1. Brachial Plexus
Dr. Sama-ul-Haque Dr. Nivin Sharaf

2. BRACHILAL PLEXUS
The brachial plexus is a somatic nerve plexus formed by intercommunications among the ventral rami of the lower four cervical nerves ( C 5 - C 8) and the first thoracic nerve (T 1). The plexus is responsible for the motor innervation to all of the muscles of the upper limb with the exception of the trapezius and levator scapula.), and the sensory innervation of the upper limb except an area just above the point of the shoulder (supplied by supraclavicular nerves) and the dorsal scapular area which is supplied by cutaneous branches of dorsal rami.

3. Spinal Nerve

4. FORMATION OF THE BRACHIAL PLEXUS
Roots
The ventral rami of spinal nerves C5 to T1 are referred to as the roots of the plexus.
Trunks
Shortly after emerging from the intervertebral foramina , these 5 roots unite to form three trunks.
The ventral rami of C5 & C6 unite to form the Upper Trunk.
The ventral ramus of C 7 continues as the Middle Trunk.
The ventral rami of C 8 & T 1 unite to form the Lower Trunk.
Divisions
Each trunk splits into an anterior division and a posterior division.
The anterior divisions usually supply flexor muscles
The posterior divisions usually supply extensor muscles

5. Location of Brachial plexus

6. Relations of Brachial plexus

7. FORMATION OF THE BRACHIAL PLEXUS CONT.
Cords
The anterior divisions of the upper and middle trunks unite to form the lateral cord.
The anterior division of the lower trunk forms the medial cord.
All 3 posterior divisions from each of the 3 cords all unite to form the posterior cord.
The cords are named according to their position relative to the axillary artery
Terminal branches:
Musculo Cutaneous
Ulnar n.
Median n.
Axillary n.
Radial n.
Terminal Branches are mixed nerves containing both sensory and motor axons.
Musculocutaneous nerve is derived from the lateral cord.
This nerve innervates the muscles in the flexor compartment of the arm
Carries sensation from the lateral ( radial) side of the forearm. (Figs. 2,3)
Ulnar nerve is derived from the medial cord
Motor innervation is mainly to intrinsic muscles of the hand
Sensory innervation is from the medial ( ulnar) 1 & 1/2 digits ( the 5th. and 1/2 of the 4th. digits). (Figs. 2,3)
Median nerve is derived from both the lateral and medial cords
Motor innervation is to most of the flexors muscles in the forearm and intrinsic muscles of the thumb (thenar muscles).
Sensory innervation is from the lateral ( radial) 3 & 1/2 digits ( the thumb and first 2 and 1/2 fingers). (Figs. 2,3)
Axillary nerve is derived from the posterior cord.
Motor innervation is deltoid and teres minor muscles that act on the shoulder joint.
Sensory innervation is from the skin just below the point of the shoulder. (Figs. 2,3)
Radial nerve is also derived from the posterior cord.
Called “Great Extensor Nerve” because it innervates the extensor muscles of the elbow, wrist and fingers.
Sensory innervation is from the skin on the dorsum of the hand on the radial side. (Figs. 2,3)

9. Relations of Brachial plexus
BRANCHES (Fig. 4) Nerves that are branches from portions of the brachial plexus usually contain only 1 type of axon; either sensory or motor)
From the Roots
Dorsal Scapular nerve
Derived from C5 root
Motor nerve to the Rhomboideus major and minor muscles
Long Thoracic nerve
Derived from C 5,6,7
Innervates the serratus anterior muscle
From the Upper Trunk
Nerve to subclavius muscle
Suprascapular nerve
Innervates supra and infraspinatus muscles
From the Lateral Cord
Lateral Pectoral nerve
Innervates the clavicular head of the pectoralis major muscle
From the Medial Cord
Medial Pectoral nerve
Innervates the sternocostal head of the pectoralis major muscle
Innervates the pectoralis minor muscle
Note : the medial and lateral pectoral nerve often join together to act as a single nerve innervating both the pectoralis major & minor muscles
Cutaneous Branches
Medial brachial cutaneous
Carries sensation from the lower medial portion of the arm
Medial antebrachial cutaneous
Carries sensation from the medial (ulnar portion of the forearm)

10. Brachial Plexus

11. Relation with Axillary Artery
Pectoralis minor is the land mark where divisions turn into cords, cords are related to the axillary artery “ medial, lateral, and posterior to the axillary artery

12. Postfixed Brachial Plexus

13. Brachial Plexus Injuries
The brachial plexus lies in the posterior triangle of the neck between the scalenus anterior and scalenus medius muscles. At the root of the neck, it lies behind the clavicle.
The most common injury is severe traction with the arm in abduction e.g. after a motor cycle accident. Partial paralysis may also result from shoulder dislocation. Direct injury to the brachial plexus can result from a stab or gunshot wound. :

14. Brachial Plexus Injuries
In Adults:
Sports most commonly associated:
Football, baseball, basketball,
volleyball, wrestling, and
gymnastics.
Nerve injuries can result from: Blunt force trauma, poor posture or chronic repetitive stress.

15. Brachial Plexus Injuries
Patients generally present with pain and/or muscle weakness.
Some patients may experience muscle atrophy.

16. Brachial Plexus Injuries
Result:  Anesthesia  Paralysis 1. Complete 2. Incomplete

17. Erb- Duchenne palsy
Injury to Superior part of Plexus. Occurrence: Due to excessive increase in the angle between neck and the shoulder. Roots Involved:  C5 and C6 Muscles Involved:  Shoulder  Arm

20. Vacuum Extractor delivery

21. Forceps delivery

22. Falling on Shoulder

24. Excessive Stretching

26. Direct Blow

29. What is Waiter’s tip or Porter’s tip position?

30. Erb- Duchenne palsy
Clinical Appearance: Motor Loss:  Adducted Shoulder  Medially Rotated Arm  Extended Elbow Sensory Loss: Lateral aspect of Upper Limb (uncommon)

32. Waiter’s tip position
Characteristic position - adduction and internal rotation of the arm with forearm pronated
Forearm extension normal
Biceps reflex absent

34. Waiter’s tip palsy
Erb's palsy is caused by damage to the brachial plexus during delivery of the neonate. This is mostly limited to the 5th and 6th cervical nerves

36. klumpke paralysis or Palsy
Injury to Inferior part of Plexus. Occurrence: Excessive abduction of arm. Less common then Injury to Superior part of Plexus. Roots Involved:  C8 and T1

37. klumpke paralysis or Palsy
Clinical Appearance: Motor Loss:  Small muscles of Hand Sensory Loss:  Medial aspect of Upper Limb

38. Person grasping something to prevent a fall

39. Baby’s upper limb is pulled excessively during delivery

40. Claw Hand
Aetiology:
brachial plexus lesion (C8-T1),Ulnar, and/ or Median nerve injury
This occurs when all fingers are clawed. It is the result of hyperextension at the metacarpophalangeal joints and flexion of the interphalangeal joints.

41. Claw Hand

42. Involves Inferior part of Plexus
Cervical Rib
Involves Inferior part of Plexus

43. References http://www.upstate.edu/cdb/education/grossanat/limbs2.shtml

44. Thank You