Seventh cervical nerve perforating the middle scalene muscle: a possible clinical and surgical application

Introduction: In most of cases, the emergency of the nervous roots of the brachial plexus in the posterior cervical triangle occur between the anterior and middle scalene muscles. However, anatomic variations in the brachial plexus are not rare. Methods: In the laboratory of Human Anatomy of the "Faculdade de Ciências Médicas de Minas Gerais" 106 cadavers were dissected. There were dissected the cervical region of all of the cadavers bilaterally. Results: In routinely dissection in the laboratory of human anatomy of the "Faculdade de Ciências Médicas de Minas Gerais" we've found in the left cervical region of a male cadaver the ventral branch of the seventh cervical nerve (C7) perforating the substance of the middle scalene muscle. Conclusion: Professionals that work with this region on the practice must pay attention to this and other variations in the constitution of the brachial plexus in the clinic and surgical procedures to avoid complications.(AU)

The scalenus accessorious muscle / El músculo escaleno accesorio

Many of the anatomical variations that are inadequately described or quantified are actually more clinically and surgically significant than being just anatomical curiosities. We report about such a variation where an aberrant slip existed in the scalene group, in a 56 year old embalmed female cadaver. This kind of variation may affect the size of the scalene triangle, and thus, may potentially result in varied signs and symptoms in patients vulnerable to thoracic outlet syndrome (TOS). Proximity of the scalene muscles to the brachial plexus, subclavian artery and vein, coexisting with aberrant slips or bundles may also predispose to compression syndromes.

Muchas de las variaciones anatómicas no están suficientemente descritas o cuantificadas y son actualmente clínica y quirúrgicamente significativas más que curiosidades anatómicas. Reportamos una variación anatómica en el grupo de los músculos escalenos, presente en un cadáver de una mujer de 56 años. Este tipo de variación puede afectar el tamaño del triángulo escalénico y por lo tanto, puede potencialmente resultar en variados signos y síntomas en pacientes vulnerables al síndrome de salida torácica. La proximidad de los músculos escalenos con el plexo braquial, arteria y vena suclavias, coexistiendo con fascículos aberrantes pueden predisponer a síndromes de compresión.