Prediction of acute encephalopathy with biphasic seizures and late reduced diffusion in patients with febrile status epilepticus

Risk factors for post-encephalopathic epilepsy in patients with acute encephalopathy with biphasic seizures and late reduced diffusion

BACKGROUND

Post-encephalopathic epilepsy (PEE) is a serious complication of acute encephalopathy syndromes, and is more frequent in patients with acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) than in children with acute encephalopathy. However, a risk factor analysis using laboratory findings in the acute phase of AESD has not yet been performed. Therefore, the present study examined risk factors of AESD-related PEE using laboratory parameters in the acute phase of AESD.

METHODS

We retrospectively screened 27 pediatric patients with AESD for inclusion, and enrolled 20 ("the PEE group", n = 6; "the non-PEE group", n = 14) according to inclusion criteria.

RESULTS

The incidence of AESD-related PEE was 30 %, and the median duration from the onset of AESD to the development of PEE was 2.5 months (range, 1-32). The most common types of seizures were focal seizures, epileptic spasms, and startle seizures: 4 out of 6 patients (66.7 %) had intractable epilepsy. The median values of alanine aminotransferase (ALT) in the 1st and 2nd seizure phases of AESD and aspartate aminotransferase (AST) in the 2nd seizure phase were significantly higher in the PEE group than in the non-PEE group (p < 0.01).

CONCLUSIONS

This is the first study to report higher serum levels of ALT and AST at the onset of AESD as risk factors for AESD-related PEE. We also provided a detailed description on the clinical characteristics on AESD-related PEE, which are consistent with previous findings.

A nationwide survey of adenovirus-associated encephalitis/encephalopathy in Japan

BACKGROUND

Adenovirus is a major pathogen causing febrile illness among children. It may also cause acute encephalitis/encephalopathy. This study aimed to elucidate the clinical features of adenovirus-associated encephalitis/encephalopathy (AdVE) among children in Japan.

METHODS

A nationwide survey of children with AdVE was conducted. An initial survey was distributed among pediatricians to obtain information about children with AdVE treated between January 2014 and March 2019. A second survey was used to obtain the clinical information of children with AdVE from hospitals that responded to the initial survey and those identified from a literature search of the reported cases. We collected demographic data and information about symptoms of infection, neurological symptoms, laboratory parameters, treatment, and outcomes. Outcomes were determined using the Pediatric Cerebral Performance Category Score.

RESULTS

Clinical information was available for 23 children with a median age of 39 months. Two had preexisting neurological disorders and six had a history of febrile seizures. The outcome was good in 15 patients and poor in eight patients. Serum lactate dehydrogenase, glucose, and ammonia levels were higher among children with a poor outcome compared to those with a good outcome. Clinically mild encephalitis/encephalopathy with a reversible splenial lesion was the most common type (n = 8), followed by acute encephalopathy with biphasic seizures and late reduced diffusion (n = 7).

CONCLUSION

A prior history of febrile seizures was frequent in children with AdVE. Several different subtypes of acute encephalopathy were seen in children with AdVE, and the outcome was poor in those with acute encephalopathy with biphasic seizures and late reduced diffusion and hemorrhagic shock and encephalopathy syndrome. Elevated lactate dehydrogenase, glucose, and ammonia levels on admission were found to correlate with a poor outcome.

A serial analysis of serum aspartate aminotransferase levels in patients with acute encephalopathy with biphasic seizures and late reduced diffusion and prolonged febrile seizure

BACKGROUND

There are no established biomarkers for diagnosing acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) in the early acute phase, called "the 1st seizure phase". Based on our clinical experience, we hypothesized that serial examinations of blood levels of aspartate aminotransferase (AST) in children with febrile convulsive status epilepticus (FCSE) revealed higher levels in patients with AESD in the 1st seizure phase than in those with prolonged febrile seizures (PFs).

METHODS

To test our presented hypothesis, we retrospectively investigated changes in serum AST in patients with FCSE due to AESD (n = 11) or PFs (n = 27) who were serially examined within 48 h of the onset of convulsions.

RESULTS

The rate of increase in AST was significantly higher in patients with AESD than in those with PFs. The rate of increase in AST correlated with previously reported scoring systems, i.e., Yokochi and Tottori scores, for the prediction of AESD. A positive correlation between the rate of increase in AST and creatinine levels in the first examination were observed; however, creatinine levels did not significantly differ between the AESD and PFs groups in the first or second examination. Blood levels of pH, ammonia, and sugar in the first examination and C-reactive protein in the second examination were significantly higher in the AESD group than in the PFs group.

CONCLUSIONS

The present study revealed that the rate of increase in AST was significantly higher in patients with AESD than in those with PFs. A novel predictive scoring system needs to be established in combination with the rate of increase in AST and reported clinical parameters, which will improve the prognosis of patients with FCSE.

Risk Factors of Prehospital Emergency Care for Acute Encephalopathy in Children With Febrile Status Epilepticus

BACKGROUND

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) often develops in children with febrile status epilepticus (FSE) with neurological sequelae. No study has investigated the associations between prehospital emergency care and AESD onset.

METHODS

We retrospectively collected the data of children with FSE (>30 min) treated in Tottori University Hospital. We evaluated the prehospital emergency care information, investigating its association with AESD development.

RESULTS

We identified 11 patients with AESD and 44 with FSE. The time from onset to the arrival of the emergency medical services (EMS) (OR: 1.12, P = 0.015) and hospital arrival (OR: 1.07, P = 0.009) was positively associated with AESD development. In contrast, oxygen saturation levels in ambulances (OR: 0.901, P = 0.013) are negatively associated with AESD development. The time from onset to arrival at the hospital was associated with the time from onset to the administration of antiseizure medications (ASMs) (correlation coefficient: 0.857, P < 0.001), which was significantly associated with AESD development (OR: 1.04, P = 0.039). The cutoff values were 17 minutes from onset to the arrival of EMS (OR: 27.2, P = 0.003), 38 minutes to hospital arrival (OR: 5.71, P = 0.020), and 50 minutes of administration of ASMs (OR: 7.11, P = 0.009).

CONCLUSIONS

Prolonged time from onset to hospital arrival and hypoxia in ambulances were associated with AESD development. Shortening transport time, improving respiratory management in ambulances, and the early administration of ASMs might play a role in preventing the development of AESD.

Arterial spin labeling image findings in the acute phase in paediatric patients with acute encephalopathy with biphasic seizures and late reduced diffusion

Introduction

Diagnosing acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) after the first seizure (early seizure/seizures, ES/ESs) is challenging because a reduced apparent diffusion coefficient (ADC) in the cortical or subcortical white matter, often described as having a "bright-tree appearance (BTA)," is usually not observed until secondary seizures (late seizures, LSs) occur. Previous studies have reported hypoperfusion on arterial spin labeling (ASL) within 24 h after ES/ESs in patients with AESD and hyperperfusion within 24 h after LS onset. This study aimed to investigate cerebral blood flow in the hyperacute phase (between ES/ESs and LSs) using ASL in patients with AESD.

Methods

Eight ASL images were acquired in six patients with AESD admitted to our hospital from October 2021 to October 2022. ASL findings in the hyperacute phase were investigated and video-electroencephalogram findings obtained around ASL image acquisition in the hyperacute phase were evaluated.

Results

Four ASL images were obtained for three patients before LS onset, with three images showing hyperperfusion areas and one image showing hypoperfusion areas. These hyperperfuion regions coincided with BTA on subsequent images of these patients.In one patient, the first ASL image was obtained in the late hyperacute phase and revealed hyperperfusion areas with a slightly abnormal change on diffusion-weighted image (DWI), which were not accompanied by ADC abnormalities. The second ASL image obtained 51 h after the first ASL, and before LS onset revealed more prominent hyperperfusion areas than the first ASL image, which were accompanied by BTA. In another patient, the ASL image obtained 82 h after ES revealed hyperperfusion areas without abnormal change on DWI or ADC.

Conclusion

This study revealed that two patients exhibited hyperperfusion regions and another patient exhibited hypoperfusion regions among three patients who underwent ASL imaging during the period from 24 h after ES/ESs to LSs in patients with LSs or cooling initiation in patients without LSs due to early anaesthesia induction (late hyperacute phase). Further prospective studies on cerebral blood flow are required to explore the relationship among the timing of image acquisition, the presence of electrographic seizures, and ASL findings in patients with AESD.

A nationwide survey of human metapneumovirus-associated encephalitis/encephalopathy in Japan

BACKGROUND

As there have been no comprehensive reports of human metapneumovirus-associated encephalopathy (hMPVE), this study examined the clinical features of hMPVE in children in Japan.

METHOD

A nationwide survey of children with hMPVE was conducted using a structured research form. An initial survey asked pediatricians about children with hMPVE treated between 2014 and 2018. A second survey obtained patient information from hospitals that responded to the initial survey and those identified as having treated cases from a literature search. We collected demographic data, symptoms of hMPV infection, neurological symptoms, laboratory data, treatment, and outcomes. Outcomes were determined using the Pediatric Cerebral Performance Category Score.

RESULT

Clinical information was available for 16 children. Their median age was 37 months. Six had preexisting neurological disorders. The interval between the onsets of infection and hMPVE was 4 days. Outcomes were good in 11 patients and poor in 5. There were no significant differences in demographic data, neurological symptoms, or laboratory data between the patients with good and poor outcomes. The encephalopathy subtypes were acute encephalopathy with biphasic seizures and late reduced diffusion in 3, clinically mild encephalitis/encephalopathy with a reversible splenial lesion in 3, hemorrhagic shock and encephalopathy syndrome in 2, and others in 8.

CONCLUSION

The outcomes of children with hMPVE were not very different from those of acute encephalopathy due to other viruses. We found no factors associated with poor outcomes.

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.

Clinical and laboratory characteristics of complex febrile seizures in the acute phase: a case-series study in Japan

BACKGROUND

Patients with complex febrile seizures (CFS) often display abnormal laboratory results, unexpectedly prolonged seizures, and/or altered consciousness after admission. However, no standardized values have been established for the clinical and laboratory characteristics of CFS in the acute phase, making the management of CFS challenging. This study aimed to determine the clinical and laboratory characteristics of children with CFS during the acute phase. In particular, the duration of impaired consciousness and the detailed distribution of blood test values were focused.

METHODS

We retrospectively reviewed medical records of a consecutive pediatric cohort aged 6-60 months who were diagnosed with CFS and admitted to Kobe Children's Hospital between October 2002 and March 2017. During the study period, 486 seizure episodes with confirmed CFS were initially reviewed, with 317 seizure episodes included in the analysis. Detailed clinical and laboratory characteristics were summarized.

RESULTS

Among 317 seizure episodes (296 children with CFS), 302 required two or fewer anticonvulsants to be terminated. In 296 episodes showing convulsive seizures, median seizure duration was 30.5 min. The median time from onset to consciousness recovery was 175 min. Impaired consciousness lasting > 6, 8, and 12 h was observed in 13.9%, 7.6%, and 1.9% patients with CFS, respectively. Additionally, the distribution of aspartate aminotransferase, lactate dehydrogenase, creatinine, and glucose were clarified with 3, 10, 50, 90, and 97 percentile values.

CONCLUSION

This study detailed the clinical and laboratory findings of acute-phase CFS using the data of the largest 15-year consecutive cohort of children with CFS. These results provide important information for appropriate acute management of CFS.

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

BACKGROUND

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a common type of acute encephalopathy in Japan; the condition is clinically characterized by prolonged seizures as the initial neurological symptom, followed by late seizures 4-6 days later. It is difficult to differentiate AESD from prolonged febrile seizures (PFSs). Here, we explored the use of electroencephalography to differentiate AESD from PFSs.

METHODS

We studied the electroencephalograms (EEGs) of children <6 years of age diagnosed with AESD or PFSs; all EEGs were recorded within 48 h of seizure onset (i.e., before the late seizures of AESD). Two pediatric neurologists evaluated all EEGs, focusing on the basic rhythm, slowing during wakefulness/arousal by stimuli, spindles, fast waves, and slowing during sleep.

RESULTS

The EEGs of 14 children with AESD and 31 children with PFSs were evaluated. Spindles were more commonly reduced or absent in children with AESD than in those with PFSs (71% vs. 31%, p = 0.021). Fast waves were also more commonly reduced or absent in children with AESD (21% vs. 0%, p = 0.030). The rates of all types of slowing did not differ between children with AESD and those with PFSs, but continuous or frequent slowing during sleep was more common in the former (50% vs. 17%, p = 0.035).

CONCLUSIONS

EEG findings may usefully differentiate AESD from PFSs. Reduced or absent spindles/fast waves and continuous or frequent slowing during sleep are suggestive of AESD in children with prolonged seizures associated with fever.

Incidence and risk factors of acute encephalopathy with biphasic seizures in febrile status epilepticus

OBJECTIVE

To clarify the incidence and risk factors of acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) in pediatric patients with febrile status epilepticus (FSE).

METHODS

We retrospectively surveyed patients with FSE (≥20 min and ≥40 min) who were younger than 6 years by mailing a questionnaire to 1123 hospitals in Japan. The survey period was 2 years. We then collected clinical data on patients with prolonged febrile seizures (PFS) ≥40 min and those with AESD, and compared clinical data between the PFS and AESD groups.

RESULTS

The response rate for the primary survey was 42.3%, and 28.0% of hospitals which had applicable cases responded in the secondary survey. The incidence of AESD was 4.3% in patients with FSE ≥20 min and 7.1% in those with FSE ≥40 min. In the second survey, a total of 548 patients had FSE ≥40 min (AESD group, n = 93; PFS group, n = 455). Univariate analysis revealed significant between-group differences in pH, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, creatine kinase, NH₃, procalcitonin (PCT), uric acid, blood urea nitrogen, creatinine (Cr), and lactate. Multivariate analysis using stratified values showed that high PCT was an only risk factor for AESD. A prediction score of ≥3 was indicative of AESD, as determined using the following indexes: HCO3^- < 20 mmol/L (1 point), Cl <100 mEq/L (1 point), Cr ≥0.35 mg/dL (1 point), glucose ≥200 mg/dL (1 point), and PCT ≥1.7 pg/mL (2 points). The scoring system had sensitivity of 84.2% and specificity of 81.0%.

CONCLUSION

Incidence data and prediction scores for AESD will be useful for future intervention trials for AESD.

Predicting the Onset of Acute Encephalopathy With Biphasic Seizures and Late Reduced Diffusion by Using Early Laboratory Data

Background: Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) often causes various neurological sequelae, necessitating early and objective differentiation of AESD from a febrile seizure (FS). Therefore, we developed a scoring system that predicts AESD onset using only early laboratory data. Methods: We selected patients with AESD or FS admitted to the Tottori University Hospital between November 2005 and September 2020 and collected laboratory data from onset to discharge in patients with FS and from onset to the second neurological events in patients with AESD. Results: We identified 18 patients with AESD and 181 patients with FS. In comparison with patients with FS, patients with AESD showed statistically significant increases in ammonia (NH3), blood sugar (BS), and serum creatinine (Cr) levels, and the white blood cell (WBC) count, and a significant decrease in pH at <3 h from onset. We set the cut-off values and adjusted the weight of each of these parameters based on data obtained <3 h from onset and proposed a scoring system for predicting AESD. This system showed 91% sensitivity and 94% specificity for distinguishing AESD from FS. These accuracies were only slightly improved by the addition of information related to consciousness and seizure duration (sensitivity, 91%; specificity, 96%). Conclusion: NH3, BS, and Cr levels, WBC count, and pH were significantly different between patients with AESD and patients with FS at <3 h from seizure onset. This scoring system using these data may enable the prediction of AESD onset for patients under sedation or without precise clinical information.

Truncal Instability and Titubation in Patients With Acute Encephalopathy With Reduced Subcortical Diffusion

The present retrospective study aimed to investigate the presence of truncal instability or titubation after the first seizure and second phase in patients with acute encephalopathy with reduced subcortical diffusion (AED). Of the 15 patients with AED who were admitted to our hospital for 3 years and 2 months and had reached developmental milestones for sitting before disease onset, six experienced moderate-to-severe truncal instability while sitting after the first seizure. These patients had a significantly longer first seizure duration and significantly lower GCS scores 12-24 h after the first seizure, as well as significantly higher Tada score and Creatinine and blood glucose levels than those with mild or no truncal instability while in a seated position after the first seizure. Three 1-year-old children with bilateral frontal lobe lesions, particularly in the bilateral prefrontal lobe regions, demonstrated truncal titubation, which has not previously been reported as a clinical feature of AED. Tada score reported to be a predictor of AED prognosis and truncal instability in the sitting position after the first seizure may represent disease severity, but not the specific lesions. Conversely, truncal titubation might be suggestive of bilateral frontal lobe lesions, particularly in patients without severe instability. Further studies on the role of bilateral prefrontal lobe lesions to truncal titubation in patients with AED using more objective evaluation methods, such as stabilometry, are necessary.

Prediction of AESD and neurological sequelae in febrile status epilepticus

OBJECTIVE

The clinical prediction rule (CPR) for acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) was developed with an area under the receiver operating characteristic curve (AUC) of 0.95 - 0.96. Our objective was to verify the AESD CPR in a new cohort and compare the utilities of three CPRs of acute encephalopathy: the Tada, Yokochi, and Nagase criteria.

METHODS

We reviewed the clinical data and medical charts of 580 consecutive patients (aged < 18 years) with febrile convulsive status epilepticus lasting for ≥ 30 min in 2002 - 2017 and measured the performance of the CPRs in predicting AESD and sequelae.

RESULTS

The CPRs predicted AESD with an AUC of 0.84 - 0.88. The Tada criteria predicted AESD with a positive predictive value (PPV) of 0.25 and a negative predictive value (NPV) of 0.99. The Yokochi criteria predicted AESD with a PPV and NPV of 0.20 and 0.95, respectively, after 12 h. The Nagase criteria predicted AESD with a PPV and NPV of 0.14 and 1.00, respectively, after 6 h. The PPVs of the Tada, Yokochi, and Nagase criteria for sequelae were 0.28, 0.28, and 0.17, respectively; the corresponding NPVs were 0.97, 0.95, and 0.98, respectively.

CONCLUSIONS

The effectiveness of the AESD CPR in a new cohort was lower than that in the derivation study. CPRs are not sufficient as diagnostic tests, but they are useful as screening tests. The Nagase criteria are the most effective for screening among the three CPRs due to their high NPV and swiftness.

Guidelines for the diagnosis and treatment of acute encephalopathy in childhood

The cardinal symptom of acute encephalopathy is impairment of consciousness of acute onset during the course of an infectious disease, with duration and severity meeting defined criteria. Acute encephalopathy consists of multiple syndromes such as acute necrotizing encephalopathy, acute encephalopathy with biphasic seizures and late reduced diffusion and clinically mild encephalitis/encephalopathy with reversible splenial lesion. Among these syndromes, there are both similarities and differences. In 2016, the Japanese Society of Child Neurology published 'Guidelines for the Diagnosis and Treatment of Acute Encephalopathy in Childhood', which made recommendations and comments on the general aspects of acute encephalopathy in the first half, and on individual syndromes in the latter half. Since the guidelines were written in Japanese, this review article describes extracts from the recommendations and comments in English, in order to introduce the essence of the guidelines to international clinicians and researchers.

Acute encephalopathy with biphasic seizures and late reduced diffusion: A case report

RATIONALE

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) has been reported almost exclusively in the Japanese population.

PATIENT CONCERNS

A 17-month-old male patient presented with fever and seizures, and subsequently fell into a coma. On the second day, he recovered consciousness. On the fourth day, he developed complex partial seizures and fell into a coma again. On day 10, the fever and seizures subsided. Head computed tomography on the first day showed no abnormalities. Brain diffusion-weighted images on the fourth day revealed reduced diffusion in the bilateral subcortical white matter.

DIAGNOSIS

A diagnosis of AESD was made.

INTERVENTIONS

The patient was treated with corticosteroids and intravenous immunoglobulin.

OUTCOMES

At the 4-month follow-up, the patient was able to walk independently, and the epileptic seizures were well controlled.

LESSONS

AESD is a rare entity, and treatment with corticosteroids and intravenous immunoglobulin can lead to a favorable prognosis. Clinicians should be aware of this condition, and clinicoradiological features can suggest the diagnosis.

Early steroid pulse therapy among children with influenza virus-associated encephalopathy

Background

Influenza virus-associated encephalopathy (IAE) can lead to neurological sequela and mortality among children. Therefore, instant recognition and therapeutic intervention for IAE are crucial. In some clinical subtypes of IAE, steroid pulse therapy might be beneficial, especially when it is administered in the early phase. However, early identification of patients who may benefit from steroid pulse therapy is sometimes difficult. We aimed to assess the effectiveness of early steroid pulse therapy among children with IAE.

Methods

In this retrospective observational study, we used a national database that covers half of the acute care inpatients across Japan to identify inpatients aged ≤ 18 years with a diagnosis of IAE between July 2010 and March 2017. Unfavorable outcome was defined as a composite outcome of sequela including Japan Coma Scale ≥ 10 at discharge, requiring tracheostomy, mechanical ventilation, enteral tube feeding, rehabilitation at discharge, or in-hospital death. Propensity score matching was performed to compare unfavorable outcome and in-hospital mortality between patients with and without steroid pulse therapy within 2 days of admission.

Results

Among 692 patients included in the study, the mean age was 5.8 years, and 55.8% were male. The overall in-hospital mortality was 1.3%, and the proportion of the unfavorable outcome was 15.0%. We observed no significant difference in the unfavorable outcome between matched patients (168 patients in each group) with and without early steroid pulse therapy (13.7% vs 8.3%; P = 0.16) or in-hospital mortality (0.6% vs 1.2%; P = 1.0).

Conclusions

We did not observe the effectiveness of early steroid pulse therapy on patient outcomes among children with IAE in our study population including all clinical subtypes of IAE. Further studies considering severity of illness are warranted to determine whether steroid pulse therapy is beneficial, especially for specific clinical subtypes of IAE.

Determinants of outcomes for acute encephalopathy with reduced subcortical diffusion

Acute encephalopathy with reduced subcortical diffusion (AED), characterised by seizure onset and widespread reduced apparent diffusion coefficient in the cortex/subcortical white matter, is one of the most common acute encephalopathies in children in East Asia. This 14-year single-centre retrospective study on 34 patients with AED showed that therapeutic hypothermia was used for patients with more severe consciousness disturbance after the first seizure or second phase initiation, extrapolating from neonatal hypoxic encephalopathy and adult post-cardiac arrest syndrome. The basal ganglia/thalamus lesions and the Tada score were the poor outcome determinants in the multivariate analysis. The correlation between the worse outcomes and the duration from the first seizure to the initiation of therapeutic hypothermia was observed only in the patients with AED cooled before the second phase. This correlation was not observed in the overall AED population. There was a moderate negative association between the worse outcomes and the duration between the first seizure and the second phase. Therefore, the basal ganglia/thalamus lesions and the Tada score were the outcome determinants for patients with AED. Further investigation is required to examine the efficacy of therapeutic hypothermia in this population while considering the timing of the therapeutic hypothermia initiation and the second phase.

Acute encephalopathy with biphasic seizures and late reduced diffusion in a Spanish girl

We report a case of a 22-month-old Spanish girl who presented acute encephalopathy with biphasic seizures and late reduced diffusion (AESD). Serum procalcitonin (PCT) reached a maximum of 50.5 ng/mL on the first day whereas C-reactive protein (CRP) peaked at 1.21 mg/dL on the second. At the time of discharge, right spastic hemiparesis persisted. MR spectroscopy on day 23 revealed a decrease in N-acetylaspartate and an increase in choline. To our knowledge, we report the first case of AESD in Europe. These findings support the role of PCT and PCT/CRP ratio in the early diagnosis of AESD and correlation of MR spectroscopy findings with neurological outcome.

Perfusion abnormality on three-dimensional arterial spin labeling in patients with acute encephalopathy with biphasic seizures and late reduced diffusion

PURPOSE

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most common encephalopathy subtype in Japanese children. Few case reports have shown perfusion abnormality on arterial spin labeling (ASL) in patients with AESD. The present study aimed to review the chronological change of cerebral perfusion on three-dimensional (3D) ASL in patients with AESD.

METHODS

Twenty consecutive patients with AESD were enrolled; the patients underwent MRI including 3D ASL. The clinical course of AESD was divided into four phases according to the time from occurrence of seizures to MRI. Two neuroradiologists independently assessed presence or absence, distribution, and severity of perfusion abnormality using ASL and qualitatively scored perfusion abnormality using a five-point grading system. The level of interobserver agreement in the evaluation was analyzed using weighted κ statistics. Additionally, the signal ratio of abnormal perfusion region and peri-central sulcus region on ASL was semi-quantitatively evaluated. Moreover, we qualitatively compared the distribution between perfusion abnormality on ASL and bright tree appearance (BTA) on diffusion-weighted image (DWI).

RESULTS

ASL showed hypoperfusion from 8.5 to 22 h after early seizures (ESs) and hyperperfusion within 24 h after late seizures (LSs). Various perfusions were found >3 days after LSs. Interobserver agreement for qualitative scored perfusion abnormality was good (κ = 0.77). The distribution of abnormal perfusion was relatively consistent with BTA.

CONCLUSION

In AESD, cerebral perfusion changes with time. ASL showed hypoperfusion from 8.5 to 22 h after ESs, hyperperfusion within 24 h after LSs in patients with AESD.

The assessment of mild encephalopathy with a reversible splenial lesion (MERS) using high b-value DWI

INTRODUCTION

Mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) was shown to have a transient reduction in diffusion. Such changes would be used as an early detection to reduce excessive treatments and promote recovery without sequelae. The current research evaluated the high b-value (b = 3000 s/mm) diffusion-weighted imaging (DWI) assessment in MERS.

METHODS

Sixteen pediatric patients showed MERS used DWI (b = 1000 and 3000 s/mm). To record number of lesions, the signal intensities, signal-to-noise ratios (SNRs), contrast-to-noise ratios (CNRs), contrast ratios (CRs), the apparent diffusion coefficients (ADCs) were measured in the normal parenchyma and lesions.

RESULTS

Lesions were more apparent with high b-value. The ADC values and CNR in the lesions and surrounding normal brain parenchyma were relatively low at a high compared to standard b-value DWI (SNR: 144.67 ± 33.03, 85.72 ± 31.50; CNR: 20.82 ± 17.64, 49.62 ± 33.06; for b = 1000 and 3000 s/mm). The CR was significantly higher at a high compared to low b-value DWI (CR: 0.06 ± 0.07 versus 0.40 ± 0.14).

CONCLUSION

High b-value DWI could detect more lesions and could obviously improve the detection of lesions in pediatric patients with MERS.

Predicting the outcomes of targeted temperature management for children with seizures and/or impaired consciousness accompanied by fever without known etiology

BACKGROUND

Seizures and/or impaired consciousness accompanied by fever without known etiology (SICF) is common in the pediatric emergency setting. No optimal strategy for the management of SICF in childhood currently exists. We previously demonstrated the effectiveness of targeted temperature management (TTM) against SICF with a high risk of morbidity; however, some patients with SICF develop neurological sequelae despite TTM, which necessitate additional neuroprotective treatment. The clinical characteristics of these severe cases have not been studied. Accordingly, the aim of this study was to identify the clinical characteristics of children with SICF who exhibit poor outcomes after TTM.

METHODS

The medical records of children admitted to Kobe Children's Hospital (Kobe, Japan) between October 2002 and September 2016 were retrospectively reviewed. Patients with SICF treated using TTM were included and divided into the satisfactory and poor outcome groups. Univariate and multivariate logistic regression analyses were used to compare clinical characteristics and laboratory findings between the two groups.

RESULTS

Of the 73 included children, 10 exhibited poor outcomes. Univariate logistic regression analysis revealed that acute circulatory failure before TTM initiation, the use of four or more types of anticonvulsants, methylprednisolone pulse therapy, and an aspartate aminotransferase (AST) level ≥73 IU/L were associated with poor outcomes. Multivariate logistic regression analysis identified an elevated AST level as a significant independent predictor of a poor outcome.

CONCLUSIONS

An elevated AST level within 12 h of onset in children with SICF is an independent predictor of a poor outcome after TTM initiated within 24 h of onset.

Early risk factors for mortality in children with seizure and/or impaired consciousness accompanied by fever without known etiology

BACKGROUND

Children who present with seizure and/or impaired consciousness accompanied by fever without known etiology (SICF) may be diagnosed with either acute encephalopathy (AE) or febrile seizure (FS). Although approximately 5% of AE cases are fatal, it is difficult to identify fatal cases among children with SICF, which are often critical by the time of diagnosis. Thus, early prediction of outcomes for children with SICF, prior to diagnosis, may help to reduce mortality associated with AE. The aim of the present study was to identify clinical and laboratory risk factors for mortality acquired within 6 h of onset among children with SICF.

METHODS

We retrospectively reviewed the medical records of children who had been admitted to Kobe Children's Hospital (Kobe, Japan) with SICF between October 2002 and September 2015. We compared clinical and laboratory characteristics acquired within 6 h of onset and outcomes between survivors and non-survivors using univariate and multivariate analyses.

RESULTS

The survivor and non-survivor groups included 659 and nine patients, respectively. All patients in the non-survivor group received a final diagnosis of AE. Univariate analysis revealed significant differences between the groups with regard to seizure duration and the following laboratory parameters: aspartate transaminase (AST), alanine aminotransferase, lactate dehydrogenase, sodium, and lactate. The multivariate analysis identified AST as a significant independent factor associated with mortality.

CONCLUSIONS

Elevation of AST within 6 h of onset is independently correlated with mortality in children with SICF. Our result may elucidate earlier intervention for patients with high risk of mortality.

Serum Procalcitonin Levels in Acute Encephalopathy with Biphasic Seizures and Late Reduced Diffusion

Procalcitonin (PCT) is used as a biomarker in severe infections. Here, we retrospectively investigated levels of serum PCT, C-reactive protein (CRP), and inflammatory cytokines (IL-6, TNF-α, and IFN-γ) in the second phase of patients with acute encephalopathy with biphasic seizures and late reduced diffusion (AESD). Nine AESD pediatric patients (4 men, 5 women; AESD group) admitted to Okayama University Hospital from 2010 to 2016 were compared with 10 control patients with febrile seizures (FS) (3 men, 7 women; FS group). Mean PCT concentrations (ng/mL) in the AESD and FS groups were significantly different, at 9.8 ± 6.7 and 0.8 ± 0.9, respectively (p = 0.0006). CRP (mg/dL) were 0.79 ± 0.89 and 1.4 ± 1.0 (p = 0.94), respectively; IL-6 (pg/mL) were 449.7 ± 705.0 and 118.3 ± 145.4 (p = 0.20), respectively; TNF-α (pg/mL) were 18.6 ± 12.5 and 16.6 ± 6.0 (p = 0.67), respectively; and IFN-γ (pg/mL) were 79.6 ± 158.5 and 41.9 ± 63.7 (p = 0.56), respectively. Ratios of PCT to CRP were 27.5 ± 34.2 and 3.2 ± 6.8 (p < 0.0001), respectively. The sensitivity and specificity in the diagnosis of AESD using a cutoff of PCT/CRP ratio of 1.0 were 79% and 100%, respectively. These results suggest that PCT and the PCT/CRP ratio are useful in auxiliary diagnosis of the second stage of AESD, and in AESD, PCT is likely to increase through a different mechanism.

A case of acute encephalopathy with biphasic seizures and late reduced diffusion: Utility of arterial spin labeling sequence

A 1-year-old boy was admitted because of febrile status epilepticus (FSE). A secondary cluster of seizures was seen on day 5 after onset, and the patient eventually displayed developmental delay. Conventional magnetic resonance imaging (MRI) showed no abnormal findings on day 1 after onset, but showed reduced diffusion in the subcortical regions of bilateral frontal lobes on day 5 after onset. Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) was diagnosed. Arterial spin labeling (ASL) revealed reduced cerebral blood flow (CBF) in bilateral frontal lobes on day 1 after onset and showed increased CBF in the corresponding region in the subacute phase. Outcomes after prolonged febrile seizures are usually good, but mental deficit and/or epilepsy often remain in AESD. Discriminating between these syndromes is difficult, because no useful biomarkers have been identified. Reduced CBF in bilateral frontal lobes was observed on ASL on day 1 of FSE in the present case, and this finding may be predictive of developing AESD.