Neuro-immunological complications post COVID-19 vaccination: two case reports [version 1; peer review: 2 approved with reservations]

Purpose: To add to the growing literature regarding the possible link between the onset of Guillain Barre syndrome (GBS) and Bickerstaff brainstem encephalitis (BBE) and the coronavirus disease (COVID-19) vaccines. Case reports: The first patient is a 38-year-old man that presented muscle weakness and an unsteady gait for a duration of one week. Initially, he developed an unsteady gait, then gradually worsening generalized muscle fatigue and ascending weakness in all limbs. He tested positive for GM1 and GQ1D antibodies, and magnetic resonance imaging (MRI) of the lumbar spine with contrast and nerve conduction study (NCS) results were both suggestive of acute motor axonal neuropathy (AMAN). The second patient is a 54-year-old man that developed generalized fatigue and subjective fever associated with headache and blurry vision followed by bulbar dysfunction. During hospitalization, his consciousness level started to be affected and he developed ataxia with ophthalmoparesis. A diagnosis of BBE was made based on clinical, imaging, and cerebrospinal fluid (CSF) findings. Conclusion: Since temporal relationships do not signify causation, we cannot draw any conclusions regarding the association between COVID-19 vaccines and these neurological disorders. However, it is vital that new cases are reported so that the knowledge base is built upon, and to increase healthcare workers’ vigilance for early signs of GBS or BBE.