Suprascapular neuropathy

Injury from pressure on/trauma to the shoulder, stab wounds above the scapula, improper use of crutches, stretching of the nerve, eg. volleyball players during serving, r/o rupture of the rotator cuff. In athletics intense activity over weeks may cause it. Baseball pitchers are susceptible. Volleyball players, weight lifters and wrestlers are susceptible to developing it. Many athletes have exclusive or predominant involvement of the infraspinatus muscle.

Clinically one sees difficulty initiating abduction of the arm and externally rotating the arm, with an aching pain in the shoulder joint.The sign is selective wasting and weakness of the supraspinatus and infraspinatus muscles. Testing the deltoid separately means taking the fully abducted arm and having the patient pull backwards; also looking for deltoid atrophy. Also useful are tenderness in the suprascapular notch and pain evoked by forced adduction of the arm.

Gradual onset neuropathies may be due to ganglia in the suprascapular notch and spinoglenoid notch, or malignant tumors from the scapula. True entrapment neuropathies within the notch to a spur or ligament. Inherited calcification of the ligament may occur.

Differential includes ABN (acute brachial neuritis) , and less commonly shoulder joint/rotator cuff disorders, disuse wasting, or combined shoulder/nerve injury. EMG is definitive. MRI can look at entrapment in the suprascapular notch, and determine which muscles and hence which nerves are involved.

Treatment may involve rest, physiotherapy, injections, suprascapular notch exploration (supraglenoid notch if only infraspinatus is involved).