EDX Evaluation of the Brachial Plexus-Dr. Jorgensen EDX of Brachial Plexopathies

Dr. Jorgensen EDX of Brachial Plexopathies

Pdf Summary

The document discusses the topic of brachial plexopathies, specifically focusing on the anatomy, clinical settings, electrodiagnostic patterns, and the limitations of using sensory nerve conduction studies (NCS) to differentiate between radiculopathy and plexopathy.<br /><br />The brachial plexus is situated between the cervical roots (radiculopathy) and peripheral nerves (e.g., carpal tunnel syndrome). It is not prone to degeneration or overuse. The anatomy of the brachial plexus includes the roots emerging from the neural foramen, trunks passing through the supraclavicular fossa, divisions situated deep to the clavicle, and cords located infraclavicularly, deep to the pectoralis major and minor muscles.<br /><br />Key details regarding the anatomy are highlighted, such as the innervation of the levator scapulae, rhomboid major, and rhomboid minor muscles by the dorsal scapular nerve (C5), as well as the involvement of the long thoracic nerve (C6, C7, C8) in neuralgic amyotrophy.<br /><br />The document mentions the variability in plexus anatomy and discusses when to consider a brachial plexopathy, including instances involving trauma, surgery, sudden non-traumatic sensory or motor complaints in the upper limb, suspected radiculopathy with negative imaging, history of radiation or malignancy in the axillary region, and history of upper lobe lung malignancy or breast cancer.<br /><br />The electrodiagnostic patterns of nerve disease, such as axon loss, conduction block, and conduction slowing, are described. However, it is noted that the detection of conduction block in brachial plexus lesions is technically difficult. The document emphasizes the use of motor amplitudes rather than sensory amplitudes in severe cases to differentiate between radiculopathy and plexopathy.<br /><br />The limitations of using sensory NCS to differentiate between radiculopathy and plexopathy are discussed. The variability in normal values of NCS, both between people and among people (side-to-side), makes it challenging to confidently determine abnormality unless the damage is severe. Hence, sensory amplitudes should not be solely relied upon in distinguishing between pre and post-ganglionic lesions.<br /><br />Overall, the document provides an overview of brachial plexopathies, including its anatomy, clinical settings, electrodiagnostic patterns, and the challenges associated with using sensory NCS to differentiate between radiculopathy and plexopathy.

Keywords

brachial plexopathies

anatomy

clinical settings

electrodiagnostic patterns

sensory nerve conduction studies

radiculopathy

plexopathy

nerve disease

axon loss

conduction block