Pediatric Neurology 53 (2015) 93e94
Contents lists available at ScienceDirect
Pediatric Neurology journal homepage: www.elsevier.com/locate/pnu
Visual Diagnosis
Fatal Acute Necrotizing Encephalopathy: Clinical Presentation and Imaging Findings Kenichi Suga MD, PhD *, Kazuhiro Mori MD, PhD Department of Pediatrics, Tokushima Prefectural Central Hospital, Tokushima, Japan
A 1-year-old Japanese boy was admitted with fever, altered consciousness, generalized tonic seizures, and irregular respiration. Magnetic resonance imaging revealed swelling of both thalami with hyperintensity on diffusion-
weighted imaging (DWI) and a low apparent diffusion coefficient (ADC) (Figure). T2-weighted imaging showed hyperintensity of the thalamus, amygdala, tegmentum of the midbrain and pons, and subcortical white matter;
FIGURE. Magnetic resonance imaging on admission. Diffusion-weighted imaging (DWI) shows symmetrical high-intensity signals in the swollen thalami. Apparent diffusion coefficient (ADC) maps display a marked decrease in the central thalamus with surrounding hyperintense signals. T2-weighted imaging shows hyperintensity and T1-weighted imaging shows hypointensity in the thalamus and tegmentum of the midbrain (white arrows).
* Communications should be addressed to: Dr. Suga; Department of Pediatrics; Tokushima Prefectural Central Hospital; 1-10-3 Kuramotocho; Tokushima, Tokushima 770-8539, Japan. E-mail address: [email protected] 0887-8994/$ e see front matter Ó 2015 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.pediatrneurol.2015.03.026
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K. Suga, K. Mori / Pediatric Neurology 53 (2015) 93e94
T1-weighted imaging showed hypointensity in these same areas. Electroencephalography showed no electrical activity. We diagnosed acute necrotizing encephalopathy. Four hours after admission, the patient was intubated because of apnea. He was comatose and exhibited absence of brainstem reflexes. Shock state and multiple organ failure rapidly developed. On hospital day 4, Cushing phenomena and central diabetes insipidus were identified. He was finally pronounced brain dead based on examinations by different physicians at 48 hours apart. Discussion
The hallmark of acute necrotizing encephalopathy is multiple symmetrical lesions affecting the thalami, putamina, and cerebral white matter bilaterally.1 The central lesions in the thalamus exhibit hyperintensity on DWI and a low ADC, suggesting cytotoxic edema, whereas surrounding lesions show hypointensity on DWI but a high ADC, suggesting vasogenic edema. Serious vasogenic edema might occur through a local breakdown of the blood-brain barrier related to cytokine storm.2 Central cytotoxic edema might arise as a secondary effect of ischemic changes. Lee et al. examined the thalamus in six
acute necrotizing encephalopathy patients, finding hyperintensity on DWI and a low ADC in four patients, hypointensity on DWI and a high ADC in one patient, and no change in DWI or ADC in one patient.3 Brainstem involvement, rather than findings for DWI and ADC, suggests poor outcome.3 Influenza and human herpesvirus-6 are representative pathogens for acute necrotizing encephalopathy.4 Our clinical observations suggested human herpesvirus-6 as the most likely pathogen for the fulminant encephalopathy in this patient.
References 1. Mizuguchi M, Hayashi M, Nakano I, et al. Concentric structure of thalamic lesions in acute necrotizing encephalopathy. Neuroradiology. 2002;44:489-493. 2. Mizuguchi M, Abe J, Mikkaichi K, et al. Acute necrotising encephalopathy of childhood: a new syndrome presenting with multifocal, symmetric brain lesions. J Neurol Neurosurg Psychiatry. 1995;58: 555-561. 3. Lee CG, Kim JH, Lee M, Lee J. Clinical outcome of acute necrotizing encephalopathy in related to involving the brain stem of single institution in Korea. Korean J Pediatr. 2014;57:264-270. 4. Hoshino A, Saitoh M, Oka A, et al. Epidemiology of acute encephalopathy in Japan, with emphasis on the association of viruses and syndromes. Brain Dev. 2012;34:337-343.
Contents lists available at ScienceDirect
Pediatric Neurology journal homepage: www.elsevier.com/locate/pnu
Visual Diagnosis
Fatal Acute Necrotizing Encephalopathy: Clinical Presentation and Imaging Findings Kenichi Suga MD, PhD *, Kazuhiro Mori MD, PhD Department of Pediatrics, Tokushima Prefectural Central Hospital, Tokushima, Japan
A 1-year-old Japanese boy was admitted with fever, altered consciousness, generalized tonic seizures, and irregular respiration. Magnetic resonance imaging revealed swelling of both thalami with hyperintensity on diffusion-
weighted imaging (DWI) and a low apparent diffusion coefficient (ADC) (Figure). T2-weighted imaging showed hyperintensity of the thalamus, amygdala, tegmentum of the midbrain and pons, and subcortical white matter;
FIGURE. Magnetic resonance imaging on admission. Diffusion-weighted imaging (DWI) shows symmetrical high-intensity signals in the swollen thalami. Apparent diffusion coefficient (ADC) maps display a marked decrease in the central thalamus with surrounding hyperintense signals. T2-weighted imaging shows hyperintensity and T1-weighted imaging shows hypointensity in the thalamus and tegmentum of the midbrain (white arrows).
* Communications should be addressed to: Dr. Suga; Department of Pediatrics; Tokushima Prefectural Central Hospital; 1-10-3 Kuramotocho; Tokushima, Tokushima 770-8539, Japan. E-mail address: [email protected] 0887-8994/$ e see front matter Ó 2015 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.pediatrneurol.2015.03.026
94
K. Suga, K. Mori / Pediatric Neurology 53 (2015) 93e94
T1-weighted imaging showed hypointensity in these same areas. Electroencephalography showed no electrical activity. We diagnosed acute necrotizing encephalopathy. Four hours after admission, the patient was intubated because of apnea. He was comatose and exhibited absence of brainstem reflexes. Shock state and multiple organ failure rapidly developed. On hospital day 4, Cushing phenomena and central diabetes insipidus were identified. He was finally pronounced brain dead based on examinations by different physicians at 48 hours apart. Discussion
The hallmark of acute necrotizing encephalopathy is multiple symmetrical lesions affecting the thalami, putamina, and cerebral white matter bilaterally.1 The central lesions in the thalamus exhibit hyperintensity on DWI and a low ADC, suggesting cytotoxic edema, whereas surrounding lesions show hypointensity on DWI but a high ADC, suggesting vasogenic edema. Serious vasogenic edema might occur through a local breakdown of the blood-brain barrier related to cytokine storm.2 Central cytotoxic edema might arise as a secondary effect of ischemic changes. Lee et al. examined the thalamus in six
acute necrotizing encephalopathy patients, finding hyperintensity on DWI and a low ADC in four patients, hypointensity on DWI and a high ADC in one patient, and no change in DWI or ADC in one patient.3 Brainstem involvement, rather than findings for DWI and ADC, suggests poor outcome.3 Influenza and human herpesvirus-6 are representative pathogens for acute necrotizing encephalopathy.4 Our clinical observations suggested human herpesvirus-6 as the most likely pathogen for the fulminant encephalopathy in this patient.
References 1. Mizuguchi M, Hayashi M, Nakano I, et al. Concentric structure of thalamic lesions in acute necrotizing encephalopathy. Neuroradiology. 2002;44:489-493. 2. Mizuguchi M, Abe J, Mikkaichi K, et al. Acute necrotising encephalopathy of childhood: a new syndrome presenting with multifocal, symmetric brain lesions. J Neurol Neurosurg Psychiatry. 1995;58: 555-561. 3. Lee CG, Kim JH, Lee M, Lee J. Clinical outcome of acute necrotizing encephalopathy in related to involving the brain stem of single institution in Korea. Korean J Pediatr. 2014;57:264-270. 4. Hoshino A, Saitoh M, Oka A, et al. Epidemiology of acute encephalopathy in Japan, with emphasis on the association of viruses and syndromes. Brain Dev. 2012;34:337-343.
