Clinicoembryological Submission of Unusual Variation in Course and Branching Pattern of Lateral Cord of Brachial Plexus – A Case Report

Variations are commonly observed and being reported in the formation of lateral cord of brachial plexus and in the communicationof branches of lateral cord of brachial plexus, but formation of median nerve by lateral root of median nerve from lateral cord andmedial root of median nerve from medial cord at a substantially low level is quite unusual and the case reports regarding piercingof the coracobrachialis by lateral cord of brachial plexus are infrequent. The present case report describes an unusual unilateralcourse of lateral cord piercing the coracobrachialis and ensuing path followed by its various branches as well as unusuallylow-level formation of median nerve from lateral and medial roots coming from the lateral and medial cord of brachial plexus,respectively. This was witnessed in the infraclavicular part of the brachial plexus during the routine gross anatomy dissectionof the left upper extremity in a 35-year-old Indian male cadaver. Since axilla and upper half of the arm are challenging areasfor surgical procedures, so the unusual variations being reported in this case may help the surgeons of different specialties inexploration of neuronal tumor, shoulder reconstructive surgery shoulder arthroscopy, and using the coracobrachialis flap fordifferent surgical purposes.

Bilateral Variations In The Branching Pattern Of The Lateral Cord Of Brachial Plexus: A Case Report

Variations in the branches of the brachial plexus are not uncommon. In the present report, variation in thebranching pattern of the lateral cord is described along with the absence of the musculocutaneous nerve. Thelateral cutaneous nerve of the forearm was a direct continuation of the lateral cord. These kinds of variations ofnerve branches are more prone to injuries during upper arm and axillary surgeries. Knowledge regardingvariations in the brachial plexus is utmost important for surgeons, anesthesiologist, clinicians and anatomists.

Variations In The Branching Pattern Of The Cords Of The Brachial Plexus

Introduction: Brachial plexus has been the subject of various studies as it is an important nerve plexus at thejunction of neck and upper limb. For procedures like neurotisation, nerve grafting and shoulder joint surgery byanterior approach, knowledge of brachial plexus and its variation will be helpful to prevent any iatrogenictrauma to the nerves. Aim of this study was to find out about the variation in the branching pattern of the cordsof brachial plexus.Methods: The present study was carried out by dissection of 120 (60 right and 60 left) upper limbs in 60embalmed cadavers that were available in the department of Anatomy of Seth G. S. Medical College and KEMhospital Mumbai.Result: Variations were encountered in the branching pattern of lateral and posterior cord, while medial cordbranches did not show any variation.Conclusion: Knowledge pertaining to the variation in the branching pattern of the cords of brachial plexus willguide the operating surgeon to prevent any iatrogenic trauma.

Variant Patterns Of Brachial Plexus – A Cadaveric Study In North Indian Population

Background: The brachial plexus is constituted by the ventral rami of C5-T1 spinal nerves. It forms a network ofterminal nerves that innervate the upper limb. Variations of brachial plexus are common and a better awarenessof variations is very crucial to achieve successful results in its surgical procedures. The aim of present studywas to find the variant patterns of brachial plexus and to discuss their developmental and clinical significance.Materials and Method: 50 upper limbs belonging to 25 formalized and well preserved male cadavers obtainedfrom the Department of Anatomy, constituted the material for the study. These were dissected and roots, trunks,cords and terminal branches of brachial plexus were exposed. The variant patterns were noted and photographed.Results: Out of 50 limbs, 5 limbs showed variations of brachial plexus at different levels.All the variations seenwere unilateral. Out of 5 variant patterns seen, different types of communications between musculocutaneousand median nerve were observed in 4 limbs (8%).Out of 4, in 1 limb (2%) medial cord joined with lateral root ofmedian nerve to form mediano-ulnar nerve which after a distance of 1cm bifurcated into median and ulnarnerve. In one limb (2%), there was no distinction between medial and lateral cord. Instead a single anterior cordwas formed by union of anterior divisions of all the three trunks anterior to axillary artery.Conclusion: The variant patterns of brachial plexus are usually more prone to accidental injuries and entrapmentneuropathies. Knowledge of such variations may provide additional anatomical information for the cliniciansduring diagnosis of unusual clinical symptoms and also for surgeons during surgical exploration of axilla andarm to avoid damage to these nerves.

The Formation Of Lateral Cord Of Brachial Plexus And Its Branches – A Cadaveric Study

Introduction: The lateral cord of brachial plexus is formed from the anterior divisions of upper and middletrunks, formed from roots C5, C6 and C7. Variations in the formation and branching of lateral cord are notuncommon. Considering its variations, a detailed knowledge is necessary to neurosurgeons, anaesthetists andorthopedicians to avoid complications.Materials and Methods: The present study was conducted in the Department of Anatomy, Mamata MedicalCollege, Khammam. 70 formalin fixed upper limbs [35 cadavers] were dissected for a period of 5 years. Formationand branching of lateral cord of brachial plexus were observed and variations are taken into consideration.Observations: Out of 70 limbs dissected, we observed communication between the lateral cord and medial rootof median nerve in 10 limbs. In 2 limbs musculo-cutaneous nerve was not formed. In 3 limbs musculo-cutaneousnerve did not pierce the coracobrachialis. In 7 limbs low union of medial and lateral roots of median nerve wasobserved. In 2 limbs, lateral pectoral nerve arises from upper trunkConclusion: The lateral cord and its branches show variations more frequently than medial and posterior cordsof brachial plexus

Bilateral Variations in Median Nerve Formation with Embryological Basis and Clinical Correlation.

During routine dissection of upper limb of a 68 year old male cadaver bilateral variations in median nerve were observed. On the left side the lateral cord pierced coracobrachialis without giving the lateral root of median nerve and after coming out of coracobrachialis it bifurcated in to musculocutaneous nerve and lateral root of median nerve. The medial root of median nerve continued up to the middle of arm and joined the lateral root and formed the median nerve in the middle of arm instead of axilla. On the right side there were two lateral roots of the median nerve that joined the medial root to form the median nerve. The musculocutaneous nerve after piercing coracobrachialis gave a communicating branch to the median nerve in the lower part of front of arm. These variations can lead to unusual innervation and entrapment neuropathies. Identification of these variants are valuable during surgeries performed in and around axilla and flexor compartment of arm.

Median Nerve as a Nerve of Anterior Compartment of Arm with its Variant Formation.

Absence ofMusculocutaneous nerve and unusual formation and innervation ofMedian nerve were noted in left upper limb during anatomical dissection of 60 yr old female cadaver.Median nerve normally does not give any branch in arm but in this case it innervates all the muscles of anterior compartment of arm in place of Musculocutaneous nerve. Here we discussed its embryology. It is important to be aware of such possible anatomical variations in routine clinical practice.

Compression of Brachial Vein between Two Lateral Roots of Median Nerve -A Case Report

During gross anatomy dissection, variation in the formation of median nerve of the upper limb was discovered in the right upper extremity of a 57-year-old male cadaver. Three roots contributed to the formation of median nerve instead of usual two roots i.e. two lateral roots and one medial root. After being formed the median nerve descended medial to the axillary artery. Between the two lateral roots brachial vein passed to open into the axillary vein. Anatomical variations in the formation of nerves and their unusual relationship to the surrounding structures can be the cause of nerve compression syndromes and vascular problems.

Formation and Branching Pattern of Cords of Brachial Plexus- A Cadaveric Study In North Indian Population.

BACKGROUND: The anatomical variations in the different parts of brachial plexus in human have been described by many authors. These variations have clinical significance for the surgeons, radiologists and the anatomists. A lot of work has been done on the morphology of branching pattern of the different cords of brachial plexus but almost all the workers are silent about their morphometry. That’s why this study is planned on morphology & morphometry of branching pattern of different cords of brachial plexus. MATERIAL AND METHODS: The present study was conducted on 60 upper limbs belonging to 30 cadavers (Male:Female = 28:02), (Right:Left = 30:30) obtained from Department of Anatomy, Govt. Medical College, Amritsar. These were dissected to expose the different components of brachial plexus. OBSERVATIONS: Out of 60 limbs, the lateral and the medial cords were formed in the usual way in 56 limbs, while the posterior cord was normal in 57 limbs. The average lengths of lateral, medial & posterior cords were 3.37 cm, 4.05 cm & 1.95 cm respectively. The branches of lateral cord depicted more variations in the form of origin as compared with those of medial & posterior cords. The distance of different branches of all the cords from the point of origin to parent cord varied between the two sides of same cadaver as well as on the same side of different cadavers. DISCUSSION & CONCLUSION: The present study on the adult human cadavers is an essential prerequisite for the initial built up of the data base at the grass root level. The anatomy has always provided a bedrock for the sound surgical endeavors. It definitely has an upper edge to widely and indiscriminately used radiological and sophisticated CT and MRI observations which carry a margin of error inherent to any diagnostic procedure because no doubt the machines are a good bet but the eyes see the best.

Anatomical variation in musculocutaneous nerve –A cadaveric study.

Introduction:-Variation in origin, branching pattern, course and termination of musculocutaneous nerve are common. These anatomical variations important for anatomist, clinicians, anaesthetics and surgeons for avoid unexpected complication. Material & method:- Detailed study of 50 upper limbs of cadavers carried out in last 3 year. Result –in this study 4% cases there is absence of musculocutaneous nerve. Musculocutaneous nerve not piercing coracobrachialis and communicate with median nerve in 4% cases and musculocutaneous nerve rejoins with median nerve in 2% cases. Conclusion:- In this study we found significant variation in musculocutaneous nerve which is important for surgeons, while planning surgery in axilla and arm to avoid injury.

Communication Between Musculocutaneous and Median Nerve – Different Types and Their Incidence in North Indian Population.

The variations of the median nerve and the musculocutaneous nerve, like the communication between the two, may prove valuable in the traumatology of the shoulder joint and the upper arm region and in situations when the surgeon has to isolate and trace the median and musculocutaneous nerve distally. The present study was conducted on 60 upper limbs belonging to 30 cadavers (Male:Female = 28:02), (Right:Left = 30:30) obtained from Dept. of Anatomy, Govt. Medical College, Amritsar, Punjab. Brachial plexuses were exposed as per standard guidelines. The observations recorded were as follows: 1). The musculocutaneous nerve was absent in six (10%) limbs; the muscles usually supplied by this being supplied by median nerve in two limbs and by lateral cord (coracobrachialis) and median nerve (biceps and brachialis) in the other four limbs. 2). A single communication between the musculocutaneous and the median nerve was encountered in the six (10%) limbs. It was in the upper third of the upper arm, proximal to the entrance of the musculocutaneous nerve into the coracobrachialis muscle. 3.) A complete fusion of the musculocutaneous nerve and the median nerve after normal formation of the former was seen in four (6.66%) limbs. Out of these four limbs; in 1 limb, coracobrachialis; in 2 limbs, coracobrachialis and biceps and in one limb all three muscles of the anterior compartment were supplied by musculocutaneous nerve before its fusion with the median nerve.

A rare variation in the formation of the lateral cord and median nerve of brachial plexus : a case report.

Brachial plexus is the plexus of nerves that supplies the upper limb. The Anatomical variations of the brachial plexus in humans have clinical significance to surgeons, radiologists and anatomists. Variation in the origin and distribution of branches of brachial plexus are common but variation in the roots, trunks and cords are very rare. Here we report a rare variation in the formation of lateral cord and variation in origin of median nerve. Lateral cord was formed by anterior division of upper trunk alone (C5, C6 ), but an additional intermediate cord between medial & lateral cord was found which was a continuation of anterior division of middle trunk (C7) . Median nerve was formed by: A lateral root carrying C5and C6 fibers arising from lateral cord, intermediate cord carrying C7 fibers and medial root of medial cord carrying C8 and T1 fibers.

Anomalous Branching Pattern of Lateral Cord of Brachial Plexus / Padrón de Ramos Anómalos del Fascículo Lateral del Plexo Braquial

During routine dissection, an unusual formation of median nerve was detected in the right upper limb of a 55 year old male cadaver. The median nerve had an additional contribution from lateral cord. The two branches of the lateral cord designated as upper and the lower branches were observed at different levels. The upper branch was in close contact with the third part of the axillary artery and it crossed the vessel anteriorly to unite with a branch of the medial cord to form the median nerve. The median nerve thus formed was related medially to the axillary artery (instead of the normal position of being anterolateral). The median nerve descended below and was joined by an additional lower branch from the lateral cord. Interestingly, the ulnar nerve which arose from the medial cord, descended below and was joined within its fascial sheath by the medial cutaneous nerve of the forearm The presence of such an additional branch from the lateral cord contributing to the formation of median nerve and its unusual relation of being medial to the axillary artery may be of immense clinical interest to neurologists diagnosing nerve lesions and surgeons who are exposed to the topographical anatomy of the neural structures during radical neck dissection. The additional branch of the lateral cord may compress upon the axillary artery to cause vascular insufficiency.

Durante una disección de rutina fue encontrada una formación inusual del nervio mediano en el miembro superior derecho, de un inividuo de sexo masculino, de 55 años de edad. El nervio mediano tenía una contribución adicional del facículo lateral. Los dos ramos del fascículo lateral, designados como ramos superior e inferior, fueron observados a diferentes niveles. El ramo superior tuvo un estrecho contacto con la tercera parte de la arteria axilar y cruzaba la vena axilar anteriormente para unirse con un ramo del fascículo medial y formar el nervio mediano. El nervio mediano así formado estaba relacionado medialmente con la arteria axilar (en vez de su posición normal de situación anterolateral). El nervio mediano se dirigía hacia bajo y se unía con un ramo inferior adicional del fascículo lateral. El nervio ulnar, que se originaba del fascículo medial, descendía posterior y se unía en la vaina fascial con el nervio cutáneo medial del antebrazo. La presencia de un ramo adicional del fascículo lateral contribuyendo a la formación del nervio mediano y su inusual relación con la arteria axilar, tiene un interés clínico para los neurólogos, quienes diagnostican lesiones nerviosas, y cirujanos que están expuestos a encontrar variaciones de estructuras nerviosas durante disecciones radicales de cuello. El ramo adicional del fascículo lateral puede comprimir la arteria axilar y causar insuficiencia vascular.