Parsonage Turner Syndrome MRI

Clinically : Middle aged male with Left side severe neck and shoulder pain followed by left shoulder abduction weakness.

MRI cervical spine normal.

Neurological examination mentions rotator cuff abductor weakness and latissimus dorsi wasting. 

NCV findings positive, confirmed left side supra scapular neuropathy. 

MRI shows diffuse T2 hyper intense odema involving supra and infra spinatous muscle.
Deltoid muscle spared. No obvious para labral cyst or supra glenoid notch cyst to cause supra scapular nerve compression.
Clinically spontaneous sudden onset without history of trauma or weight lifting.

Clinical history and imaging findings are typical of Parsonage Turner Syndrome.

Parsonage Turner Syndrome 

An acute idiopathic brachial neuritis.
Male predominance,majority between 3rd to 7th decade.
Clinical presentation is typically quite sudden painful shoulder girdle followed by progressive weakness.
Symptoms non-specific and can mimic numerous other much more common conditions.
Condition is unilateral in two-thirds of cases.
A combination of history, EMG with suprascapular neuropathy and imaging findings makes the diagnosis.
The etiology is uncertain, although viral infection or immunological cause is suspected.
In almost all cases (97%) the suprascapular nerve is involved and muscles are supraspinatus and infraspinatus (innervated by suprascapular nerve.
The most striking features on MRI are denervation changes in muscles with diffuse high T2 signal. Gradually atrophy and fatty infiltration on follow up imaging or chronic cases.
Typically self-limiting and requires supportive therapy. 90% will have excellent recovery by three years.