Discussion
Patients have presented with a wide ranging symptoms of COVID-19. Seizures have been a documented presentation of COVID-19 occurring at various stages of illness and even in individuals without underlying neurological illness.1,2,3,4 Beta coronaviruses SARS-CoV and MERS-CoV have been associated with neurological symptoms are attributed to the upregulation of proinflammatory cytokines following initial viral pneumonia.5
Potential mechanisms that could contribute to seizures in COVID-19 include interaction with angiotensin-converting enzyme 2 (ACE2) in neuronal and glial cells, and cytokine storm effects, specifically mediated by IL-6.6 Cytokine release syndrome (CRS) has also been documented after administration of well-known monoclonal antibody treatments7.
The BLAZE-1 study, which led to the emergency use authorization of bamlanivimab, reported no cases of seizures or serious adverse effects– other than anaphylaxis– in the 101 patients that received bamlanivimab. However, only 3% of participants (9 patients) in BLAZE-1 who received bamlanivimab were 75 years of age or older and there was no reported correlation of adverse events to age groups, making adverse effects in older adults even less certain.8 When applying the Adverse Drug Reaction Probability Scale, often known as the Naranjo Algorithm, to this case, the likeliness of bamlanivimab causing seizures in this case is “Possible” (score 3 of 13)9, suggesting a temporal sequence of events related to bamlanivimab. This may also be explained by characteristics of the patient’s diagnosis of COVID-19.