Biphasic Seizures Research Articles

Efficacy of a mitochondrial drug cocktail in preventing acute encephalopathy with biphasic seizures and late reduced diffusion

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is difficult to differentiate from prolonged febrile seizures during the acute phase. Mitochondrial dysfunction-induced energy depletion is among the key mechanisms underlying acute encephalopathy. Therefore, this study aimed to examine the efficacy of a “mitochondrial cocktail” in preventing AESD. We retrospectively studied children experiencing status epilepticus associated with fever lasting more than 30 min, focusing on those who received the mitochondrial cocktail between February 2016 and December 2020, and those who did not receive it within 24 h between February 2012 and January 2014. The mitochondrial cocktail contained vitamins B1, C, and E; biotin; coenzyme Q10; and l-carnitine. AESD occurred in 1 of 41 (2.4 %) patients in the administration group and 7 of 39 (17.9 %) patients in the non-administration group. The incidence of AESD was lower in the administration group than in the non-administration group, with a significant difference (p = 0.027). The incidence of encephalopathy, including cases classified as AESD and unclassified, was 7/41 (17.1 %) and 7/39 (17.9 %) in the administration and non-administration groups, respectively, with no significant difference. However, the number of cases with worsening pediatric cerebral performance category scores was significantly lower in the administration group compared to the non-administration group (p = 0.015). In conclusion, early administration of the mitochondrial cocktail may help prevent AESD. Some encephalopathy cases do not progress to a biphasic state or develop AESD. Thus, the mitochondrial cocktail should be administered as early as possible to prevent AESD.

Elevated cerebrospinal fluid neuronal injury biomarkers within 24 hours of onset in infection-triggered acute encephalopathy compared to complex febrile seizures

ObjectiveThis study aimed to measure and compare cerebrospinal fluid neuronal injury biomarkers in the acute phase of complex febrile seizure (CFS) and infection-triggered acute encephalopathy (AE). Furthermore, we determined the pathogenesis of AE with biphasic seizures and late reduced diffusion (AESD). MethodsPediatric patients with febrile status epilepticus who visited Hyogo Prefectural Kobe Children's Hospital from November 1, 2016, to December 31, 2022, and whose cerebrospinal fluid samples were collected within 24 h of neurological symptom onset were included. Patients were classified as having CFS or infection-triggered AE according to their definitions. Patients with AE were further categorized into AESD or unclassified AE. Cerebrospinal fluid biomarkers (neuron-specific enolase, growth differentiation factor 15 [GDF-15], S100 calcium-binding protein B [S100B], glial fibrillary acidic protein, and tau protein were measured and compared among the groups. ResultsTotal of 63 patients (45 with CFS and 18 with AE) were included. Among the AE patients, nine were classified as having AESD and nine as having unclassified AE. S100B levels were significantly higher in patients with AESD than in patients with CFS (485 pg/ml vs. 175.3 pg/ml) and were even higher in patients with AESD and neurological sequelae (702.4 pg/ml). GDF-15 levels were significantly elevated in patients with AE compared to patients with CFS (85.8 pg/ml vs. 23.6 pg/ml). ConclusionsThe elevation of S100B suggests that activated astrocytes may be closely associated with the early pathology of AESD. Elevated GDF-15 levels in infection-triggered AE suggest the activation of defense mechanisms caused by stronger neurological injury.

International consensus definitions for infection-triggered encephalopathy syndromes.

To develop standardized diagnostic criteria for 'infection-triggered encephalopathy syndrome (ITES)' and five specific clinical syndromes of ITES. The draft definitions were based on existing criteria, standardized, and discussed by a panel of international experts using nominal group technique over 18 months to achieve consensus. All criteria use the same format: (1) presence of infection/fever; (2) clinical features including encephalopathy; (3) neuroradiological features on magnetic resonance imaging; (4) exclusion of other causes. We first highlighted differences between ITES and infectious and autoimmune encephalitis, which is the most important differential diagnosis. Consensus was achieved to define five specific ITESs: acute encephalopathy with biphasic seizures and late reduced diffusion; acute necrotizing encephalopathy; mild encephalopathy with a reversible splenial lesion; acute fulminant cerebral oedema; and acute shock with encephalopathy and multiorgan failure. Two further conditions that are currently classified as epilepsy syndromes but have similar features to ITES, namely febrile infection-related epilepsy syndrome and hemiconvulsion-hemiplegia-epilepsy syndrome, are also discussed. The consensus definition is expected to improve awareness of this disease concept, provide diagnostic framework, and facilitate future international research and clinical trials.

Clinical characteristics and prognosis of paediatric respiratory syncytial virus-related encephalopathy

BackgroundTo understand the clinical characteristics and prognosis of respiratory syncytial virus (RSV)-related encephalopathy in children.MethodsA retrospective analysis of the data of children who were diagnosed with RSV-related encephalopathy and admitted to the paediatric intensive care unit (PICU) of Beijing Children’s Hospital between November 2016 and November 2023 was performed.ResultsFour hundred and sixty-four children with RSV infection were treated in the PICU, and eight of these patients (1.7%) were diagnosed with RSV-related encephalopathy. The mean age of the patients was 24.89 (5.92 ∼ 36.86) months. Two patients had underlying diseases. The time from the onset of illness to impaired consciousness was 3 (1.88–3.75) days. Five patients had convulsions, and three patients had an epileptic status. The serum procalcitonin (PCT) level was 1.63 (0.24, 39.85) ng/ml for the eight patients, and the cerebrospinal fluid (CSF) protein level was 232 (163 ∼ 848) g/L. Among the 8 patients, four patients underwent electroencephalogram (EEG) monitoring or examination. One patient showed continuous low-voltage, nonresponsive activity, and another patient displayed persistent slow waves, the remaining two patients had negative results. One patient had a combination of acute necrotizing encephalopathy (ANE) and acute encephalopathy with biphasic seizures and late reduced diffusion (AESD). Additionally, one patient had ANE, and another had acute brain swelling (ABS). One patient died in the hospital, and the other seven patients were discharged with improvement. Routine follow-up was conducted for 4.58(0.5 ∼ 6.50) years, and all patients fully recovered.ConclusionsRSV-related encephalopathy could have varying clinical manifestations, and some types, such as ANE and ABS, are dangerous and can lead to death.

Acute encephalopathy with biphasic seizures and late reduced diffusion with concurrent transverse myelitis.

We describe a patient with acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) with unique features, including concurrent transverse myelitis. A 2-year-old previously healthy girl had clinical findings consistent with AESD, occurring in association with influenza A infection. The posterior brain regions were most severely affected, resulting in cortical blindness. She also developed bilateral limb weakness, and spine MRI revealed transverse myelitis in the cervical region. She was treated acutely with intravenous methylprednisolone. Serum anti-myelin oligodendrocyte glycoprotein and anti-aquaporin-4 antibodies were negative, as was an anti-extractable nuclear antigen panel. Although her clinical presentation was severe, she improved dramatically over the following months, and 6 months following initial presentation, her parents felt she had returned to baseline. This is the first report of AESD occurring in combination with transverse myelitis. The co-occurrence of the two conditions is unlikely to be coincidental, suggesting that there may be a shared or overlapping immunological pathway involved. The patient's recovery was impressive, which could partially relate to the acute treatment with corticosteroids.

Acute subdural hematoma in an infant with a biphasic clinical course and late reduced diffusion

Background: Bright tree appearance (BTA) is a characteristic finding on diffusion-weighted magnetic resonance (MR) imaging with transient high intensity in the white matter. BTA is characteristic of infants with acute encephalopathy with biphasic seizures, but it has also been reported in head trauma cases. In this report, we describe an infant case of traumatic brain injury that demonstrated a biphasic clinical course and late reduced diffusion (TBIRD). Case Description: A 5-month-old boy suffered from head trauma and developed coma and seizures. Computed tomography scans revealed acute subdural hematoma on the right side. He underwent an emergency operation to remove the hematoma but subsequently had seizure clusters for three days. Diffusion-weighted MR imaging revealed BTA in the right cerebral hemisphere. He was treated with antiepileptic agents and fully recovered to pre-injury condition, and MR imaging no further revealed any BTA 20 days after head trauma. He developed no complications at the 10-month postoperative follow-up. Conclusion: We reported a case of TBIRD following head trauma in the infant. The pathogenesis remains unclear, but we consider the possibility of biphasic seizures in infant head trauma cases, and we should appropriately administer the anticonvulsants and carefully check for MR imaging.

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

BackgroundPost-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. MethodsWe 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. ResultsThe 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). ConclusionsThis 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.

Clinical and imaging features of acute encephalopathy with biphasic seizures and late reduced diffusion in children

Objective: To explore the clinical and imaging features of acute encephalopathy with biphasic seizures and late reduced diffusion(AESD) in children. Methods: For the case series study, 21 children with AESD from Peking University First Hospital, Provincial Children's Hospital Affiliated to Anhui Medical University, Children's Hospital of Fudan University, and Shanxi Children's Hospital who were diagnosed and treated from October 2021 to July 2023 were selected. Clinical data were collected to summarize their clinical information, imaging, and laboratory tests, as well as treatment and prognostic characteristics. Descriptive statistical analysis was applicated. Results: Of the 21 cases with AESD, 11 were males and 10 were females, with the age of onset of 2 years and 6 months (1 year and 7 months, 3 years and 6 months). Of the 21 cases, 18 were typical cases with biphasic seizures. All typical cases had early seizures within 24 hours before or after fever onset. Among them, 16 cases had generalized seizures, 2 cases had focal seizures, and 7 cases reached the status epilepticus. Of the 21 cases, 3 atypical cases had late seizures in biphasic only. The late seizures in the 21 cases occurred on days 3 to 9. The types of late seizures included focal seizures in 12 cases, generalized seizures in 6 cases, and both focal and generalized seizures in 3 cases. Diffusion-weighted imaging (DWI) test on days 3 to 11 showed reduced diffusion of subcortical white matter which was named "bright tree sign" in all cases. The diffuse cerebral atrophy predominantly presented in the front-parietal-temporal lobes was found in 19 cases between day 12 and 3 months after the onset of the disease. Among 21 cases, 20 had been misdiagnosed as autoimmune encephalitis, central nervous system infection, febrile convulsions, posterior reversible encephalopathy syndrome, acute disseminated encephalomyelitis, and hemiconvulsion-hemiplegia-epilepsy syndrome. All the cases received high-dose gammaglobulin and methylprednisolone pulse therapy with poor therapeutic effect. By July 2023, 18 cases were under follow-up. Among them, 17 cases were left with varying degrees of neurologic sequelae, including 11 cases with post-encephalopathic epilepsy; 1 recovered completely. Conclusions: AESD is characterized by biphasic seizures clinically and "bright tree sign" on DWI images. Symptomatic and supportive treatments are recommended. The immunotherapy is ineffective. The prognosis of AESD is poor, with a high incidence of neurological sequelae and a low mortality.

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

BackgroundAdenovirus 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. MethodsA 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. ResultsClinical 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). ConclusionA 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.

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

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. 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. 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. 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.

Severe and rare neurological manifestations following COVID-19 infection in children: A Malaysian tertiary centre experience

IntroductionSince the emergence of COVID-19, we have experienced potent variants and sub-variants of the virus with non-specific neurological manifestations. We observed a surge of the Omicron variant of COVID-19 patients with neurological manifestations where less cases of multisystem inflammatory syndrome in children (MIS-C) were reported. This article describes our experience of children with severe and rare neurological manifestations following COVID-19 infection. MethodsThis is a retrospective observational case series of patients under 18 years old who fulfilled the WHO COVID-19 case definition and were referred to our paediatric neurology unit at Hospital Tunku Azizah Kuala Lumpur. Their demographic data, neurological symptoms, laboratory and supporting investigations, neuroimaging, treatment and outcomes were collected and analysed. ResultsThere were eleven patients with neurological manifestations who fulfilled the WHO COVID-19 case definition. Nine patients presented with seizures and/or encephalopathy, one patient with eye opsoclonus and another patient with persistent limbs myokymia. Based on the history, clinical, electrophysiological and radiological findings, two of them had febrile infection-related epilepsy syndrome, two had acute disseminated encephalomyelitis, two had acute necrotising encephalopathy of childhood, one each had hemiconvulsion-hemiplegia-epilepsy syndrome, acute encephalopathy with bilateral striatal necrosis, hemi-acute encephalopathy with biphasic seizures and reduced diffusion, infection-associated opsoclonus and myokymia. ConclusionsThis case series highlighted a wide spectrum of neurological manifestations of COVID-19 infection. Early recognition and prompt investigations are important to provide appropriate interventions. It is essential that these investigations should take place in a timely fashion and COVID-19 quarantine period should not hinder the confirmation of various presenting clinical syndromes.

Neuroimaging in acute infection-triggered encephalopathy syndromes.

Acute encephalopathy associated with infectious diseases occurs frequently in Japanese children (400-700 children/year) and is the most common in infants aged 0-3 years. Acute encephalopathy is classified into several clinicoradiological syndromes; acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most common subtype, followed by clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) and acute necrotizing encephalopathy (ANE). Neuroimaging, especially magnetic resonance imaging (MRI), is useful for the diagnosis, assessment of treatment efficacy, and evaluation of the pathophysiology of encephalopathy syndromes. MRI findings essential for diagnosis include delayed subcortical reduced diffusion (bright tree appearance) for AESD, reversible splenial lesions with homogeneously reduced diffusion for MERS, and symmetric hemorrhagic thalamic lesions for ANE. We reviewed several MRI techniques that have been applied in recent years, including diffusion-weighted imaging for the characterization of cerebral edema, arterial spin labeling for evaluating cerebral perfusion, and magnetic resonance spectroscopy for evaluating metabolic abnormality.

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

BackgroundAcute 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. MethodsWe 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. ResultsWe 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). ConclusionsProlonged 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.

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

BackgroundThere 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). MethodsTo 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. ResultsThe 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. ConclusionsThe 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.

CSF neopterin and quinolinic acid are biomarkers of neuroinflammation and neurotoxicity in FIRES and other infection-triggered encephalopathy syndromes.

Infection-triggered encephalopathy syndromes (ITES) are potentially devastating neuroinflammatory conditions. Although some ITES syndromes have recognisable MRI neuroimaging phenotypes, there are otherwise few biomarkers of disease. Early detection to enable immune modulatory treatments could improve outcomes. We measured CSF neopterin, quinolinic acid, kynurenine and kynurenine/tryptophan ratio using a liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) system. The CSF of 18 children with ITES were compared with acute encephalitis (n = 20), and three control groups, namely epilepsy (n = 20), status epilepticus (n = 18) and neurogenetic controls (n = 20). The main ITES phenotypes in 18 patients were acute encephalopathy with biphasic seizures and late restricted diffusion (AESD, n = 4), febrile infection-related epilepsy syndrome (FIRES n = 4) and other ITES phenotypes. Influenza A was the most common infectious trigger (n = 5), and 50% of patients had a preceding notable neurodevelopmental or family history. CSF neopterin, quinolinic acid and kynurenine were elevated in ITES group compared to the three control groups (all p < 0.0002). The ROC (area under curve) for CSF neopterin (99.3%, CI 98.1-100) was significantly better than CSF pleocytosis (87.3% CI 76.4-98.2) (p = 0.028). Elevated CSF neopterin could discriminate ITES from other causes of seizures, status epilepticus and febrile status epilepticus (all p < 0.0002). The elevated CSF metabolites normalised during longitudinal testing in two patients with FIRES. CSF neopterin and quinolinic acid are neuroinflammatory and excitotoxic metabolites. This CSF metabolomic inflammatory panel can discriminate ITES from other causes of new onset seizures or status epilepticus, and rapid results (4 h) may facilitate early immune modulatory therapy.

Clinical characteristics and short-term prognosis of 22 cases with SARS-CoV-2 infection associated acute encephalopathy

Objective: To investigate the clinical features and short-term prognosis of patients with SARS-CoV-2 infection associated acute encephalopathy (AE). Methods: Retrospective cohort study. The clinical data, radiological features and short-term follow-up of 22 cases diagnosed with SARS-CoV-2 infection associated AE in the Department of Neurology, Beijing Children's Hospital from December 2022 to January 2023 were retrospectively analyzed. The patients were divided into cytokine storm group, excitotoxic brain damage group and unclassified encephalopathy group according to the the clinicopathological features and the imaging features. The clinical characteristics of each group were analyzed descriptively. Patients were divided into good prognosis group (≤2 scores) and poor prognosis group (>2 scores) based on the modified Rankin scale (mRS) score of the last follow-up. Fisher exact test or Mann-Whitney U test was used to compare the two groups. Results: A total of 22 cases (12 females, 10 males) were included. The age of onset was 3.3 (1.7, 8.6) years. There were 11 cases (50%) with abnormal medical history, and 4 cases with abnormal family history. All the enrolled patients had fever as the initial clinical symptom, and 21 cases (95%) developed neurological symptoms within 24 hours after fever. The onset of neurological symptoms included convulsions (17 cases) and disturbance of consciousness (5 cases). There were 22 cases of encephalopathy, 20 cases of convulsions, 14 cases of speech disorders, 8 cases of involuntary movements and 3 cases of ataxia during the course of the disease. Clinical classification included 3 cases in the cytokine storm group, all with acute necrotizing encephalopathy (ANE); 9 cases in the excitotoxicity group, 8 cases with acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) and 1 case with hemiconvulsion-hemiplegia syndrome; and 10 cases of unclassified encephalopathy. Laboratory studies revealed elevated glutathione transaminase in 9 cases, elevated glutamic alanine transaminase in 4 cases, elevated blood glucose in 3 cases, and elevated D-dimer in 3 cases. Serum ferritin was elevated in 3 of 5 cases, serum and cerebrospinal fluid (CSF) neurofilament light chain protein was elevated in 5 of 9 cases, serum cytokines were elevated in 7 of 18 cases, and CSF cytokines were elevated in 7 of 8 cases. Cranial imaging abnormalities were noted in 18 cases, including bilateral symmetric lesions in 3 ANE cases and "bright tree appearance" in 8 AESD cases. All 22 cases received symptomatic treatment and immunotherapy (intravenous immunoglobulin or glucocorticosteroids), and 1 ANE patient received tocilizumab. The follow-up time was 50 (43, 53) d, and 10 patients had a good prognosis and 12 patients had a poor prognosis. No statistically significant differences were found between the two groups in terms of epidemiology, clinical manifestations, biochemical indices, and duration of illness to initiate immunotherapy (all P>0.05). Conclusions: SARS-CoV-2 infection is also a major cause of AE. AESD and ANE are the common AE syndromes. Therefore, it is crucial to identify AE patients with fever, convulsions, and impaired consciousness, and apply aggressive therapy as early as possible.

SARS-CoV-2-Related Pediatric Encephalopathy with Biphasic Convulsions and Cortical Blindness: A Case Report

AbstractAcute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is an encephalopathy syndrome that develops during the febrile phase of infection and is characterized by biphasic seizures and bright tree appearance (BTA) on imaging. In this study, we examined a 1-year-old child who was diagnosed with AESD caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. He had a fever for 2 days and was diagnosed with coronavirus disease 2019 on the day of consultation based on a positive antigen test for SARS-CoV-2. The seizures had stopped on arrival to hospital; however, symptoms of encephalopathy persisted. Despite being treated for acute encephalopathy with steroid pulse therapy, vitamins, and remdesivir, he had poor expressive language, and electroencephalography showed generalized slow waves. A repeat head magnetic resonance imaging showed BTA in the parietal and occipital lobes, and seizures recurred during hospital stay. He was also found to have cortical blindness. At the 4-month follow-up, the vision gradually improved and the hand movements recovered. SARS-CoV-2 infection can cause febrile convulsions, which can lead to the development of AESD. Furthermore, a subtype of AESD has occipital lobe predominant lesions that can cause visual impairment.

Severe pediatric acute encephalopathy syndromes related to SARS-CoV-2.

To clarify whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection cause acute encephalopathy in children and which are the most common syndromes that cause them and what are the outcomes. A nationwide web-based survey among all members of the Japanese Society of Child Neurology to identify pediatric patients aged < 18 years who developed acute encephalopathy in Japan between 1 January 2020 and 31 May 2022 associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection confirmed by polymerase chain reaction or antigen tests using pharyngeal swabs. Acute encephalopathy was defined as acute onset of impaired consciousness lasting > 24 h or an altered mental state; neurological symptoms arising within 2 weeks of onset of COVID-19 or multisystem inflammatory syndrome in children (MIS-C)/pediatric inflammatory multisystem syndrome (PIMS); evidence of SARS-CoV-2 infection; and reasonable exclusion of other diseases. Patients were divided into the known clinico-radiological acute encephalopathy syndrome group and unexplained or unclassifiable acute encephalopathy group. Outcomes were assessed by pediatric cerebral performance category (PCPC) score at hospital discharge. Of the 3,802 society members, 217 representing institutions responded, and 39 patients with suspected acute encephalopathy were reported, of which 31 met inclusion criteria. Of these patients, 14 were diagnosed with known clinico-radiological acute encephalopathy syndromes, with acute encephalopathy with biphasic seizures and late reduced diffusion (five patients) being the most common. Five developed acute encephalopathy associated with MIS-C/PIMS. Among 31 patients, 9 (29.0%) had severe sequelae or died (PCPC ≥ 4). Two of three patients with encephalopathy with acute fulminant cerebral edema and two with hemorrhagic shock and encephalopathy syndrome died. The PCPC scores were higher in the known clinico-radiological acute encephalopathy syndrome group than in the unexplained or unclassifiable acute encephalopathy group (P < 0.01). Acute encephalopathy related to SARS-CoV-2 infection was demonstrated to be more severe than that caused by other viruses in Japan. Acute encephalopathy syndromes characterized by specific neuroradiological findings was associated with poor clinical outcomes.

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

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

Early Phase Increase in Serum TIMP-1 in Patients with Acute Encephalopathy with Biphasic Seizures and Late Reduced Diffusion.

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most frequent subtype of acute encephalopathy syndrome among Japanese children. Exanthem subitum is the most common causative infectious disease of AESD. We herein retrospectively analyzed serum and cerebrospinal fluid (CSF) concentrations of matrix metalloproteinase-9 (MMP-9), tissue inhibitor matrix metalloproteinase-1 (TIMP-1), and seven cytokines in patients with AESD or prolonged febrile seizure (FS) to assess the pathophysiology of AESD and detect biomarkers for diagnosing AESD in the early phase. Serum and CSF samples were obtained from 17 patients with AESD (1st seizure phase group, n = 7; 2nd seizure phase group, n = 10) and 8 with FS. The concentrations of MMP-9, TIMP-1, and seven cytokines were measured by enzyme-linked immunosorbent assays or cytometric bead arrays. Serum concentrations of TIMP-1 were significantly higher in the 1st seizure phase group than in the 2nd seizure phase group. No significant differences were observed in serum concentrations of MMP-9 or the MMP-9/TIMP-1 ratio. The MMP-9-independent increase in circulating TIMP-1 concentrations observed in the present study may be associated with the pathophysiology of AESD in the 1st seizure phase.