Upper Extremity Syndromes

Thoracic Outlet Syndrome—Postural Type: Ultrasound Imaging of Pectoralis Minor and Brachial Plexus Abnormalities

“…A key element of the pathophysiology in postural TOS involves progressive PMM shortening [1]. This shortening causes scapular protraction with forward “collapse” of the shoulder girdle and relative closure of the thoracic outlet [1,13], which leads to upper limb symptoms, as described by Simons et al [13]: “stretch and torsion of the brachial plexus and axillary artery can occur as they hook beneath the pectoralis minor muscle where it attaches to the coracoid process.” Sucher and Glassman [12] demonstrated “indentation” of the PMM by the BP at 90° of abduction in a cadaver specimen, and Sucher [9] illustrated the NVB pulling against the posterior edge of the PMM during arm abduction in TOS. By contrast, NMUS of normal subjects may demonstrate slight plexus contact against the PMM in abduction but no significant indentation or symptoms.…”

“…NMUS has unique applications for the postural type of TOS; as some researchers have noted, “evaluation of proximal nerves is often problematic when using electrodiagnostic techniques and may be more easily studied with ultrasound” [16]. My experience with this type of postural TOS [1,2,9,12,17,18] suggests that the PMM is contributory, and NMUS now appears to support these prior clinical impressions. Palpation of increased tension and trigger points in the PMM, combined with shoulder protraction, suggests that the PMM has shortened.…”

“…Compression in all types of TOS may occur superiorly at the interscalene space, the costoclavicular space, or beneath the pectoralis minor muscle (PMM). The PMM location is recognized as a common and important site of compression in both the postural and nonpostural types of TOS [1‐3,9‐13].…”

Carpal Tunnel Syndrome: Diagnosis and Treatment

“…Nerve compression in the upper limb can occur at a number of sites and can affect the three major nerves together with their branches, both sensory and motor, in this area namely, the median, the ulnar and the radial nerve (30). Among all the upper extremity compression neuropathies, the carpal tunnel syndrome (CTS) is the most prevalent complaint affecting people in a variety of professions, and release of the carpal tunnel is one of the most frequently performed operations.…”