CSF neopterin, quinolinic acid and kynurenine/tryptophan ratio are biomarkers of active neuroinflammation.

BACKGROUND: Defining the presence of acute and chronic brain inflammation remains a challenge to clinicians due to the heterogeneity of clinical presentations and aetiologies. However, defining the presence of neuroinflammation, and monitoring the effects of therapy is important given its reversible and potentially damaging nature. We investigated the utility of CSF metabolites in the diagnosis of primary neuroinflammatory disorders such as encephalitis and explored the potential pathogenic role of inflammation in epilepsy. METHODS: Cerebrospinal fluid (CSF) collected from 341 paediatric patients (169 males, median age 5.8 years, range 0.1-17.1) were examined. The patients were separated into a primary inflammatory disorder group (n = 90) and epilepsy group (n = 80), who were compared with three control groups including neurogenetic and structural (n = 76), neurodevelopmental disorders, psychiatric and functional neurological disorders (n = 63), and headache (n = 32). FINDINGS: There were statistically significant increases of CSF neopterin, kynurenine, quinolinic acid and kynurenine/tryptophan ratio (KYN/TRP) in the inflammation group compared to all control groups (all p < 0.0003). As biomarkers, at thresholds with 95% specificity, CSF neopterin had the best sensitivity for defining neuroinflammation (82%, CI 73-89), then quinolinic acid (57%, CI 47-67), KYN/TRP ratio (47%, CI 36-56) and kynurenine (37%, CI 28-48). CSF pleocytosis had sensitivity of 53%, CI 42-64). The area under the receiver operating characteristic curve (ROC AUC) of CSF neopterin (94.4% CI 91.0-97.7%) was superior to that of CSF pleocytosis (84.9% CI 79.5-90.4%) (p = 0.005). CSF kynurenic acid/kynurenine ratio (KYNA/KYN) was statistically decreased in the epilepsy group compared to all control groups (all p ≤ 0.0003), which was evident in most epilepsy subgroups. INTERPRETATION: Here we show that CSF neopterin, kynurenine, quinolinic acid and KYN/TRP are useful diagnostic and monitoring biomarkers of neuroinflammation. These findings provide biological insights into the role of inflammatory metabolism in neurological disorders and provide diagnostic and therapeutic opportunities for improved management of neurological diseases. FUNDING: Financial support for the study was granted by Dale NHMRC Investigator grant APP1193648, University of Sydney, Petre Foundation, Cerebral Palsy Alliance and Department of Biochemistry at the Children's Hospital at Westmead. Prof Guillemin is funded by NHMRC Investigator grant APP 1176660 and Macquarie University.

Decreased cerebrospinal fluid kynurenic acid in epileptic spasms: A biomarker of response to corticosteroids.

BACKGROUND: Epileptic (previously infantile) spasms is the most common epileptic encephalopathy occurring during infancy and is frequently associated with abnormal neurodevelopmental outcomes. Epileptic spasms have a diverse range of known (genetic, structural) and unknown aetiologies. High dose corticosteroid treatment for 4 weeks often induces remission of spasms, although the mechanism of action of corticosteroid is unclear. Animal models of epileptic spasms have shown decreased brain kynurenic acid, which is increased after treatment with the ketogenic diet. We quantified kynurenine pathway metabolites in the cerebrospinal fluid (CSF) of infants with epileptic spasms and explored clinical correlations. METHODS: A panel of nine metabolites in the kynurenine pathway (tryptophan, kynurenine, kynurenic acid, 3-hydroxykynurenine, xanthurenic acid, anthranilic acid, 3-hydroxyanthranilic acid, quinolinic acid, and picolinic acid) were measured using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). CSF collected from paediatric patients less than 3 years of age with epileptic spasms (n=34, 19 males, mean age 0.85, median 0.6, range 0.3-3 yrs) were compared with other epilepsy syndromes (n=26, 9 males, mean age 1.44, median 1.45, range 0.3-3 yrs), other non-inflammatory neurological diseases (OND) (n=29, 18 males, mean age 1.47, median 1.6, range 0.1-2.9 yrs) and inflammatory neurological controls (n=12, 4 males, mean age 1.80, median 1.80, range 0.8-2.5 yrs). FINDINGS: There was a statistically significant decrease of CSF kynurenic acid in patients with epileptic spasms compared to OND (p<0.0001). In addition, the kynurenic acid/kynurenine (KYNA/KYN) ratio was lower in the epileptic spasms subgroup compared to OND (p<0.0001). Epileptic spasms patients who were steroid responders or partial steroid responders had lower KYNA/KYN ratio compared to patients who were refractory to steroids (p<0.005, p<0.05 respectively). INTERPRETATION: This study demonstrates decreased CSF kynurenic acid and KYNA/KYN in epileptic spasms, which may also represent a biomarker for steroid responsiveness. Given the anti-inflammatory and neuroprotective properties of kynurenic acid, further therapeutics able to increase kynurenic acid should be explored. FUNDING: Financial support for the study was granted by Dale NHMRC Investigator grant APP1193648, Petre Foundation, Cerebral Palsy Alliance and Department of Biochemistry at the Children's Hospital at Westmead. Prof Guillemin is funded by NHMRC Investigator grant APP1176660 and Macquarie University.

Age of Diagnosis, Fidelity and Acceptability of an Early Diagnosis Clinic for Cerebral Palsy: A Single Site Implementation Study.

Cerebral palsy (CP) diagnosis is historically late, at between 12 and 24 months. We aimed to determine diagnosis age, fidelity to recommended tests and acceptability to parents and referrers of an early diagnosis clinic to implement a recent evidence-based clinical guideline for the early diagnosis of CP. A prospective observational case series of infants <12 months with detectable risks for CP attending our clinic was completed with data analysed cross-sectionally. Infants had a high risk of CP diagnosis at a mean age of 4.4 (standard deviation [SD] 2.3) months and CP diagnosis at 8.5 [4.1] months. Of the 109 infants seen, 57% had a diagnosis of CP or high risk of CP, showing high specificity to our inclusion criteria. Parent and referrer acceptability of the clinic was high. Paediatricians had the highest rate of referral (39%) followed by allied health (31%), primary carer (14%) and other health workers (16%). Fidelity to the guideline was also high. All infants referred <5 mths had the General Movements Assessment (GMA) and all except one had the Hammersmith Infant Neurological Examination (HINE) administered. N = 92 (84%) of infants seen had neuroimaging, including n = 53 (49%) who had magnetic resonance imaging (MRI), showing recommended tests are feasible. Referral to CP-specific interventions was at 4.7 [3.0] months, sometimes before referral to clinic. Clinicians can be confident CP can be diagnosed well under 12 months using recommended tools. This clinic model is acceptable to parents and referrers and supports access to CP-specific early interventions when they are likely to be most effective.

Early Diagnosis and Classification of Cerebral Palsy: An Historical Perspective and Barriers to an Early Diagnosis.

Since the 1800s, there have been calls in the literature for the early diagnosis of cerebral palsy (CP). However, diagnosis still often occurs late, from 12 to 24 months in high income countries and as late as 5 years in low resource settings. This is after the optimal timeframe for applying interventions which could harness neuroplastic potential in the developing brain. Multiple barriers exist which affect clinicians' confidence in diagnosing CP early. These range from the lack of definitive biomarkers to a lack of curative treatments for CP. Further barriers to diagnosis are proposed including; (a) difficulty finding a congruent fit with the definition of CP in an infant, where expected activity limitations might not yet be apparent; and (b) differences in the presentation of motor type and topography classifications between infants and children. These barriers may affect a clinicians' confidence using "pattern recognition" in the differential diagnosis process. One of the central tenets of this paper is that diagnosis and classification are different, involving different instruments, and are more accurately conducted separately in infants, whereas they are fundamentally interconnected in older children and inform therapeutic decisions. Furthermore, we need to be careful not to delay early diagnosis because of the low reliability of early classification, but instead uncouple these two processes. Ongoing implementation of best practice for early detection requires creative solutions which might include universal screening for CP. Implementation and accompanying knowledge translation studies are underway to decrease the average age of diagnosis in CP.

Characterization of the human myelin oligodendrocyte glycoprotein antibody response in demyelination.

Over recent years, human autoantibodies targeting myelin oligodendrocyte glycoprotein (MOG Ab) have been associated with monophasic and relapsing central nervous system demyelination involving the optic nerves, spinal cord, and brain. While the clinical relevance of MOG Ab detection is becoming increasingly clear as therapeutic and prognostic differences from multiple sclerosis are acknowledged, an in-depth characterization of human MOG Ab is required to answer key challenges in patient diagnosis, treatment, and prognosis. Herein, we investigated the epitope, binding sensitivity, and affinity of MOG Ab in a cohort of 139 and 148 MOG antibody-seropositive children and adults (n = 287 patients at baseline, 130 longitudinal samples, and 22 cerebrospinal fluid samples). MOG extracellular domain was also immobilized to determine the affinity of MOG Ab. MOG Ab response was of immunoglobulin G1 isotype, and was of peripheral rather than intrathecal origin. High affinity MOG Ab were detected in 15% paediatric and 18% adult sera. More than 75% of paediatric and adult MOG Ab targeted a dominant extracellular antigenic region around Proline42. MOG Ab titers fluctuated over the progression of disease, but affinity and reactivity to Proline42 remained stable. Adults with a relapsing course intrinsically presented with a reduced immunoreactivity to Proline42 and had a more diverse MOG Ab response, a feature that may be harnessed for predicting relapse. Higher titers of MOG Ab were observed in more severe phenotypes and during active disease, supporting the pathogenic role of MOG Ab. Loss of MOG Ab seropositivity was observed upon conformational changes to MOG, and this greatly impacted the sensitivity of the detection of relapsing disorders, largely considered as more severe. Careful consideration of the binding characteristics of autoantigens should be taken into account when detecting disease-relevant autoantibodies.

Magnetic resonance imaging in enterovirus-71, myelin oligodendrocyte glycoprotein antibody, aquaporin-4 antibody, and multiple sclerosis-associated myelitis in children.

AIM: We used magnetic resonance imaging (MRI) to compare the neuroimaging of children with their first episode of clinical enterovirus 71-associated transverse myelitis (EV71-TM), myelin oligodendrocyte glycoprotein antibody positive transverse myelitis (MOG-TM), aquaporin-4 antibody positive transverse myelitis (AQP4-TM), transverse myelitis in multiple sclerosis (MS-TM), and unclassified transverse myelitis (UNC-TM). METHOD: We performed a retrospective blinded radiological assessment and compared the neuroimaging of 52 children (32 females, 20 males; mean age 9y 8mo, SD 5y 5mo, range 5mo-17y) presenting with their first episode of myelitis caused by EV71-TM (n=11), MOG-TM (n=10), AQP4-TM (n=9), MS-TM (n=13), and UNC-TM (n=9). RESULTS: In the EV71-TM group, lesions were distributed throughout the cord and enhancement of nerve roots (ventral and dorsal) was common. The MOG-TM group had lesions distributed throughout the cord and most commonly longitudinally extensive transverse myelitis and lesions involving the grey matter alone on axial scans. The AQP4-TM group had lesions distributed in the cervicothoracic spine, cavitation, and contrast enhancing lesions. All patients with AQP4-TM had an abnormal brain MRI scan. The MS-TM group characteristically had multiple short segment lesions of the cord involving the cervicothoracic spine. The UNC-TM group did not have distinctive spinal MRI findings but had a relative paucity of lesions on their brain MRI scans. INTERPRETATION: There are neuroimaging findings that are helpful in differentiating between myelitis associated with EV71, MOG, AQP4, and multiple sclerosis in children. These features may be useful early in the presentation of transverse myelitis while awaiting infectious/immunological testing, and/or further demyelinating events. WHAT THIS PAPER ADDS: Magnetic resonance imaging can help identify aetiologies for children presenting with a first episode of myelitis. Entervirus-71-associated myelitis lesions are distributed throughout the cord and enhancement of nerve roots is common. Lesions distributed throughout the cord are commonly seen in myelin oligodendrocyte-associated myelitis. Aquaporin-4-associated myelitis lesions are distributed in the cervicothoracic spine, cavitation and contrast enhancing lesions are common. Short segment lesions in the cervicothoracic spine are commonly seen in multiple sclerosis-associated myelitis.

IMÁGENES DE RESONANCIA MAGNÉTICA EN ENTEROVIRUS-71, ANTICUERPOS DE GLICOPROTEÍNA DE LA MIELINA DEL OLIGODENDROCITO, ANTICUERPOS AQUAPORIN-4, Y ESCLEROSIS MÚLTIPLE-ASOCIADA A MIELITIS EN NIÑOS: OBJETIVO: Utilizamos imágenes de resonancia magnética (IRM) para comparar la neuroimagen de los niños con su primer episodio clínico de enterovirus 71-asociado a mielitis transversa (EV71-TM), mielitis transversa con anticuerpos de glicoproteína de la mielina del oligodendrocito positivos (MOG-TM), mielitis transversa con anticuerpos aquaporin-4 positivos (AQP4-TM), mielitis transversa en esclerosis múltiple (MS-TM) y mielitis transversa no clasificada (UNC-TM). MÉTODO: Se realizó un análisis radiológico, ciego, retrospectivo y se comparó la neuroimagen de 52 niños (32 mujeres, 20 varones; con edad promedio 9 años 8 meses, La DS 5 años 5 meses, el rango de 5 meses -17 años) que presentaron su primer episodio de mielitis causada por EV71-TM (n= 11), MOG-TM (n= 10), AQP4-TM (n= 9), MS-TM (n= 13) y UNC-TM (n= 9). RESULTADOS: En el grupo de EV71-TM, fue común observar lesiones distribuidas a través de la medula con realce de las raíces de nervio (ventrales y dorsales). El grupo de MOG-TM tenía lesiones distribuidas a través de la médula, más comúnmente mielitis transversa longitudinalmente extensa y lesiones que implican solamente la sustancia gris en exploraciones axiales. El grupo AQP4-TM tenía lesiones distribuidas en la medula cervicodorsal, cavitación y lesiones con realce en el contraste. Todos Pacientes con AQP4-TM tenían una IRM cerebral anormal. El grupo de MS-TM característicamente tenía lesiones múltiples de segmentos pequeños de la medula que involucran las regiones cervical y dorsal. El grupo UNC-TM no tenía hallazgos de IRM distintivos en la medula espinal, pero tenía una relativa escasez de lesiones cerebrales IRM. INTERPRETACIÓN: Hay hallazgos de neuroimagen en niños que son útiles en diferenciar entre mielitis asociada a EV71, a MOG, a AQP4, y esclerosis múltiple. Estas características pueden ser útiles al inicio de la presentación de la mielitis transversa mientras se espera la prueba infecciosa/inmunológica y/u otros acontecimientos desmielinizantes.

IMAGEM POR RESSONÂNCIA MAGNÉTICA EM ENTEROVÍRUS-71, ANTICORPO DA GLICOPROTEÍNA DE OLIGODENDRÓCITO DA MIELINA, ANTICORPO AQUAPORINA-4, E MIELITE ASSOCIADA A ESCLEROSE MÚLTIPLA EM CRIANÇAS: OBJETIVO: Usamos imagens de ressonância funcional (IRM) para comparar as neuroimagens de crianças com o primeiro episósio de mielite transversa clínica associada a enterovírus-71 (MT-EV71), mielite transversa positiva para anticorpo da glicoproteína de oligodendrócit oda mielina (MT-GOM), mielite transversa positiva para anticorpo aquaporina-4 (MT-AQP4), mielite transversa em esclerose múltipla (MT-EM), e mielite transversa não classificada (MT-NC). MÉTODO: Realizamos uma avaliação radiológica retrospectiva cega, e comparamos a neuroimagem de 52 crianças (32 do sexo feminino, 20 do sexo masculino; média de idade 9a 8m, DP 5a 5m, variação 5m-17a) apresentando seu primeiro episódio de mielite causada por MT-EV71 (n=11), MT-GOM (n=10), MT-AQP4 (n=9), MT-EM (n=13), e MT-NC (n=9). RESULTADOS: No grupo MT-EV71, as lesões se distribuíram por toda a medula, e realces das raízes nervosas (ventrais e dorsais) eram comuns. O grupo MT-GOM teve lesões distribuídas por toda a medula, e mais comumente mielite transversa extensiva longitudinalmente e lesões envolvendo apenas a substância cinzenta nas imagens axiais. O grupo MT-AQP4 teve lesões distribuídas na coluna cérvico-torácica, cavitação, e lesões realçadas pelo contraste. Todos os pacientes com MT-AQP4 -tiveram uma IRM cerebral anormal. O grupo MT-EM caracteristicamente teve múltiplas lesões de segmentos curtos da medula envolvendo a região cérvico-torácica. O grupo MT-NC não teve achados distintivos de IRM espinhal, mas tiveram relativamente menos lesões nas imagens cerebrais. INTERPRETAÇÃO: Há achados de neuroimagem úteis para diferenciar a mielite associada com EV71, GOM, AQP4 e esclerose múltipla em crianças. Estes aspectos podem ser úteis na apresentação precoce da mielite transversa, enquanto se aguarda testes infecciosos/imunológicos, e e/ou outros eventos desmielinizantes.

Clinical course, therapeutic responses and outcomes in relapsing MOG antibody-associated demyelination.

OBJECTIVE: We characterised the clinical course, treatment and outcomes in 59 patients with relapsing myelin oligodendrocyte glycoprotein (MOG) antibody-associated demyelination. METHODS: We evaluated clinical phenotypes, annualised relapse rates (ARR) prior and on immunotherapy and Expanded Disability Status Scale (EDSS), in 218 demyelinating episodes from 33 paediatric and 26 adult patients. RESULTS: The most common initial presentation in the cohort was optic neuritis (ON) in 54% (bilateral (BON) 32%, unilateral (UON) 22%), followed by acute disseminated encephalomyelitis (ADEM) (20%), which occurred exclusively in children. ON was the dominant phenotype (UON 35%, BON 19%) of all clinical episodes. 109/226 (48%) MRIs had no brain lesions. Patients were steroid responsive, but 70% of episodes treated with oral prednisone relapsed, particularly at doses <10 mg daily or within 2 months of cessation. Immunotherapy, including maintenance prednisone (P=0.0004), intravenous immunoglobulin, rituximab and mycophenolate, all reduced median ARRs on-treatment. Treatment failure rates were lower in patients on maintenance steroids (5%) compared with non-steroidal maintenance immunotherapy (38%) (P=0.016). 58% of patients experienced residual disability (average follow-up 61 months, visual loss in 24%). Patients with ON were less likely to have sustained disability defined by a final EDSS of ≥2 (OR 0.15, P=0.032), while those who had any myelitis were more likely to have sustained residual deficits (OR 3.56, P=0.077). CONCLUSION: Relapsing MOG antibody-associated demyelination is strongly associated with ON across all age groups and ADEM in children. Patients are highly responsive to steroids, but vulnerable to relapse on steroid reduction and cessation.

High sensitivity and specificity in proposed clinical diagnostic criteria for anti-N-methyl-D-aspartate receptor encephalitis.

AIM: To determine the validity of the proposed clinical diagnostic criteria for anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis in paediatric patients. METHOD: The diagnostic criteria for anti-NMDAR encephalitis proposed by Graus et al. (2016) use clinical features and conventional investigations to facilitate early immunotherapy before antibody status is available. The criteria are satisfied if patients develop four out of six symptom groups within 3 months, together with at least one abnormal investigation (electroencephalography/cerebrospinal fluid) and reasonable exclusion of other disorders. We evaluated the validity of the criteria using a retrospective cohort of paediatric patients with encephalitis. Twenty-nine patients with anti-NMDAR encephalitis and 74 comparison children with encephalitis were included. RESULTS: As expected, the percentage of patients with anti-NMDAR encephalitis who fulfilled the clinical criteria increased over time. During the hospital inpatient admission, most patients (26/29, 90%) with anti-NMDAR encephalitis fulfilled the criteria, significantly more than the comparison group (3/74, 4%) (p<0.001). The median time of fulfilling the criteria in patients with anti-NMDAR encephalitis was 2 weeks from first symptom onset (range 1-6). The sensitivity of the criteria was 90% (95% confidence interval 73-98) and the specificity was 96% (95% confidence interval 89-99). INTERPRETATION: The proposed diagnostic criteria for anti-NMDAR encephalitis have good sensitivity and specificity. Incomplete criteria do not exclude the diagnosis. WHAT THIS PAPER ADDS: The proposed clinical diagnostic criteria for anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis by Graus et al. (2016) have high sensitivity and specificity in paediatric patients. The median time of fulfilling the criteria in patients with anti-NMDAR was 2 weeks from first symptom onset.

In children requiring intravenous fluid for hydration maintenance, which out of hypotonic saline and isotonic saline is less likely to result in the development of hyponatraemia?

The administration of intravenous fluids remains a common intervention for hospitalised children. Commonly used hypotonic fluids administered at maintenance rates provide 2-4 mmol/kg/day of sodium. Being hypotonic, the development of hyponatraemia remains a risk. The consequences of hyponatraemia are not insignificant, with possibilities of irreversible neurological morbidity and mortality. There is currently no clear consensus on the optimal composition of fluids to be used for intravenous rehydration. A review of the available literature suggests that children who receive isotonic fluid have a lower risk of developing hyponatraemia, regardless of the rate of administration. This result is most applicable in the first 24 h of administration in a wide age group of paediatric patients with varying severities of illness.

Utility of CSF Cytokine/Chemokines as Markers of Active Intrathecal Inflammation: Comparison of Demyelinating, Anti-NMDAR and Enteroviral Encephalitis.

BACKGROUND: Despite the discovery of CSF and serum diagnostic autoantibodies in autoimmune encephalitis, there are still very limited CSF biomarkers for diagnostic and monitoring purposes in children with inflammatory or autoimmune brain disease. The cause of encephalitis is unknown in up to a third of encephalitis cohorts, and it is important to differentiate infective from autoimmune encephalitis given the therapeutic implications. AIM: To study CSF cytokines and chemokines as diagnostic biomarkers of active neuroinflammation, and assess their role in differentiating demyelinating, autoimmune, and viral encephalitis. METHODS: We measured and compared 32 cytokine/chemokines using multiplex immunoassay and APRIL and BAFF using ELISA in CSF collected prior to commencing treatment from paediatric patients with confirmed acute disseminated encephalomyelitis (ADEM, n = 16), anti-NMDAR encephalitis (anti-NMDAR E, n = 11), and enteroviral encephalitis (EVE, n = 16). We generated normative data using CSF from 20 non-inflammatory neurological controls. The sensitivity of CSF cytokine/chemokines to diagnose encephalitis cases was calculated using 95th centile of control values as cut off. We correlated CSF cytokine/chemokines with disease severity and follow up outcome based on modified Rankin scale. One-way hierarchical correlational cluster analysis of molecules was performed in different encephalitis and outcome groups. RESULTS: In descending order, CSF TNF-α, IL-10, IFN-α, IL-6, CXCL13 and CXCL10 had the best sensitivity (>79.1%) when all encephalitis patients were included. The combination of IL-6 and IFN-α was most predictive of inflammation on multiple logistic regression with area under the ROC curve 0.99 (CI 0.97-1.00). There were no differences in CSF cytokine concentrations between EVE and anti-NMDAR E, whereas ADEM showed more pronounced elevation of Th17 related (IL-17, IL-21) and Th2 (IL-4, CCL17) related cytokine/chemokines. Unlike EVE, heat map analysis showed similar clustering of cytokine/chemokine molecules in immune mediated encephalitis (ADEM and anti-NMDAR E). Th1 and B cell (CXCL13 and CXCL10) molecules clustered together in patients with severe encephalopathy at admission and worse disability at follow up in all encephalitis. There was no correlation between CSF neopterin and IFN-γ or IFN-α. CONCLUSION: A combination panel of cytokine/chemokines consisting of CSF TNF-α, IL-10, IFN-α, IL-6, CXCL13 and CXCL10 measured using multiplex immunoassay may be used to diagnose and monitor intrathecal inflammation in the brain. Given their association with worse outcome, certain key chemokines (CXCL13, CXCL10) could represent potential therapeutic targets in encephalitis.

B Cell, Th17, and Neutrophil Related Cerebrospinal Fluid Cytokine/Chemokines Are Elevated in MOG Antibody Associated Demyelination.

BACKGROUND: Myelin oligodendrocyte glycoprotein antibody (MOG Ab) associated demyelination represents a subgroup of autoimmune demyelination that is separate from multiple sclerosis and aquaporin 4 IgG-positive NMO, and can have a relapsing course. Unlike NMO and MS, there is a paucity of literature on immunopathology and CSF cytokine/chemokines in MOG Ab associated demyelination. AIM: To study the differences in immunopathogenesis based on cytokine/chemokine profile in MOG Ab-positive (POS) and -negative (NEG) groups. METHODS: We measured 34 cytokines/chemokines using multiplex immunoassay in CSF collected from paediatric patients with serum MOG Ab POS [acute disseminated encephalomyelitis (ADEM = 8), transverse myelitis (TM = 2) n = 10] and serum MOG Ab NEG (ADEM = 5, TM = 4, n = 9) demyelination. We generated normative data using CSF from 20 non-inflammatory neurological controls. RESULTS: The CSF cytokine and chemokine levels were higher in both MOG Ab POS and MOG Ab NEG demyelination groups compared to controls. The CSF in MOG Ab POS patients showed predominant elevation of B cell related cytokines/chemokines (CXCL13, APRIL, BAFF and CCL19) as well as some of Th17 related cytokines (IL-6 AND G-CSF) compared to MOG Ab NEG group (all p<0.01). In addition, patients with elevated CSF MOG antibodies had higher CSF CXCL13, CXCL12, CCL19, IL-17A and G-CSF than patients without CSF MOG antibodies. CONCLUSION: Our findings suggest that MOG Ab POS patients have a more pronounced CNS inflammatory response with elevation of predominant humoral associated cytokines/chemokines, as well as some Th 17 and neutrophil related cytokines/chemokines suggesting a differential inflammatory pathogenesis associated with MOG antibody seropositivity. This cytokine/chemokine profiling provides new insight into disease pathogenesis, and improves our ability to monitor inflammation and response to treatment. In addition, some of these molecules may represent potential immunomodulatory targets.

Eye movement disorders are an early manifestation of CACNA1A mutations in children.

AIM: The alpha-1 isoform of the calcium channel gene is expressed abundantly in neuronal tissue, especially within the cerebellum. Mutations in this gene may manifest with hemiplegic migraine, spinocerebellar ataxia type 6 (SCA6) and episodic ataxia type 2 (EA2) in adults. There are reports of children with CACAN1A mutations presenting with paroxysmal tonic upgaze, abnormal saccades and congenital nystagmus as well as severe forms of hemiplegic migraine. The aim of this study was to review the clinical presentation and subsequent course of all children with a CACNA1A mutation who presented to a tertiary children's hospital. METHOD: We reviewed retrospectively nine children with a proven CACNA1A mutation who presented to the Children's Hospital at Westmead between 2005-2015. The initial and subsequent clinical presentation, radiological features and molecular genetic profile of each child was reviewed. RESULTS: Nine children presented to out institute over a 10 year period; six were female and three male. The median age of presentation was 1.2 years. Eye movement disorders were the presenting feature in eight children. Three of these children later presented with severe hemiplegic migraine episodes often requiring ICU care. Affected children also had developmental delay and developed classical hemiplegic migraine, episodic ataxia and seizures. Calcium channel blockers were used with some efficacy in preventing severe HM episodes. INTERPRETATION: Eye movement disorders are an early manifestation of CACNA1A mutations in children. Improved recognition of the CACNA1A phenotype in childhood is important for early diagnosis, counselling and appropriate emergency management. There is some early evidence that calcium channel blockers may be an effective prophylactic agent for the severe hemiplegic migraine episodes.

Postencephalitic epilepsy and drug-resistant epilepsy after infectious and antibody-associated encephalitis in childhood: Clinical and etiologic risk factors.

To define the risk factors for postencephalitic epilepsy (PE) and drug-resistant epilepsy (DRE) in childhood following infectious and autoimmune encephalitis, we included 147 acute encephalitis patients with a median follow-up of 7.3 years (range 2-15.8 years). PE was defined as the use of antiepileptic drugs (AEDs) for ≥24 months, and DRE was defined as the persistence of seizures despite ≥2 appropriate AEDs at final follow-up. PE and DRE were diagnosed in 31 (21%) and 15 (10%) of patients, respectively. The features during acute encephalitis predictive of DRE (presented as odds ratio [OR] with confidence intervals [CIs]) were status epilepticus (OR 10.8, CI 3.4-34.3), visual disturbance (6.4, 1.4-29.9), focal seizures (6.2, 1.9-20.6), magnetic resonance imaging (MRI) hippocampal/amygdala involvement (5.0, 1.7-15.4), intensive care admission (4.7, 1.4-15.4), use of >3 AEDs (4.5, 1.2-16.1), MRI gadolinium enhancement (4.1, 1.2-14.2), any seizure (3.9, 1.1-14.4), and electroencephalography (EEG) epileptiform discharges (3.9, 1.3-12.0). On multivariable regression analysis, only status epilepticus remained predictive of DRE in all models. DRE was common in herpes simplex virus (3/9, 33%) and unknown (8/40, 20%) encephalitis, but absent in acute disseminated encephalomyelitis (ADEM) (0/32, 0%), enterovirus (0/18), and anti-N-methyl-d-aspartate receptor-NMDAR encephalitis (0/9). We have identified risk factors for DRE and demonstrated "high-risk," and "low-risk" etiologies.

Radiological differentiation of optic neuritis with myelin oligodendrocyte glycoprotein antibodies, aquaporin-4 antibodies, and multiple sclerosis.

BACKGROUND: Recognizing the cause of optic neuritis (ON) affects treatment decisions and visual outcomes. OBJECTIVE: We aimed to define radiological features of first-episode demyelinating ON. METHODS: We performed blinded radiological assessment of 50 patients presenting with first-episode myelin oligodendrocyte glycoprotein (MOG) antibody-associated ON (MOG-ON; n=19), aquaporin-4 (AQP4) antibody-associated ON (AQP4-ON; n=11), multiple sclerosis (MS)-associated ON (MS-ON; n=13), and unclassified ON (n=7). RESULTS: Bilateral involvement was more common in MOG-ON and AQP4-ON than MS-ON (84% vs. 82% vs. 23%), optic nerve head swelling was more common in MOG-ON (53% vs. 9% vs. 0%), chiasmal involvement was more common in AQP4-ON (5% vs. 64% vs. 15%), and bilateral optic tract involvement was more common in AQP4-ON (0% vs. 45% vs. 0%). Retrobulbar involvement was more common in MOG-ON, whereas intracranial involvement was more common in AQP4-ON. MOG-ON and AQP4-ON had longer lesion lengths than MS-ON. The combination of two predictors, the absence of magnetic resonance imaging brain abnormalities and a higher lesion extent score, showed a good ability to discriminate between an autoantibody-associated ON (MOG or AQP4) and MS. AQP4-ON more frequently had severe and sustained visual impairment. CONCLUSION: MOG-ON and AQP4-ON are more commonly bilateral and longitudinally extensive. MOG-ON tends to involve the anterior optic pathway, whereas AQP4-ON the posterior optic pathway.

Infectious and autoantibody-associated encephalitis: clinical features and long-term outcome.

BACKGROUND AND OBJECTIVES: Pediatric encephalitis has a wide range of etiologies, clinical presentations, and outcomes. This study seeks to classify and characterize infectious, immune-mediated/autoantibody-associated and unknown forms of encephalitis, including relative frequencies, clinical and radiologic phenotypes, and long-term outcome. METHODS: By using consensus definitions and a retrospective single-center cohort of 164 Australian children, we performed clinical and radiologic phenotyping blinded to etiology and outcomes, and we tested archived acute sera for autoantibodies to N-methyl-D-aspartate receptor, voltage-gated potassium channel complex, and other neuronal antigens. Through telephone interviews, we defined outcomes by using the Liverpool Outcome Score (for encephalitis). RESULTS: An infectious encephalitis occurred in 30%, infection-associated encephalopathy in 8%, immune-mediated/autoantibody-associated encephalitis in 34%, and unknown encephalitis in 28%. In descending order of frequency, the larger subgroups were acute disseminated encephalomyelitis (21%), enterovirus (12%), Mycoplasma pneumoniae (7%), N-methyl-D-aspartate receptor antibody (6%), herpes simplex virus (5%), and voltage-gated potassium channel complex antibody (4%). Movement disorders, psychiatric symptoms, agitation, speech dysfunction, cerebrospinal fluid oligoclonal bands, MRI limbic encephalitis, and clinical relapse were more common in patients with autoantibodies. An abnormal outcome occurred in 49% of patients after a median follow-up of 5.8 years. Herpes simplex virus and unknown forms had the worst outcomes. According to our multivariate analysis, an abnormal outcome was more common in patients with status epilepticus, magnetic resonance diffusion restriction, and ICU admission. CONCLUSIONS: We have defined clinical and radiologic phenotypes of infectious and immune-mediated/autoantibody-associated encephalitis. In this resource-rich cohort, immune-mediated/autoantibody-associated etiologies are common, and the recognition and treatment of these entities should be a clinical priority.

Confirmed enterovirus encephalitis with associated steroid-responsive acute disseminated encephalomyelitis: an overlapping infection and inflammation syndrome.

BACKGROUND: Inflammatory disorders of the central nervous system have generally been separated into infectious or immune-mediated aetiologies. However, there are emerging examples of confirmed infectious viral infection of the brain followed by secondary inflammation or autoimmunity that is amenable to immune suppressive therapies. METHODS: We report four children with confirmed enterovirus encephalitis (CSF enterovirus PCR positivity), who had MRI evidence of inflammatory demyelination compatible with ADEM. RESULTS: Two patients had a monophasic course, whereas two had a biphasic course. Serum myelin oligodendrocyte glycoprotein antibodies were negative in two tested patients, although all patients had mirrored CSF and serum oligoclonal bands. All four patients only improved with introduction of immune therapy (corticosteroids in three, corticosteroid and intravenous immunoglobulin in one). CONCLUSION: These cases provide a further example of the overlap between CNS infection and immune mediated CNS disease. Randomised controlled trials investigating immune therapies in encephalitis are required.

Antibodies to MOG have a demyelination phenotype and affect oligodendrocyte cytoskeleton.

OBJECTIVE: To examine the clinical features of pediatric CNS demyelination associated with positive myelin oligodendrocyte glycoprotein (MOG) antibodies and to examine the functional effects of MOG antibody on oligodendrocyte cytoskeleton. METHODS: We measured MOG antibody using a fluorescence-activated cell sorting live cell-based assay in acute sera of 73 children with CNS demyelination (DEM) (median age 8 years, range 1.3-15.3) followed for a median of 4 years. We used MO3.13 cells to examine immunoglobulin (Ig) G effects on oligodendrocyte cytoskeleton using 3D deconvolution imaging. RESULTS: MOG antibodies were found in 31/73 patients with DEM (42%) but in 0/24 controls. At first presentation, MOG antibody-positive patients were more likely to have bilateral than unilateral optic neuritis (ON) (9/10 vs 1/5, respectively, p = 0.03), less likely to have brainstem findings (2/31 vs 16/42, p = 0.005), more likely to have a raised erythrocyte sedimentation rate >20 mm/h (9/19 vs 3/21, p = 0.05), less likely to have intrathecal oligoclonal bands (0/16 vs 5/27, p = 0.18), and less likely to be homozygous or heterozygous for human leukocyte antigen DRB1*1501 (3/18 vs 7/22, p = 0.46). MOG antibody positivity varied according to clinical phenotype, with ON and relapsing ON most likely to be seropositive. Two relapsing MOG antibody-positive patients treated with mycophenolate mofetil remain in remission and have become MOG antibody seronegative. Oligodendrocytes incubated with purified IgG from MOG antibody-positive patients showed a striking loss of organization of the thin filaments and the microtubule cytoskeleton, as evidenced by F-actin and ß-tubulin immunolabelings. CONCLUSIONS: MOG antibody may define a separate demyelination syndrome, which has therapeutic implications. MOG antibody has functional effects on oligodendrocyte cytoskeleton.

Risk of multiple sclerosis after a first demyelinating syndrome in an Australian Paediatric cohort: clinical, radiological features and application of the McDonald 2010 MRI criteria.

BACKGROUND: The risk of multiple sclerosis (MS) is dependent on multiple variables, including geographical location. There is increasing interest in the early recognition and treatment of MS in children. METHOD: Using univariate and multivariate analysis, we determined the clinical and radiological features that were predictive of MS in 88 children from New South Wales, Australia, with a first acute demyelinating syndrome (ADS) who were followed for a minimum of one year. We tested the McDonald, KIDMUS, Callen and Verhey MRI criteria for paediatric MS. RESULTS: After a mean follow-up of 5.2 years, 13/88 (15%) of children had MS. Using multivariate analysis, preceding infection was protective of MS, and corpus callosal lesions, the combined presence of both well and poorly demarcated lesions, and contrast-enhancing lesions on MRI were predictive of MS. The sensitivity and specificity of the respective radiological criteria were McDonald 2005 (69%, 68%), McDonald 2010 (58%, 95%), KIDMUS (8%, 100%), Callen (69%, 85%) and Verhey (62%, 84%). When McDonald 2010 criteria were applied to baseline and serial scans, the sensitivity and specificity was 91% and 93%. CONCLUSION: Despite the long follow-up, the risk of MS appears lower in New South Wales children compared to previously reported cohorts. Radiological features are more predictive than clinical features in predicting MS. The McDonald 2010 criteria performed well although the dissemination in time criteria on baseline scans is difficult to apply to children with encephalopathy.

Clinical association of intrathecal and mirrored oligoclonal bands in paediatric neurology.

AIM: Biomarkers such as autoantibodies, neopterin, and oligoclonal bands (OCBs) are increasingly used for the diagnosis of treatable inflammatory central nervous system (CNS) disorders. We investigated the correlation between the results of OCB testing and clinical diagnoses in a large contemporary cohort of children with a broad range of neurological conditions. METHOD: Cerebrospinal fluid (CSF) and serum from 200 children (94 females, 106 males; age range 2 mo-15 y 10 mo, mean age 6 y 9 mo, SD ±4.9) who underwent CSF investigation for their neurological condition were tested for OCBs using isoelectric focusing. RESULTS: The patients were divided into those with inflammatory (n=58) and non-inflammatory (n=142) CNS disorders. Intrathecal OCBs (OCBs restricted to the CSF) were found in 11 out of 58 (19%) of those with inflammatory CNS disorders compared with none of the 142 patients with non-inflammatory CNS disorders (p<0.001). Diseases associated with intrathecal OCB were multiple sclerosis, Rasmussen encephalitis, N-methyl-d-aspartate receptor (NMDAR) encephalitis, voltage-gated potassium channel (VGKC) encephalopathy, herpes (HSV) encephalitis, 'other' encephalitides, acute cerebellar ataxia, and aseptic meningitis. Mirrored OCBs (identical OCBs in the serum and CSF) were less specific but were still found in 14 out of 58 (24%) children with inflammatory CNS disorders compared with only 6 out of 142 (4%) children with non-inflammatory CNS disorders (p<0.001). Diseases associated with mirrored OCBs included acute disseminated encephalomyelitis (ADEM), VGKC encephalopathy, West syndrome, NMDAR encephalitis, 'other' encephalitides, polio-like illness, Rasmussen encephalitis, cerebral vasculitis, metachromatic leukodystrophy, and bacterial meningitis. Intrathecal OCBs and mirrored OCBs had a positive predictive value for inflammatory CNS disease of 1 (95% confidence interval [CI] 0.68-1) and 0.7 (95% CI 0.46-0.87) respectively. CONCLUSION: Intrathecal OCBs were restricted to patients with inflammatory CNS disorders. They are a useful, but non-specific, biomarker of CNS inflammation of multiple causes. Mirrored OCBs are less specific, but still support a possible inflammatory CNS disorder. The presence of either intrathecal or mirrored OCBs should raise suspicion of an inflammatory CNS disorder.