Encephalitis and cytokine storm secondary to respiratory viruses in children: Two case reports

INTRODUCTION: Encephalitis is a syndrome characterized by brain damage secondary to an inflammatory process that is manifested by cognitive impairment and altered cerebral spinal fluid analysis; it may evolve with seizures and coma. Despite viral infections representing the main cause of encephalitis in children, respiratory syncytial virus (RSV) and parainfluenza virus are mostly associated with respiratory presentations. Uncommonly, the inflammatory phenomena from encephalitis secondary to viral agents may present with an exacerbated host response, the so-called cytokine storm. The link between these infectious agents and neurologic syndromes resulting in a cytokine storm is rare, and the underlying pathophysiology is still poorly understood. CASE PRESENTATION: A 5-year-old girl and a 2-year-old boy infected with parainfluenza and RSV, respectively, were identified through nasopharyngeal polymerase chain reaction. They were admitted into the pediatric intensive care unit due to encephalitis and multiple organ dysfunction manifested with seizures and hemodynamic instability. Magnetic resonance imaging findings from the first patient revealed a bilateral hypersignal on fluid-attenuated inversion recovery in the cerebral hemispheres, especially in the posterior parietal and occipital regions. The girl also had elevated IL-6 levels during the acute phase and evolved with a fast recovery of the clinical presentations. The second patient progressed with general systemic complications followed by cerebral edema and death. CONCLUSION: Encephalitis secondary to respiratory viral infection might evolve with cytokine storm and multiorgan inflammatory response in children.