Presentation
Shoulder pain for several months, not responding to treatment.
Patient Data
There is oedema involving supraspinatus and infraspinatus muscles with loss of volume and fatty infiltration of both muscles, mainly supraspinatus.
The other rotator cuff muscles, as well as deltoid muscle, are normal in size and signal intensity.
No rotator cuff tear. No masses or cysts in the region of the suprascapular and spinoglenoid notches. No paralabral cysts. Normal looking quadrilateral space.
Normal glenoid labrum and articular surface. Normal bone marrow signal. No joint effusion.
Case Discussion
Appearances in this case are highly suggestive of Parsonage-Turner syndrome, as there is no compression of the suprascapular nerve by a cyst or a mass.
Parsonage-Turner syndrome is an acute idiopathic brachial neuritis. Males are affected more than females. Two-thirds of cases are unilateral.
The suprascapular nerve is involved in almost all cases. The supraspinatus and infraspinatus muscles are commonly involved, followed by the deltoid muscle.
The affected muscles look initially normal. After few weeks, oedema due to denervation develops in the involved muscles and gradual loss of muscle volume and fatty infiltration take place.
The disease is self-limiting and treatment is conservative.