The axonal damage marker tau protein in the cerebrospinal fluid is increased in patients with acute encephalopathy with biphasic seizures and late reduced diffusion

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.

Promising candidate cerebrospinal fluid biomarkers of seizure disorder, infection, inflammation, tumor, and traumatic brain injury in pediatric patients

Cerebrospinal fluid (CSF) is a dynamic metabolically active body fluid that has many important roles and is commonly analyzed in pediatric patients, mainly to diagnose central nervous system infection and inflammation disorders. CSF components have been extensively evaluated as biomarkers of neurological disorders in adult patients. Circulating microRNAs in CSF are a promising class of biomarkers for various neurological diseases. Due to the complexity of pediatric neurological disorders and difficulty in acquiring CSF samples from pediatric patients, there are challenges in developing CSF biomarkers of pediatric neurological disorders. This review aimed to provide an overview of novel CSF biomarkers of seizure disorders, infection, inflammation, tumor, traumatic brain injuries, intraventricular hemorrhage, and congenital hydrocephalus exclusively observed in pediatric patients.

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.

One-month-old boy with group B streptococcal meningitis, subdural effusion, and high levels of interleukin-6

Meningitis is associated with elevated levels of inflammatory cytokines in the blood, cerebrospinal fluid (CSF), and subdural fluid. Subdural effusion prolongs fever in patients with meningitis. However, the reason for this remains unclear. A healthy one-month-old boy was admitted after presenting with bacterial meningitis. He was administered meropenem, cefotaxime, and dexamethasone intravenously. On the 3rd day, blood and CSF cultures revealed the presence of Group B Streptococcus from samples collected on day 1. Subsequently, ampicillin and gentamicin replaced the previous combination of antimicrobials used. On the 4th day, brain magnetic resonance imaging with contrast showed bilateral cerebral ventriculitis and left subdural effusion. On the 11th day, since the subdural effusion had worsened, we performed a subdural puncture from the anterior fontanelle. Owing to the prolonged fever, he was intravenously injected immunoglobulin on day 13. He was afebrile on day 23. Antimicrobials were administered for 28 days. Levels of interleukin-6 (IL-6) in the serum and CSF were the highest on the 1st day at 20,600 pg/mL and 170,000 pg/mL, respectively, and decreased upon treatment. IL-6 concentration in the subdural fluid (30,000 pg/mL) was much higher than that in the serum (9 pg/mL) and CSF (2600 pg/mL). To the best of our knowledge, this is the first report on the cytokines in subdural fluid in patients with group B Streptococcal meningitis. Subdural effusion maintained high levels of IL-6 even after the levels in the blood and CSF decreased dramatically. This could explain why subdural effusion prolongs fever in patients with meningitis.

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.

Acute encephalopathy with biphasic seizures and late reduced diffusion (central sparing type)—MRI and MR spectroscopy findings

Acute encephalopathy with biphasic seizure and late reduced diffusion (AESD) is a clinico-radiologic syndrome of acute encephalopathy characterized by biphasic seizure and altered consciousness in acute phase followed by restricted diffusion in bilateral cerebral parenchyma on magnetic resonance imaging (MRI) in the subacute stage. Here, we present the MRI and magnetic resonance spectroscopy (MRS) findings in a case of AESD presenting in 4-year child and diagnosed based on clinico-radiological correlation.

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.

Diagnostic and prognostic factors for acute encephalopathy

BACKGROUND

Acute encephalopathy has the possibility of sequelae. While early treatment is required to prevent the development of sequelae, differential diagnosis is of the utmost priority. The aim of this study was therefore to identify parameters that can facilitate early diagnosis and prediction of outcome of acute encephalopathy.

METHODS

We reviewed the medical charts of inpatients from 2005 to 2011 and identified 33 patients with febrile status epilepticus. Subjects were classified into an acute encephalopathy group (n = 20) and a febrile convulsion group (n = 13), and the parameters serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), ammonia (NH₃ ), cerebrospinal fluid (CSF) tau protein, and CSF interleukin-6 compared between them. Furthermore, the relationship between each parameter and prognosis was investigated in the encephalopathy group.

RESULTS

Significant differences in serum AST, ALT, and LDH were observed between the febrile convulsion and acute encephalopathy group. Moreover, a significant difference in serum LDH was noted between the patients with and without developmental regression at the time of hospital discharge in the encephalopathy group. In particular, CSF tau protein was found to be highly likely to indicate progress, with CSF tau protein >1000 pg/dL associated with poor prognosis leading to developmental regression.

CONCLUSION

Serum AST, ALT and LDH may be related to early diagnosis and prognosis, and should be carefully investigated in patients with encephalopathy. CSF tau protein could also be used as an indicator of poor prognosis in acute encephalopathy.

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

INTRODUCTION

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most common subtype of acute encephalopathy among children in Japan. The pathogenesis of AESD is mostly delayed cerebral edema caused by excitotoxic injury. It is difficult to discriminate AESD and complex febrile seizure in the early phase. Many cases have neurologic sequelae because early intervention is difficult.

METHODS

To establish an early diagnostic method, we assessed 213 hospitalized cases of febrile status epilepticus (FSE) between January 2004 and August 2014. We categorized FSE cases into an AESD group and a non-AESD group and compared their clinical courses, laboratory data and cranial computed tomography (CT) findings.

RESULTS

Of 213 hospitalized FSE cases, 19 (9%) were AESD. Univariate analysis showed that the AESD group took a significantly longer time to wake after FSE, had a higher degree of respiratory acidemia, and higher levels of serum AST, ALT, LD, hyperglycemia and hyperammonemia than the non-AESD group. We developed a scoring model that predicts AESD based on multivariate analysis. Using cut-off points of 4 and more with this scoring model, we could identify the AESD cases with 93% sensitivity and 91% specificity. These scores also had a positive correlation with prognosis.

DISCUSSION

Our scoring model enables early diagnosis of AESD. Patients with high scores should be observed carefully and early intervention should be considered.

Serum tau protein as a marker of disease activity in enterohemorrhagic Escherichia coli O111-induced hemolytic uremic syndrome

Tau protein levels in cerebrospinal fluid (CSF) and serum are elevated in patients with various central nervous system diseases. We investigated whether serum tau protein levels are useful for predicting and assessing disease activity of acute encephalopathy (AE) in enterohemorrhagic Escherichia coli (EHEC) O111-induced hemolytic uremic syndrome (HUS; EHEC encephalopathy). Serum samples were obtained from 14 patients with EHEC O111/HUS, 20 patients with non-EHEC-related AE, and 20 age- and sex-matched healthy controls. CSF samples were obtained from 2 patients with EHEC encephalopathy and 20 patients with non-EHEC-related AE. Tau protein levels and levels of several proinflammatory cytokines were quantified by enzyme-linked immunosorbent assays. Results were compared with the clinical features of EHEC encephalopathy, including magnetic resonance image (MRI) findings. Serum tau levels in patients with EHEC encephalopathy were significantly elevated compared with those in patients with EHEC O111/HUS without encephalopathy, patients with non-EHEC-related AE, and healthy controls. The ratio of CSF tau levels to serum tau levels was >1.0 in all patients with non-EHEC-related AE but <1.0 in 2 patients with EHEC encephalopathy. Serum tau protein levels increased rapidly and markedly in patients with severe EHEC 0111/HUS and encephalopathy when HUS occurred, but were not elevated in mild patients, even in the HUS phase. Furthermore, changes in serum tau protein levels in patients with EHEC encephalopathy were consistent with abnormalities on brain MRI and were positively correlated with proinflammatory cytokine levels. Our results indicate that serum tau protein might be useful to predict and assess disease activity of EHEC encephalopathy.

Changes in cerebrospinal fluid biomarkers in human herpesvirus-6-associated acute encephalopathy/febrile seizures

To determine the involvement of oxidative stress in the pathogenesis of acute encephalopathy associated with human herpesvirus-6 (HHV-6) infection, we measured the levels of oxidative stress markers 8-hydroxy-2'-deoxyguanosine (8-OHdG) and hexanoyl-lysine adduct (HEL), tau protein, and cytokines in cerebrospinal fluid (CSF) obtained from patients with HHV-6-associated acute encephalopathy (HHV-6 encephalopathy) (n = 16) and complex febrile seizures associated with HHV-6 (HHV-6 complex FS) (n = 10). We also examined changes in CSF-8OHdG and CSF-HEL levels in patients with HHV-6 encephalopathy before and after treatment with edaravone, a free radical scavenger. CSF-8-OHdG levels in HHV-6 encephalopathy and HHV-6 complex FS were significantly higher than in control subjects. In contrast, CSF-HEL levels showed no significant difference between groups. The levels of total tau protein in HHV-6 encephalopathy were significantly higher than in control subjects. In six patients with HHV-6 infection (5 encephalopathy and 1 febrile seizure), the CSF-8-OHdG levels of five patients decreased after edaravone treatment. Our results suggest that oxidative DNA damage is involved in acute encephalopathy associated with HHV-6 infection.

Serum tau protein level serves as a predictive factor for neurological prognosis in neonatal asphyxia

BACKGROUND

Tau protein is a microtubule-associated protein that is present in axons. Elevated tau protein levels in cerebrospinal fluid or serum are associated with several central nervous system diseases and can indicate neuronal injury.

OBJECTIVE

In the present study, we measured and then compared serum tau protein levels between infants with neonatal asphyxia and control subjects. We examined these data to investigate the correlation between serum tau protein levels and neurological outcomes after neonatal asphyxia.

PATIENTS AND METHODS

Serum tau protein levels were determined by an enzyme-linked immunosorbent assay in 19 neonates with neonatal asphyxia. Of these 19 neonates, 3 had severe spastic tetraplegia, and 1 had west syndrome. A group of 19 unaffected neonates was included in the study as a control group.

RESULTS

Serum tau protein levels on postnatal day 3 were significantly higher in the poor outcome group than those in the good outcome (p=0.010) and control groups (p=0.006). On postnatal day 7, serum tau protein levels again were significantly higher in the poor outcome group than those in the good outcome (p=0.007) and control groups (p=0.006).

CONCLUSIONS

The present findings indicate serum tau protein levels measured on postnatal days 3 and 7 can predict neurological prognosis following neonatal asphyxia.

Serum and cerebrospinal fluid levels of visinin-like protein-1 in acute encephalopathy with biphasic seizures and late reduced diffusion

BACKGROUND

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) has recently been recognized as an encephalopathy subtype. Typical clinical symptoms of AESD are biphasic seizures, and MRI findings show reduced subcortical diffusion during clustering seizures with unconsciousness after the acute phase. Visinin-like protein-1 (VILIP-1) is a recently discovered protein that is abundant in the central nervous system, and some reports have shown that VILIP-1 may be a prognostic biomarker of conditions such as Alzheimer's disease, stroke, and brain injury.

METHODS

However, there have been no reports regarding serum and cerebrospinal fluid (CSF) levels of VILIP-1 in patients with AESD. We measured the serum and CSF levels of VILIP-1 in patients with AESD, and compared the levels to those in patients with prolonged febrile seizures (FS).

RESULTS

Both serum and CSF levels of VILIP-1 were significantly higher in patients with AESD than in patients with prolonged FS. Serum and CSF VILIP-1 levels were normal on day 1 of AESD.

CONCLUSIONS

Our results suggest that both serum and CSF levels of VILIP-1 may be one of predictive markers of AESD.

Cyclosporine for acute encephalopathy with biphasic seizures and late reduced diffusion

BACKGROUND

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most common syndrome among the acute encephalopathies, and is associated with a high incidence of neurologic sequelae. This study examined the efficacy of cyclosporine (CsA) for the treatment of AESD.

METHODS

Fourteen children with AESD were recruited and categorized as group A (not receiving CsA) and group B (receiving CsA). Clinical course, laboratory data, magnetic resonance imaging (MRI), and outcome were analyzed retrospectively. We divided the patients into three types according to the distribution of abnormalities on MRI: frontal lobe predominant type, unilateral cerebral hemisphere type, and diffuse type. We used the Pediatric Cerebral Performance Category scale (PCPC) and the Pediatric Overall Performance Category scale (POPC) as prognostic measures.

RESULTS

Of the 14 children, five were boys (age range, 9-32 months). PCPC score was: 1 for seven patients, 2 for three patients, and 3 for four patients. There was no significant difference in PCPC between groups A and B (P = 0.293). POPC score was: 1 for six patients, 2 for five patients, and 3 for three patients. There was a significant difference in POPC between groups A and B when patients with the frontal lobe predominant type were excluded (P = 0.020).

CONCLUSIONS

CsA could improve the neurological prognosis of patients with AESD, except for those with frontal lobe predominant type.

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.

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.

Cerebrospinal fluid brain injury biomarkers in children: a multicenter study

BACKGROUND

Cerebrospinal fluid (CSF) biomarkers reflecting neuronal and astroglial injury, such as total tau (T-tau), glial fibrillary acidic protein (GFAP), and neurofilament light (NFL), have been extensively investigated in neurologic diseases in adults, but no large study has investigated these biomarkers in children.

METHODS

This study presents a detailed evaluation of CFS T-tau, GFAP, NFL, and CSF:albumin ratio in a large cohort of pediatric patients. This is a retrospective multicenter study on pediatric patients aged <16 years (n = 607), where neuronal injury biomarkers T-tau, GFAP, NFL, and CSF albumin ratio were analyzed during 2000-2010 at the Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Sweden. The patients were grouped into eight categories: epilepsy, infectious and inflammatory central nervous system disorders, progressive encephalopathy, static encephalopathy, tumors, movement disorders, miscellaneous disorders, and a control group.

RESULTS

T-tau, GFAP, and NFL were increased in progressive encephalopathy (P < 0.001), epilepsy (P < 0.001), and infectious and inflammatory central nervous system disorders (P < 0.001) compared with controls. T-tau was the biomarker with the highest diagnostic accuracy with the area under the curve of 0.83 (95% confidence interval (CI), 0.77-0.90; P < 0.0001) for progressive encephalopathy followed by epilepsy 0.80 (95% CI, 0.75-0.87; P < 0.0001). The combination of all four biomarkers further improved the area under the curve for the progressive encephalopathy 0.87 (95% CI, 0.77-0.89; P < 0.0001), followed by epilepsy 0.81 (95% CI, 0.74-0.80; P = 0.030). The combination of the biomarkers also separated progressive from static encephalopathy 0.88 (95% CI, 0.83-0.93; P < 0.0001).

CONCLUSIONS

CSF T-tau, GFAP, and NFL are differently altered across different neurologic diseases in children. Importantly, the biomarker pattern distinguishes between progressive and static neurologic disorders.

Acute encephalopathy with biphasic seizures and late reduced diffusion

Acute encephalopathy with biphasic seizures and reduced diffusion (AESD) is a syndrome of encephalopathy characterized by biphasic seizures and altered consciousness in the acute stage followed in the subacute stage by restricted diffusion in the subcortical white matter on magnetic resonance imaging. The etiology of AESD has been attributed to viral infection like influenza A and human herpes virus 6. The exact pathogenesis of AESD is uncertain. Here we report a case of AESD, diagnosed based on clinicoradiological correlation.

Cerebrospinal fluid biomarkers in neurological diseases in children

Analysis of cerebrospinal fluid (CSF) biomarkers is an integral part of neurology. Basic CSF biomarkers, such as CSF/serum albumin ratio and CSF cell counts, have been used to diagnose inflammatory and infectious CNS disorders in adults and children for decades. During recent years, however, numerous biomarkers for neuronal and astroglial injury, as well as disease-specific protein inclusions, have been developed for neurodegenerative disorders in adults. The overall aim of this paper is to give an updated overview of some of these biomarkers with special focus on their possible relevance to neurological disorders in children and adolescents.

Prognostic factors in acute encephalopathy with reduced subcortical diffusion

OBJECTIVES

Acute encephalopathy with reduced subcortical diffusion (AED) covers a spectrum including not only typical acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) but also atypical AESD with monophasic clinical course, or more severe subtypes. Aim of this study is to analyze prognostic factors of AED.

MATERIALS & METHODS

We recruited 33 children with AED, that is, widespread diffusion restriction in cortical and subcortical structures. Their clinical courses, laboratory data, MRI, and the efficacy of treatment were analyzed retrospectively.

RESULTS

Of the 33 children, 20 were males and the mean age at diagnosis was 22 months. Eighteen children had good outcome and 15 had poor outcome. Univariate analysis showed loss of consciousness 24 h after the onset, prolonged seizure at the onset, and mechanical ventilation to be weak predictors of poor outcome. Maximal aspartate aminotransferase, alanine aminotransferase, and creatinine kinase levels were significantly higher in the poor outcome group. Multivariate analysis showed loss of consciousness 24 h after the onset and prolonged seizure at the onset to be poor predictors of AED. Treatment with steroids and/or immunoglobulins did not result in better outcome.

CONCLUSION

Prolonged seizure at the onset and loss of consciousness 24 h after the onset were seen at early stages of severe AED. Using these features, a prospective study of early intervention in AED should be conducted to further analyze the efficacy of its treatment.

Elevation of tau protein levels in the cerebrospinal fluid of children with West syndrome

PURPOSE

West syndrome is an epileptic encephalopathy with a poor developmental outcome. Tau protein levels in the cerebrospinal fluid (CSF) are reported to be markers of axonal damage and neurodegeneration. This study aimed to investigate axonal damage and the effects of adrenocorticotropic hormone (ACTH) therapy on axons in West syndrome, as measured by tau protein levels in CSF.

METHODS

Tau protein levels in CSF before and after ACTH therapy were determined by an enzyme-linked immunosorbent assay in 26 children with West syndrome. Of these 26 children, 18 were symptomatic, and 8 had a cryptogenic form of West syndrome. A group of 41 unaffected children was included in the study as a control group.

RESULTS

The levels of tau protein in CSF were significantly higher in children with West syndrome than in the control group, and these levels remained high after ACTH therapy. ACTH therapy was effective for 20 of the 26 children with West syndrome, and their CSF tau protein levels were significantly higher after ACTH therapy than before therapy.

CONCLUSION

Our results suggest that axonal damage occurs in West syndrome, as judged by tau protein levels in CSF.

Oxidative stress markers and phosphorus magnetic resonance spectroscopy in a patient with GLUT1 deficiency treated with modified Atkins diet

Glucose transporter type 1 deficiency syndrome is an inborn error of glucose transport across blood-tissue barriers, and the modified Atkins diet is an effective and well-tolerated treatment. To investigate the effects of the modified Atkins diet, we examined the cerebrospinal fluid markers and performed phosphorus magnetic resonance spectroscopy in a patient with glucose transporter type 1 deficiency syndrome before and after the modified Atkins diet. Cerebrospinal fluid levels of the oxidative stress markers, 8-hydroxy-2'-deoxyguanosine and hexanoyl-lysine adduct, were markedly increased above the cutoff index and were normalized 18 months after the modified Atkins diet. Phosphorus magnetic resonance spectroscopy measurements showed 18% increase of PCr/γ-ATP ratio after the modified Atkins diet. These results suggest that the modified Atkins diet may reduce oxidative stress in the brain and improve energy reserve capacity, which is important in sustaining electrophysiological activities essential for performing brain functions.

Focal encephalopathy with recurrent episodes of epileptic status and cluster mimicking hemiconvulsion-hemiplegia-epilepsy syndrome

Hemiconvulsion-hemiplegia-epilepsy syndrome is characterized by unilateral convulsions during fever, transient hemiplegia, and subsequent partial epilepsy with atrophy in the cerebrum. A 9-year-old boy with a history of West syndrome and hypoglycemic attacks had three episodes of epileptic status and clusters mimicking HHE syndrome over a 2-year period. Magnetic resonance imaging revealed the involvement of the right and left cerebrums. Because no abnormalities were detected in an endocrine examination, screening tests for metabolic errors, or magnetic resonance spectroscopy, a diagnosis of metabolic errors was not supported. Immunohistochemistry using the patient's sera showed binding of the serum immunoglobulin with neurons in the temporal and occipital cerebral cortices, indicating the possible involvement of autoimmune mechanisms in this case. Focal encephalopathy should be considered in children showing convulsions, psychiatric disorders, and/or involuntary movements for several months in a row. In such cases, immunohistochemistry using the patient's sera may be useful for the investigation of the pathogenesis of the illness.

Oxidative stress in patients with clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS)

We examined oxidative stress markers, tau protein and cytokines in the cerebrospinal fluid (CSF) in six patients with clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS). In the CSF, 8-hydroxy-2'-deoxyguanosine (8-OHdG) and hexanoyl-lysine adduct levels increased over the cutoff index in four and one out of six MERS patients, respectively. The CSF IL-6 and IL-10 levels were increased in three out of six patients, two of which had extended lesion of the cerebral white matter. The CSF value of tau protein, marker of the axonal damage, was not increased, and neuron specific enolase (NSE) in the CSF was not increased. The increased 8-OHdG levels in the CSF, DNA oxidative stress marker, in four MERS patients, suggesting involvement of oxidative stress in MERS. MERS is occasionally accompanied with hyponatremia, although our patients lacked hyponatremia. It is possible that the disequilibrium of systemic metabolism including electrolytes may lead to facilitation of oxidative stress and reversible white matter lesion in MERS. The increase of cytokine production seems to be involved in the distribution of lesions in MERS.

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

BACKGROUND

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is characterized clinically by biphasic seizures and late magnetic resonance imaging abnormalities, such as reduced subcortical diffusion from day 3 onwards, often accompanied with some neurological sequelae. In the early stages of the disease, AESD closely resembles its far more prevalent and relatively benign counterpart, febrile seizure (FS).

METHODS

We measured and compared the serum or cerebrospinal fluid (CSF) levels of S100B, neuron-specific enolase (NSE), and total tau protein in 43 patients with FS and 18 patients with AESD, at any point during the disease. To assess early diagnostic validity, we compared these biomarkers in 43 FS and eight AESD patients, with whom the day 0-2 samples were available. We used the receiver-operator characteristic curve to evaluate the diagnostic values of these markers.

RESULTS

The levels of all biomarkers were significantly higher in AESD than FS patients. When only day 0-2 samples from AESD patients were used, the levels of all the measured biomarkers, except serum NSE, were still significantly higher in patients with AESD than in FS, suggesting that AESD could damage astrocytes, neurons, and axons, even in the early stages of the disease. According to the receiver-operator characteristic curve analyses, CSF S100B (cut-off value, 100 pg/mL) and CSF total tau protein (cut-off value, 100 pg/mL) were better predictors of AESD than other biomarkers.

CONCLUSION

The combination of CSF S100B and CSF total tau protein resulted in a positive predictive value of AESD 83.3%, which could be helpful for early diagnosis, facilitating early therapeutic interventions.