Case of the Week
Section Editors: Matylda Machnowska1 and Anvita Pauranik2
1University of Toronto, Toronto, Ontario, Canada
2BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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May 24, 2018
Parsonage-Turner Syndrome
- Background:
- A rare, acute neuropathy affecting mainly the upper brachial plexus, with an annual incidence of 2/100,000 people
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Multiple precipitating factors including trauma, bacterial or viral infections, surgeries, vaccinations, pregnancy, childbirth, or psychological stress
- Clinical Presentation:
- Characterized by 3 successive stages:
- Painful phase: severe neuropathic pain often involving the shoulder girdle
- Weakness and sensory phase: most often affects the superior trunk, suprascapular nerve, or long thoracic nerve, with corresponding amyotrophy
- Recovery phase: quality and length dependent on the severity of axonal loss
- Characterized by 3 successive stages:
- Key Diagnostic Features:
- Diagnosis is clinical, with actual prevalence likely higher than in reported literature.
- MRI of the brachial plexus will usually show T2 hyperintensity of a root/trunk/cord/branch of the brachial plexus with perineural edema.
- MRI may show T2 hyperintensity of the affected muscles (infraspinatus, supraspinatus, serratus anterior, trapezius, etc.) resulting from edema or increased capillary blood volume.
- Recent studies show that a “bullseye” sign can accurately localize hourglass constrictions of affected nerves on MRI.
- Differential Diagnoses:
- Hyperalgesic cervical root disorder: diagnosed with cervical CT or MRI showing osteophyte formation, stenosis, or other degenerative changes impinging on the nerve roots
- Entrapment neuropathy: diagnosed with MRI showing swelling and increased size and signal of nerve with affected muscle atrophy and visualization of causative factor
- Shoulder joint disorder: diagnosed with MRI
- Acute transverse myelitis: diagnosed with MRI showing an increased T2 signal occupying greater than two-thirds of the cross-sectional area of the cord, with a variable pattern of enhancement and no diffusion restriction
- Treatment:
- Phase-dependent:
- Painful phase: corticosteroids
- Weakness and sensory phase: analgesics, NSAIDs
- Recovery phase: physical therapy and rehabilitation
- Phase-dependent:
