COVID-19 vaccine induced opsoclonus-myoclonus-ataxia syndrome

Objective: We present a 15-year-old girl who developed opsoclonus-myoclonus-ataxia syndrome (OMS)within 24 hoursafter the injection of a COVID-19 mRNA vaccine.

Method: We retrospectively analyzed the patient’s data from the database of Kocaeli University Medical Faculty Hospital.

Results: A15-year-old girl presented with complaints of fever, malaise, headache, subjective vertigo and fainting. On physical examination, she had a fever of 38°C, ataxia, and opsoclonus. She had a history of two COVID-19 infections, the first one was 15 months and the second one 3 months ago,respectively. COVID-19 mRNA vaccine (Pfizer‐BioNTech) was administered a day before her hospitalization. Whole blood count and serum biochemistry were normal. Erythrocyte sedimentation rate was 58 mm/h. Brain MRI, EEG and serologic tests against autoimmune encephalitis were normal. Tumor screening was negative.There was no response to intravenous immunoglobulin (IVIG) therapy, so rituximab was ordered.

Conclusions: Vaccines against viruses rarely cause neurological abnormalities. Several neurologic adverse-effects also have been reported after COVID-19 vaccines, such as facial palsy, Guillain-Barre syndrome or transverse myelitis. The presented case is the first case diagnosed as opsoclonus-myoclonus-ataxia syndrome due to COVID-19 vaccination.