This narrative review defines neurogenic pectoralis minor syndrome (NPMS) as subclavicular brachial plexus compression, distinct from thoracic outlet syndrome. It walks through the history, physical exam, provocative maneuvers, and diagnostic muscle blocks used to distinguish and confirm both conditions. Conservative and surgical treatment options are also reviewed.
When a young athlete presents with hand paresthesia and arm pain but no neck pain or occipital headache, think pectoralis minor syndrome rather than classic thoracic outlet syndrome.
The mental model: NTOS lives above the clavicle (scalene triangle, neck symptoms), NPMS lives below it (subclavicular and axillary tenderness). At least 75% of NTOS patients also have NPMS, so always palpate both the scalene and pectoralis minor.
The lidocaine muscle block is the key confirmatory step. A muscle block relaxes the compressing muscle, unlike a plexus block that simply anesthetizes the arm.
The most actionable number is surgical: isolated NPMS tenotomy is 85% successful, but drops to 35% when NTOS coexists. Failing to recognize a second compression site predicts a failed operation and the need for later thoracic outlet decompression. Start conservative with pectoralis minor stretching for three months before offering tenotomy.
This narrative review defines neurogenic pectoralis minor syndrome (NPMS) as subclavicular brachial plexus compression, distinct from thoracic outlet syndrome. It walks through the history, physical exam, provocative maneuvers, and diagnostic muscle blocks used to distinguish and confirm both conditions. Conservative and surgical treatment options are also reviewed.
When a young athlete presents with hand paresthesia and arm pain but no neck pain or occipital headache, think pectoralis minor syndrome rather than classic thoracic outlet syndrome.
The mental model: NTOS lives above the clavicle (scalene triangle, neck symptoms), NPMS lives below it (subclavicular and axillary tenderness). At least 75% of NTOS patients also have NPMS, so always palpate both the scalene and pectoralis minor.
The lidocaine muscle block is the key confirmatory step. A muscle block relaxes the compressing muscle, unlike a plexus block that simply anesthetizes the arm.
The most actionable number is surgical: isolated NPMS tenotomy is 85% successful, but drops to 35% when NTOS coexists. Failing to recognize a second compression site predicts a failed operation and the need for later thoracic outlet decompression. Start conservative with pectoralis minor stretching for three months before offering tenotomy.