# Brainstem Encephalitis: An Atypical Manifestation of Zika Virus Infection in Brazil

## TL;DR

A 21-year-old woman in Brazil developed brainstem encephalitis as a rare complication of Zika virus infection, highlighting its neuroinvasive potential.

## Contribution

This case report adds to the understanding of atypical neurological manifestations of Zika virus, particularly brainstem encephalitis.

## Key findings

- Zika virus can cause brainstem encephalitis, presenting with confusion, speech impairment, and gait disturbance.
- Treatment with corticosteroids and antiepileptic drugs led to significant clinical improvement in the patient.
- The case emphasizes the need to consider Zika virus in the differential diagnosis of encephalitis in endemic regions.

## Abstract

Zika virus (ZIKV), once considered a relatively benign pathogen, has emerged as a cause of severe neurological complications, including Guillain-Barrè Syndrome and encephalitis. This report presents the case of a 21-year-old Brazilian woman who initially presented with fever, rash, and arthralgia. Seven days later, she developed confusion, speech impairment, and gait disturbance. Following a tonic-clonic seizure, neurological examination revealed dysphonia, dysarthria and facial palsy, suggestive of brainstem involvement. ZIKV infection was detected by positive IgM serology and a plaque reduction neutralization test. The patient was treated with corticosteroids and antiepileptic drugs, leading to substantial clinical improvement, and discharge after 25 days of hospitalization. This case underscores the neuroinvasive potential of ZIKV and highlights the importance of early recognition and management of atypical neurological manifestations. It also reinforces the need to consider ZIKV in the differential diagnosis of encephalitis, particularly in endemic regions, and contributes to the growing understanding of ZIKV neurotropism and possible therapeutic approaches for severe presentations.