Classic ketogenic diet versus further antiseizure medicine in infants with drug-resistant epilepsy (KIWE): a UK, multicentre, open-label, randomised clinical trial.

BACKGROUND: Many infancy-onset epilepsies have poor prognosis for seizure control and neurodevelopmental outcome. Ketogenic diets can improve seizures in children older than 2 years and adults who are unresponsive to antiseizure medicines. We aimed to establish the efficacy of a classic ketogenic diet at reducing seizure frequency compared with further antiseizure medicine in infants with drug-resistant epilepsy. METHODS: In this phase 4, open-label, multicentre, randomised clinical trial, infants aged 1-24 months with drug-resistant epilepsy (defined as four or more seizures per week and two or more previous antiseizure medications) were recruited from 19 hospitals in the UK. Following a 1-week or 2-week observation period, participants were randomly assigned using a computer-generated schedule, without stratification, to either a classic ketogenic diet or a further antiseizure medication for 8 weeks. Treatment allocation was masked from research nurses involved in patient care, but not from participants. The primary outcome was the median number of seizures per day, recorded during weeks 6-8. All analyses were by modified intention to treat, which included all participants with available data. Participants were followed for up to 12 months. All serious adverse events were recorded. The trial is registered with the European Union Drug Regulating Authorities Clinical Trials Database (2013-002195-40). The trial was terminated early before all participants had reached 12 months of follow-up because of slow recruitment and end of funding. FINDINGS: Between Jan 1, 2015, and Sept 30, 2021, 155 infants were assessed for eligibility, of whom 136 met inclusion criteria and were randomly assigned; 75 (55%) were male and 61 (45%) were female. 78 infants were assigned to a ketogenic diet and 58 to antiseizure medication, of whom 61 and 47, respectively, had available data and were included in the modifified intention-to-treat analysis at week 8. The median number of seizures per day during weeks 6-8, accounting for baseline rate and randomised group, was similar between the ketogenic diet group (5 [IQR 1-16]) and antiseizure medication group (3 [IQR 2-11]; IRR 1·33, 95% CI 0·84-2·11). A similar number of infants with at least one serious adverse event was reported in both groups (40 [51%] of 78 participants in the ketogenic diet group and 26 [45%] of 58 participants in the antiseizure medication group). The most common serious adverse events were seizures in both groups. Three infants died during the trial, all of whom were randomly assigned a ketogenic diet: one child (who also had dystonic cerebral palsy) was found not breathing at home; one child died suddenly and unexpectedly at home; and one child went into cardiac arrest during routine surgery under anaesthetic. The deaths were judged unrelated to treatment by local principal investigators and confirmed by the data safety monitoring committee. INTERPRETATION: In this phase 4 trial, a ketogenic diet did not differ in efficacy and tolerability to a further antiseizure medication, and it appears to be safe to use in infants with drug-resistant epilepsy. A ketogenic diet could be a treatment option in infants whose seizures continue despite previously trying two antiseizure medications. FUNDING: National Institute for Health and Care Research.

Care and three-year outcomes of children with Benign Epilepsy with Centro-Temporal Spikes in England.

PURPOSE: Benign Epilepsy with Centro-Temporal Spikes (BECTS) is a pediatric epilepsy with typically good seizure control. Although BECTS may increase patients' risk of developing neurological comorbidities, their clinical care and short-term outcomes are poorly quantified. METHODS: We retrospectively assessed adherence to National Institute for Health and Care Excellence (NICE) guidelines relating to specialist referral, electroencephalogram (EEG) conduct and annual review in the care of patients with BECTS, and measured their seizure, neurodevelopmental and learning outcomes at three years post-diagnosis. RESULTS: Across ten centers in England, we identified 124 patients (74 male) diagnosed with BECTS between 2015 and 2017. Patients had a mean age at diagnosis of 8.0 (95% CI = 7.6-8.4) years. 24/95 (25%) patients were seen by a specialist within two weeks of presentation; 59/100 (59%) received an EEG within two weeks of request; and 59/114 (52%) were reviewed annually. At three years post-diagnosis, 32/114 (28%) experienced ongoing seizures; 26/114 (23%) had reported poor school progress; 15/114 (13%) were diagnosed with a neurodevelopmental disorder (six autism spectrum disorder, six attention-deficit/hyperactivity disorder); and 10/114 (8.8%) were diagnosed with a learning difficulty (three processing deficit, three dyslexia). Center-level random effects models estimated neurodevelopmental diagnoses in 9% (95% CI: 2-16%) of patients and learning difficulty diagnoses in 7% (95% CI: 2-12%). CONCLUSIONS: In this multicenter work, we found variable adherence to NICE guidelines in the care of patients with BECTS and identified a notable level of neurological comorbidity. Patients with BECTS may benefit from enhanced cognitive and behavioral assessment and monitoring.

Functional hemispherotomy for epilepsy in the very young.

OBJECTIVE: Epilepsy is one of the most common neurological disorders in children. Among very young children, one-third are resistant to medical treatment, and lack of effective treatment may result in adverse outcomes. Although functional hemispherotomy is an established treatment for epilepsy, its outcome in the very young child has not been widely reported. In this study the authors investigated seizure and developmental results after hemispherotomy in children younger than 3 years. METHODS: The authors reviewed a prospective database of all children younger than 3 years with medically intractable epilepsy who underwent functional hemispherotomy at the authors' institution during the period between 2012 and 2020. Demographic data, epilepsy history, underlying etiology, operative and transfusion details, and seizure and developmental outcomes were analyzed. RESULTS: Twelve patients were included in this study. The mean age (± SD) at seizure onset was 3 ± 2.6 months and at surgery was 1.3 ± 0.77 years, with a mean follow-up of 4 years. Diagnoses included hemimegalencephaly (n = 5), hemidysplasia (n = 2), hypoxic/hemorrhagic (n = 2), traumatic (n = 1), Sturge-Weber syndrome (n = 1), and mild hemispheric structural abnormality with EEG/PET correlates (n = 1). Eleven patients achieved an Engel class I outcome, and 1 patient achieved Engel class IV at last follow-up. No deaths, infections, cerebrovascular events, or unexpected long-term neurological deficits were recorded. All children progressed neurodevelopmentally following surgery, but their developmental levels remained behind their chronological age, with an overall mean composite Vineland Adaptive Behavior Scale score of 58 (normal: 86-114, low: < 70). One patient required insertion of a subdural peritoneal shunt, 1 patient required dural repair for a CSF fluid leak, and 1 patient required aspiration of a pseudomeningocele. In 2 patients, both of whom weighed less than 5.7 kg, the first operation was incomplete due to blood loss. CONCLUSIONS: Hemispherotomy in children younger than 3 years offers excellent seizure control and an acceptable risk-to-benefit ratio in well-selected patients. Families of children weighing less than 6 kg should be counseled regarding the possibility of staged surgery. Postoperatively, children continue to make appropriate, despite delayed, developmental progress.

Pediatric stereo-electroencephalography: effects of robot assistance and other variables on seizure outcome and complications.

OBJECTIVE: The safety of stereo-electroencephalography (SEEG) has been investigated; however, most studies have not differentiated pediatric and adult populations, which have different anatomy and physiology. The purpose of this study was to assess SEEG safety in the pediatric setting, focusing on surgical complications and the identification of patient and surgical risk factors, if any. The authors also aimed to determine whether robot assistance in SEEG was associated with a change in practice, surgical parameters, and clinical outcomes. METHODS: The authors retrospectively studied all SEEG cases performed in their department from December 2014 to March 2020. They analyzed both demographic and surgical variables and noted the types of surgery-related complications and their management. They also studied the clinical outcomes of a subset of the patients in relation to robot-assisted and non-robot-assisted SEEG. RESULTS: Sixty-three children had undergone 64 SEEG procedures. Girls were on average 3 years younger than the boys (mean age 11.1 vs 14.1 years, p < 0.01). The overall complication rate was 6.3%, and the complication rate for patients with left-sided electrodes was higher than that for patients with right-sided electrodes (11.1% vs 3.3%), although the difference between the two groups was not statistically significant. The duration of recording was positively correlated to the number of implanted electrodes (r = 0.296, p < 0.05). Robot assistance was associated with a higher number of implanted electrodes (mean 12.6 vs 7.6 electrodes, p < 0.0001). Robot-assisted implantations were more accurate, with a mean error of 1.51 mm at the target compared to 2.98 mm in nonrobot implantations (p < 0.001). Clinical outcomes were assessed in the first 32 patients treated (16 in the nonrobot group and 16 in the robot group), 23 of whom proceeded to further resective surgery. The children who had undergone robot-assisted SEEG had better eventual seizure control following subsequent epilepsy surgery. Of the children who had undergone resective epilepsy surgery, 42% (5/12) in the nonrobot group and 82% (9/11) in the robot group obtained an Engel class IA outcome at 1 year (χ2 = 3.885, p = 0.049). Based on Kaplan-Meier survival analysis, the robot group had a higher seizure-free rate than the nonrobot group at 30 months postoperation (7/11 vs 2/12, p = 0.063). Two complications, whose causes were attributed to the implantation and head-bandaging steps, required surgical intervention. All complications were either transient or reversible. CONCLUSIONS: This is the largest single-center, exclusively pediatric SEEG series that includes robot assistance so far. SEEG complications are uncommon and usually transient or treatable. Robot assistance enabled implantation of more electrodes and improved epilepsy surgery outcomes, as compared to those in the non-robot-assisted cases.

Seizure improvement following vagus nerve stimulator (VNS) battery change with cardiac-based seizure detection automatic stimulation (AutoStim): early experience in a regional paediatric unit.

PURPOSE: The recent VNS models (AspireSR® Model 106, SenTiva™ Model 1000 (VNS Therapy®, LivaNova)) include a new function of cardiac-based seizure detection (CBSD) automatic stimulation, known as 'AutoStim'. This algorithm uses tachycardia as a proxy to a seizure, and the battery delivers a closed-loop electrical current in addition to its programmed stimulation. This function leads to further seizure reduction in adults, but this advantage has not been reported in the paediatric population. This study aims to investigate whether battery change with AutoStim leads to further seizure reduction in children. METHODS: This observational study included the first 10 cases of VNS battery change from non-AutoStim to AutoStim function. During the battery change operation, the new VNS was switched on, with the same normal and magnet mode settings as the previous VNS. The AutoStim mode was activated at the same time. Data on seizure burden were collected at 3 time points: (1) before the first VNS insertion, (2) before battery replacement (post-1st VNS) and (3) 12 months post-battery change (post-AutoStim). The net effect of AutoStim, the only changed parameter, was evaluated by comparing the seizure burden prior to and 12 months following battery change in each child. RESULTS: The seizure reduction improved significantly from 60 to 83% following battery change with AutoStim. Categorising the outcome according the McHugh classification, children achieving class I and II outcome (≥ 50% seizure reduction) improved from 70 to 90%. CONCLUSION: This is the first study to demonstrate the additional efficacy of AutoStim in children treated with VNS.

Abolishing spontaneous epileptiform activity in human brain tissue through AMPA receptor inhibition.

OBJECTIVE: The amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) is increasingly recognized as a therapeutic target in drug-refractory pediatric epilepsy. Perampanel (PER) is a non-competitive AMPAR antagonist, and pre-clinical studies have shown the AMPAR-mediated anticonvulsant effects of decanoic acid (DEC), a major medium-chain fatty acid provided in the medium-chain triglyceride ketogenic diet. METHODS: Using brain tissue resected from children with intractable epilepsy, we recorded the effects of PER and DEC in vitro. RESULTS: We found resected pediatric epilepsy tissue exhibits spontaneous epileptic activity in vitro, and showed that DEC and PER inhibit this epileptiform activity in local field potential recordings as well as excitatory synaptic transmission. INTERPRETATION: This study confirms AMPAR antagonists inhibit epileptiform discharges in brain tissue resected in a wide range of pediatric epilepsies.

Phenotypic and genetic spectrum of epilepsy with myoclonic atonic seizures.

OBJECTIVE: We aimed to describe the extent of neurodevelopmental impairments and identify the genetic etiologies in a large cohort of patients with epilepsy with myoclonic atonic seizures (MAE). METHODS: We deeply phenotyped MAE patients for epilepsy features, intellectual disability, autism spectrum disorder, and attention-deficit/hyperactivity disorder using standardized neuropsychological instruments. We performed exome analysis (whole exome sequencing) filtered on epilepsy and neuropsychiatric gene sets to identify genetic etiologies. RESULTS: We analyzed 101 patients with MAE (70% male). The median age of seizure onset was 34 months (range = 6-72 months). The main seizure types were myoclonic atonic or atonic in 100%, generalized tonic-clonic in 72%, myoclonic in 69%, absence in 60%, and tonic seizures in 19% of patients. We observed intellectual disability in 62% of patients, with extremely low adaptive behavioral scores in 69%. In addition, 24% exhibited symptoms of autism and 37% exhibited attention-deficit/hyperactivity symptoms. We discovered pathogenic variants in 12 (14%) of 85 patients, including five previously published patients. These were pathogenic genetic variants in SYNGAP1 (n = 3), KIAA2022 (n = 2), and SLC6A1 (n = 2), as well as KCNA2, SCN2A, STX1B, KCNB1, and MECP2 (n = 1 each). We also identified three new candidate genes, ASH1L, CHD4, and SMARCA2 in one patient each. SIGNIFICANCE: MAE is associated with significant neurodevelopmental impairment. MAE is genetically heterogeneous, and we identified a pathogenic genetic etiology in 14% of this cohort by exome analysis. These findings suggest that MAE is a manifestation of several etiologies rather than a discrete syndromic entity.

Utility and safety of plasma exchange in paediatric neuroimmune disorders.

AIM: Our aim was to ascertain the indications, side effects, and outcomes in children receiving therapeutic plasma exchange (TPE) for neurological disorders. METHOD: Medical records were retrospectively reviewed for 58 consecutive children (age ≤16y) undergoing 67 courses of TPE across four tertiary centres. Patient characteristics, treatment schedules, complications, and outcomes were analysed. RESULTS: Median age at initiation of TPE was 9 years (range 1-15y). Indications included peripheral nervous system (PNS; n=18) and central nervous system (CNS; n=40) disorders. Courses comprised a median six exchanges (range 2-179) over 8 days (range 3-466). Forty-two out of 58 (73%) children were severely disabled (bedridden) at initiation and 24 out of 58 (41%) were admitted to intensive care units. Treating clinicians' impression of response was positive in 16 out of 18 of those with PNS disorders versus 22 out of 40 with CNS disorders (p=0.016). Improvements in disability (modified Rankin Scale) occurred in 13 out of 58 (22%) children by completion of TPE (p=0.003). Complications occurred in 40 out of 67 (60%) courses, of which 16 out of 67 (24%) were line related. Potentially life-threatening complications occurred in 2 out of 67 (3%) courses. INTERPRETATION: This cohort study provides safety and efficacy information for clinicians and families and a basis for future prospective studies. WHAT THIS PAPER ADDS: Disability scores for severe neuroimmune disorders remained stable or improved during therapeutic plasma exchange treatment. Complications occurred frequently but were typically mild and correctable.

UTILIDAD Y SEGURIDAD DEL INTERCAMBIO DE PLASMA EN TRASTORNOS NEUROINMUNES PEDIÁTRICOS: OBJETIVO: Nuestro objetivo fue determinar las indicaciones, los efectos secundarios y los resultados en niños que recibieron intercambio terapéutico de plasma (TPE) para trastornos neurológicos. MÉTODO: Se revisaron retrospectivamente los registros médicos de 58 niños consecutivos (≤16 años) que se sometieron a 67 cursos de TPE en cuatro centros terciarios. Se analizaron las características de los pacientes, los esquemas de tratamiento, las complicaciones y los resultados. RESULTADOS: La edad mediana al inicio de la TPE fue de 9 años (rango 1-15 años). Las indicaciones incluían trastornos del sistema nervioso periférico (SNP; n = 18) y del sistema nervioso central (SNC; n = 40). Los cursos comprendieron una mediana de 6 intercambios (rango 2-179) durante 8 días (rango 3-466). Cuarenta y dos de 58 (73%) niños presentaban un grado de discapacidad severa (postrados en cama) al inicio y 24 de 58 (41%) fueron ingresados en unidades de cuidados intensivos. El tratamiento de la impresión de respuesta de los médicos fue positivo en 16 de 18 de las personas con trastornos de SNP versus 22 de 40 en trastornos del SNC (p = 0,016). Las mejoras en la discapacidad (escala de Rankin modificada) se produjeron en 13 de los 58 (22%) niños al completar el TPE (p = 0,003). Las complicaciones ocurrieron en 40 de 67 cursos (60%), de los cuales 16 de 67 (24%) estaban relacionados con la línea. Complicaciones potencialmente peligrosas para la vida ocurrieron en 2 de 67 (3%) cursos. INTERPRETACIÓN: Este estudio de cohorte proporciona información de seguridad y eficacia para profesionales y familiares y una base para futuros estudios prospectivos.

UTILIDADE E SEGURANÇA DA TRANSFERÊNCIA DE PLASMA EM TRANSTORNOS NEUROIMUNES PEDIÁTRICOS: OBJETIVO: Nosso objetivo foi verificar as indicações, efeitos colaterais, e resultados em crianças recebendo transferência terapêutica de plasma (TTP) para transtornos neurológicos. MÉTODO: Registros médicos foram retrospectivamente revisados para 58 crianças (idade ≤16a) passando por 67 cursos de TTP em quatro centros terciários. Características dos pacientes, rotina de tratamento, complicações e resultados foram analisados. RESULTADOS: A idade mediana ao início da TTP foi 9 anos (variação 1-15 anos). Indicações incluíram transtornos do sistema nervoso periférico (SNP; n = 18) e sistema nervoso central (SNC; n = 40) disorders. Os cursos compreenderam uma mediana de seis transferências (variação 2-179) em 8 dias (variação 3-466). Quarenta e duas em 58 (73%) crianças estavam severamente incapacidadas (acamadas) no início e 24 em 58 (41%) foram admitidas em unidades de cuidado intensivo. A impressão de resposta dos clínicos que as tratavam foi positiva em 16 de 18 daquelas com transtornos do SNP versus 22 de 40 daquelas com desordens do SNC (p = 0,016). Melhoras na incapacidade (Escala de Rankin modificada) ocorreram em 13 de 58 (22%) crianças ao final da TTP (p = 0,003). Complicações ocorreram em 40 de 67 (60%) cursos, dos quais 16 em 67 (24%) eram relacionados à linha. Complicações com potencial risco de vida ocorreram em 2 de 67 (3%) cursos. INTERPRETAÇÃO: Este estudo de coorte fornece informação sobre a segurança e eficácia para clínicos e famílias, e uma base para futuros estudos prospectivos.

Clinical features, course, and outcomes of a UK cohort of pediatric moyamoya.

OBJECTIVE: To describe characteristics and course of a large UK cohort of children with moyamoya from multiple centers and examine prognostic predictors. METHODS: Retrospective review of case notes/radiology, with use of logistic regression to explore predictors of outcome. RESULTS: Eighty-eight children (median presentation age 5.1 years) were included. Thirty-six presented with arterial ischemic stroke (AIS) and 29 with TIA. Eighty had bilateral and 8 unilateral carotid circulation disease; 29 patients had posterior circulation involvement. Acute infarction was present in 36/176 hemispheres and chronic infarction in 86/176 hemispheres at the index presentation. Sixty-two of 82 with symptomatic presentation had at least one clinical recurrence. Fifty-five patients were treated surgically, with 37 experiencing fewer recurrences after surgery. Outcome was categorized as good using the Recovery and Recurrence Questionnaire in 39/85 patients. On multivariable analysis, presentation with TIA (odds ratio [OR] 0.09, 95% confidence interval [CI] 0.02-0.35), headache (OR 0.10, 95% CI 0.02-0.58), or no symptoms (OR 0.08, 95% CI 0.01-0.68) was less likely to predict poor outcome than AIS presentation. Posterior circulation involvement predicted poor outcome (OR 4.22, 95% CI 1.23-15.53). Surgical revascularization was not a significant predictor of outcome. CONCLUSIONS: Moyamoya is associated with multiple recurrences, progressive arteriopathy, and poor outcome in half of patients, especially with AIS presentation and posterior circulation involvement. Recurrent AIS is rare after surgery. Surgery was not a determinant of overall outcome, likely reflecting surgical case selection and presentation clinical status.

Ketogenic diet in the treatment of epilepsy in children under the age of 2 years: study protocol for a randomised controlled trial.

BACKGROUND: The incidence of epilepsy is greatest in the first 2 years of life, an age group where there is generally a poor prognosis for both seizure control and neurodevelopmental outcome. Early control of seizures can be associated with better developmental outcome but many of the epilepsies presenting in infancy are poorly responsive to antiepileptic medication. The ketogenic diet (KD) is a high-fat, low-carbohydrate diet designed to mimic the effects of starvation on the body. Dietary fat is converted into ketones in the body and used as an energy source by the brain. The KD has been shown to be successful in controlling seizures in many observational studies, and in two randomised controlled trials (RCTs) in older children. However, little evidence is available in the very young. METHODS/DESIGN: An open-label RCT where eligible children (age 3 months to 2 years with epilepsy who have failed two antiepileptic drugs (AEDs)) undergo baseline assessment, including medical and seizure history. Participants then start an observation period (7 or 14 days) with documentation of seizure frequency. Randomisation will occur on day 8 or day 15 to receive the KD or a further AED; the allocated treatment will commence on day 15, with instruction and training. A second assessment (4 weeks after start of treatment) will include a clinical review and tolerability questionnaire (modified Hague Scale of Side Effects - for those allocated to the KD group). Assessments will be repeated at 8 weeks after the start of treatment including biochemical investigations, after which, according to patient response, KD (diet group) or AED (standard AED group) will then be continued or changed. Those in the AED group who have failed to achieve seizure control at the 8-week assessment will then be offered KD outside the context of the trial. Those in the KD arm who fail to achieve seizure control will be changed to standard clinical management. All patients will be followed up for 12 months from randomisation for retention, seizure outcome, quality of life and neurodevelopmental status. DISCUSSION: The slow rate of recruitment is an ongoing practical issue. There is a limitation to the number of eligible patients compared to what was predicted, mainly due to the nature of this patient group. After a substantial amendment to widen inclusion criteria and reduce the baseline period to 7 days for patients with a high seizure burden, the rate of recruitment steadily increased. A number of operational concerns regarding dietetic time were also highlighted impacting on the recruitment rate. However, the combination of a low dropout rate and the opening of further centres, the trial should successfully meet the final recruitment target. All nine centres are now recruiting and we hope to open further centres within the UK. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02205931 . Registered on 16 December 2013.

Management of children and young people with headache.

Headache is very common in children and young people. The correct advice and treatment requires consideration of a wide differential diagnosis between primary and secondary headaches, and also of the different types of primary headache. The International Classification of Headache Disorders gives useful descriptions and diagnostic criteria that are especially useful for primary headaches. The National Institute for Health and Care Excellence (NICE) Clinical Guideline 150 provides evidence-based recommendations on treatments for adults and young people from age 12 years. However, the same principles can be applied to younger children when a specific diagnosis can be made. Key recommendations from the NICE Quality Standards include, establishing a precise diagnosis if possible, avoiding, diagnosing and treating medication overuse headache, and combining a triptan with a non-steroidal anti-inflammatory drug or paracetamol as the first-line acute/rescue treatment for migraine with or without aura. Although rare in children and young people, it is important to diagnose new daily persistent headache, as it responds poorly or not at all to medication; and paroxysmal hemicrania as it responds very well to indomethacin but not to other commonly used analgesics. When faced with difficulties in reaching a precise diagnosis or in finding effective therapies, further advice should be sought from a children's headache clinic or specialist.

Recessive ITPA mutations cause an early infantile encephalopathy.

OBJECTIVE: To identify the etiology of a novel, heritable encephalopathy in a small group of patients. METHODS: Magnetic resonance imaging (MRI) pattern analysis was used to select patients with the same pattern. Homozygosity mapping and whole exome sequencing (WES) were performed to find the causal gene mutations. RESULTS: Seven patients from 4 families (2 consanguineous) were identified with a similar MRI pattern characterized by T2 signal abnormalities and diffusion restriction in the posterior limb of the internal capsule, often also optic radiation, brainstem tracts, and cerebellar white matter, in combination with delayed myelination and progressive brain atrophy. Patients presented with early infantile onset encephalopathy characterized by progressive microcephaly, seizures, variable cardiac defects, and early death. Metabolic testing was unrevealing. Single nucleotide polymorphism array revealed 1 overlapping homozygous region on chromosome 20 in the consanguineous families. In all patients, WES subsequently revealed recessive predicted loss of function mutations in ITPA, encoding inosine triphosphate pyrophosphatase (ITPase). ITPase activity in patients' erythrocytes and fibroblasts was severely reduced. INTERPRETATION: Until now ITPA variants have only been associated with adverse reactions to specific drugs. This is the first report associating ITPA mutations with a human disorder. ITPase is important in purine metabolism because it removes noncanonical nucleotides from the cellular nucleotide pool. Toxicity of accumulated noncanonical nucleotides, leading to neuronal apoptosis and interference with proteins normally using adenosine triphosphate/guanosine triphosphate, probably explains the disease. This study confirms that combining MRI pattern recognition to define small, homogeneous patient groups with WES is a powerful approach for providing a fast diagnosis in patients with an unclassified genetic encephalopathy.

N-methyl-D-aspartate receptor antibody-mediated neurological disease: results of a UK-based surveillance study in children.

OBJECTIVE: N-methyl-D-aspartate receptor antibody (NMDAR-Ab) encephalitis is a well-recognised clinico-immunological syndrome that presents with neuropsychiatric symptoms cognitive decline, movement disorder and seizures. This study reports the clinical features, management and neurological outcomes of paediatric NMDAR-Ab-mediated neurological disease in the UK. DESIGN: A prospective surveillance study. Children with NMDAR-Ab-mediated neurological diseases were voluntarily reported to the British Neurological Surveillance Unit (BPNSU) from November 2010 to December 2011. Initial and follow-up questionnaires were sent out to physicians. RESULTS: Thirty-one children fulfilled the criteria for the study. Eight presented during the study period giving an incidence of 0.85 per million children per year (95% CI 0.64 to 1.06); 23 cases were historical. Behavioural change and neuropsychiatric features were present in 90% of patients, and seizures and movement disorders both in 67%. Typical NMDAR-Ab encephalitis was reported in 24 children and partial phenotype without encephalopathy in seven, including predominantly psychiatric (four) and movement disorder (three). All patients received steroids, 22 (71%) received intravenous immunoglobulin, 9 (29%) received plasma exchange,and 10 (32%) received second-line immunotherapy. Of the 23 patients who were diagnosed early, 18 (78%) made a full recovery compared with only 1 of 8 (13%) of the late diagnosed patients (p=0.002, Fisher's exact test). Seven patients relapsed, with four needing additional second-line immunotherapy. CONCLUSIONS: Paediatric NMDAR-Ab-mediated neurological disease appears to be similar to adult NMDAR-Ab encephalitis, but some presented with a partial phenotype. Early treatment was associated with a quick and often full recovery.

CLN6 disease caused by the same mutation originating in Pakistan has varying pathology.

The neuronal ceroid lipofuscinoses (NCLs), the most common neurodegenerative diseases in children, are characterised by storage of autofluorescent material that has a characteristic ultrastructure. We report two families with variant late infantile NCL, both originating from Pakistan. Probands from both families were homozygous for the same mutation (c.316dupC) but had variable pathology to that currently thought to be typical for CLN6 disease, late infantile variant. The observed pathology of one proband resembled condensed fingerprints, previously described in late infantile CLN7 and CLN8 diseases, and pathology from the second proband was thought to be absent even after repeated skin biopsy, but observed after review. This mutation is the most common NCL mutation in families originating from Pakistan and could be prioritised for testing. Finally, this report contains the first prenatal diagnosis for late infantile CLN6 disease, initially made on the basis of EM and now confirmed by mutation analysis.

Striking intrafamilial phenotypic variability in Aicardi-Goutières syndrome associated with the recurrent Asian founder mutation in RNASEH2C.

Aicardi-Goutières syndrome (AGS) is an encephalopathy of early childhood which is most commonly inherited as an autosomal recessive trait. The disorder demonstrates significant genetic heterogeneity with causative mutations in five genes identified to date. Although most patients with AGS experience a severe neonatal or infantile presentation, poor neurodevelopmental outcome and reduced survival, clinical variability in the onset and severity of the condition is being increasingly recognized. A later presentation with a more variable effect on development, morbidity and mortality has been particularly observed in association with mutations in SAMHD1 and RNASEH2B. In contrast, the recurrent c.205C > T (p.R69W) RNASEH2C Asian founder mutation has previously only been identified in children with a severe AGS phenotype. Here, to our knowledge, we present the first report of marked phenotypic variability in siblings both harboring this founder mutation in the homozygous state. In this family, one female child had a severe AGS phenotype with an onset in infancy and profound developmental delay, whilst an older sister was of completely normal intellect with a normal head circumference and was only diagnosed because of the presence of chilblains and a mild hemiplegia. An appreciation of intrafamilial phenotypic expression is important in the counseling of families considering prenatal diagnosis, and may also be relevant to the assessment of efficacy in future clinical trials. In addition, marked phenotypic variation raises the possibility that more mildly affected patients are not currently identified.

Paediatric autoimmune encephalopathies: clinical features, laboratory investigations and outcomes in patients with or without antibodies to known central nervous system autoantigens.

OBJECTIVE: To report the clinical and investigative features of children with a clinical diagnosis of probable autoimmune encephalopathy, both with and without antibodies to central nervous system antigens. METHOD: Patients with encephalopathy plus one or more of neuropsychiatric symptoms, seizures, movement disorder or cognitive dysfunction, were identified from 111 paediatric serum samples referred from five tertiary paediatric neurology centres to Oxford for antibody testing in 2007-2010. A blinded clinical review panel identified 48 patients with a diagnosis of probable autoimmune encephalitis whose features are described. All samples were tested/retested for antibodies to N-methyl-D-aspartate receptor (NMDAR), VGKC-complex, LGI1, CASPR2 and contactin-2, GlyR, D1R, D2R, AMPAR, GABA(B)R and glutamic acid decarboxylase. RESULTS: Seizures (83%), behavioural change (63%), confusion (50%), movement disorder (38%) and hallucinations (25%) were common. 52% required intensive care support for seizure control or profound encephalopathy. An acute infective organism (15%) or abnormal cerebrospinal fluid (32%), EEG (70%) or MRI (37%) abnormalities were found. One 14-year-old girl had an ovarian teratoma. Serum antibodies were detected in 21/48 (44%) patients: NMDAR 13/48 (27%), VGKC-complex 7/48(15%) and GlyR 1/48(2%). Antibody negative patients shared similar clinical features to those who had specific antibodies detected. 18/34 patients (52%) who received immunotherapy made a complete recovery compared to 4/14 (28%) who were not treated; reductions in modified Rankin Scale for children scores were more common following immunotherapies. Antibody status did not appear to influence the treatment effect. CONCLUSIONS: Our study outlines the common clinical and paraclinical features of children and adolescents with probable autoimmune encephalopathies. These patients, irrespective of positivity for the known antibody targets, appeared to benefit from immunotherapies and further antibody targets may be defined in the future.

Movement disorders associated with complex regional pain syndrome in children.

The aim of the present study was to review the history, clinical course, treatment, and outcome of movement disorders in children and young people with complex regional pain syndrome (CRPS). Case notes were reviewed retrospectively of children and young people who presented with movement disorders in CRPS to our tertiary paediatric pain service over a period of 13 years. Ten children with CRPS presented with movement disorders (eight females, two males). The age at first presentation with symptoms of CRPS ranged from 8 to 15 years (mean 11 y 2 mo, median 13 y). The most common movement disorder was dystonia (n=8), followed by tremors (n=3) and myoclonus (n=3); two patients had all three movement disorders. The movement disorder affected mainly the lower limb (n=9) with a predilection for the foot (n=7) and was frequently initiated by minor trauma (n=7). Follow-up ranged from 6 months to 14 years. The outcome was variable, with good prognosis in nearly half of the cases: four children experienced complete resolution of symptoms. Two children showed a slight improvement. Four children showed no improvement. Movement disorders in CRPS are under-recognized in children. The management has to be multidisciplinary with an expertise in paediatric pain.