- Discussion: - hx: persistant pain > 6 months: (poor prognosis);
- diff dx:
- breast cancer (lower plexus and painful)
- radiation therapy (upper plexus and painless)
- parsonage-turner syndrome : (may first affect suprascapular)
- pancoast tumor:
- Exam: of Brachial Plexus:
- vascular:
- axillary artery avulsion (may be as high as 20%)
- consider arteriogram;
- neuro exam of the brachial plexus:
- preganglionic vs postganglionic:
- preganglionic injuries have little potential for recovery;
- supraclavicular deficits:
- suprascapular (supraspinatus);
- dorsal scapular (rhomboids);
- long thoracic (serratus): hence winging of scapula may indicate preganglionic injury;
- infraclavicular deficits:
- medial and lateral pecotoral (pectoralis major and minor);
- thoracodorsal (latissimus): muscle is fired when patient coughs;
- subscapular (subscaplaris)
- cords:
- lateral cord: anterior divisions of the upper and middle trunk merge to form the lateral cord;
- medial cord: anterior division from the lower trunk forms the medial cord
- posterior cord:
- posterior divisions merge to become the posterior cord;
- shoulder abduction determines function of the axillary nerve;
- wrist extension determines low radial nerve function and elbow extension determines high radial nerve function;
- other:
- median and ulnar nerve function are determined by examining finger and wrist motion;
- elbow flexion evaluates musculocutaneous function;
- Radiographic Studies:
- CXR: (elevated hemidiaphram)
- scapulothoracic dissociation
- lateral translation of the shoulder girdle (measured from spinous process to medial border of scapula and AC widening
- associated w/ complete and permanent brachial plexopathy (and possible vascular injury);
- mortality rate of upto 10%
- ref: Scapulothoracic dissociation: a devastating injury.
- C-Spine X-ray: (associated C spine fractures)
- Arteriogram;
- CT myelogram: (rarely need to get myelograms)
- may be used to help dx a preganglionic lesion;
- this study but should be delayed 6-12 wks, since a clot of blood may occlude the opening of pseudomenigocele;
- finding of a large diverticula or meningocele is diagnostic for a preganglionic root avulsion (as opposed to a post ganglionic extra-foraminal rupture);
- ref: Imaging of posttraumatic brachial plexus injury.
- EMG:
- some authors advocate EMG after 7-10 days, noting that a normal sensory evoked potential obtained from an anesthetic finger indicates
that the lesion is preganglionic (otherwise there is a more distal nerve injury);
- problem with early EMG, is that preganglionic injuries may occur along w/ dorsal root ganglion injuries which will falsely
indicate a postganglionic injury, and inaddition, early EMG cannot distinguish between to axonotmesis and neurotmesis;
- traditionally EMG has been performed at 3-4 weeks (look for F wave);
- w/ preganglionic lesion, see denervating potentials in segmental paraspinal muscles innervated by the posterior primary rami;
- references:
- Sensory nerve conduction after traction injuries of the brachial plexus.
- Clinical Diagnosis, Testing, and Electromyographic Study in Brachial Plexus Traction Injuries.
- The role of somatosensory evoked potentials and nerve conduction studies in the surgical management of brachial plexus injuries.
- Clinical examination versus routine and paraspinal electromyographic studies in predicting the site of lesion in brachial plexus injury.
- Initial Treatment:
- avoid a sling because of the propensity to acquire a fixed internally rotated and flexed shoulder, and will have stiff elbow;
- keep C-collar on and look for associatted C spine fractures
- in children and adults, if biceps function has not return after 3 mo. then consider operation;
- Surgical Treatment:
- Shoulder in brachial plexus injuries:
- Steindler Flexorplasty:
- w/ severe injury, one option is AEA if the shoulder muscles are functioning
Brachial plexus surgery.