Bilateral Parsonage-Turner Syndrome After COVID-19 Vaccination. A Case Report and Review of the Literature

Parsonage---Turner syndrome (PTS; neuralgic amyotrophy) is a generally unilateral neuritis with sudden onset, severe shoulder or upper arm pain. Although the intense pain is usually self-limiting, two-thirds of patients experience pro-gressive motor weakness, narrowed range of motion, reflex changes, dysesthesias and chronic neuropathic pain in the shoulder girdle musculature and proximal upper limb muscles. The aetiology is unclear, in addition to some idiopath-ic cases the most common triggers of PTS are surgery, trauma, infection or vaccination. It is reported after SARS-CoV-2 infection, and unilateral PTS has been described in some cases following different types of COVID-19 vaccines. We are currently presenting the case of a middle-aged woman who developed partial neuralgic amyotrophy on the right shoulder one month after receiving the second dose of the BNT162b2 COVID-19 mRNA vaccine (Pfizer-BioNTech), and seven months later the symptoms appeared in the contralateral upper limb. The diagnosis of PTS was also confirmed by magnetic resonance and electrodiagnostic examination. The PTS is not an uncommon condi-tion, but in the absence of knowledge it is rarely thought of. The purpose of this report is to draw attention to the possibility of PTS in shoulder or upper arm pain following both SARS-CoV-2 infection and COVID-19 vaccination, as early diagnosis and adequate therapy may help to shorten the course of the disease.