Disclosures: Kayli Gimarc, MD: No financial relationships or conflicts of interest

Case Description: Patient developed right medial pectoral atrophy and weakness while involved in competitive rowing and intensive weightlifting regimen, 6 years prior to presentation. In the interim, after stopping bench press, symptoms improved. He then began intensive firefighter training 6 months prior to presentation and had progression of right medial pectoral atrophy and new left medial pectoral atrophy. He had no other weakness or sensation changes. Differential included muscle tear, brachial plexopathy, cervical radiculopathy, and peripheral nerve injury. MRI cervical spine, chest, and shoulder were unremarkable for abnormal cord signal or brachial plexus abnormality but showed fatty atrophy of right medial pectoralis major. Examination was significant for right greater than left medial pectoral atrophy and diminished volitional activation, with normal cranial nerves, sensation, and reflexes.

Setting: Tertiary care clinic

Patient: 27-year-old male rower and weightlifter with bilateral pectoral atrophy Assessment/

Results: Needle electromyography (EMG) revealed isolated right greater than left medial pectoral mononeuropathy with evidence of ongoing denervation and no motor recruitment in right upper sternal head. All other muscles tested by needle EMG and sensory and motor nerve conduction studies were normal, suggesting right brachial plexopathy or cervical radiculopathy were unlikely. Patient was evaluated by plastic surgery and it was hypothesized that medial pectoral mononeuropathy may be due to compression of the medial pectoral nerves by pectoralis minor muscles. Patient was offered surgical exploration and neurolysis should site of compression be found, and didn’t ultimately follow up.

Discussion: Bilateral isolated medial pectoral neuropathy in the setting of intensive weightlifting is a rarely reported etiology. One hypothesized cause in this population is intramuscular compression of the medial pectoral nerve within the hypertrophied pectoralis minor muscle.

Conclusion: Earlier recognition and EMG-guided diagnosis of medial pectoral nerve palsy in weightlifters would help guide recommendations for activity modification, expedite referral for consideration of surgical intervention, and maximize potential for nerve recovery.

Level of Evidence: Level V

« Back to AAPM&R Annual Assembly 2020

PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/bilateral-medial-pectoral-nerve-palsy-in-a-weightlifter/