Clinical Characteristics of Acute Encephalopathy of Obscure Origin: A Biphasic Clinical Course Is a Common Feature

Y. Maegaki; A. Kondo; R. Okamoto; T. Inoue; K. Konishi; A. Hayashi; Y. Tsuji; S. Fujii; K. Ohno

doi:10.1055/s-2006-955928

Neuropediatrics, Table of Contents

Neuropediatrics 2006; 37(5): 269-277
DOI: 10.1055/s-2006-955928

Original Article

Georg Thieme Verlag KG Stuttgart · New York

Clinical Characteristics of Acute Encephalopathy of Obscure Origin: A Biphasic Clinical Course Is a Common Feature

Y. Maegaki¹ , A. Kondo¹ , R. Okamoto¹ , T. Inoue¹ , K. Konishi² , A. Hayashi² , Y. Tsuji² , S. Fujii³ , K. Ohno¹

¹Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago, Japan
²Division of Pediatrics and Perinatology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago, Japan
³Division of Radiology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago, Japan

Abstract

Objective: To evaluate the clinical characteristics of acute encephalopathy of obscure origin (AE). Study design: We examined clinical, imaging, and laboratory findings in children with AE. Specific subtypes of AE such as Reye's syndrome (RS), acute necrotizing encephalopathy (ANE), hemorrhagic shock and encephalopathy (HSE), acute encephalitis with refractory, repetitive partial seizures (AERRPS), and hemiconvulsion-hemiplegia syndrome (HH) were diagnosed. Other AE patients were regarded as non-specific subtype. Results: Nineteen patients were identified; specific AEs in 14 and non-specific AE in 5. Patients with RS, ANE, HSE frequently showed neuroimaging abnormalities (9/9) and significant elevation of liver enzymes (7/9) within 2 days after onset. Prognoses were extremely poor; early death in 6 and severe neurological sequelae in 3. Two of the 3 HH patients and 4 of the 5 non-specific AE patients showed biphasic clinical courses (AEBC); consciousness levels transiently improved following initial seizures and were exacerbated at the fourth to sixth days. In AEBC, neuroimaging abnormalities were rarely observed during the acute phase (1/5) but were detectable at clinical exacerbation. They rarely showed severely abnormal elevation in liver enzymes (1/6) and resulted in mild to moderate neurological sequelae (6/6). Conclusion: A biphasic clinical course is a common feature in HH and non-specific AE.

Key words

Acute encephalopathy of obscure origin - biphasic clinical course - MRI - EEG - status epilepticus

Full Text

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MD Yoshihiro Maegaki

Division of Child Neurology
Institute of Neurological Sciences
Faculty of Medicine
Tottori University

36-1 Nishi-Cho

Yonago 683-8504

Japan

Email: maegaki@grape.med.tottori-u.ac.jp