Quadriparesis with different diagnoses after COVID-19 vaccination: Case series and literature review.

Following vaccination with adenoviral vector-based ChAdOx1 nCoV-19, serious neurological adverse events have been reported. Here we report two cases who presented with quadriparesis following the adenoviral vector-based ChAdOx1 nCoV-19 vaccine. A 55-year-old male patient presented with quadriparesis after 8 days of the second dose of ChAdOx1 nCoV-19 vaccination. Imaging showed features of stroke with right basilar artery thrombosis; he was started on anticoagulation following which the patient's neurological status improved and he was discharged during the 7 week of hospital stay. A 19-year-old male patient presented with quadriparesis after 16 days of the first dose of ChAdOx1 nCoV-19 vaccination. Cerebral spinal fluid and nerve conduction study was suggestive of Guillain-Barre syndrome (GBS). Two doses of intravenous immunoglobulin were given, following which the patient's neurological status improved and he was discharged in the 11 week of his hospital stay. Awareness of neurological adverse effects and emphasis on the underlying mechanism of vaccine-induced thrombotic thrombocytopenia (VITT) and molecular mimicry in patients presenting with quadriparesis following ChAdOx1 nCoV-19 vaccination is important.