Varying Patterns of CNS Imaging in Influenza A Encephalopathy in Childhood

Purpose The brain imaging findings in children with neurological complications associated with influenza A infections are presented and analyzed and pathological imaging changes including atypical intracerebral hemorrhages in these patients are discussed. Methods Neuroimaging findings in six children with influenza encephalopathy following influenza A infection between 2012–2017 were retrospectively investigated. Of these five underwent magnetic resonance imaging (MRI) and one computed tomography (CT). Gene analysis was performed in two cases with acute necrotizing encephalitis of childhood (ANEC). Results The MRI findings of one child were concordant with mild encephalopathy with a reversible splenial lesion (MERS); this patient recovered but remained aphasic. In two cases MRI showed typical bilateral thalamic lesions as a feature of ANEC; genetic testing facilitated the diagnosis in one case. One of the patients died, the other showed little improvement. The remaining three patients had multiple diffuse cerebral hemorrhages predominantly affecting the supratentorial white matter after influenza A infection complicated by pneumonia, rhabdomyolysis and sepsis requiring extracorporeal membrane oxygenation (ECMO). Conclusion Neurological complications in children associated with influenza A infection may include MERS and ANEC. Additionally, atypical disseminated intracerebral hemorrhages as a complication of influenza A infection is reported.