Chronic inflammatory demyelinating polyneuropathy following COVID-19 vaccination: a case report and literature review

Abstract Background Severe post-vaccination neurological complications are rare. Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is an immune-mediated polyneuropathy affecting the peripheral nerve roots, which is not well described as a post-vaccination side effect. Here, we present a rare complication of vaccination against SARS-CoV-2, reaching a diagnosis of CIDP. Case presentation A 67-year-old diabetic male presented with lower extremity paresthesia and weakness following the third dose of the Sinopharm (BBIBP-CorV) vaccine. Despite initial dismissal as a diabetic complication, symptoms escalated, affecting all extremities. Electromyography study revealed abnormal spontaneous activity with chronic reinnervation changes, which was more significant in the lower extremities. Based on the clinical course, radiographic imaging, and laboratory data, a diagnosis of CIDP with severe axonal demyelinating features was established. Treatment with intravenous immunoglobulin (IVIg), prednisolone, and azathioprine resulted in marked improvement of the upper extremities but limited recovery in distal lower extremity muscles. Conclusion Although CIDP is a rare complication following COVID-19 vaccination, it should be considered in the differential diagnosis. Timely diagnosis of vaccine-induced CIDP is challenging, and any delay can adversely affect treatment response in affected patients.