Solving the Etiology of Developmental and Epileptic Encephalopathy with Spike-Wave Activation in Sleep (D/EE-SWAS).

OBJECTIVE: To understand the etiological landscape and phenotypic differences between 2 developmental and epileptic encephalopathy (DEE) syndromes: DEE with spike-wave activation in sleep (DEE-SWAS) and epileptic encephalopathy with spike-wave activation in sleep (EE-SWAS). METHODS: All patients fulfilled International League Against Epilepsy (ILAE) DEE-SWAS or EE-SWAS criteria with a Core cohort (n = 91) drawn from our Epilepsy Genetics research program, together with 10 etiologically solved patients referred by collaborators in the Expanded cohort (n = 101). Detailed phenotyping and analysis of molecular genetic results were performed. We compared the phenotypic features of individuals with DEE-SWAS and EE-SWAS. Brain-specific gene co-expression analysis was performed for D/EE-SWAS genes. RESULTS: We identified the etiology in 42/91 (46%) patients in our Core cohort, including 29/44 (66%) with DEE-SWAS and 13/47 (28%) with EE-SWAS. A genetic etiology was identified in 31/91 (34%). D/EE-SWAS genes were highly co-expressed in brain, highlighting the importance of channelopathies and transcriptional regulators. Structural etiologies were found in 12/91 (13%) individuals. We identified 10 novel D/EE-SWAS genes with a range of functions: ATP1A2, CACNA1A, FOXP1, GRIN1, KCNMA1, KCNQ3, PPFIA3, PUF60, SETD1B, and ZBTB18, and 2 novel copy number variants, 17p11.2 duplication and 5q22 deletion. Although developmental regression patterns were similar in both syndromes, DEE-SWAS was associated with a longer duration of epilepsy and poorer intellectual outcome than EE-SWAS. INTERPRETATION: DEE-SWAS and EE-SWAS have highly heterogeneous genetic and structural etiologies. Phenotypic analysis highlights valuable clinical differences between DEE-SWAS and EE-SWAS which inform clinical care and prognostic counseling. Our etiological findings pave the way for the development of precision therapies. ANN NEUROL 2024;96:932-943.

Clinical features associated with epilepsy occurrence, resolution, and drug resistance in children with cerebral palsy: A population-based study.

AIM: To investigate clinicoradiological features associated with epilepsy, its resolution, and drug resistance in children with cerebral palsy (CP). METHOD: Data were gathered from the New South Wales/Australian Capital Territory CP Register, encompassing children with CP born between 2003 and 2015 (n = 1916). Clinical features and the severity of impairments were compared among three groups: children with current epilepsy (n = 604), those with resolved epilepsy by age 5 years (n = 109), and those without epilepsy (n = 1203). Additionally, a subset of the registry cohort attending Children's Hospital Westmead (n = 256) was analysed to compare epilepsy and treatment characteristics between drug-responsive (n = 83) and drug-resistant groups (n = 147) using logistic regression and hierarchical cluster analysis. RESULTS: Manual Ability Classification System levels IV and V, intellectual impairment, and vision impairment were found to be associated with epilepsy in children with CP on multivariable analysis (p < 0.01). Moderate to severe intellectual impairment and bilateral spastic CP were independent positive and negative predictors of epilepsy persistence at the age of 5 years respectively (p < 0.05). Microcephaly and multiple seizure types were predictors of drug-resistant epilepsy (area under the receiver operating characteristic curve of 0.83; 95% confidence interval 0.77-0.9). Children with a known genetic cause (14%) and CP epilepsy surgery group (4.3%) formed specific clinical subgroups in CP epilepsy. INTERPRETATION: Our study highlights important clinical associations of epilepsy, its resolution, and treatment response in children with CP, providing valuable knowledge to aid in counselling families and identifying distinct prognostic groups for effective medical surveillance and optimal treatment.

Exome sequencing for patients with developmental and epileptic encephalopathies in clinical practice.

AIM: To assess the clinical utility of exome sequencing for patients with developmental and epileptic encephalopathies (DEEs). METHOD: Over 2 years, patients with DEEs were recruited for singleton exome sequencing. Parental segregation was performed where indicated. RESULTS: Of the 103 patients recruited (54 males, 49 females; aged 2 weeks-17 years), the genetic aetiology was identified in 36 out of 103 (35%) with management implications in 13 out of 36. Exome sequencing revealed pathogenic or likely pathogenic variants in 30 out of 103 (29%) patients, variants of unknown significance in 39 out of 103 (38%), and 34 out of 103 (33%) were negative on exome analysis. After the description of new genetic diseases, a molecular diagnosis was subsequently made for six patients or through newly available high-density chromosomal microarray testing. INTERPRETATION: We demonstrate the utility of exome sequencing in routine clinical care of children with DEEs. We highlight that molecular diagnosis often leads to changes in management and informs accurate prognostic and reproductive counselling. Our findings reinforce the need for ongoing analysis of genomic data to identify the aetiology in patients in whom the cause is unknown. The implementation of genomic testing in the care of children with DEEs should become routine in clinical practice. WHAT THIS PAPER ADDS: The cause was identified in 35% of patients with developmental and epileptic encephalopathies. KCNQ2, CDKL5, SCN1A, and STXBP1 were the most frequently identified genes. Reanalysis of genomic data found the cause in an additional six patients. Genetic aetiology was identified in 41% of children with seizure onset under 2 years, compared to 18% with older onset. Finding the molecular cause led to management changes in 36% of patients with DEEs.

Status epilepticus outcomes among vaccinated and unvaccinated children: A population-based study.

AIM: To determine the proportion of first status epilepticus (SE) cases that are vaccine-proximate (VP-) and compare clinical outcomes to non-vaccine-proximate (NVP-) cases. METHODS: Birth records for 1,440,807 Australian children born in 1998-2012, were probabilistically linked to hospitalizations, deaths, and vaccination history available to 2013. First SE coded hospitalizations were categorized as VP-SE or NVP-SE; clinical severity and post-SE vaccination coverage were compared. SE rates were calculated. RESULTS: Of 867 first SE cases (7.9 per 100,000 person-years), 31 (3.6%) were VP-SE; 16 followed dose-1 measles vaccine (1.2 SE per 100,000 doses). Compared with NVP-SE, VP-SE cases were younger (1.0 vs 2.6 years, P < 0.0001) and had longer hospitalizations (4 vs 3 days, P = 0.005). There was no difference in the proportion of VP-SE cases with a coinfection diagnosis compared to NVP-SE (25.8% vs 19.9%, P = 0.42). Controlling for age and history of hospitalization for a neurological condition, intensive care unit (ICU) admission had a stronger association with coinfection (aOR 2.52 (95%CI 1.78-3.57)) than having VP-SE (aOR 1.41 (0.66-3.01)). Groups had similar SE recurrence rates at 12-months (12.9% VP vs 16.9% NVP, P = 0.56) and reduced vaccine uptake following initial SE (from 93.5% to 56.3%). CONCLUSION: Proportionally few first SE cases were VP-SE, with higher ICU admission rates mostly explained by younger age and higher coinfection rates. Vaccination plans are needed to improve vaccine uptake following SE.

Accelerated long-term forgetting in children with temporal lobe epilepsy: A timescale investigation of material specificity and executive skills.

Recently, children with temporal lobe epilepsy (TLE) were found to be at risk of accelerated long-term forgetting (ALF). In this study, we examined the temporal trajectory of ALF, while exploring the relationship between ALF, executive skills, and epilepsy variables. Fifty-one children, (23 with TLE and 28 typically developing) completed a battery of neuropsychological tests of verbal and visual memory, executive skills, and two experimental memory tasks (verbal and visual) involving recall after short (30-min) and extended (1-day and 2-week) delays. Side of seizure focus and hippocampal integrity were considered. On the visual task (Scene Memory), children with TLE performed comparably to typically developing children following a 30-min and 1-day delay, although worse than typically developing children at 2 weeks: ALF was observed in children with right TLE focus. The two groups did not differ on the experimental verbal memory task. Children with TLE also had worse performance than typically developing children on standardized verbal memory test and on tests of executive skills (i.e., verbal generativity, inhibition, working memory, complex attention). Only complex attention was associated with visual ALF. ALF was present for visuo-spatial materials in children with TLE at two weeks, and children with right TLE were most susceptible. A relationship was identified between complex attention and long-term forgetting. The findings extend our understanding of difficulties in long-term memory formation experienced by children with TLE.

Integrated in silico and experimental assessment of disease relevance of PCDH19 missense variants.

PCDH19 is a nonclustered protocadherin molecule involved in axon bundling, synapse function, and transcriptional coregulation. Pathogenic variants in PCDH19 cause infantile-onset epilepsy known as PCDH19-clustering epilepsy or PCDH19-CE. Recent advances in DNA-sequencing technologies have led to a significant increase in the number of reported PCDH19-CE variants, many of uncertain significance. We aimed to determine the best approaches for assessing the disease relevance of missense variants in PCDH19. The application of the American College of Medical Genetics and Association for Molecular Pathology (ACMG-AMP) guidelines was only 50% accurate. Using a training set of 322 known benign or pathogenic missense variants, we identified MutPred2, MutationAssessor, and GPP as the best performing in silico tools. We generated a protein structural model of the extracellular domain and assessed 24 missense variants. We also assessed 24 variants using an in vitro reporter assay. A combination of these tools was 93% accurate in assessing known pathogenic and benign PCDH19 variants. We increased the accuracy of the ACMG-AMP classification of 45 PCDH19 variants from 50% to 94%, using these tools. In summary, we have developed a robust toolbox for the assessment of PCDH19 variant pathogenicity to improve the accuracy of PCDH19-CE variant classification.

NEXMIF encephalopathy: an X-linked disorder with male and female phenotypic patterns.

PURPOSE: Pathogenic variants in the X-linked gene NEXMIF (previously KIAA2022) are associated with intellectual disability (ID), autism spectrum disorder, and epilepsy. We aimed to delineate the female and male phenotypic spectrum of NEXMIF encephalopathy. METHODS: Through an international collaboration, we analyzed the phenotypes and genotypes of 87 patients with NEXMIF encephalopathy. RESULTS: Sixty-three females and 24 males (46 new patients) with NEXMIF encephalopathy were studied, with 30 novel variants. Phenotypic features included developmental delay/ID in 86/87 (99%), seizures in 71/86 (83%) and multiple comorbidities. Generalized seizures predominated including myoclonic seizures and absence seizures (both 46/70, 66%), absence with eyelid myoclonia (17/70, 24%), and atonic seizures (30/70, 43%). Males had more severe developmental impairment; females had epilepsy more frequently, and varied from unaffected to severely affected. All NEXMIF pathogenic variants led to a premature stop codon or were deleterious structural variants. Most arose de novo, although X-linked segregation occurred for both sexes. Somatic mosaicism occurred in two males and a family with suspected parental mosaicism. CONCLUSION: NEXMIF encephalopathy is an X-linked, generalized developmental and epileptic encephalopathy characterized by myoclonic-atonic epilepsy overlapping with eyelid myoclonia with absence. Some patients have developmental encephalopathy without epilepsy. Males have more severe developmental impairment. NEXMIF encephalopathy arises due to loss-of-function variants.

Severe speech impairment is a distinguishing feature of FOXP1-related disorder.

AIM: To delineate the speech and language phenotype of a cohort of individuals with FOXP1-related disorder. METHOD: We administered a standardized test battery to examine speech and oral motor function, receptive and expressive language, non-verbal cognition, and adaptive behaviour. Clinical history and cognitive assessments were analysed together with speech and language findings. RESULTS: Twenty-nine patients (17 females, 12 males; mean age 9y 6mo; median age 8y [range 2y 7mo-33y]; SD 6y 5mo) with pathogenic FOXP1 variants (14 truncating, three missense, three splice site, one in-frame deletion, eight cytogenic deletions; 28 out of 29 were de novo variants) were studied. All had atypical speech, with 21 being verbal and eight minimally verbal. All verbal patients had dysarthric and apraxic features, with phonological deficits in most (14 out of 16). Language scores were low overall. In the 21 individuals who carried truncating or splice site variants and small deletions, expressive abilities were relatively preserved compared with comprehension. INTERPRETATION: FOXP1-related disorder is characterized by a complex speech and language phenotype with prominent dysarthria, broader motor planning and programming deficits, and linguistic-based phonological errors. Diagnosis of the speech phenotype associated with FOXP1-related dysfunction will inform early targeted therapy. What this paper adds Individuals with FOXP1-related disorder have a complex speech and language phenotype. Dysarthria, which impairs intelligibility, is the dominant feature of the speech profile. No participants were receiving speech therapy for dysarthria, but were good candidates for therapy Features of speech apraxia occur alongside persistent phonological errors. Language abilities are low overall; however, expressive language is a relative strength.

Damaging de novo missense variants in EEF1A2 lead to a developmental and degenerative epileptic-dyskinetic encephalopathy.

Heterozygous de novo variants in the eukaryotic elongation factor EEF1A2 have previously been described in association with intellectual disability and epilepsy but never functionally validated. Here we report 14 new individuals with heterozygous EEF1A2 variants. We functionally validate multiple variants as protein-damaging using heterologous expression and complementation analysis. Our findings allow us to confirm multiple variants as pathogenic and broaden the phenotypic spectrum to include dystonia/choreoathetosis, and in some cases a degenerative course with cerebral and cerebellar atrophy. Pathogenic variants appear to act via a haploinsufficiency mechanism, disrupting both the protein synthesis and integrated stress response functions of EEF1A2. Our studies provide evidence that EEF1A2 is highly intolerant to variation and that de novo pathogenic variants lead to an epileptic-dyskinetic encephalopathy with both neurodevelopmental and neurodegenerative features. Developmental features may be driven by impaired synaptic protein synthesis during early brain development while progressive symptoms may be linked to an impaired ability to handle cytotoxic stressors.

The Genetic Landscape of Epilepsy of Infancy with Migrating Focal Seizures.

OBJECTIVE: Epilepsy of infancy with migrating focal seizures (EIMFS) is one of the most severe developmental and epileptic encephalopathies. We delineate the genetic causes and genotype-phenotype correlations of a large EIMFS cohort. METHODS: Phenotypic and molecular data were analyzed on patients recruited through an international collaborative study. RESULTS: We ascertained 135 patients from 128 unrelated families. Ninety-three of 135 (69%) had causative variants (42/55 previously reported) across 23 genes, including 9 novel EIMFS genes: de novo dominant GABRA1, GABRB1, ATP1A3; X-linked CDKL5, PIGA; and recessive ITPA, AIMP1, KARS, WWOX. The most frequently implicated genes were KCNT1 (36/135, 27%) and SCN2A (10/135, 7%). Mosaicism occurred in 2 probands (SCN2A, GABRB3) and 3 unaffected mothers (KCNT1). Median age at seizure onset was 4 weeks, with earlier onset in the SCN2A, KCNQ2, and BRAT1 groups. Epileptic spasms occurred in 22% patients. A total of 127 patients had severe to profound developmental impairment. All but 7 patients had ongoing seizures. Additional features included microcephaly, movement disorders, spasticity, and scoliosis. Mortality occurred in 33% at median age 2 years 7 months. INTERPRETATION: We identified a genetic cause in 69% of patients with EIMFS. We highlight the genetic heterogeneity of EIMFS with 9 newly implicated genes, bringing the total number to 33. Mosaicism was observed in probands and parents, carrying critical implications for recurrence risk. EIMFS pathophysiology involves diverse molecular processes from gene and protein regulation to ion channel function and solute trafficking. ANN NEUROL 2019;86:821-831.

Accelerated long-term forgetting in children with genetic generalized epilepsy: The temporal trajectory and contribution of executive skills.

PURPOSE: Long-term memory, which is critical for social and vocational functioning, is impaired in children with genetic generalized epilepsy (GGE). In this study, we examined the relationship between the temporal pattern of long-term forgetting for visual and verbal materials and executive skills in children with GGE. METHOD: Thirty-two children, 17 with GGE and 25 typically developing age-matched controls completed standardized tests of short-term memory (recall after a 30-minute delay), executive skills, and experimental long-term memory tasks (one verbal and one visual) involving recall after one short (30-minute), and two long (1-day, 2-week) delays. RESULTS: On the long-term visual memory task, children with GGE performed comparably with typically developing children at a 30-minute delay (p = .298), although obtained lower object placement accuracy score, at 1 day (p = .039) and at 2 weeks (p = .022) relative to typically developing children. On the verbal task, the between-group difference was not significant at any delay. In children with GGE, poorer object placement accuracy at two weeks correlated with lower visuospatial short-term memory (r = -0.624, p = .005) and verbal working memory (r = -0.448, p = .041). CONCLUSIONS: This study provided several novel findings. For the first time, accelerated long-term forgetting (ALF) was found in long-term visual memory in children with GGE, despite comparable learning and recall at 30 min. Study results indicated that deficits in long-term visual memory are present after one day, increase over time, and may relate to reduced executive skills. Our findings can be used to inform our understanding of the temporal trajectory of ALF and contribution of executive skills.

Deficits in all aspects of social competence identified in children who have undergone epilepsy surgery.

Research on social competence of children who undergo epilepsy surgery is limited. This cross-sectional study aimed to determine the frequency and pattern of impairments in social competence (domains: social skills, social adjustment, and social performance) in a cohort of children who underwent surgery for intractable epilepsy at a single epilepsy surgical center. In addition, we explored the relationships between social competence with epilepsy variables, surgical variables, and seizure outcomes. Fifteen children (5 to 16 years) who underwent focal cortical resection for intractable epilepsy more than 2 years ago (2.58-7.42 years) participated. Parents completed standardized, age-normed questionnaires, assessing three domains of social competence. Demographic and clinical information were obtained from parents and medical records and verified by Pediatric Neurologists and Clinical Nurse Consultant. Individual and group analyses were conducted. Seventy-three percent (n = 11/15) of children were seizure-free. Individual analyses revealed high rates of impairments (scores >1 standard deviation of the mean); 11 out of 15 children (73.3%) obtained a score that fell in the impaired range on at least one domain of social competence, with 5 of these 15 children (30.0%) obtaining impaired scores across domains. Conversely, group analyses of questionnaires completed by parents revealed that compared with norms, children had significant difficulties in all domains of social competence: social skills, social adjustment, and social performance. No significant relationships were found between domains of social competence and epilepsy and surgical variables. In conclusion, children who underwent epilepsy surgery have significantly reduced social competence relative to the norms. Longitudinal studies examining social competence pre- and postsurgery are needed to determine whether surgery improves social competence and whether this is dependent on epilepsy outcomes.

BRAT1 encephalopathy: a recessive cause of epilepsy of infancy with migrating focal seizures.

Epilepsy of infancy with migrating focal seizures (EIMFS), one of the most severe developmental and epileptic encephalopathy syndromes, is characterized by seizures that migrate from one hemisphere to the other. EIMFS is genetically heterogeneous with 33 genes. We report five patients with EIMFS caused by recessive BRAT1 variants, identified via next generation sequencing. Recessive pathogenic variants in BRAT1 cause the rigidity and multifocal seizure syndrome, lethal neonatal with hypertonia, microcephaly, and intractable multifocal seizures. The epileptology of BRAT1 encephalopathy has not been well described. All five patients were profoundly impaired with seizure onset in the first week of life and focal seizure migration between hemispheres. We show that BRAT1 is an important recessive cause of EIMFS with onset in the first week of life, profound impairment, and early death. Early recognition of this genetic aetiology will inform management and reproductive counselling.

Etiology is the key determinant of neuroinflammation in epilepsy: Elevation of cerebrospinal fluid cytokines and chemokines in febrile infection-related epilepsy syndrome and febrile status epilepticus.

OBJECTIVE: To investigate intrathecal inflammation using cerebrospinal fluid (CSF) cytokines and chemokines in a subgroup of pediatric epilepsy patients with frequent daily seizures. METHODS: We measured 32 cytokines/chemokines using multiplex immunoassay in CSF collected from pediatric patients with febrile infection-related epilepsy syndrome (FIRES)/FIRES-related disorders (FRD; n = 6), febrile status epilepticus (FSE; n = 8), afebrile status epilepticus (ASE; n = 8), and chronic epilepsy with frequent daily seizures (n = 21) and compared the results with noninflammatory neurological disorders (NIND; n = 20) and encephalitis (n = 43). We also performed longitudinal CSF cytokine/chemokine studies in three cases with FIRES/FRD. RESULTS: The median age of onset of seizures was 2.4 years (range = 0.08-12.5). Median CSF timing from the onset of seizures was longer in chronic epilepsy (540 days), whereas FIRES, FSE, and ASE had CSF tested within 1-2 days of onset of seizures (P < .001). The elevation of cytokines/chemokines was higher in FIRES followed by FSE, when compared to chronic epilepsy and NIND controls. Th1-associated cytokines/chemokines (TNF-α, CXCL9, CXCL10, CXCL11), IL-6, CCL2, CCL19, and CXCL1 (P < .05) were elevated in FIRES, in contrast to the elevation of a broader network of cytokines/chemokines in encephalitis. The cytokines/chemokines (CXCL9, CXCL10, CXCL11, and CCL19) were elevated in FSE when compared to ASE despite the similar median seizure duration and timing of CSF testing in relation to seizures. Chronic epilepsy generally lacked significant elevation of cytokines/chemokines despite frequent daily seizures. The median concentrations of the cytokines/chemokines rapidly declined on serial testing during the course of illness in all three FIRES/FRD cases. SIGNIFICANCE: We identify significant differences in CSF cytokine/chemokine profile between FIRES/FRD and encephalitis. The prominent elevation of CSF cytokines and chemokines in FIRES/FRD and to a lesser extent FSE highlights that the cytokine/chemokine elevation is significantly associated with the etiology of the underlying process rather than purely reactive. However, it is unclear whether the immune activation contributes to the disease process.

Facial emotion perception and social competence in children (8 to 16 years old) with genetic generalized epilepsy and temporal lobe epilepsy.

Facial emotion perception (FEP) impairments are common in adults with epilepsy and associated with impaired psychosocial functioning. Research into the presence of FEP deficits in children with epilepsy and the functional implications of these deficits is limited. The primary aims of this study were to assess FEP abilities in children (8 to 16 years old) with genetic generalized epilepsy (GGE) and temporal lobe epilepsy (TLE) and examine whether FEP is related to everyday social functioning. Forty-four children (8 to 16 years) with epilepsy (22 GGE, 22 TLE) and 22 typically developing controls completed the Pictures of Facial Affect (POFA) battery to assess FEP and a brief test of intellectual functioning (intelligence quotient [IQ]). Parents completed questionnaires assessing social competence of their child. Neurologists completed the Global Assessment of Severity of Epilepsy (GASE) scale as a measure of overall epilepsy severity. Demographic and clinical information was obtained from medical records and clinical interviews with parents. Findings revealed significant, overall FEP impairments and reduced social competence in children with GGE and TLE compared to controls. The magnitude of FEP impairment (i.e., across all emotions) was comparable in the two epilepsy groups, yet different emotions were impaired in each group: children with GGE were impaired in recognizing anger and disgust, whereas children with TLE were impaired in sadness and disgust, compared to controls. Contrary to expectations, total FEP accuracy was not significantly correlated with social competence in either epilepsy group. In conclusion, children with GGE and TLE have significant impairments recognizing emotional expressions on faces. Further research is needed to examine whether underlying FEP impairments relate to social and emotional functioning in children with epilepsy.

Isolated seizures during the first episode of relapsing myelin oligodendrocyte glycoprotein antibody-associated demyelination in children.

Myelin oligodendrocyte glycoprotein (MOG) antibodies have a strong association with acute disseminated encephalomyelitis (ADEM) in children, and bilateral and recurrent optic neuritis in children and adults. Recent reports suggest that seizures and encephalopathy may occur in children and adults with MOG antibody-associated disease. We describe the clinical, laboratory, and radiological course of four MOG antibody-positive children who first presented with isolated seizures without fulfilling clinical or radiological criteria for ADEM or other central nervous system demyelination syndromes, who months to years later developed more typical demyelination. This case series highlights a novel observation that isolated seizures in the absence of ADEM may be the index presentation for MOG antibody-associated disease, which should therefore be considered a form of autoimmune epilepsy. It would be reasonable to test for MOG antibodies in children with seizures accompanied by subtle inflammatory changes on magnetic resonance imaging or cerebrospinal fluid analyses, particularly if followed by demyelination, given the clinical and therapeutic implications of an expedited diagnosis in minimizing long-term disability. WHAT THIS PAPER ADDS: Isolated seizures in the absence of acute disseminated encephalomyelitis may be the index presentation for myelin oligodendrocyte glycoprotein antibody-associated demyelination.

CONVULSIONES AISLADAS DURANTE UNA PRIMERA RECAÍDA DE UN EVENTO DESMIELINIZANTE ASOCIADA A ANTICUERPOS CONTRA LA GLICOPROTEINA DE LOS OLIGODENDROCITOS DE LA MIELINA: Los anticuerpos contra la Glicoproteina de los Oligodendrocitos de la Mielina (MOG) están fuertemente asociados con la Encefalomielitis Aguda Diseminada (EMAD) en niños, y con la Neuritis Óptica bilateral recurrente en niños y adultos. Recientes reportes sugieren que convulsiones y encefalopatía pueden presentarse con enfermedad asociada a anticuerpos MOG. Describimos la evolución clínica, serologica y radiológica de cuatro niños con anticuerpos positivos para MOG cuya primera presentación fueron convulsiones aisladas sin cumplir todos los criterios cínicos ni radiológicos para EMAD u otro síndrome desmielinizante del sistema nervioso central; y, que luego de meses a años, desarrollaron una desmielinización típica. Esta serie de casos resalta una nueva observación, en la cual, convulsiones aisladas en ausencia de EMAD puede ser la presentación de enfermedad asociada a anticuerpos para MOG; y, por lo tanto, debe ser considerada una forma de epilepsia autoinmune. Sería razonable buscar anticuerpos para MOG en aquellos niños con convulsiones que se acompañan de cambios inflamatorios sutiles en la resonancia magnética y análisis de líquido cefalorraquídeo, en particular, en aquellos que posteriormente desarrollan desmielinización teniendo en cuenta las implicancias clínicas y terapéuticas de realizar un diagnóstico rápido con el fin de minimizar la discapacidad a largo plazo.

CONVULSÕES ISOLADAS DURANTE O PRIMEIRO EPISÓDIO DE DESMIELINIZAÇÃO ASSOCIADA AO ANTICORPO DE GLICOPROTEÍNA DE OLIGODENDRÓCITO DA MIELINA EM CRIANÇAS: Anticorpos de glicoproteína de oligodendrócito da mielina (GOM) têm forte associação com encefalomielite aguda disseminada (EMAD) em crianças, e com neurite óptica bilateral e recorrente em crianças e adultos. Relatos recentes sugerem que convulsões e encefalopatia podem ocorrer em adultos e crianças com doença associada aos anticorpos GOM. Descrevemos o curso clínico, laboratorial, e radiológico de crianças com anticorpos GOM positivos que apresentaram convulsões isoladas pela primeira vez, sem preencher os critérios clínicos e radiológicos para EMAD ou para outras síndromes desmielinizantes do sistema nervoso central, que nos meses ou anos seguintes desenvolveram desmielinização mais típica. Esta série de casos realça uma nova observação de que convulsões isoladas na ausência de EMAD podem ser sinal de doença relacionada ao anticorpo GOM, e deve portanto ser considerada uma forma de epilepsia auto-imune. Seria razoável testar anticorpos GOM em crianças com convulsões acompanhada de doenças inflamatórias sutis à ressonância magnética ou na análise do fluido cérebro-espinhal, particularmente se seguida por desmielinização, dadas as implicações clínicas e terapêuticas do diagnóstico rápido em minimizar incapacidades no longo prazo.

Cannabidiol for treating drug-resistant epilepsy in children: the New South Wales experience.

OBJECTIVE: To evaluate the tolerability and safety of cannabidiol for treating drug-resistant epilepsy in children, and to describe adverse events associated with such treatment. STUDY DESIGN: Prospective, open label cohort study. SETTING: Three tertiary NSW referral centres with paediatric neurology services. PARTICIPANTS: First 40 children enrolled in the NSW Compassionate Access Scheme for children with drug-resistant epilepsy and uncountable daily seizures. INTERVENTION: Children received cannabidiol as an adjunct anti-epileptic drug, titrated to a maximum of 25 mg/kg/day, for up to 12 weeks. OUTCOME MEASURES: Adverse events, withdrawals, and caregiver and physician Global Impression of Change assessments were recorded at 4, 8 and 12 weeks. Seizure frequency could not be reliably recorded because of disease severity. RESULTS: Thirty-nine patients reported at least one adverse event; many were deemed unrelated to cannabidiol treatment. The most frequent treatment-related adverse event was somnolence (15 participants), which resolved spontaneously in ten patients; it was particularly frequent in patients taking higher clobazam doses. Gastrointestinal effects (nausea, vomiting, diarrhoea) were each reported by seven to nine participants. Four children were withdrawn from treatment, including one with elevated transaminase levels. The caregivers of 12 children felt the overall health of their children had much or very much improved; clinicians assessed seven children as being much or very much improved. CONCLUSION: Cannabidiol as an adjunct treatment had some subjective benefit for overall health, with a manageable adverse event profile. Monitoring changes in liver function and awareness of potential drug interactions is essential. Whether the reported benefit is attributable to cannabidiol cannot be established in an open label study of participants with severe intractable epilepsy.

Seizure outcome after corpus callosotomy in a large paediatric series.

AIM: To describe 20 years of experience with corpus callosotomy at Great Ormond Street Hospital for Children, London and the Children's Hospital at Westmead, Sydney. METHOD: Records of patients who underwent corpus callosotomy between January 1995 and December 2015 were reviewed. Complications of surgery and changes in seizure type and frequency, injuries, and use of antiepileptic drugs were recorded. Drop attacks were analysed using Kaplan-Meier event-free survival curves. Multivariable regression analysis was used to assess the effect of clinical characteristics on outcome at last follow-up. RESULTS: Inclusion criteria were met for 55 patients younger than 18 years of age. Median follow-up length was 36 months. At the last follow-up, 26 out of 55 patients (47%) had rare or no drop attacks. In those without a good outcome at final follow-up, 26 out of 29 (90%) had drop attacks return within 12 months of surgery. There were no preoperative predictors of developing drop attacks postoperatively. The median number of antiepileptic drugs significantly reduced from three to two. Transient neurological complications were experienced by 11 out of 55 patients (20%) and 6 out of 55 patients had surgical complications (11%). INTERPRETATION: Corpus callosotomy is a well-tolerated procedure that is effective at reducing the severity of drop attacks in paediatric patients. Drop attacks that do return are likely to do so within 12 months and the number of antiepileptic drugs can be significantly reduced. WHAT THIS PAPER ADDS: Corpus callosotomy is an effective palliative treatment and well tolerated in children. Good outcomes for the first 12 months after surgery were likely to continue. The number of antiepileptic drugs can be significantly reduced after corpus callosotomy. Patients with fewer than three types of seizure had better outcomes. There were fewer injuries from drop attacks after surgery.

Attention deficits in children with epilepsy: Preliminary findings.

OBJECTIVE: Attention difficulties are a common clinical complaint among children with epilepsy. We aimed to compare a range of attentional abilities between groups of children with two common epilepsy syndromes, Temporal Lobe Epilepsy (TLE) and Idiopathic Generalized Epilepsy (IGE), and to healthy controls. We also investigated whether epilepsy factors (laterality of seizure focus, epilepsy onset, duration, and severity) were related to attentional abilities. METHODS: Multiple dimensions of attention (selective, sustained, and divided attention and attentional control) were assessed directly with standardized neuropsychological measures in 101 children aged 6-16years (23 children with TLE, 20 with IGE and 58 healthy controls). Attention was also assessed indirectly, via a parent-report measure. RESULTS: Children with TLE performed worse than children with IGE (p=0.013) and healthy controls (p<0.001) on a test of attentional control, but no between-group differences were apparent on tests of other attentional abilities. Compared to healthy controls, greater attention problems were reported by parents of children with TLE (p=0.006) and IGE (p=0.012). Left-hemisphere seizure focus and greater epilepsy severity were associated with poorer attentional control and sustained-divided attention, respectively, but no other epilepsy factors were associated with attentional abilities. SIGNIFICANCE: These findings suggest that children with localization-related epilepsy, but not generalized epilepsy, may be at risk of deficits in attentional control. Interventions aimed at improving attentional control may be targeted at children with localization-related epilepsy, particularly those with a left-hemisphere seizure focus, who appear to be particularly susceptible to this type of attentional deficit.

Cerebrospinal fluid cyto-/chemokine profile during acute herpes simplex virus induced anti-N-methyl-d-aspartate receptor encephalitis and in chronic neurological sequelae.

AIM: To examine the cytokine/chemokine profile of cerebrospinal fluid (CSF) during acute herpes simplex virus-induced N-methyl-d-aspartate receptor (NMDAR) autoimmunity and in chronic/relapsing post-herpes simplex virus encephalitis (HSE) neurological syndromes. METHOD: We measured longitudinal serial CSF cyto-/chemokines (n=34) and a glial marker (calcium-binding astroglial protein, S100B) in one patient during acute HSE and subsequent anti-NMDAR encephalitis, and compared the results with those from two patients with anti-NMDAR encephalitis without preceding HSE. We also compared cyto-/chemokines in cross-sectional CSF samples from three children with previous HSE who had ongoing chronic or relapsing neurological symptoms (2yr 9 mo-16y after HSE) with those in a group of children having non-inflammatory neurological conditions (n=20). RESULTS: Acute HSE showed elevation of a broad range of all T-helper-subset-related cyto-/chemokines and S100B whereas the post-HSE anti-NMDAR encephalitis phase showed persistent elevation of two of five T-helper-1 (chemokine [C-X-C motif] ligand 9 [CXCL9], CXCL10), three of five predominantly B-cell (CXCL13, CCL19, a proliferation-inducing ligand [APRIL])-mediated cyto-/chemokines, and interferon-α. The post-HSE anti-NMDAR encephalitis inflammatory response was more pronounced than anti-NMDAR encephalitis. All three chronic post-HSE cases showed persistent elevation of CXCL9, CXCL10, and interferon-α, and there was histopathological evidence of chronic lymphocytic inflammation in one biopsied case 7 years after HSE. Two of three chronic cases showed a modest response to immune therapy. INTERPRETATION: HSE-induced anti-NMDAR encephalitis is a complex and pronounced inflammatory syndrome. There is persistent CSF upregulation of cyto-/chemokines in chronic or relapsing post-HSE neurological symptoms, which may be modifiable with immune therapy. The elevated cyto-/chemokines may be targets of monoclonal therapies.