CASE REPORT
A CASE REPORT WITH RARE ANOMALY IN BRACHIAL PLEXUS
Jyoti Kiran Kohli1
HOW TO CITE THIS ARTICLE:
Jyoti Kiran Kohli. “A Case Report with Rare Anomaly in Brachial Plexus”. Journal of Evidence Based
Medicine and Healthcare; Volume 1, Issue 3, May 2014; Page: 123-128.
ABSTRACT: During routine dissection studies we encountered a nervous anomaly in an
embalmed male cadaver aged 40years. The anomaly was bilaterally present in the upper
extremity. The medial cutaneous nerve of forearm was communicating with the intercostobrachial
nerve giving cutaneous supply to the medial side of arm and continuing further in forearm. Such
a variation is not yet described in available literature.
INTRODUCTION: Medial cutaneous nerve of forearm arises from the medial cord, derived from
eight cervical and first thoracic ventral rami. It supplies a ramus piercing the deep fascia to
supply skin over biceps almost to elbow. It divides into anterior and posterior branches. The
anterior branch supplies skin of anteromedial aspect of forearm till wrist where it connects with
palmer cutaneous branch of ulnar nerve. The posterior branch curves round medial epicondyle to
back of forearm to supply skin there and medial border of wrist. It connects with
1. Medial cutaneous nerve of arm
2. Posterior cutaneous of forearm
3. Dorsal branch of ulnar.(5)
Medial cutaneous nerve of the arm arises from the medial cord, traverses axilla and goes
to the arm where it terminates by giving cutaneous supply to arm. Midway
- It communicates with intercostobrachial nerve,
- It connects with posterior branch of medial cutaneous nerve of forearm- (5)
Intercostobrachial nerve is the lateral cutaneous branch of second thoracic nerve which
communicates with medial cutaneous nerve of arm in axilla and supplies skin of upper half of
posterior and medial aspect of arm.(5)
Normal variations seen:
- Medial cutaneous nerve of arm and intercostobrachial nerve are connected in a plexiform
manner in axilla.
- Intercostobrachial nerve is large and reinforced by part of lateral cutaneous branch of third
intercostal nerve, replacing medial cutaneous nerve of arm.
- Second intercostobrachial nerve often branches off from anterior part of third lateral
cutaneous nerve.(5)
OBSERVATIONS: Medial cutaneous nerve of forearm was communicating with
intercostobrachial nerve and giving cutaneous supply to arm (Branch given at the level of
insertion of coracobrachialis).
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CASE REPORT
It further supplies skin of forearm by dividing into anterior and posterior divisions below
the epicondyle. Medial cutaneous nerve of arm was seen communicating with the
intercostobrachial nerve terminating, and supplying fat of axilla.
Figure 1
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CASE REPORT
Figure 2
1. COMMUNICATION BETWEEN INTERCOSTOBRACHIAL AND MEDIAL CUTANEOUS NERVE
OF FOREARM.
2. INTERCOSTOBRACHIAL NERVE.
3. MEDIAL CUTANEOUS NERVE OF FOREARM.
Figure 3
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CASE REPORT
1. ST – SUPERIOR TRUNK
A- AXILLARY ARTERY
2. MT- MIDDLE TRUNK
CB- CORACO BRACHIALIS MUSCLE
3. IT- INFERIOR TRUNK
4. LC – LATERAL CORD
MN – MEDIAN NERVE
5. PC- POSTERIOR CORD
UN- ULNAR NERVE
6. MC- MEDIAL CORD
MCN – MUSCULOCUTANEOUS NERVE
7. MCNF – MEDIAL CUTANEOUS NERVE OF FOREARM
8. LCNF – LATERAL CUTANEOUS NERVE OF FOREARM
9. LR – LATERAL ROOT OF MEDIAN NERVE
10. MR- MEDIAL ROOT OF MEDIAN NERVE
Figure 4
DISCUSSION: The brachial plexus is a large and very important plexus situated partly in the
neck and in the axilla. Although the plexus is normally formed from ventral rami C5 to C8 and T1,
variations in the pattern of the plexus can be due to abnormal formation during the development
of the trunks, divisions or cords. Walsh was the first, to describe the anatomic variations in the
formation of the brachial plexus in a man.(10)
The brachial plexus may be injured while falling on the side of the head or the shoulder,
because the nerve in the plexus can get violently stretched. The plexus may also be injured by
direct violence or gunshot wounds, by violent traction in arm or in reducing glenohumeral
dislocation.
Twenty nine types of plexus were described by KERR (1918) and 27 by HIRASAWA
(1931). Union of anterior division of medial cord with the medial root of median nerve was found
in1/75 arms by KERR (1918), in none of HIRASAWA 200 arms (1931) and 1/200 fetal arms by
OBARA(1950). LE MINOR (1990) appears to have recorded the only other instance in which the
lateral cord and musculocutaneous nerve pierced coracobrachialis. (1, 2, 4, 7)
According to TOUNTAS and BERGMAN,(7, 6) the musculocutaneous nerve arises from the
lateral cord (90.5%), from the lateral and posterior cords(4%), from the median nerve(2%)as
two separate bundles from the medial and lateral cords (1.4%) or from posterior cord(1.4%).
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WATANABE et.al reported two cases of fusion of musculocutaneous and median nerve.
Communication between musculocutaneous and median nerve is considered as a revenant from
phylogenetic or comparative viewpoint.(6)
Knowledge of variations in anatomy is important to anatomists, radiologists, anesthetists
and surgeons, and has gained more importance due to the wide use and reliance on computer
imaging in diagnostic medicine. Also, the presence of anatomic variations of the peripheral
system is often used to explain unexpected clinical signs and symptoms. Descriptions of nerve
variations are useful in clinical/surgical practice since an anatomical variation can be the cause of
a nerve palsy syndrome due to a different relation of a nerve and a related muscle.(11)
All these anomalies were noted but anomalies seen here in our case is not reported till
date to the best of our knowledge.
CLINICAL IMPORTANCE:
Medial cutaneous nerve of arm and forearm provides sensation to medial cutaneous nerve
of arm, as it originates from C8 to T1 and branches from medial cord.
Keeping in mind about multiple variations of brachial plexus cases should be examined or
operated carefully during surgical or elect physiologic procedures.
This nerve is expandable and thus used as a nerve graft and sensory examination
confirms its utility (specially the anterior branch of medial cutaneous nerve of arm which can be
harvested while sparing the posterior branch).(11)
This nerve provides sensation to medial forearm and posterior division provides sensation
to the natural resting surface of elbow and forearm.
The anterior division is expandable and can be used as nerve graft material, while
posterior division is spared.(11)
The likelihood of arterial and nervous anomalies should not be overlooked by vascular and
plastic surgeons and radiologists. So before performing an operation on these patients
angiography is also required to avoid excessive bleeding or any unnecessary complication.(10)
Nerve can be injured during medical elbow surgical procedures and can lead to painful
neuroma formation when injured.(9)
These cases can also be presented in clinics as referred pain (neuralgia) to forearm or to
axilla.
REFERENCES:
1. HIRASAWA K (1931) SERIE A: Untersuchungen iiber das periphere nervensystem. Heft 2:
plexus brachialis und die nerven der oberen Extremitat, Arbeiten aus der dritten abeilung
des Anatomischen Institutes des Kaiser Lichen Universidad Kyoto.1-190.
2. KERR AT (1918) the brachial plexus of nerves in man the variations in its formation and
branches. American Journal of anatomy23.285-395.
3. L SARIKCIOGLU, N, COSKUN and O, OZKAN (2001) surg Radiol Anat: A case with multiple
anamolies in the upper limb 23:65-68.
4. OBARA M (1958) on the brachial plexus of the Japanese fetus. Nippon ikadaigaku zasshi
25.94-123 (in Japanese with English abstract).
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CASE REPORT
5. WILLIAMS PL, WARWICK R, DYSON M, BANNISTERLH (1989) Gray’s Anatomy, Churchill
living stones Edinbergh. pp 1130-1137.
6. WATANABE M. TAKATSUJI K, SAKAMOTO N, MORITA Y, ITOH (1985) two cases of fusion of
musculocutaneous and median nerves.
7. TOUNTAS C, BERGMAN R (1993) Anatomic variations of the upper extremity, CHURCHILL
LIVINGSTONE, New York pp 223-224.
8. TOSHIO NAKATANI, SHIGENORI TANAKA, SHIGEKI MIZUKAMI (1998) J, Anat; Two rare
anomalies of the brachial plexus, pp. 303-304,
9. HERSHMAN EB. Brachial plexus injuries, Clin sports med9:311-319, 1990.
10. AHMET UZUN, SAITBILGIC. Some variations in the formation of the brachial plexus in
infants, Tr. j. of medical sciences 29:573-577, 1999.
11. VALERIA PAULA ET. Al. Brachial plexus variations in its formation and main branches, Acta
Cir Bras vol. 18, suppl 5, 2003.
AUTHORS:
1. Jyoti Kiran Kohli
PARTICULARS OF CONTRIBUTORS:
1. Associate Professor, Department of
Anatomy, SGT Medical College, Gurgaon,
Haryana.
NAME ADDRESS EMAIL ID OF THE
CORRESPONDING AUTHOR:
Dr. Jyoti Kiran Kohli,
E-12, 1st Floor,
Lajpatnagar 1st,
New Delhi - 110024.
E-mail: jkk702003@yahoo.co.in
Date
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Submission: 18/05/2014.
Peer Review: 19/05/2014.
Acceptance: 30/05/2014.
Publishing: 11/06/2014.
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