Cerebellar and brainstem stroke possibly associated with booster dose of BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine.

As COVID-19 vaccination becomes widely available and administered globally, there have been several reports of side effects attributed to the vaccine. This report highlights a patient who developed stroke 2 days following the administration of the COVID-19 vaccine, although its association remains uncertain. A man in his late 30s developed acute neurological symptoms 2 days after receiving the booster dose of the BNT162b2 (Pfizer-BioNTech) mRNA COVID-19 vaccine. History and neurological examination suggested a posterior circulation stroke, which was confirmed by MRI, as a right-sided posterior inferior cerebellar artery stroke. Full workup did not suggest other causes of the stroke. Due to the patient's age and well-controlled risk factors, it was presumed to be a rare adverse effect of the vaccine. Medical management with aspirin, statin therapy and rehabilitation led to the improvement of symptoms and enabled ongoing restoration of function. Further cases of stroke following administration of COVID-19 vaccine have been documented in the literature, but the association is yet to be established.