C5-T1 provides cutaneous and motor supply to the upper extremity.
Roots – 5 Anterior rami of the spinal nerves
Trunks – Superior (C5-6), Middle (C7), Inferior (C8-T1)
Divisions – Each truck slpits into 2 so there are 6 divisions. Anterior and posterior for each trunk.
Cords - Posterior = 3 posterior divisions of each trunk (C5-T1)
Lateral = Anterior divisions of Sup. & middles trunks (C5-7)
Medial = Continuation of Ant. Division of Inf. Trunk (C8-T1)
Branches – 5 terminal branches
Musculocutaneous (C5-7) from lateral cord
Axillary (C5-6) from posterior cord
Radial (C5-T1) terminal branch of posterior cord
Median (C5/6-T1) from lateral and medial cords
Ulnar (C8-T1) from medial cord
Lesions (rare)
Signs and symptoms can range from anaesthesia to complete paralysis, depending on location of injury. Can occur as a result of trauma, tumour or inflammation, usually traumatic or obstetric. Most damage as a result of excessive stretching (fall on to head and shoulder, violent pulling on arm, reduction of shoulder dislocation).
Divided into 3 types:
Upper Plexus Lesion (C5-7)– Excessive lateral neck flexion away from shoulder (forceps delivery or falling on to shoulder with head moving away). This leads to Erb’s palsy and ‘Waiter’s tip’ deformity (arm hangs medially rotated, forearm extended and pronated). Most common ytype of lesion.
Whole Plexus Lesion – Less frequent, more traumatic. Sensory and power loss to whole upper extremity.
Lower Plexus Lesion (C8-T1) – Least commonly occuring. From sudden upward pulling on an adducted arm (eg. Falling froma tree and grabing a branch) leading to Klumpke’s paralysis (effects intrinsic muscles of the hand plus wrist and finger flexors. Characterised by clawed hand due to no Ulnar nerve supply).
Musculocutaneous Lesions (C5-7) – Coracobrachialis, Brachialis and Biceps Brachii & Lateral cutaneous nerve of forearm. Rare. Can occur due to excessive hypertrophy and compression of the nerve between biceps brachii aponeuris and brachioradialis fascia, or can get stretch during shoulder dislocation.
Weakness of elbow flexion and forearm supination. Sensory disturbance on radial side of forearm. Reduced biceps DTR.
Axillary Lesions (C5-6) – Deltoid and Teres Minor & lateral cutaneous nerve of arm (Sergeant’s stripes). Can occur with shoulder dislocation, accounts for 0.3-6% of Brachial Plexus injuries. Deltoid weakness and atrophy with sensory loss around the deltoid. Symtoms may also include not being able to bend the arm at the elbow.
Radial Lesions (C5-T1) - Triceps Brachii, Supinator, Anconeus, forearm extensors and brachioradialis & Posterior cutaneous nerve of the arm. Can be damaged with a stab wound to the chest (damaging the posterior cord, as this is the terminal branch of post. Cord) or more commonly with a fracture to the Humerus as the nerve runs in the radial groove. Persistent injury can occur with prolonged use of crutches or extended periods of leaning on the elbows. Weakness in brachioradialis, wrist extension and finger flexion (writs drop).
Median Lesions (C6-T1) – Forearm flexors (except FCR and part of FDP) 1st & 2nd lumbricals and thenar muscles (LOAF). Cutaneous supply to lateral palm, palmer suface of thumb & lateral 3 ½ fingers. Dorsal surface of distal phalanges 1 7 2 plus the thumb. Only nerve to go through the Crapal tunnel. Can be compressed underneath Struthers’ ligamnet (between humerus and medial epicondyle of humerus – not presnt in everyone), in the bicepital aponeurosis, between 2 heads of pronator teres and in the carpal tunnel. It can also be damaged with a penetrating injury to the forearm. High lesions are at elbow or foreamr, low lesions are at the wrist. ‘Ape hand’ deformity (can’t abduct or oppose the thumb due to loss of thenar muscles), sensory loss to thum, index finger, long finger and lateral ½ of ring finger, weakness in pronation, wrist and finger flexion, difficulty with daily activities using the hand (esp. gripping).
Ulnar Lesions (C8-T1) - FCU, the medial two bellies of FDP, intrinsic muscles of the hand (except the thenar muscles and lumbricals 1 & 2). Sensory to skin on medial side of hand, little finger and medial ½ of ring finger (palmer and doral surfaces). Can be damaged in cubital tunnel or tunnel of Guyon by fracture or compression. Sensory disruption into the little finger, weakness in the hand, wasting of the lumbricals, ‘ulnar claw’.
Roots – 5 Anterior rami of the spinal nerves
Trunks – Superior (C5-6), Middle (C7), Inferior (C8-T1)
Divisions – Each truck slpits into 2 so there are 6 divisions. Anterior and posterior for each trunk.
Cords - Posterior = 3 posterior divisions of each trunk (C5-T1)
Lateral = Anterior divisions of Sup. & middles trunks (C5-7)
Medial = Continuation of Ant. Division of Inf. Trunk (C8-T1)
Branches – 5 terminal branches
Musculocutaneous (C5-7) from lateral cord
Axillary (C5-6) from posterior cord
Radial (C5-T1) terminal branch of posterior cord
Median (C5/6-T1) from lateral and medial cords
Ulnar (C8-T1) from medial cord
Lesions (rare)
Signs and symptoms can range from anaesthesia to complete paralysis, depending on location of injury. Can occur as a result of trauma, tumour or inflammation, usually traumatic or obstetric. Most damage as a result of excessive stretching (fall on to head and shoulder, violent pulling on arm, reduction of shoulder dislocation).
Divided into 3 types:
Upper Plexus Lesion (C5-7)– Excessive lateral neck flexion away from shoulder (forceps delivery or falling on to shoulder with head moving away). This leads to Erb’s palsy and ‘Waiter’s tip’ deformity (arm hangs medially rotated, forearm extended and pronated). Most common ytype of lesion.
Whole Plexus Lesion – Less frequent, more traumatic. Sensory and power loss to whole upper extremity.
Lower Plexus Lesion (C8-T1) – Least commonly occuring. From sudden upward pulling on an adducted arm (eg. Falling froma tree and grabing a branch) leading to Klumpke’s paralysis (effects intrinsic muscles of the hand plus wrist and finger flexors. Characterised by clawed hand due to no Ulnar nerve supply).
Musculocutaneous Lesions (C5-7) – Coracobrachialis, Brachialis and Biceps Brachii & Lateral cutaneous nerve of forearm. Rare. Can occur due to excessive hypertrophy and compression of the nerve between biceps brachii aponeuris and brachioradialis fascia, or can get stretch during shoulder dislocation.
Weakness of elbow flexion and forearm supination. Sensory disturbance on radial side of forearm. Reduced biceps DTR.
Axillary Lesions (C5-6) – Deltoid and Teres Minor & lateral cutaneous nerve of arm (Sergeant’s stripes). Can occur with shoulder dislocation, accounts for 0.3-6% of Brachial Plexus injuries. Deltoid weakness and atrophy with sensory loss around the deltoid. Symtoms may also include not being able to bend the arm at the elbow.
Radial Lesions (C5-T1) - Triceps Brachii, Supinator, Anconeus, forearm extensors and brachioradialis & Posterior cutaneous nerve of the arm. Can be damaged with a stab wound to the chest (damaging the posterior cord, as this is the terminal branch of post. Cord) or more commonly with a fracture to the Humerus as the nerve runs in the radial groove. Persistent injury can occur with prolonged use of crutches or extended periods of leaning on the elbows. Weakness in brachioradialis, wrist extension and finger flexion (writs drop).
Median Lesions (C6-T1) – Forearm flexors (except FCR and part of FDP) 1st & 2nd lumbricals and thenar muscles (LOAF). Cutaneous supply to lateral palm, palmer suface of thumb & lateral 3 ½ fingers. Dorsal surface of distal phalanges 1 7 2 plus the thumb. Only nerve to go through the Crapal tunnel. Can be compressed underneath Struthers’ ligamnet (between humerus and medial epicondyle of humerus – not presnt in everyone), in the bicepital aponeurosis, between 2 heads of pronator teres and in the carpal tunnel. It can also be damaged with a penetrating injury to the forearm. High lesions are at elbow or foreamr, low lesions are at the wrist. ‘Ape hand’ deformity (can’t abduct or oppose the thumb due to loss of thenar muscles), sensory loss to thum, index finger, long finger and lateral ½ of ring finger, weakness in pronation, wrist and finger flexion, difficulty with daily activities using the hand (esp. gripping).
Ulnar Lesions (C8-T1) - FCU, the medial two bellies of FDP, intrinsic muscles of the hand (except the thenar muscles and lumbricals 1 & 2). Sensory to skin on medial side of hand, little finger and medial ½ of ring finger (palmer and doral surfaces). Can be damaged in cubital tunnel or tunnel of Guyon by fracture or compression. Sensory disruption into the little finger, weakness in the hand, wasting of the lumbricals, ‘ulnar claw’.