- 東京女子医科大学雑誌 (ISSN:00409022)
- vol.87, no.Extra1, pp.E54-E64, 2017-05-31 (Released:2017-07-31)
Acute encephalopathy in childhood is life-threatening and may cause death or neurological sequelae. Acute-phase clinical symptoms are pyrexia, seizures, and disturbance of consciousness. Many cases of influenza-associated encephalopathy in childhood have been reported in Japan, which is diagnosesd by its characteristic clinical course and finding from magnetic resonance imaging (MRI) of the head. Several cases have been characterized by hypercytokinemia, therefore, anti-proinflammatory cytokine therapy, such as methylprednisolone pulse therapy and intravenous immunoglobulin therapy, has been recommended for treating encephalopathy. Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a subtype of influenza-associated encephalopathy. However, AESD can be induced not only by influenza virus but also by other pathogens. The clinical course is characterized by a febrile seizure (usually >30 minutes) as the initial neurological symptom on day 1, followed by recurrent seizures on days 4-6. On days 3-9, lesions can be detected in the subcortical white matter by diffusion-weighted MRI. Although the mortality rate due to AESD is not high, associated neurological sequelae are frequently observed. An excitotoxic injury with delayed neuronal death is considered to be the primary pathogenic mechanism of AESD, although hypercytokinemia and metabolic failure can also occur. Control of the initial and recurrent seizures may affect outcomes.