Brachial and lumbosacral plexopathies: A review

Abstract

Diseases of the brachial and lumbosacral plexus are uncommon and complex. The diagnosis of plexopathies is often challenging for the clinician, both in terms of localizing a patient's symptoms to the plexus as well as determining the etiology. The non-specific clinical features and similar presentations to other root, nerve, and non-neurologic disorders emphasize the importance of a high clinical index of suspicion for a plexopathy and comprehensive clinical evaluation. Various diagnostic tests, including electrodiagnostic (EDX) studies, neuroimaging (including ultrasound, MRI, or PET), serologic studies, and genetic testing, may be used to confirm a plexopathy and assist in identifying the underlying etiology. EDX testing plays an important role in confirming a plexopathy defining the localization, pathophysiology, chronicity, severity, and prognosis. Given the complexity of the plexus anatomy, multiple common and uncommon NCS and an extensive needle examination is often required, and a comprehensive, individualized approach to each patient is necessary. Treatment of plexopathies often focuses on symptomatic management although, depending on the etiology, specific targeted treatments may improve outcome. This article reviews the clinical features, EDX approaches, and evaluation and treatment of brachial and lumbosacral plexopathies.

Keywords: Brachial plexus; Electrodiagnosis; Imaging; Inflammatory; Lumbosacral plexus; Neoplastic; Radiation; Thoracic outlet syndrome; Trauma.

Fig. 1

The brachial plexus. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)

Fig. 2

Ulnar motor NCS with stimulation through the brachial plexus in a patient with a medial cord brachial plexopathy, demonstrating a focal conduction block between Erb’s point and the upper arm.

Fig. 3

Myelogram and computed tomography demonstrating large pseudomeningocoele (arrows) from traumatic C7 root avulsion.

Fig. 4

MRI of the brachial plexus demonstrating increased signal and multifocal constrictions (arrows) in the right lower trunk in a patient with neuralgic amyotrophy.

Fig. 5

The thoracic outlet. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)

Fig. 6

A cervical rib compressing the brachial plexus in thoracic outlet syndrome. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)

Fig. 7

MRI demonstrating a left brachial plexus schwannoma (arrow).

Fig. 8

MRI demonstrating increased signal and thickening of the entire left brachial plexus (arrow) in a patient with radiation-induced brachial plexopathy.

Fig. 9

The lumbosacral plexus and branches in coronal view. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)

Fig. 10

The lumbar and sacral plexus in lateral view. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)

Fig. 11

Branches of the lumbar plexus. (Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.)