The state of pediatric tuberous sclerosis complex epilepsy care: Results from a national survey.

OBJECTIVE: Epilepsy associated with tuberous sclerosis complex (TSC) can be challenging to treat and is associated with significant disease burden. Our objective was to better understand the state of epilepsy care of TSC amongst pediatric neurologists in Canada, identify gaps in care and determine whether access to a dedicated TSC clinic has an impact on epilepsy management. METHODS: A survey was developed after a literature review and discussion amongst two pediatric epileptologists and one nurse practitioner with expertise in TSC about the state of epilepsy care of TSC patients in Canada. Canadian pediatric neurologists were asked to participate in sharing their experiences via an anonymous web-based survey through the Canadian League Against Epilepsy (CLAE) and the Canadian Neurological Sciences Federation (CNSF). RESULTS: Fifty-seven responses were received. Access to a dedicated TSC clinic was reported by 25% (n = 14). Sixty percent (n = 34) reported performing serial EEG monitoring in infants with TSC and 57% (n = 33) started prophylactic antiseizure therapy when EEG abnormalities were detected, regardless of whether there was access to a TSC clinic (P = .06 and P = .29, respectively). While 52% (n = 29) did not feel comfortable prescribing mTORi for epilepsy, 65% (n = 36) indicated they would consider it with additional training. Epilepsy surgery was offered in 93% (n = 13) of centers with a dedicated TSC clinic but only 45% of centers without a TSC clinic (n = 19) (P = .002). SIGNIFICANCE: Our findings demonstrate the variability in neurological care of pediatric patients with TSC as it pertains to epilepsy management. There is a need for the establishment of epilepsy practice guidelines and a national network to support clinical practice, research, and education.

Epilepsy Management in Tuberous Sclerosis Complex: Existing and Evolving Therapies and Future Considerations.

Tuberous sclerosis complex (TSC) is a rare autosomal dominant condition that affects multiple body systems. Disruption of the mammalian target of rapamycin (mTOR) pathway results in abnormal cell growth, proliferation, protein synthesis, and cell differentiation and migration in TSC. In the central nervous system, mTOR disruption is also believed to influence neuronal excitability and promote epileptogenesis. Epilepsy is the most common neurological manifestation of TSC and affects 80% to 90% of individuals with high rates of treatment resistance (up to 75%). The onset of epilepsy in the majority of individuals with TSC occurs before the age of two years, which is a critical time in neurodevelopment. Both medically refractory epilepsy and early-onset epilepsy are associated with intellectual disability in TSC, while seizure control and remission are associated with lower rates of cognitive impairment. Our current knowledge of the treatment of epilepsy in TSC has expanded immensely over the last decade. Several new therapies such as preemptive vigabatrin therapy in infants, cannabidiol, and mTOR inhibitors have emerged in recent years for the treatment of epilepsy in TSC. This review will provide clinicians with a comprehensive overview of the pharmacological and nonpharmacological therapies available for the treatment of epilepsy related to TSC.

Ketonuria and Seizure Control in the Medium Chain Triglyceride and Classic Ketogenic Diets.

We hypothesized that children receiving medium-chain triglyceride ketogenic diet (MCTKD) experience similar seizure reduction despite lower ketosis compared with classic ketogenic diet (CKD). Children initiating CKD or MCTKD were enrolled in a prospective observational study. Forty-five children completed 6 months of KD (n = 17 MCTKD, n = 28 CKD). The proportion achieving ≥50% seizure reduction was 71% CKD group and 59% MCTKD group; ≥90% reduction was 32% and 36% in CKD and MCTKD groups, respectively. CKD had higher urine ketones (≥8 mmol/L: 79% vs. 36%, p = 0.005). Children receiving MCTKD experience similar seizure control to CKD despite lower urine ketone measures.

The Phenotypic Spectrum of Tuberous Sclerosis Complex: A Canadian Cohort.

OBJECTIVE: We aimed to further elucidate the phenotypic spectrum of Tuberous Sclerosis Complex (TSC) depending on genotype. METHODS: A retrospective review of patients seen in the TSC clinic at the Hospital for Sick Children was conducted and the frequency of TSC manifestations was compared based on genotype. RESULTS: Nineteen-patients had TSC1 mutations, 36 had TSC2 mutations and 11 had no mutation identified (NMI). Patients with TSC2 mutations had a higher frequency of early-onset epilepsy and more frequent systemic manifestations. The NMI group had milder neurologic and systemic manifestations. Our data did not demonstrate that intellectual disability and infantile spasms were more common in TSC2 mutations. CONCLUSIONS: This is the first Canadian pediatric cohort exploring the genotype-phenotype relationship in TSC. We report that some manifestations are more frequent and severe in TSC2 mutations and that NMI may have a milder phenotype. Disease surveillance and counseling should continue regardless of genotype until this is better elucidated.

Neutropenia in Children Treated With Ketogenic Diet Therapy.

OBJECTIVES: The objectives were to investigate the relationship between ketogenic diet therapy and neutropenia in children with epilepsy. METHODS: A retrospective chart review of children who initiated ketogenic diet at the Hospital for Sick Children between January 1, 2000, and May 1, 2018 was performed. Factors associated with the development of neutropenia during ketogenic diet therapy were evaluated and the relationship between development of a significant or suspected infection and neutrophil count was analyzed. RESULTS: One hundred two children met inclusion criteria and were followed on the diet for up to 24 months. Thirteen of 102 (13%) children were neutropenic at diet initiation. In the remaining 89 children, 27 developed neutropenia. Developing neutropenia was significantly associated with the ketogenic diet at 6 (13%), 12 (23%), and 24 (25%) months follow-up. Developing neutropenia was associated with higher urinary ketones (OR = 4.26, 95% CI: 1.27, 14.15) and longer duration of ketogenic diet therapy (OR = 3.29, 95% CI: 1.42, 7.96). There was no significant association between development of a clinically significant infection and neutropenia. CONCLUSION: Ketogenic diet therapy is associated with neutropenia in children with epilepsy, however, it does not have a significant clinical impact. Concern regarding neutropenia should not discourage the use of the ketogenic diet in children.

The effect of mTOR inhibition on obstructive hydrocephalus in patients with tuberous sclerosis complex (TSC) related subependymal giant cell astrocytoma (SEGA).

PURPOSE: Mammalian target of rapamycin inhibitors (mTORi) are known to effectively reduce the size of subependymal giant cell astrocytomas (SEGAs), which are benign brain lesions associated with Tuberous Sclerosis Complex (TSC) that commonly cause obstructive hydrocephalus (OH). This retrospective case series reviews an institutional experience of the effect of mTORi on OH in patients with TSC-related SEGA. METHODS: Thirteen of 16 identified patients with TSC-related SEGA treated with mTORi from October 2007 to December 2018 were included. Serial magnetic resonance imaging (MRI) and clinical charts were reviewed to correlate symptoms and signs of increased intracranial pressure (iICP) with ventriculomegaly on MRI. A proposed ventriculomegaly scale was used: none (< 7 mm), mild (7-10 mm), moderate (11-30 mm), and severe (> 30 mm). OH was defined as moderate or severe ventriculomegaly, based on the largest measurement. RESULTS: Patients' median age at start of mTORi was 13 (6-17) years and five (38%) patients were female. Eight patients had OH at the time of mTORi initiation, five of whom were asymptomatic. Six patients had improvement of hydrocephalus on serial MRI imaging with mTORi therapy, while seven patients had no change based on the ventriculomegaly scale used. All three patients who presented with symptoms of iICP and had OH also had papilledema. None had worsening of hydrocephalus or required shunt placement. Out of five patients with symptoms of iICP, four avoided surgery. CONCLUSION: Most patients had asymptomatic OH at the time of diagnosis, and ventricular enlargement was not correlated with iICP symptoms. mTORi was successful for treatment of OH from TSC-related SEGA, even in the setting of acute symptoms of iICP.

KCNT1-related epilepsy: An international multicenter cohort of 27 pediatric cases.

OBJECTIVE: Through international collaboration, we evaluated the phenotypic aspects of a multiethnic cohort of KCNT1-related epilepsy and explored genotype-phenotype correlations associated with frequently encountered variants. METHODS: A cross-sectional analysis of children harboring pathogenic or likely pathogenic KCNT1 variants was completed. Children with one of the two more common recurrent KCNT1 variants were compared with the rest of the cohort for the presence of particular characteristics. RESULTS: Twenty-seven children (15 males, mean age = 40.8 months) were included. Seizure onset ranged from 1 day to 6 months, and half (48.1%) exhibited developmental plateauing upon onset. Two-thirds had epilepsy of infancy with migrating focal seizures (EIMFS), and focal tonic seizures were common (48.1%). The most frequent recurrent KCNT1 variants were c.2800G>A; p.Ala934Thr (n = 5) and c.862G>A; p.Gly288Ser (n = 4). De novo variants were found in 96% of tested parents (23/24). Sixty percent had abnormal magnetic resonance imaging (MRI) findings. Delayed myelination, thin corpus callosum, and brain atrophy were the most common. One child had gray-white matter interface indistinctness, suggesting a malformation of cortical development. Several antiepileptic drugs (mean = 7.4/patient) were tried, with no consistent response to any one agent. Eleven tried quinidine; 45% had marked (>50% seizure reduction) or some improvement (25%-50% seizure reduction). Seven used cannabidiol; 71% experienced marked or some improvement. Fourteen tried diet therapies; 57% had marked or some improvement. When comparing the recurrent variants to the rest of the cohort with respect to developmental trajectory, presence of EIMFS, >500 seizures/mo, abnormal MRI, and treatment response, there were no statistically significant differences. Four patients died (15%), none of sudden unexpected death in epilepsy. SIGNIFICANCE: Our cohort reinforces common aspects of this highly pleiotropic entity. EIMFS manifesting with refractory tonic seizures was the most common. Cannabidiol, diet therapy, and quinidine seem to offer the best chances of seizure reduction, although evidence-based practice is still unavailable.

A Review of Investigations for Patients With Tuberous Sclerosis Complex Who Were Referred to the Tuberous Sclerosis Clinic at The Hospital for Sick Children: Identifying Gaps in Surveillance.

OBJECTIVE: As a newly established tuberous sclerosis clinic (TSC) clinic at The Hospital for Sick Children, we reviewed our referrals to determine if children with TSC received appropriate surveillance as advised by the 2012 International Tuberous Sclerosis Complex Consensus Recommendations. METHODS: We completed a retrospective review of all patients seen in the TSC clinic from January 2016 to December 2017 to determine if children referred to the clinic had appropriate surveillance as suggested by the Tuberous Sclerosis Complex Consensus Recommendations. RESULTS: Ninety patients were seen in the TSC clinic. The median age at first visit was 9.9 years, and 47 were males. Seventy-six percent had undergone genetic testing before the initial clinic visit; however, genetic counseling was completed in only 66%. Brain magnetic resonance imaging was completed in 94%, abdominal imaging was completed in 91%, and an echocardiography and electrocardiography in 88% and 83%, respectively. In addition, dermatology and ophthalmology evaluations were completed in 78% and 91%, respectively. Assessment of TSC-associated neuropsychiatric disorders (TAND) was only completed in 4% of the patients. CONCLUSIONS: Systems surveillance was completed in the majority before the first TSC clinic visit. However, TSC-associated neuropsychiatric disorder screening was completed in few cases. This suggests that referring physicians may not be familiar with the neuropsychiatric manifestations of TSC and that there may be underdiagnosed or undertreated illness. Future emphasis should be placed on educating all practitioners to assess and treat tuberous sclerosis complex-associated neuropsychiatric disorder in tuberous sclerosis complex.

Position Statement on the Use of Medical Cannabis for the Treatment of Epilepsy in Canada.

In Canada, recreational use of cannabis was legalized in October 2018. This policy change along with recent publications evaluating the efficacy of cannabis for the medical treatment of epilepsy and media awareness about its use have increased the public interest about this agent. The Canadian League Against Epilepsy Medical Therapeutics Committee, along with a multidisciplinary group of experts and Canadian Epilepsy Alliance representatives, has developed a position statement about the use of medical cannabis for epilepsy. This article addresses the current Canadian legal framework, recent publications about its efficacy and safety profile, and our understanding of the clinical issues that should be considered when contemplating cannabis use for medical purposes.

Énoncé de position quant à l'utilisation du cannabis médical dans le traitement de l'épilepsie. L'utilisation du cannabis à des fins récréatives a été légalisée au Canada en octobre 2018. Parallèlement à ce changement de politique, de récentes publication visant à évaluer l'efficacité du cannabis dans le traitement de l'épilepsie, de même qu'une sensibilisation médiatique accrue en ce qui concerne son utilisation, ont eu pour effet d'augmenter l'intérêt du grand public à son égard. Le Comité médical thérapeutique de la Ligue canadienne contre l'épilepsie (LCCE), de concert avec un groupe multidisciplinaire d'experts et des représentants de l'Alliance canadienne de l'épilepsie, a ainsi élaboré un énoncé de position en ce qui regarde l'utilisation du cannabis médical dans le traitement de l'épilepsie. Cet article entend donc aborder le cadre légal qui prévaut actuellement au Canada et examiner de récentes publications s'étant penchées sur le profil sécuritaire et sur l'efficacité du cannabis. De plus, nous voulons apporter un éclairage au sujet des aspects cliniques dont il faudrait tenir compte au moment d'envisager l'utilisation du cannabis à des fins médicales.

STXBP1 encephalopathy is associated with awake bruxism.

Heterozygous mutations in syntaxin-binding protein 1 (STXBP1) gene are associated with early infantile epileptic encephalopathy 4 (EIEE4). This condition is characterized by epilepsy, developmental delay (DD), and various movement disorders. Herein, we will report 5 unrelated patients with different de novo mutations in STXBP1. In addition, we conducted an online survey through Facebook to identify the incidence of bruxism (BRX) in these patients. Four out of 5 patients (80%) presented with awake BRX (A-BRX). Bruxism was also reported in 81.4% (57/70) of the patients with STXBP1 encephalopathy through the online questionnaire. No consistent correlation was identified between the type of mutation and development of movement disorders or BRX. This is the first study to demonstrate A-BRX in patients with STXBP1 mutation. Given the role of STXBP1 in exocytosis of neurotransmitters and other manifestations of dopamine dysregulation in patients with STXBP1-EIEE4, we suggest that in patients with STXBP1 encephalopathy, A-BRX might be the result of the involvement of dopaminergic circuits.

A prospective open-label trial of a CBD/THC cannabis oil in dravet syndrome.

INTRODUCTION: Both Δ9 Tetrahydrocannabidiol (THC) and cannabidiol (CBD) components of cannabis, have been shown to have anticonvulsant effects. Cannabis oils are used to treat seizures in drug-resistant epilepsy (DRE). Recent trials provide data on dosing, side effects, and efficacy of CBD, yet there is a paucity of information on THC in epilepsy. Primary objective was to establish dosing and tolerability of TIL-TC150 - a cannabis plant extract produced by Tilray®, containing 100 mg/mL CBD and 2 mg/mL THC- in children with Dravet syndrome. Secondary objectives were to assess impact of therapy on seizures, electroencephalogram (EEG) and quality of life. METHODS: Twenty children received add-on therapy with TIL-TC150. The dose ranged from 2 to 16 mg/kg/day of CBD and 0.04 to 0.32 mg/kg/day of THC. Patients were monitored for tolerability and adverse events, and secondary objectives. RESULTS: Nineteen participants completed the 20-week intervention. Mean dose achieved was 13.3 mg/kg/day of CBD (range 7-16 mg/kg/day) and 0.27 mg/kg/day of THC (range 0.14-0.32 mg/kg/day). Adverse events, common during titration included somnolence, anorexia, and diarrhea. Abnormalities of liver transaminases and platelets were observed with concomitant valproic acid therapy. There was a statistically significant improvement in quality of life, reduction in EEG spike activity, and median motor seizure reduction of 70.6%, with 50% responder rate of 63%. CONCLUSIONS: TIL-TC150 was safe and well tolerated in our subjects. TIL-TC150 treatment resulted in a reduction in seizure counts, spike index on EEG, and improved quality of life measures. This study provides safety and dosing information for THC-containing cannabinoid preparations.

Prevalence of Genetic Disorders and GLUT1 Deficiency in a Ketogenic Diet Clinic.

Between July of 2012 and December of 2014, 39 patients were enrolled prospectively to investigate the prevalence of glucose transporter 1 (GLUT1) deficiency in a ketogenic diet clinic. None of them had GLUT1 deficiency. All patients seen in the same clinic within the same period were reviewed retrospectively. A total of 18 of these 85 patients had a genetic diagnosis, including GLUT1 deficiency, pathogenic copy number variants, congenital disorder of glycosylation, neuronal ceroid lipofuscinosis type II, mitochondrial disorders, tuberous sclerosis, lissencephaly, and SCN1A-, SCN8A-, and STXBP1-associated epileptic encephalopathies. The prevalence of genetic diagnoses was 21% and prevalence of GLUT1 deficiency was 2.4% in our retrospective cohort study.

The Utility of Surveillance Electroencephalography to Guide Early Antiepileptic Drug Therapy in Infants With Tuberous Sclerosis Complex.

BACKGROUND: Seizures are a common early presentation in infants with tuberous sclerosis complex (TSC) and can be preceded by electrographic changes on electroencephalography (EEG) before clinical seizure onset. A limited number of studies have addressed the initial EEG findings in TSC and the outcome of early treatment with antiepileptic medication prior to clinical seizure onset. METHODS: We describe two infants with tuberous sclerosis complex whose surveillance EEG showed focal seizures that were not previously recognized by caregivers. We review previously reported patients with TSC with early EEG findings. Our patients were started on vigabatrin after the onset of focal seizures with the aim of preventing seizure recurrence, halting the possible progression to infantile spasms or focal seizures, and preventing neurodevelopmental decline. RESULTS: Both patients remain seizure free and have reached appropriate developmental milestones. CONCLUSIONS: We recommend early serial EEG monitoring once a diagnosis of TSC is suspected or confirmed in infants. Additional prospective studies are needed to assess the long-term outcome of early antiepileptic drug initiation as soon as electrographic seizure activity is detected.

Co-occurrence of 16p13.11 microdeletion and ring chromosome 20 syndrome.

A previously healthy 16-year-old girl of Jamaican descent presented with a 1-year history of progressive daytime somnolence, sleep attacks (sudden irresistible episodes of sleep), and paroxysms of altered level of consciousness. Her parents also reported irritability, mood lability, and hyperphagia. Her history was notable for a mild learning disability diagnosed at 9 years of age. Before symptom onset, she attended regular class at school with average academic performance and was independent in instrumental activities of daily living. On examination, she was normocephalic and nondysmorphic and had no focal neurologic deficits.

Validation of actigraphy with continuous video-electroencephalography in children with epilepsy.

BACKGROUND: The relationship between epilepsy and sleep is bidirectional as seizures disrupt sleep and coexisting sleep disorders have detrimental effects on seizure control and quality of life for both the children and their families. Previous research has reported on sleep disturbance in children with epilepsy primarily by subjective parental reports. Actigraphy may provide a more accurate objective evaluation of sleep, but the validity of this sleep measure for children with epilepsy has not yet been assessed. The primary objective of this study was to validate the use of actigraphy as a tool in studying sleep patterns in children with epilepsy. METHODS: This was a prospective study comparing sleep and wake epochs recorded for 24 h simultaneously by actigraphy and by continuous video-electroencephalography (VEEG) monitoring in 27 patients aged 2-18 years with medically refractory epilepsy. RESULTS: Strong correlations were found between actigraphy and VEEG sleep variables including night sleep period (r = 0.99), night sleep time (r = 0.96), duration of night wake time (r = 0.93) and number of significant wakings during the night (r = 0.81). CONCLUSION: The study results validate that actigraphy is a reliable and objective clinical and research tool for evaluating sleep and wakefulness in children with epilepsy.

Can children with hyperlipidemia receive ketogenic diet for medication-resistant epilepsy?

The very-high-fat ketogenic diet can worsen lipid levels in children with pre-existing hyperlipidemia by increasing serum lipoproteins and reducing antiatherogenic high-density lipoproteins. A retrospective chart review of 160 children treated with the ketogenic diet from September 2000 to May 2011 was performed. Twelve children with pre-existing hyperlipidemia were identified. Lipid levels including total cholesterol, low-density lipoprotein, triglycerides, high-density lipoprotein, and total cholesterol/high-density lipoprotein were measured pre-diet and at 3, 6, and 12 months of treatment. During treatment, there was a significant reduction in mean total cholesterol, low-density lipoprotein, and total cholesterol/high-density lipoprotein. Total cholesterol and low-density lipoprotein were normalized in 8 and 7 children at 6 months; and 9 and 9 children at 12 months respectively. At 6 and 12 months, tot cholesterol/HDL ratio was normalized in 5 and 7 children respectively. Diet modifications were made to achieve healthy lipid levels. By extrapolating the data, it suggests lipid levels can be controlled in children and adults with ketogenic diet treatment.