Novel treatment of enterovirus encephalitis associated with B-cell depleting therapy

• Enteroviruses can cause neuroinvasive disease with severe neurological sequelae. • B-cell depleting therapy increases the risk of enterovirus encephalitis. • Diagnosis is challenging requiring samples from CSF, throat and stool. • Combination antiviral, IVIg and steroid use can lead to complete recovery. Enteroviruses typically manifest as a self-limiting coryzal illness. However, in children and immunocompromised adults, they can cause neuroinvasive disease with serious neurological sequelae. We report the use of repurposed antiviral drugs to treat severe enterovirus rhomboencephalitis in a young woman who had received ocrelizumab treatment for relapsing-remitting multiple sclerosis. The patient became critically unwell over 9 days, requiring intubation and mechanical ventilation. Given lack of clinical improvement despite intravenous immunoglobulin (day 10), steroids and removal of sedation (day 20), broad spectrum anti-RNA virus agents were added with evidence of clinical improvement over the 10 days following. Following treatment she had an excellent clinical outcome. This case highlights both the diagnostic challenges of enterovirus-related encephalitis and the potential role for combination antivirals in the management of complex cases of enterovirus encephalitis.