A patient with brachial plexus injury is likely to have sustained other concomitant injuries; head injury, fractures in the cervical spine, clavicle, scapula, and extremities, chest and abdominal trauma and vascular injuries. The neurological examination should determine the specific motor and sensory deficits. The British Medical Research Council grading system is used to measure the motor strength of each muscle.

A detailed neurological examination helps in identifying the site and severity of the injury and dictates the treatment algorithm. In partial injuries some of the functions in limb are intact. In upper brachial plexus palsy (C5, C6) shoulder and elbow functions are poor, however hand functions are preserved. Extended upper plexus palsy (C5,6,7) has additional weakness wrist and finger extension. Lower brachial plexus palsy (C8-T1) presents with poor hand functions with normal shoulder and elbow functions.

In total palsy entire limb is flail and insensate, superficial sensations being present only in the inner aspect of arm which receives innervation from the T2 dermatome. The limb hangs by the side of the body with arm and forearm being internally rotated. A positive Horner’s sign (Fig 1) indicates C8, T1 nerve root injuries with involvement of cervical sympathetics. Examination of individual muscle helps in indentifying the site of injury and forms a baseline to assess recovery. The neurological examination should determine the specific motor and sensory deficits. The British Medical Research Council (BMRC) grading system is used to measure the motor and sensory functions of the extremity (Table 1).

Table 1- Assessment of motor power by the British Medical Research Council grading system

Muscle Grade Description
5 Full range of movements against gravity with full resistance
4 Full range of movements against gravity with some resistance
3 Full range of movements against gravity
2 Full range of movements with gravity eliminated
1 Flicker of contraction
0 No contraction

Sensory examination is performed using two-point discrimination or Semmes Weinstein monofilament testing (Table 2).
Table 2- Assessment of sensory functions by the British Medical Research Council grading system

Grading Description
S0 No sensation
S1 Recovery of deep cutaneous pain sensibility
S2 Recovery of superificial cutaneous pain sensibility
S2+ Same as S2, only with over response
S3 Pain and touch sensibility with a disappearance of over response. Two-point discrimination > 15 mm
S3+ Same as S3, only localization of the stimulus is good. Two-point discrimination 7 to 15 mm
S4 Recovery of complete sensation. Two-point discrimination 2 to 6 mm

An examination of individual muscles helps in indentifying the site of injury and forms a baseline to assess recovery (Table 3).
Table 3 – Brachial plexus examination sheet

General Clinical examination
Sign Implications
Horner Sign Sympathetic ganglion injury (T1)

Diaphragmatic palsy

Phrenic nerve injury (C3-C5)

Tinel sign in neck

Root rupture (Proximal root stump may be present)
Deafferentation pain Root avulsion
Winged scapula Long thoracic nerve injury(C5-C7)
Muscle Root value Remarks (Bulk & Power)
Trapezius C3,C4, Spinal accessory nerve  
Levator scapulae C3,C4,C5  
Rhomboids C4,C5  
Supraspinatus C5,C6  
Infraspinatus C5,C6  
Serratus anterior C5,C6,C7  
Teres major C5,C6  
Subscapularis C5,C6,C7  
Pectoralis major clavicle C5,C6,C7  
Pectoralis major sternocostal C6,C7,C8 T1  
Latissimus dorsi C6,C7,C8  
Biceps and brachialis C5,C6  
Deltoid C5,C6  
Teres minor C5,C6  
Pronator quadratus C7,C8,T1  
Pronator teres C6,C7  
Flexor carpi radialis C6,C7  
Flexor digitorum profundus II, III C7,C8,T1  
Flexor digitorum superficialis C7,C8,T1  
Flexor pollicis longus C7,C8,T1  
Abductor pollicis brevis C6,C7,C8,T1  
Opponens pollicis C8,T1  
Lumbricals C8,T1  
Triceps C6,C7,C8  
Supinator C5,C6  
Brachioradialis C5,C6  
Extensor carpi radialis longus C6,C7  
Extensor carpi radialis brevis C6,C7,C8  
Extensor carpi ulnaris C7,C8  
Extensor digitorum communis C7,C8  
Extensor digiti minimi C7,C8  
Extensor indicis C7,C8  
Extensor pollicis longus C7,C8  
Abductor pollicis longus C6,C7  
Flexor carpi ulnaris C7,C8,T1  
Abductor digiti minimi C8,T1  
Flexor digitorum prof. IV, V C7,C8,T1  
Abductor pollicis C8,T1  
Opponens digiti C8,T1  
Interossei C8,T1  

 

 

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