Neurological Adverse Reactions to SARS-CoV-2 Vaccines

SARS-CoV-2 vaccines are not free of side effects and most commonly affect the central or peripheral nervous system (CNS, PNS). This narrative review aims to summarise recent advances in the nature, frequency, management, and outcome of neurological side effects from SARS-CoV-2 vaccines. CNS disorders triggered by SARS-CoV-2 vaccines include headache, cerebro-vascular disorders (venous sinus thrombosis [VST], ischemic stroke, intracerebral hemorrhage, subarachnoid bleeding, reversible, cerebral vasoconstriction syndrome, vasculitis, pituitary apoplexy, Susac syndrome), inflammatory diseases (encephalitis, meningitis, demyelinating disorders, transverse myelitis), epilepsy, and a number of other rarely reported CNS conditions. PNS disorders related to SARS-CoV-2 vaccines include neuropathy of cranial nerves, mono-/polyradiculitis (Guillain-Barre syndrome [GBS]), Parsonage-Turner syndrome (plexitis), small fiber neuropathy, myasthenia, myositis/dermatomyositis, rhabdomyolysis, and a number of other conditions. The most common neurological side effects are facial palsy, intracerebral hemorrhage, VST, and GBS. The underlying pathophysiology is poorly understood, but several speculations have been generated to explain the development of CNS/PNS disease after SARS-CoV-2 vaccination. In conclusion, neurological side effects develop with any type of SARS-CoV-2 vaccine and are diverse, can be serious and even fatal, and should be taken seriously to initiate early treatment and improve outcome and avoid fatalities.