Mariko Kasai1, Akiko Shibata2, Ai Hoshino3, Yoshihiro Maegaki4, Hideo Yamanouchi5, Jun-Ichi Takanashi6, Takanori Yamagata7, Hiroshi Sakuma8, Akihisa Okumura9, Hiroaki Nagase10, Atsushi Ishii11, Tomohide Goto12, Akira Oka13, Masashi Mizuguchi3. 1. Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: kasaim-tky@umin.ac.jp. 2. Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. 3. Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. 4. Division of Child Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Yonago, Japan. 5. Department of Pediatrics, Comprehensive Epilepsy Center, Saitama Medical University, Saitama, Japan. 6. Department of Pediatrics, Tokyo Women's Medical University Yachiyo Medical Center, Chiba, Japan. 7. Department of Pediatrics, Jichi Medical University, Tochigi, Japan. 8. Department of Brain Development and Neural Regeneration, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan. 9. Department of Pediatrics, Aichi Medical University, Aichi, Japan. 10. Division of General Pediatrics, Department of Pediatrics, Kobe University Graduate School of Medicine, Hyogo, Japan. 11. Department of Pediatrics School of Medicine, Fukuoka University, Fukuoka, Japan. 12. Division of Neurology, Kanagawa Children's Medical Center, Kanagawa, Japan. 13. Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Abstract
BACKGROUND: We previously reported the nationwide, epidemiological data of acute encephalopathy in Japan during 2007-2010. Here we conducted the second national survey of acute encephalopathy during 2014-2017, and compared the results between the two studies to elucidate the trends in the seven years' interval as well as the influence of changes in pediatric viral infections and guidelines for acute encephalopathy in Japan. METHODS: The Research Committee on Acute Encephalopathy supported by the Japanese Government sent a questionnaire to 507 hospitals throughout Japan, and collected the responses by mail. RESULTS: A total of 1115 cases from 267 hospitals reportedly had acute encephalopathy during April 2014-June 2017. In this study, the age at onset was younger, the ratios of recently established syndromes, such as acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) and clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS), were higher, and the ratio of influenza-associated encephalopathy was lower, than in the previous study. The age at onset of influenza-associated encephalopathy was lower, and that of HHV-6/7-associated encephalopathy higher, compared to the first survey. The outcomes of entire acute encephalopathy remained unchanged. CONCLUSION: Some of these changes reflected the recent trends of viral infectious diseases including 2009 influenza pandemic, and others the standardization of the diagnosis of acute encephalopathy in Japan.
BACKGROUND: We previously reported the nationwide, epidemiological data of acute encephalopathy in Japan during 2007-2010. Here we conducted the second national survey of acute encephalopathy during 2014-2017, and compared the results between the two studies to elucidate the trends in the seven years' interval as well as the influence of changes in pediatric viral infections and guidelines for acute encephalopathy in Japan. METHODS: The Research Committee on Acute Encephalopathy supported by the Japanese Government sent a questionnaire to 507 hospitals throughout Japan, and collected the responses by mail. RESULTS: A total of 1115 cases from 267 hospitals reportedly had acute encephalopathy during April 2014-June 2017. In this study, the age at onset was younger, the ratios of recently established syndromes, such as acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) and clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS), were higher, and the ratio of influenza-associated encephalopathy was lower, than in the previous study. The age at onset of influenza-associated encephalopathy was lower, and that of HHV-6/7-associated encephalopathy higher, compared to the first survey. The outcomes of entire acute encephalopathy remained unchanged. CONCLUSION: Some of these changes reflected the recent trends of viral infectious diseases including 2009 influenza pandemic, and others the standardization of the diagnosis of acute encephalopathy in Japan.
Keywords:
Acute encephalopathy; Acute encephalopathy with biphasic seizures and late reduced diffusion; Clinically mild encephalitis/encephalopathy with a reversible splenial lesion; Epidemiology; Influenza