Variation of Musculocutaneous Nervi Branching to Median Nerve and not Piercing Corocobrachialis Muscle; Case Report

Abstract

The fifth and sixth (and sometimes the fourth) cervical spinal nerves merge to form the superior trunk, and the superior trunk and the anterior part of the median nerve merge to form the fasciculus lateralis. Fasciculus lateralis is divided into two branches as lateral cord and musculocutaneous nerve. The mus-culocutaneous nerve pierces the corocobrachialis muscle muscle and then travels between the brachia-lis muscle and the biceps brachii musculus. Variations in anatomical structures are common. However, nerve variations occur more rarely in these structures. These variations are anatomically and clinically important. This case report was detected during routine dissection of a male cadaver in the Depart-ment of Anatomy, Karabuk University Faculty of Medicine. For dissection, the fossa axillaris, arm and forearm of both upper extremities were dissected. During dissection, it was found that the musculocu-taneous nerve in the left upper extremity continued without piercing the corocobrachialis muscle and gave a connecting branch to the median nerve. There are limited case studies on this nerve variation and studies show that this variational condition is important for surgical operations in this region. The-refore, this study is important for both surgical and clinical sciences.

Keywords

• Musculocutaneous nerve
• Corocobrachialis muscle
• Median nerve
• Variation

Nervus Medianus’a Dal Veren ve Musculus Corocobrachialis’i Delmeyen Nervus Musculocutaneus Varyasyonu; Olgu Sunumu

Abstract

Beşinci ve altıncı (bazen de dördüncü) servikal spinal sinirler birleşerek truncus superior’u, truncus superior ile nervus medianus’un ön bölümü de birleşerek fasciculus lateralis’i meydana getirir. Fascicu-lus lateralis’te radix lateralis ve nervus musculocutaneus olmak üzere iki dala ayrılır. Nervus musculocu-taneus’da musculus corocobrachialis kasını deler ve sonrasında musculus brachialis ile musculus biceps brachii arasında seyreder. Anatomik yapılarda varyasyonlar gözüken bir durumdur. Fakat bu yapılar içerisinde sinir varyasyonları daha nadir olarak ortaya çıkmaktadır. Bu varyasyonlarda anatomik ve klinik açıdan önemlidir. Bu olgu sunumu Karabük üniversitesi Tıp Fakültesi Anatomi Anabilim dalı’nda yer alan erkek kadavranın rutin diseksiyonu sırasında tespit edildi. Diseksiyon için her iki üst extremitenin de fossa axillaris’i, kol ve ön kol bölgesi diseke edildi. Diseksiyon sırasında sol üst extremitede yer alan nervus musculocutaneus’un musculus corocobrachialis’i delmeden devam ettiği ve nervus medianus’a birleştirici bir dal verdiği bulundu. Bu sinir varyasyonu ile ilgili sınırlı vaka çalışması bulunmakta olup çalışmalar bu varyasyonel durumun bu bölgedeki cerrahi operasyonlar için önemli olduğunu göstermek-tedir. Bundan dolayı bu çalışma hem cerrahi bilimler için hem de klinik bilimler için önem arz etmek-tedir.

Keywords

• Nervus musculocutaneus
• Musculus corocobrachialis
• Nervus medianus
• Varyasyon

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