David Buckley

Clinical, environmental, and genetic determinants of multiple sclerosis in children with acute demyelination: a prospective national cohort study

BACKGROUND HLA-DRB1*15 genotype, previous infection with Epstein-Barr virus, and vitamin D insufficiency are susceptibility factors for multiple sclerosis, but whether they act synergistically to increase risk is unknown. We aimed to assess the contributions of these risk factors and the effect of established precursors of multiple sclerosis, such as brain lesions on MRI and oligoclonal bands in CSF at the time of incident demyelination, on development of multiple sclerosis in children. METHODS In our prospective national cohort study, we assessed children who presented with incident CNS demyelination to any of the 16 paediatric health-care facilities or seven regional health-care facilities in Canada. We did univariate and multivariable analyses to assess contributions of HLA-DRB1*15, Epstein-Barr virus, vitamin D status, MRI evidence of brain lesions, and CSF oligoclonal bands as determinants of multiple sclerosis. We used classification and regression tree analyses to generate a risk stratification algorithm for clinical use. FINDINGS Between Sept 1, 2004, and June 30, 2010, we screened 332 children of whom 302 (91%) were eligible and followed-up for a median of 3·14 years (IQR 1·61-4·51). 63 (21%) children were diagnosed with multiple sclerosis after a median of 127 days (99-222). Although the risk of multiple sclerosis was increased with presence of one or more HLA-DRB1*15 alleles (hazard ratio [HR] 2·32, 95% CI 1·25-4·30), reduced serum 25-hydroxyvitamin D concentration (HR per 10 nmol/L decrease 1·11, 1·00-1·25), and previous Epstein-Barr-virus infection (HR 2·04, 0·99-4·20), no interactions between these variables were detected on multivariate analysis. Multiple sclerosis was strongly associated with baseline MRI evidence of one or more brain lesion (HR 37·9, 5·26-273·85) or CSF oligoclonal bands (6·33, 3·35-11·96), suggesting established disease. One patient diagnosed with multiple sclerosis had a normal MRI scan, and therefore sensitivity of an abnormal MRI scan for multiple sclerosis diagnosis was 98·4%. INTERPRETATION Risk of multiple sclerosis in children can be stratified by presence of HLA-DRB1*15 alleles, remote Epstein-Barr virus infection, and low serum 25-hydroxyvitamin D concentrations. Similar to previous studies in adults, brain lesions detected on MRI and CSF oligoclonal bands in children are probable precursors to the clinical onset of multiple sclerosis. Children with a normal MRI are very likely to have a monophasic illness. FUNDING Canadian Multiple Sclerosis Scientific Research Foundation.

Incidence of acquired demyelination of the CNS in Canadian children

Background: The incidence of acquired demyelination of the CNS (acquired demyelinating syndromes [ADS]) in children is unknown. It is important that physicians recognize the features of ADS to facilitate care and to appreciate the future risk of multiple sclerosis (MS). Objective: To determine the incidence, clinical features, familial autoimmune history, and acute management of Canadian children with ADS. Methods: Incidence and case-specific data were obtained through the Canadian Pediatric Surveillance Program from April 1, 2004, to March 31, 2007. Before study initiation, a survey was sent to all pediatric health care providers to determine awareness of MS as a potential outcome of ADS in children. Results: Two hundred nineteen children with ADS (mean age 10.5 years, range 0.66–18.0 years; female to male ratio 1.09:1) were reported. The most common presentations were optic neuritis (ON; n = 51, 23%), acute disseminated encephalomyelitis (ADEM; n = 49, 22%), and transverse myelitis (TM; n = 48, 22%). Children with ADEM were more likely to be younger than 10 years, whereas children with monolesional ADS (ON, TM, other) were more likely to be older than 10 years (p < 0.001). There were 73 incident cases per year, leading to an annual incidence of 0.9 per 100,000 Canadian children. A family history of MS was reported in 8%. Before study initiation, 65% of physicians indicated that they considered MS as a possible outcome of ADS in children. This increased to 74% in year 1, 81% in year 2, and 87% in year 3. Conclusion: The incidence of pediatric acquired demyelinating syndromes (ADS) is 0.9 per 100,000 Canadian children. ADS presentations are influenced by age.

The Role of Vigabatrin in Childhood Seizure Disorders: Results from a Clinical Audit

Summary:  Purpose: The emergence of visual field defects attributed to vigabatrin (VGB) treatment and intramyelinic edema in animal experiments has raised concerns about its future role in the treatment of childhood seizures.

Variable neurologic phenotype in a GEFS+ family with a novel mutation in SCN1A

PURPOSE To describe the spectrum of clinical disease in a mutliplex family with an autosomal dominant form of generalized epilepsy with febrile seizures plus (GEFS+) and determine its genetic etiology. METHODS Medical and family history was obtained on 11 clinically affected individuals and their relatives across three generations through medical chart review and home visits. A candidate gene approach including haplotype analysis and direct sequencing was used. RESULTS An epilepsy-associated haplotype was identified on 2q24. Direct sequencing of the entire SCN1A gene identified seven sequence variants. However, only one of these, c.1162 T>C, was not found in population controls. This transition in exon 8 of SCN1A predicts a substitution (Y388H) of a highly conserved tyrosine residue in the loop between transmembrane segments S5 and S6 of the sodium channel protein (Na(v)1.1). Clinical features in mutation carriers of this novel missense mutation were highly variable, ranging from febrile seizures to severe refractory epilepsy. CONCLUSION A novel missense mutation in the pore-forming region of the sodium channel gene SCN1A causes GEFS+ with a variable phenotype that includes mood and anxiety disorders, as well as ataxia, expanding the GEFS+ spectrum to include neuropsychiatric disease.

Recovery From Central Nervous System Acute Demyelination in Children

BACKGROUND: Few prospective studies have systematically evaluated the extent of recovery from incident acquired demyelinating syndromes (ADS) of the central nervous system in children. METHODS: In a national cohort study of pediatric ADS, severity of the incident attack and extent of recovery by 12 months were evaluated. Annual evaluations were used to determine current diagnoses (monophasic ADS or multiple sclerosis [MS]) and new deficits. RESULTS: Of 283 children, 244 (86%) required hospitalization for a median (interquartile range [IQR]) of 6 (3–10) days, and 184 had moderate or severe deficits; 41 children were profoundly encephalopathic, 129 were unable to ambulate independently, and 59 with optic neuritis (ON) had moderately or severely impaired vision. Those with transverse myelitis (TM) and patients with monophasic disease were more likely to have moderate or severe deficits at onset. Twenty-seven children (10%) did not experience full neurologic recovery from their incident attack; 12 have severe residual deficits. Monophasic illness, TM, and moderate or severe deficits at onset were associated with poor recovery. After a median (IQR) follow-up of 5.06 (3.41–6.97) years, 59 children (21%) were diagnosed with MS; all recovered fully from their incident ADS attacks, although 6 subsequently acquired irreversible deficits after a median (IQR) observation period of 5.93 (4.01–7.02) years. CONCLUSIONS: ADS is a serious illness, with 86% of affected Canadian children requiring hospitalization. More than 90% of children recovered physically from their ADS event, including those children experiencing onset of MS. However, permanent visual or spinal cord impairment occurred in some children with ON or TM.

Vigabatrin in childhood epilepsy: comparable efficacy for generalized and partial seizures.

Thirty-one patients, aged 12.6 +/- 5.6 years, with refractory seizures for 8 +/- 4.3 years, were treated with adjunctive vigabatrin. Twenty-four percent had a > 50% reduction in seizure frequency (95% one-sided confidence interval). Generalized myoclonic, atonic, and tonic clonic and partial, with and without secondary generalization, seizures were all reduced at a mean dose of 70 +/- 38 mg/kg/day. Comparison of vigabatrin therapy duration, for partial and generalized seizure groups, utilizing Kaplan-Meier methodology showed similar survival times. Vigabatrin therapy was ineffective in the four children with tuberous sclerosis. Transient somnolence, ataxia and dizziness were the most frequent side effects. A severe aggressive agitation occurred in three patients, and necessitated discontinuation of vigabatrin in one patient. Vigabatrin was as effective in generalized as in partial seizures in this study. Clinical utility may be limited by unacceptable behavioral side effects in some patients.

MRI and laboratory features and the performance of international criteria in the diagnosis of multiple sclerosis in children and adolescents: a prospective cohort study

BACKGROUND MRI and laboratory features have been incorporated into international diagnostic criteria for multiple sclerosis. We assessed the pattern of MRI lesions and contributions of cerebrospinal fluid (CSF) and serum antibody findings that best identifies children with multiple sclerosis, and the applicability of international diagnostic criteria in the paediatric context. METHODS In this prospective cohort study, detailed clinical assessments, serum and CSF studies, and MRI scans were done in youth (aged 0·46-17·87 years) with incidental acquired demyelinating syndrome. Participants were examined prospectively to identify relapsing disease. All MRI scans were assessed using a validated scoring method. A random forest classifier identified imaging and laboratory features that best predicted a multiple sclerosis or monophasic outcome. Performance of the 2001, 2010, and 2017 international McDonald criteria for the diagnosis of multiple sclerosis, the 2016 MRI in multiple sclerosis (MAGNIMS) criteria, and our 2011 proposed (Verhey) criteria were determined; performance was adjudicated with generalised linear models. FINDINGS Between Sept 1, 2004, and June 30, 2017, we included 324 participants with median follow-up of 72 months (range 6-150), 71 (22%) participants with multiple sclerosis, 237 (73%) with monophasic acquired demyelinating syndrome, 14 (4%) with relapsing non-multiple sclerosis, and two (1%) with alternative diagnoses. We scored 2391 brain, 444 spinal, and 67 dedicated orbital MRI scans. One or more T1 hypointense lesions plus one or more periventricular lesions (Verhey criteria) best predicted multiple sclerosis outcome. Performance of the 2017 McDonald criteria was comparable to the 2010 McDonald criteria and was easier to adjudicate. The ability of CSF oligoclonal bands to substitute for the requirement for both enhancing and non-enhancing lesions in the 2017 McDonald criteria improved its performance compared with the 2010 criteria. Myelin oligodendrocyte testing at baseline did not improve performance of the 2017 McDonald criteria. INTERPRETATION The 2017 McDonald criteria for the diagnosis of multiple sclerosis, as applied at the time of incident attack, perform well in identifying children and youth with multiple sclerosis, indicating that the same diagnostic criteria for multiple sclerosis apply across the age span. The presence of so-called black holes on MRI and periventricular lesions at baseline (Verhey criteria) also effectively distinguish children with multiple sclerosis from children with monophasic demyelination. The presence of CSF oligoclonal bands improve diagnostic accuracy. Myelin oligodendrocyte glycoprotein antibodies identify children with acute disseminated encephalomyelitis, and those with relapsing non-multiple sclerosis, most of whom do not meet 2017 McDonald criteria at onset. FUNDING The Multiple Sclerosis Scientific Research Foundation and The Childrens Hospital of Philadelphia.

The Association Between Maternal Age and Cerebral Palsy Risk Factors

BACKGROUND Advanced maternal age is associated with higher frequencies of antenatal and perinatal conditions, as well as a higher risk of cerebral palsy in offspring. We explore the association between maternal age and specific cerebral palsy risk factors. METHODS Data were extracted from the Canadian Cerebral Palsy Registry. Maternal age was categorized as ≥35 years of age and less than 20 years of age at the time of birth. Chi-square and multivariate logistic regressions were performed to calculate odds ratios and their 95% confidence intervals. RESULTS The final sample consisted of 1391 children with cerebral palsy, with 19% of children having mothers aged 35 or older and 4% of children having mothers below the age of 20. Univariate analyses showed that mothers aged 35 or older were more likely to have gestational diabetes (odds ratio 1.9, 95% confidence interval 1.3 to 2.8), to have a history of miscarriage (odds ratio 1.8, 95% confidence interval 1.3 to 2.4), to have undergone fertility treatments (odds ratio 2.4, 95% confidence interval 1.5 to 3.9), and to have delivered by Caesarean section (odds ratio 1.6, 95% confidence interval 1.2 to 2.2). These findings were supported by multivariate analyses. Children with mothers below the age of 20 were more likely to have a congenital malformation (odds ratio 2.4, 95% confidence interval 1.4 to 4.2), which is also supported by multivariate analysis. CONCLUSIONS The risk factor profiles of children with cerebral palsy vary by maternal age. Future studies are warranted to further our understanding of the compound causal pathways leading to cerebral palsy and the observed greater prevalence of cerebral palsy with increasing maternal age.

Neonatal Infection in Children with Cerebral Palsy: a Registry-Based Cohort Study

BACKGROUND The goal of this study was to explore the association between neonatal infection and outcomes in children with cerebral palsy. METHODS We conducted a retrospective cohort study using the Canadian CP Registry. Neonatal infection was defined as meeting one of the following criteria: (1) septicemia, (2) septic shock, or (3) administration of antibiotics for ≥10 days. Phenotypic profiles of children with cerebral palsy with and without an antecedent neonatal infection were compared. Subgroup analysis was performed, stratified by gestational age (term versus preterm). RESULTS Of the 1229 registry participants, 505 (41.1%) were preterm, and 192 (15.6%) met the criteria for neonatal infection with 29% of preterm children having a neonatal infection compared with 6.5% in term-born children. Children with prior neonatal infection were more likely to have a white matter injury (odds ratio 2.2, 95% confidence interval 1.5 to 3.2), spastic diplegic neurological subtype (odds ratio 1.6, 95% confidence interval 1.1 to 2.3), and sensorineural auditory impairment (odds ratio 2.1, 95% confidence interval 1.4 to 3.3). Among preterm children, neonatal infection was not associated with a difference in phenotypic profile. Term-born children with neonatal infection were more likely to have spastic triplegia or quadriplegia (odds ratio 2.4, 95% confidence interval 1.3 to 4.3), concomitant white matter and cortical injury (odds ratio 4.1, 95% confidence interval 1.6 to 10.3), and more severe gross motor ability (Gross Motor Function Classification System IV to V) (odds ratio 2.6, 95% confidence interval 1.4 to 4.8) compared with preterm children. CONCLUSIONS Findings suggest a role of systemic infection on the developing brain in term-born infants, and the possibility to develop targeted therapeutic and preventive strategies to reduce cerebral palsy morbidity.

Family-centred health care for children with cerebral palsy

To identify characteristics of young children with cerebral palsy (CP), and intrinsic and extrinsic factors, that may be associated with parental perceptions regarding family‐centred health care services.