Parsonage-Turner syndrome is an acute idiopathic brachial neuritis.
There is male predominance (M:F 2:1 to 11.5:1) 1. Patients from 3 months to 85 years old have been reported, but the majority are between 3rd to 7th decade of life.
The presentation is typically quite sudden, with an onset of a painful shoulder girdle and progressive weakness. Symptoms are however non-specific and can mimic numerous other much more common conditions such as cervical spondylosis, labral tear with paralabral cyst and other suprascapular notch masses, rotator cuff deficiency, shoulder impingement, calcific tendonitis and adhesive capsulitis 1-2.
The findings are unilateral in two-thirds of cases. Bilateral involvement is reported.
The etiology is uncertain, although localized infectious (viral) or immunological process is suspected. In almost all cases (97%) the suprascapular nerve is involved and is the only nerve involved in 50% of cases 2. The axillary nerve and subscapular nerve are also sometimes involved, either in combination or alone.
The most frequently involved muscles are supraspinatus and infraspinatus (innervated by suprascapular nerve) followed by deltoid (innervated by axillary nerve).
The most striking features on MRI are denervation changes in muscles. Initially, the muscle appears normal. Over the next few weeks, high T2 signal develops. Gradually, especially in patients with a protracted course, atrophy and fatty infiltration will develop with the increase in T1 signal and decreased muscle bulk.
Treatment and prognosis
The condition is typically self-limiting with supportive therapy only being required. Weakness may persist for many years although 90% of patients will have an excellent recovery by three years 2.
History and etymology
This syndrome was first described in 1943 by Spillane 4 but popularized with a larger series in 1948 by Parsonage and Turner 3:
- Maurice John Parsonage, neurologist: UK
- John W Aldren Turner, neurologist: London, UK
Differential diagnosis on MR findings includes 1-2:
- 1. Scalf RE, Wenger DE, Frick MA et-al. MRI findings of 26 patients with Parsonage-Turner syndrome. AJR Am J Roentgenol. 2007;189 (1): W39-44. doi:10.2214/AJR.06.1136 - Pubmed citation
- 2. Gaskin CM, Helms CA. Parsonage-Turner syndrome: MR imaging findings and clinical information of 27 patients. Radiology. 2006;240 (2): 501-7. doi:10.1148/radiol.2402050405 - Pubmed citation
- 3. Parsonage MJ, Turner JW. Neuralgic amyotrophy; the shoulder-girdle syndrome. Lancet. 1948;1 (6513): 973-8. - Pubmed citation
- 4. JD. Spillane "Localised neuritis of the shoulder girdle." The Lancet, London, 1943, ii: 532-535