Work Up for Brachial Plexus Injuries       

- See: brachial plexus
- 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.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Wednesday, March 27, 2013 9:30 am