerve: a case report. Surg Radiol Anat. 2000, 22:63–65.
12. Nakatani T, Mizukami S, Tanaka S: Three cases of the musculocutaneous nerve not perforating the coracobrachialis muscle. Kaibogaku Zasshi 1997, 72:191–194. 13. Bhattarai C, Poudel PP: musculocutaneous nerves. Kathmandu Univ Med J. (KUMJ) 2009, 7:408-410. Unusual variation in
13. Tsikaras PD, Agiabasis AS, Hytiroglou PM: A variation in the formation of the brachial plexus characterized by the absence of C8 and TI fibers in the trunk of the median nerve. Bull Assoc Anat. (Nancy) 1983, 67:501-505.
14. Beheiry EE: Anatomical variations of the median nerve distribution and communication in the arm. Folia Morphol. (Warsz) 2004, 63:313-318.
15. Fregnani JH, Macéa MI, Pereira CS, Barros MD, Macéa JR: Absence of the musculocutaneous nerve: a rare anatomical variation with possible clinical-surgical implications Sao Paulo Med J. 2008, 126:288-290.
16. Nayak S: Absence of musculocutaneous nerve associated with clinically important variations in the formation, course and distribution of the median nerve - a case report. Neuroanatomy 2007, 6:49-50. 18. Prasada Rao PV, Chaudhary musculocutaneous nerve: two case reports. Clin Anat. 2001, 14:31-35. SC: Absence of
17. Rajanigandha V, Mangala P, Latha P, Savinaya S, Vasudha S, Prakash S: A case report on multiple anomalies of upper extremity. Neuroanatomy 2006, 5:44–46.
18. Arora L, Dhingra R: Absence of musculocutaneous nerve and accessory head of biceps brachii: A case report. Indian J Plast Surg. 2005, 38:144–146.
19. Nakatani T, Tanaka S. Absence of the musculocutaneous nerve with innervation of coracobrachialis biceps brachii, brachialis and the lateral border of the forearm by branches from the lateral cord of the brachial plexus. J Anat. 1997, 191:459-460.
20. Poornima GC, Satyaprasad V: Variant innervation of flexors of the arm associated with additional head of biceps brachii. Neuroanatomy 2006, 5:24–26.
21. Singhal S, Rao VV, Ravindranath R: Variations in brachial plexus and the relationship of median nerve with the axillary artery: a case report. J Brachial Plex Peripher Nerve Inj. 2007, 2:21.
22. Tuncali D, Toksoy K, Tan Baser N, Terzioglu A, Aslan G: Upper extremity nerve injuries: the significance of soft tissue associations. Neuroanatomy 2004, 3:15-17.