Parsonage-Turner syndrome, a (notso) rare cause of shoulder pain

Abstract

Parsonage-Turner syndrome is a pathology that mainly affects the brachial plexus in its upper or middle part and the peripheral nerves that originate from it. In the past, it was considered a rare disease, but recent studies show an annual incidence of about 1/1000. The clinical presentation has a characteristic course with a relatively rapid, often nocturnal onset of pain, most often localized in the proximal region of the arm and the trapezius muscle. The pain is usually not elicited by shoulder movements and is particularly severe at night. In the days following the onset of the first symptoms, there is a progressive paresis of part of the muscles of the shoulder. The diagnosis is based on the formulation of a clinical suspicion and subsequent confirmation by electro neuro-myography and imaging studies. While the main pain resolves spontaneously after 3–4 weeks, the motor disorder and a duller pain persist much longer and usually resolve within 1–3 years. While Parsonage-Turner syndrome was considered a benign disease in the past, there is now increasing evidence that a significant proportion of patients develop a chronic course characterized by persistent pain, weakness and fatigue in the affected extremity. Better clinical courses, however, appear to be favored by early treatment. It is therefore crucial to make the diagnosis as early as possible.