Serum and cerebrospinal fluid S100B, neuron-specific enolase, and total tau protein in acute encephalopathy with biphasic seizures and late reduced diffusion: a diagnostic validity

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

OBJECTIVE

This 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).

METHODS

Pediatric 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.

RESULTS

Total 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).

CONCLUSIONS

The 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.

Biochemical and Anthropometric Parameters for the Early Recognition of the Intrauterine Growth Restriction and Preterm Neonates at Risk of Impaired Neurodevelopment

BACKGROUND

S100B and Tau are implicated with both brain growth and injury. Their urinary levels in 30-to-40-day-old full-term, preterm, IUGR, and preterm-IUGR subjects were measured to investigate their possible relationship with future delayed neurodevelopment.

METHODS

Values were related to the neuro-behavioral outcome at two years of age, as well as to brain volumes and urinary NGF assessed at the same postnatal time point.

RESULTS

Using the Griffiths III test, cognitive and motor performances were determined to establish subgroups characterized by either normal or impaired neuro-behavior. The latter included preterm, IUGR, and preterm-IUGR individuals who exhibited significantly higher and lower S100B and Tau levels, respectively, along with markedly reduced cerebral volumes and urinary NGF, as previously demonstrated. Contrary to NGF, however, Tau and S100B displayed a weak correlation with brain volumes.

CONCLUSIONS

Delayed cognitive and motor performances observed in two-year-old preterm and IUGR-born individuals were also found to be associated with anomalous urinary levels of S100B and Tau, assessed at 30-40 days of the postnatal period, and their changes did not correlate with brain growth. Thus, our data suggests that, in addition to cerebral volumes and NGF, urinary S100B and Tau can also be considered as valuable parameters for the early detection of future neurodevelopmental abnormalities.

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.

Vitamin B6 in acute encephalopathy with biphasic seizures and late reduced diffusion

BACKGROUND

The initial presentation of acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is indistinguishable from that of complex febrile seizures (FS), which poses a great diagnostic challenge for clinicians. Excitotoxicity is speculated to be the pathogenesis of AESD. Vitamin B6 (VB6) is essential for the biosynthesis of gamma-aminobutyric acid, an inhibitory neurotransmitter. The aim of this study is to investigate our hypothesis that VB6 deficiency in the brain may play a role in AESD.

METHODS

We obtained cerebrospinal fluid (CSF) samples from pediatric patients with AESD after early seizures and those with FS. We measured pyridoxal 5'-phosphate (PLP) and pyridoxal (PL) concentrations in the CSF samples using high-performance liquid chromatography with fluorescence detection.

RESULTS

The subjects were 5 patients with AESD and 17 patients with FS. Age did not differ significantly between AESD and FS. In AESD, CSF PLP concentration was marginally lower (p = 0.0999) and the PLP-to-PL ratio was significantly (p = 0.0417) reduced compared to those in FS.

CONCLUSIONS

Although it is impossible to conclude that low PLP concentration and PLP-to-PL ratio are causative of AESD, this may be a risk factor for developing AESD. When combined with other markers, this finding may be useful in distinguishing AESD from FS upon initial presentation.

A Meta-Analysis of Neuron-Specific Enolase Levels in Cerebrospinal Fluid and Serum in Children With Epilepsy

Background: Studies suggest that neuron-specific enolase (NSE) levels in the cerebrospinal fluid (CSF) and serum play an important role in childhood epilepsy. However, these investigations remain controversial due to inconsistent clinical results. The present study aimed to quantitatively summarize and assess whether CSF and serum NSE levels are associated with epilepsy in children. Methods : A systematic search of the Harvard Hollis+, Clinicaltrials, Open Gray, China National Knowledge Infrastructure, and Wanfang databases was performed. Studies investigating NSE and epilepsy were identified and retrieved. Original studies with data overlapping those from other investigations and those lacking the necessary data were excluded. The included studies were extracted and synthesized, and data were analyzed using a random-effects model in R Studio and Comprehensive Meta-Analysis version 3 (Biostat, Englewood, NJ, USA). Results: Random-effects meta-analysis of 26 studies, including 1,360 patients, and 1,256 healthy control, revealed that childhood epilepsy exhibited meaningfully increased CSF and serum levels of NSE compared with controls [Hedges' g = 1.962 (95% confidence interval, 1.413-2.512); P < 0.001]. No single study meaningfully influenced the overall association between CSF and serum levels of NSE and epilepsy after sensitivity analysis. Subgroup analyses according to sample source and assay type revealed a significant association between NSE levels and epilepsy. Stratified analysis confirmed that NSE levels were significantly correlated with the severity of neurological compromise. Metaregression analyses revealed that sample size, mean age, and sex may contribute to effect-size reductions; however, sample source, assay type, and country did not moderate effect size. Funnel plots constructed using the trim-and-fill method confirmed that the outcome of the meta-analysis could not be due to publication bias. Conclusion: The results demonstrated that childhood epilepsy exhibits significantly elevated levels of NSE in the CSF and serum, thus strengthening the association between increased NSE levels and epilepsy.

Ratio of Alpha 2-Macroglobulin Levels in Cerebrospinal Fluid and Serum: An Expression of Neuroinflammation in Acute Disseminated Encephalomyelitis

BACKGROUND

Acute encephalitis and encephalopathy are life-threatening diseases in children. However, no laboratory examinations are performed for their early diagnosis and treatment. Alpha 2-macroglobulin (α2M) is a blood glycoprotein that increases during the early stages of inflammation. In the present study, we investigated the role of α2M levels in acute encephalitis and encephalopathy.

METHODS

We analyzed the cerebrospinal fluid and serum samples from patients with acute disseminated encephalomyelitis, infection-related acute encephalopathy, febrile status epilepticus, and febrile seizure simplex type. Samples were collected from the pediatric department of hospitals throughout the Fukushima Prefecture between January 1, 1999, and May 31, 2012.

RESULTS

α2M levels in the cerebrospinal fluid were 4.7 (3.8-8.4) μg/mL for acute disseminated encephalomyelitis, 2.1 (1.1-2.3) μg/mL for infection-related acute encephalopathy, 1.1 (0.9-6.4) μg/mL for febrile status epilepticus, and 1.0 (0.8-1.1) μg/mL for febrile seizure simplex type. α2M levels in patients with acute disseminated encephalomyelitis were significantly higher than those in patients with infection-related acute encephalopathy and febrile seizure simplex type (P = 0.019 and P = 0.002, respectively). The ratio of α2M level in the cerebrospinal fluid to that in the serum in patients with acute disseminated encephalomyelitis was significantly higher than the ratio in patients with febrile status epilepticus (P = 0.04). In patients with acute disseminated encephalomyelitis, α2M levels in the cerebrospinal fluid decreased with treatment.

CONCLUSIONS

Our results suggest that α2M levels in the cerebrospinal fluid reflect the neuroinflammatory status of patients with acute disseminated encephalomyelitis.

Association between Elevated Serum Tau Protein Level and Sepsis-Associated Encephalopathy in Patients with Severe Sepsis

Sepsis-associated encephalopathy (SAE) is a common complication of sepsis. It is imperative to recognize, diagnose, and effectively manage SAE at the early stages. The aim of this study was to evaluate the potential of using the serum tau protein level in the diagnosis of SAE and the prediction of SAE outcomes. This was a retrospective and observational study. The patients included in this study were diagnosed with severe sepsis or septic shock. The serum tau protein level was measured using a commercial enzyme-linked immunosorbent assay. The association between the level of serum tau protein and SAE was assessed by multiple logistic regression analysis. One hundred nine patients with severe sepsis were enrolled during a period of two years. Of the 109 enrolled patients, 27 developed SAE. The serum tau protein level was significantly higher in the patients with SAE than that of the non-SAE group. The serum tau protein level and the sequential organ failure assessment (SOFA) score were independent factors that were associated with SAE. The combined use of the serum tau protein level with the SOFA score improved the accuracy in distinguishing SAE from non-SAE patients. A cutoff value serum tau protein level of 75.92 pg/mL had 81.1% sensitivity and 86.1% specificity in predicting the 28-day mortality in patients with severe sepsis. We identified a close association between the serum tau protein level with the appearance of SAE in patients with severe sepsis. The serum tau protein level can be useful in the prediction of poor outcomes in patients with sepsis.

Increased Serum S100B Levels in Patients With Epilepsy: A Systematic Review and Meta-Analysis Study

Importance: Accumulating evidence suggests that serum levels of S100B may play a role in epilepsy. Objective: We performed a meta-analysis to quantitatively summarize the serum S100B data available for patients with epilepsy. Data source: Two independent researchers conducted a systematic investigation of the Harvard Hollis+, Open Gray, Clinicaltrials, Wanfangdata, and CNKI databases through Dec 6, 2018, for all studies published in English and Chinese. The search terms included S100B and calcium-binding protein B in combination with epilepsy. Study selection: Original studies and reported data from these search terms are included. Studies where data overlapped with other studies were excluded. Data extraction and synthesis: investigators extracted, pooled and analyzed data from the included studies using a fixed-effects model in the Comprehensive Meta-Analysis3.3 and R software. Main outcomes and measures: Peripheral blood levels of S100B in patients with epilepsy compared with controls. Aberrations in peripheral blood levels of S100B were hypothesized to be related to epilepsy. Results: a fixed-effects meta-analysis of all 18 studies, including 1,057 unique participants, indicated that patients with epilepsy had significantly increased peripheral blood levels of S100B compared to controls (Hedges g = 1.568, 95% CI =1.431-1.706, P < 0.001). Sensitivity analysis showed that no single study significantly influenced the overall association of peripheral blood levels of S100B and epilepsy. Most of the subgroup analyses, including those of country, assay type and publication language, demonstrated a statistically significant association between peripheral blood levels of S100B and epilepsy. Meta-regression analyses indicated that gender (regression coefficient [SE], -0.2524 [0.0641]; 95%CI, -0.3781 to -0.1267; P = 0.0001) and mean age (regression coefficient [SE], -0.1224 [0.0426]; 95% CI, -0.2058 to -0.0390; P = 0.0040) might present serum S100B reductions, but sample size, years, assay type, publication language and country did not show moderating effects on the effect sizes. Furthermore, the trim-and-fill method used to adjust for funnel plot asymmetry in our meta-analysis confirmed that a positive outcome is unlikely to be due to publication bias. Conclusion and relevance: the results of this meta-analysis provide evidence for a significant increase in serum S100B levels in patients with epilepsy. Serum S100B is the most worthwhile biomarker of epilepsy, which is helpful for the clinical diagnosis and prognosis of epilepsy.

Magnesium Sulfate Provides Neuroprotection in Eclampsia-Like Seizure Model by Ameliorating Neuroinflammation and Brain Edema

Eclampsia is a hypertensive disorder of pregnancy that is defined by the new onset of grand mal seizures on the basis of preeclampsia and a leading cause of maternal and fetal mortality worldwide. Presently, magnesium sulfate (MgSO₄) is the most effective treatment, but the mechanism by which MgSO₄ prevents eclampsia has yet to be fully elucidated. We previously showed that systemic inflammation decreases the seizure threshold in a rat eclampsia-like model, and MgSO₄ treatment can decrease systemic inflammation. Here, we hypothesized that MgSO₄ plays a neuroprotective role in eclampsia by reducing neuroinflammation and brain edema. Pregnant Sprague-Dawley rats were given an intraperitoneal injection of pentylenetetrazol following a tail vein injection of lipopolysaccharide to establish the eclampsia-like seizure model. Seizure activity was assessed by behavioral testing. Neuronal loss in the hippocampal CA1 region (CA1) was detected by Nissl staining. Cerebrospinal fluid levels of S100-B and ferritin, indicators of neuroinflammation, were detected by enzyme-linked immunosorbent assay, and ionized calcium binder adapter molecule 1 (Iba-1, a marker for microglia) and glial fibrillary acid protein (GFAP, a marker for astrocytes) expression in the CA1 area was determined by immunofluorescence staining. Brain edema was measured. Our results revealed that MgSO₄ effectively attenuated seizure severity and CA1 neuronal loss. In addition, MgSO₄ significantly reduced cerebrospinal fluid levels of S100-B and ferritin, Iba-1 and GFAP activation in the CA1 area, and brain edema. Our results indicate that MgSO₄ plays a neuroprotective role against eclampsia-like seizure by reducing neuroinflammation and brain edema.

The clinical and diagnostic utility of S100B in preterm newborns

Preterm birth is still the most important cause of perinatal mortality and morbidity. Follow-up studies showed that the majority of neurological abnormalities during childhood are already present in the first week after birth. In this light, the knowledge of the timing of the insult and/or of the contributing factors is of utmost relevance in order to avoid adverse neurological outcome. Notwithstanding, the considerable advances in perinatal clinical care and monitoring, the early detection of cases at risk for brain damage is still a challenge because, when radiological pictures are still negative, brain damage may be already at a subclinical stage, with symptoms hidden by therapeutic strategies. Thus, it could be very relevant to measure quantitative parameters, such as neuroproteins, able to detect subclinical lesions at a stage when routine brain monitoring procedures are still silent. In the last decade, the assay of the brain-specific protein S100B in different biological fluids proved useful information on brain function and damage in the perinatal period. Therefore, the present study provides an overview of the most recent findings on S100B role as a reliable marker of brain development/damage in preterm high risk fetuses and newborns.

Visualization of different characteristics of cerebrospinal fluid with acute encephalopathy and febrile seizures using pattern recognition analysis of 1H NMR

BACKGROUND

In acute encephalopathy, deterioration of the condition can be rapid, and early intervention is essential to prevent progression of the disease. However, in the acute period, differentiating acute encephalopathy from febrile seizures is difficult. Thus, an early diagnostic marker has been sought to enable early intervention. Proton nuclear magnetic resonance ((1)H NMR) spectroscopy is used to study the chemical characteristics of biological fluids such as cerebrospinal fluid (CSF). The purpose of this study was to ascertain if pattern recognition of (1)H NMR spectra could differentiate CSF obtained from patients with acute encephalopathy and febrile seizures.

METHODS

CSF was obtained from patients with acute encephalopathy (n = 4), complex febrile seizures (n = 9), and simple febrile seizures (n = 9).

RESULTS

NMR spectra of CSF did not visually differ across the three groups. Spectral data were analyzed by partial least squares discriminant analysis and visualized by plotting the partial least squares scores of each sample. The three patient groups clustered separately on the plots.

CONCLUSION

In this preliminary study, we were able to visualize different characteristics of CSF obtained from patients with acute encephalopathy and simple and complex febrile seizures using pattern recognition analysis of (1)H NMR data.

Serum and CSF biomarkers in acute pediatric neurological disorders

BACKGROUND

There have been numerous reports regarding serum or cerebrospinal fluid (CSF) biomarkers in various disorders; however, the validities of such biomarkers for more precise diagnoses and prognosis estimates remain to be determined, especially in pediatric patients with neurological disorders.

METHODS

Serum/CSF S100B, neuron-specific enolase, and total tau (tTau) were measured in various acute pediatric neurological disorders, and their usefulness for diagnostic and prognostic predictions was validated using receiver operating characteristic curves and area under the curve (AUC) analysis.

RESULTS

A total of 336 serum and 200 CSF specimens from 313 patients were examined, and we identified statistically significant differences that were relevant from diagnostic and prognostic viewpoints. CSF and serum tTau levels could be good predictors for diagnosis (CSF tTau; AUC=0.76) and prognosis (serum tTau; AUC=0.78).

CONCLUSIONS

Both CSF and serum tTau levels could be useful for precise diagnostic and prognostic estimations in acute pediatric neurological disorders. Further studies are needed to clarify the clinical significance of such biomarkers.

Postictal subcortical restricted diffusion in a child with focal symptomatic epilepsy

BACKGROUND

Diffusion abnormalities on MRI are well described after prolonged seizures. However, isolated, focal, subcortical restricted diffusion is uncommon.

PATIENT

A girl of Kurdish descent experienced focal-onset epilepsy secondary to a left thalamic infarction at age 3 years. At age 6 years, she developed status epilepticus in the context of a febrile illness.

RESULTS

Four days after the seizure, she had neurological deterioration including involuntary posturing movements and irritability. A brain MRI revealed left hemisphere subcortical restricted diffusion, predominantly in the frontal and occipital regions. She experienced persistent right hemiparesis for 2 months after the initial seizure.

CONCLUSIONS

This presentation is reminiscent of acute encephalopathy with biphasic seizures and late reduced diffusion, a syndrome thus far reported almost exclusively in Japan. This represents one of the few documented examples of acute encephalopathy with biphasic seizures and late reduced diffusion in an individual not of east Asian descent.

Delirious behavior or mild reduction of consciousness mimicking influenza-associated encephalopathy

BACKGROUND

During the A/H1N1 pandemic, patients suffered from impaired consciousness. They were suspected of or diagnosed as having influenza-associated encephalopathy (IAE) in an emergency situation. Their symptoms resembled those of a recently described 'unique clinical group', which were reported to have a favorable prognosis.

METHODS

We retrospectively examined 46 patients and divided them into two groups. Group IC contained the 26 patients with persisting impaired consciousness. The remainder of the patients were categorized into group R, consisting of patients with only neurological symptoms without impaired consciousness.

RESULTS

Male predominance (22 male/four female) was noted in group IC. Patient age ranged from 5 to 12 years old (mean ± SD, 7.7 ± 2.3 years). Impaired consciousness such as delirious behavior or mild reduction of consciousness lasted continuously or intermittently from 5 min to 2.5 days. On electroencephalogram, semi-rhythmic high-voltage slow waves in the parieto-occipital regions and diffuse high-voltage slow waves were observed in eight and in two patients, respectively. In group R, there was no gender predominance. Patient age ranged from 1 to 9 years old (mean ± SD, 4.1 ± 2.5 years). All group R patients were clinically diagnosed with febrile seizure.

CONCLUSIONS

Some of the characteristics in group IC resembled those of the unique clinical group, and are part of a continuous clinical spectrum. Some patients may have favorable outcome without specific treatment.

Tau protein concentrations in the cerebrospinal fluid of children with acute disseminated encephalomyelitis

BACKGROUND

Acute disseminated encephalomyelitis (ADEM) is clinically characterized by the acute onset of neurological symptoms after a viral infection or immunization, and is thought to represent an autoimmune disease directed against myelin. Tau protein is a phosphorylated microtubule-associated protein, primarily located in neuronal axons. Increased levels of tau protein in cerebrospinal fluid (CSF) are found in various pathological conditions.

METHODS

We used tau protein as a marker of axonal damage and examined its concentration in the CSF of 27 children with ADEM.

RESULTS

CSF tau protein concentration in children with ADEM was significantly higher than that in the CSF of control subjects (P=0.008). There were no significant differences in CSF tau protein concentrations in the ADEM patients with and without encephalopathy. The CSF tau protein concentration in patients with partial lesion resolution in follow-up brain MRI was significantly higher than in patients with complete lesion resolution (P=0.014).

CONCLUSIONS

In conclusion, we demonstrated that CSF tau protein concentration was significantly increased in ADEM patients. Our findings suggest that axonal damage may occur in addition to demyelination in children with ADEM.

Prognostic value of brain injury biomarkers in acute encephalitis/encephalopathy

BACKGROUND

Acute encephalitis/encephalopathy (AEE) is a devastating cause of severe neurodevelopmental sequelae or death in children. Assessing ongoing brain injury and predicting outcomes using bedside point-of-care testing is expected to be extremely valuable.

METHODS

For this study, three brain injury markers, S-100B, glial fibrillary acidic protein (GFAP), and tau protein, were measured in early cerebrospinal fluid samples of children with AEE. Subjects comprised three groups: Group 1 (non-AEE control, n = 27); Group 2 (AEE with normal resolution or mild sequelae, n = 13); and Group 3 (AEE with severe sequelae or death, i.e. "poor outcome," n = 10).

RESULTS

All marker levels were significantly higher in Group 3 than in Group 1 or 2. In Group 3, only S-100B was significantly higher in non-survivors than in survivors. For scoring assessment (range: 0-3 points), the predictive accuracies of 3 points for poor outcomes in children with AEE (i.e. Group 2 and 3, n = 23) were 91% (21/23) for S-100B, 74% (17/23) for GFAP, and 78% (18/23) for tau. When the scores were summed up for S-100B, GFAP, and tau (range: 0-9 points), and for S-100B and tau (range: 0-6 points), the patients with poor outcomes were identified more accurately using the respective thresholds of 6 points and 4 points (96% [22/23] and 100% [23/23], respectively).

CONCLUSION

Our findings suggest that combined measurement and scoring assessment of the markers, especially S-100B and tau, show promise as predictors of clinical outcomes in children with AEE.

Analysis of multiple B-value diffusion-weighted imaging in pediatric acute encephalopathy

Acute encephalopathy is a disease group more commonly seen in children. It is often severe and has neurological sequelae. Imaging is important for early diagnosis and prompt treatment to ameliorate an unfavorable outcome, but insufficient sensitivity/specificity is a problem. To overcome this, a new value (fraction of high b-pair (F_H)) that could be processed from clinically acceptable MR diffusion-weighted imaging (DWI) with three different b-values was designed on the basis of a two-compartment model of water diffusion signal attenuation. The purpose of this study is to compare F_H with the apparent diffusion coefficient (ADC) regarding the detectability of pediatric acute encephalopathy. We retrospectively compared the clinical DWI of 15 children (1–10 years old, mean 2.34, 8 boys, 7 girls) of acute encephalopathy with another 16 children (1–11 years old, mean 4.89, 9 boys, 7 girls) as control. A comparison was first made visually by mapping F_H on the brain images, and then a second comparison was made on the basis of 10 regions of interest (ROIs) set on cortical and subcortical areas of each child. F_H map visually revealed diffusely elevated F_H in cortical and subcortical areas of the patients with acute encephalopathy; the changes seemed more diffuse in F_H compared to DWI. The comparison based on ROI revealed elevated mean F_H in the cortical and subcortical areas of the acute encephalopathy patients compared to control with significant difference (P<0.05). Similar findings were observed even in regions where the findings of DWI were slight. The reduction of mean ADC was significant in regions with severe findings in DWI, but it was not constant in the areas with slighter DWI findings. The detectability of slight changes of cortical and subcortical lesions in acute encephalopathy may be superior in F_H compared to ADC.