Painless Concurrent Suprascapular and Axillary Neuropathy in a Young Elite Volleyball Player: A Case Report

Background and Objectives: Peripheral nerve injuries around the shoulder are increasingly recognized in athletes who perform repetitive overhead motions. Suprascapular neuropathy is well described in volleyball players, whereas axillary neuropathy is usually attributed to dislocation or direct trauma. Concurrent, painless, non-traumatic involvement of both nerves is rare and may be mistaken for disuse or a rotator cuff disorder. Case Presentation: A 17-year-old male national-level volleyball player presented with painless atrophy of the dominant shoulder, noticed three months earlier, without trauma, dislocation, instability or pain. Examination showed infraspinatus fossa wasting and predominantly anterior deltoid atrophy, Medical Research Council grade 4 strength in external rotation, forward elevation and abduction, intact lateral deltoid sensation, symmetrical reflexes and a negative Spurling test. Radiographs were unremarkable. Magnetic resonance imaging showed fatty degeneration and atrophy of the infraspinatus and anterior deltoid with relative preservation of the supraspinatus, and no rotator cuff tear, labral tear, paralabral cyst or space-occupying lesion. Motor nerve conduction studies showed a reduced compound muscle action potential recorded from the infraspinatus with a preserved response from the supraspinatus after suprascapular nerve stimulation, together with a reduced deltoid response after axillary nerve stimulation. Selective involvement of the infraspinatus branch was most consistent with a suprascapular lesion at or distal to the branch to the supraspinatus, clinically compatible with involvement around the spinoglenoid notch, and argued against a C5 root or upper trunk lesion. Conclusions: Painless shoulder atrophy in an overhead athlete warrants systematic evaluation for peripheral nerve injury. The pattern of motor responses can localize the lesion, but in the absence of needle electromyography a multifocal process such as neuralgic amyotrophy (Parsonage-Turner syndrome) cannot be excluded, and a sport-related traction or compression mechanism should therefore be advanced cautiously.