Acute encephalopathy with biphasic seizures and late reduced diffusion: Predictive EEG findings

Underlying Disorders in Children With Infection-Related Acute Encephalopathy

BACKGROUND

Various factors contribute to the development of infection-related acute encephalopathy (AE) in children, such as infectious agents and chronic underlying disorders. We studied underlying disorders in children with AE to identify predisposing factors of AE.

METHODS

We investigated underlying disorders or past histories in patients with two types of AE from the database in the Tokai area of Japan between 2009 and 2022: 204 patients with AE with reduced subcortical diffusion (AED) and 137 with clinically mild encephalopathy with a reversible splenial lesion (MERS). We compared them with 89 patients with acute disseminated encephalomyelitis (ADEM) to clarify the specific disorders in the two AE types.

RESULTS

The prevalence of underlying disorders in AED (34%, 70 patients) was significantly higher than that in ADEM (12%, 11 patients) (P < 0.01). The prevalence of underlying disorders in MERS was 23% (32 patients). The underlying disorders included seizure disorders, premature birth, genetic/congenital disorders, and endocrine/renal diseases. In patients with seizure disorders in AED, five patients (18%) had Dravet syndrome and four (15%) had West syndrome, whereas none with MERS had these syndromes. Twenty-five (12%) of 204 patients with AED, three (2%) with MERS, and one (1%) with ADEM were preterm or low birth weight.

CONCLUSIONS

The high prevalence of seizure disorders suggests that seizure susceptibility is an important predisposing factor in AED. Premature birth also has an impact on the development of AED. Caution is required regarding the development of AE in patients with chronic seizure disorders or premature birth.

Changes in the treatment of pediatric acute encephalopathy in Japan between 2015 and 2021: A national questionnaire-based survey

BACKGROUND

Although acute encephalopathy (AE) is the most serious disorder associated with a viral infection in childhood and often causes death or neurological sequelae, standard treatments have not been established. In 2016, the Japanese Society of Child Neurology published the "Guidelines for the Diagnosis and Treatment of Acute Encephalopathy in Childhood 2016" (AE GL 2016). We conducted a questionnaire survey to evaluate the status of the treatment of pediatric AE in 2021 and the changes in treatment before and after the publication of the AE GL 2016.

METHODS

In October 2021, questionnaires were mailed via the web to members of two mailing lists who were involved in the practice of pediatric neurological disorders.

RESULTS

Most Japanese physicians (98 %) engaged in the treatment of pediatric AE used the AE GL 2016 as a clinical reference. From 2015 to 2021, the number of institutions that implemented targeted temperature management (TTM), vitamin administration, and continuous electroencephalographic monitoring increased significantly. Regarding the targeted temperature for TTM, the proportion of patients who were treated with normothermia (36.0-37.0 °C) increased from 2015 (55 %) to 2021 (79 %). The use of corticosteroids in patients with AE caused by a cytokine storm, which is recommended in the AE GL 2016, had already been implemented in most institutions by 2015.

CONCLUSION

The AE GL 2016 could be used to disseminate the knowledge accumulated to date. Evidence of the efficacy and proper indication criteria for the treatment of AE is insufficient and must be further accumulated.

Prediction and assessment of acute encephalopathy syndromes immediately after febrile status epilepticus

OBJECTIVE

This study aimed to predict occurrence of acute encephalopathy syndromes (AES) immediately after febrile status epilepticus in children and to explore the usefulness of electroencephalogram (EEG) in the early diagnosis of AES.

METHODS

We reviewed data from 120 children who had febrile status epilepticus lasting >30 min and were admitted to our hospital between 2012 and 2019. AES with reduced diffusion on brain magnetic resonance imaging was diagnosed in 11 of these patients. EEG and serum cytokines were analyzed in AES patients. Clinical symptoms and laboratory data were compared between AES and non-AES patients. Logistic regression analysis was used to identify early predictors of AES.

RESULTS

Multivariate logistic regression identified serum creatinine as a risk factor for developing AES. A scoring model to predict AES in the post-ictal phase that included serum creatinine, sodium, aspartate aminotransferase, and glucose was developed, and a score of 2 or more predicted AES with sensitivity of 90.9% and specificity of 71.6%. Post-ictus EEG revealed non-convulsive status epilepticus in four of the seven AES patients.

CONCLUSION

Children with febrile status epilepticus may be at risk of developing severe AES with reduced diffusion. Post-ictus EEG and laboratory data can predict the occurrence of severe AES.

Unusual presentation of acute encephalopathy with biphasic seizures and late reduced diffusion in Miller-Dieker syndrome

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a unique subtype of acute encephalopathy that occurs in children. A girl aged 2 years and 8 months with Miller-Dieker syndrome (MDS) was admitted for status epilepticus and high fever. Brain MRI performed on the third day postadmission showed abnormally high intensities in the subcortical white matter on diffusion-weighted images. Acute encephalitis/encephalopathy was diagnosed based on the electroencephalography (EEG) findings of diffuse high-voltage delta waves. Six days postadmission, frequent apnoeic episodes were observed, with oxygen desaturation due to cluster seizures. Subclinical seizures were found on amplitude-integrated EEG (aEEG). The disturbance of consciousness was difficult to recognise because of severe developmental disabilities due to MDS. EEG aids in the evaluation of consciousness, and aEEG can be helpful in monitoring and controlling subclinical seizures in the biphasic phase of AESD, especially in patients with underlying neurological disorders.