The suprascapular nerve emerges from the brachial plexus to innervate the supraspinatus and infraspinatus muscle. It runs through 2 notches that constitute its weak spots: the supraclavicular notch and the spinoglenoid notch.
Paralysis for this nerve is essentially spontaneous, with no apparent cause (nerve tunnel syndrome) or it may be caused by a small developing tumour, usually a cyst.
The main sign of paralysis is weakness in the shoulder, predominantly in external rotation, sometimes associated with pain.
The treatment consists in endoscopic release. This surgery requires general anaesthesia but ambulatory care is possible.
Full recovery often spreads over a oneyear period.
For injuries diagnosed very late, an arthroscopic latissimus dorsi transfer procedure can be considered.