Acute encephalitis after COVID-19 vaccination: A case report and literature review

Abstract

Vaccine-related immune responses are one of the causes of encephalitis. Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) have been administered worldwide due to the ongoing global pandemic; cases of SARS-CoV-2 vaccination-related encephalitis were scarcely reported. An 82-year-old female was diagnosed with acute encephalitis following her first dose of vaccination with mRNA-1273 against SARS-CoV-2. The patient presented with fever and headache five days after vaccination, followed by behavior change 17 days after vaccination. Electroencephalographic recordings revealed focal slow waves in the right frontoparietal regions. Brain MRI revealed the signal change in the right middle and posterior temporal lobe. Cerebrospinal fluid analysis showed mildly elevated protein. She responded well to steroid pulse therapy and made a full recovery. The severity of the immune response following COVID-19 vaccination may be alleviated if adequate treatment is achieved. Physicians must be alert for encephalitis after vaccination to help ensure a favorable outcome.

Keywords: COVID-19; SARS-COV-2; encephalitis; neurological complications; vaccination.

Figure 1.

Summarizes the timeline of clinical course and manifestations of the patient with post-vaccination encephalitis.

Figure 2.

Post-COVID-19 vaccination encephalitis: magnetic resonance imaging (MRI) of the brain demonstrates prominent T2 fluid attenuated inversion recovery (FLAIR)-hyperintense lesions in the right middle temporal (a) and posterior temporal (c) regions with gadolinium enhancement (b, d). The EEG recordings exhibit intermittent focal slow waves in the right frontocentral to parietal regions (e). Post-treatment brain MRI (at 20 days after admission) shows attenuated signal intensity on the T2 FLAIR image (f, h), in the absence of enhancement in the middle-posterior temporal gyri (g, i). EEG findings were normal (j).