History
The index of suspicion for a brachial plexus injury is much higher for severe shoulder-girdle injuries, particularly motorcycle accidents and motor vehicle accidents (MVAs). The mechanism of injury should be considered; these injuries may occur in the setting of polytrauma. The presence of other injuries necessitating sedation indicates that detailed follow-up examination of the upper extremity may be needed.
The patient may present with the following symptoms:
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Pain, especially of the neck and shoulder - Pain over a nerve is common with rupture, as opposed to lack of percussion tenderness with avulsion
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Paresthesias and dysesthesias
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Weakness or heaviness in the extremity
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Diminished pulses - Vascular injury may accompany traction injury
Physical Examination
The standard advanced trauma life support (ATLS) protocol should be followed. Abrasions to the head, helmet, or tip of the shoulder suggest supraclavicular injury. Ptosis (lid droop), enophthalmos (sinking of the eye into the orbit), anhidrosis, and miosis (small pupil), or Horner syndrome, suggest a complete lower-plexus lesion (see the image below), in that the sympathic ganglion for T1 is in close proximity to the brachial plexus.
Traumatic brachial plexus injury. Patient has ptosis and miosis of right eye secondary to complete lower brachial plexus lesion.
Swelling about the shoulder can be dramatic. Diminished or absent pulses suggest vascular injury, and special consideration should be given to rupture of the subclavian vessels. Clavicle fractures often are palpable. Careful inspection and palpation of the axial skeleton may reveal concomitant injuries. Each cervical root should be examined individually for motor and sensory function as soon as circumstances allow.
Some special considerations are warranted for the neurologic examination. Sensory examination is extremely important. Deep pressure sensation may be the only clue to continuity in a nerve with no motor function or other sensation (see Table 1 below). The deep pressure test involves applying full pinch to the nail base and pulling the patient's finger outward. Any burning suggests continuity of the tested nerve. When no burning is elicited, these examination findings are less helpful because a neurapraxia can persist for more than 6 months.
Table 1. Deep Pressure Test (Open Table in a new window)
Location of Deep Pressure Test |
Affected Spinal Nerve |
Nerve |
Affected Cord |
Thumb |
C6 |
Median nerve |
Lateral cord |
Middle finger |
C7 |
Median nerve |
Lateral cord |
Little finger |
C8 |
Ulnar nerve |
Medial cord |
Examination of wrist and finger sensation and motion with respect to the median, ulnar, and radial nerves may help locate the lesion within the brachial plexus.
Motor examination is also useful (see Table 2 below). Significant variations occur among the spinal nerves within the cord and account for most of the anomalous patterns of innervation. These variations may make identifying the levels involved challenging. In addition, C4 may contribute a branch to the plexus up to 60% of the time. When C4 makes a significant contribution to the plexus, the plexus is called prefixed. A prefixed cord can explain recovery in the distribution of a nerve root clinically presumed to be avulsed.
Table 2. Guide to Motor Testing (Open Table in a new window)
Cervical Root |
Clinically Relevant Gross Motor Function |
C5 |
Shoulder abduction, extension, and external rotation; some elbow flexion |
C6 |
Elbow flexion, forearm pronation and supination, some wrist extension |
C7 |
Diffuse loss of function in the extremity without complete paralysis of a specific muscle group, elbow extension, consistently supplies the latissimus dorsi |
C8 |
Finger extensors, finger flexors, wrist flexors, hand intrinsics |
T1 |
Hand intrinsics |
In performing the motor examination, it is important to keep in mind that most individual muscles have contributions from multiple cervical levels (see the image below).
Traumatic brachial plexus injury. Human cadaveric dissection of right brachial plexus shows that clavicle and some soft tissues have been resected. Nerve roots are exiting their respective foramina at right-hand border. Uppermost nerve root observed is C5, with C6, C7, and C8 also visible. Cords of plexus can be observed at left-hand margin. Note axillary artery at bottom.
Elbow flexion and extension determine musculocutaneous and high radial nerve function. Shoulder abduction tests the axillary nerve, which comes off the posterior cord. The posterior cord may also affect deltoid function by the radial nerve. The latissimus dorsi is innervated by the thoracodorsal nerve off the posterior cord and may be tested by palpation of the muscle while the patient coughs.
Pectoralis muscles can be palpated as the patient adducts the arm against resistance (the medial pectoral nerve to the sternal head comes off the medial cord, whereas the lateral pectoral nerve to the clavicular head comes off the lateral cord). The long thoracic nerve innervates the serratus anterior, and the dorsal scapular nerve innervates the rhomboids; thus, winging of the scapula may help localize the injury.
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Traumatic brachial plexus injury. Patient has ptosis and miosis of right eye secondary to complete lower brachial plexus lesion.
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Traumatic brachial plexus injury. Human cadaveric dissection of right brachial plexus shows that clavicle and some soft tissues have been resected. Nerve roots are exiting their respective foramina at right-hand border. Uppermost nerve root observed is C5, with C6, C7, and C8 also visible. Cords of plexus can be observed at left-hand margin. Note axillary artery at bottom.
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Traumatic brachial plexus injury. Initial anteroposterior chest radiograph of patient involved in accident with 18-wheeled truck. Clavicle fracture observed on initial chest radiograph was important in signaling need for further evaluation of injury because patient was intubated and unresponsive secondary to closed head injury. Scapulothoracic dissociation was suspected on close review of chest CT scan, and brachial plexus injury was noted once patient became responsive.
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Traumatic brachial plexus injury. Plain CT scan obtained during initial workup of same patient as in preceding image. Fracture of right scapula is visible, as is right pulmonary contusion and significant periscapular swelling. Scapulothoracic dissociation was suspected on basis of clavicle fracture, scapula fracture, brachial plexus palsy, and high-energy mechanism of injury (ie, accident with 18-wheeled truck). CT scan is oblique; high-quality anteroposterior chest radiograph demonstrating lateral displacement of right scapula was obtained later to confirm diagnosis.
Tables
Location of Deep Pressure Test |
Affected Spinal Nerve |
Nerve |
Affected Cord |
Thumb |
C6 |
Median nerve |
Lateral cord |
Middle finger |
C7 |
Median nerve |
Lateral cord |
Little finger |
C8 |
Ulnar nerve |
Medial cord |
Cervical Root |
Clinically Relevant Gross Motor Function |
C5 |
Shoulder abduction, extension, and external rotation; some elbow flexion |
C6 |
Elbow flexion, forearm pronation and supination, some wrist extension |
C7 |
Diffuse loss of function in the extremity without complete paralysis of a specific muscle group, elbow extension, consistently supplies the latissimus dorsi |
C8 |
Finger extensors, finger flexors, wrist flexors, hand intrinsics |
T1 |
Hand intrinsics |
