Effect of neonatal seizure burden and etiology on the long-term outcome: data from a randomized, controlled trial.

Background: Neonatal seizures are common, but the impact of neonatal seizures on long-term neurologic outcome remains unclear. We addressed this question by analyzing data from an early-phase controlled trial of bumetanide to treat neonatal seizures. Methods: Neonatal seizure burden was calculated from continuous video-EEG data. Neurologic outcome was determined by standardized developmental tests and post-neonatal seizure recurrence. Results: Of 111 enrolled neonates, 43 were randomized to treatment or control groups. There were no differences in neurologic outcome between treatment and control groups. A subgroup analysis was performed for 84 neonates with acute perinatal brain injury (57 HIE, 18 stroke, 9 ICH), most of whom (70%) had neonatal seizures. There was a significant negative correlation between seizure burden and developmental scores (p<0.01). Associations between seizure burden and developmental scores were stronger in HIE and stroke groups compared with ICH (p<0.05). Conclusion: Bumetanide showed no long-term beneficial or adverse effects, as expected based on treatment duration versus duration of neonatal seizures. For neonates with perinatal brain injury, higher neonatal seizure burden correlated significantly with worse developmental outcome, particularly for ischemic versus hemorrhagic brain injury. These data highlight the need for further investigation of the long-term effects of both neonatal seizure severity and etiology.

Comparing the environmental impact of reusable and disposable dental examination kits: a life cycle assessment approach.

Introduction The global climate crisis has increased the emphasis placed on the sustainability and environmental consequences of our actions. The dental examination accounts for a large portion of dentistry's carbon footprint, more specifically, the production, sterilisation, transport, use and disposal of the dental examination kit. An attributional life cycle assessment (LCA) was carried out to compare the impact of a reusable stainless-steel examination kit and that of a disposable plastic examination kit.Materials and methods All inputs, outputs and processes across the life cycle were accounted for using Ecoinvent database v3.7.1 and openLCA software. Impacts were considered across 16 European-recommended environmental impact categories and eight human health impact categories.Results The disposable kit performed worse across all categories of ecological and human health harm. Categories with most notable impact were climate change, metal-mineral and fossil fuel resource depletion and water scarcity. Impacts were primarily attributable to material processing, instrument production and sterilisation procedures.Conclusion Healthcare is responsible for a significant proportion of greenhouse gas emissions. The single-use examination kit poses greater ecological and human health threat than does the reusable examination kit; this aligns closely with related research in the field. The dentist seeking to adopt more environmentally-conscientious practices should consider using a reusable, stainless-steel examination kit.

Infantile spasms: Assessing the diagnostic yield of an institutional guideline and the impact of etiology on long-term treatment response.

OBJECTIVE: Neuroimaging and genetic testing have been proposed for diagnostic evaluation of infantile spasms (IS), establishing etiology in ~60% of multicenter IS cohorts. A retrospective analysis of the yield of diagnostic etiology following an institutionally established guideline for investigation/treatment of IS was conducted, and the association between etiological subgroups and sustained response to standard treatment was evaluated. METHODS: Etiology of IS, neuroimaging, and genetic results were extracted from clinical records. Etiology was categorized as acquired or nonacquired, the latter including syndromic patients, nonsyndromic patients with confirmed etiology, and unknown cases. Regression analyses, using clinical variables including subtypes of etiology, were conducted to determine which factors correlated with favorable (spasm freedom at last follow-up after two or fewer standard treatments) versus unfavorable treatment outcome (refractory spasms despite two standard treatments or relapse). RESULTS: We included 127 IS patients (60% males) with a follow-up of 2.4 years (range = .6-5 years). All patients had neuroimaging, and 95% of patients in the nonacquired category (103 of 108 patients) had genetic testing. Etiology was identified in 103 of 127 (81%, 95% confidence interval = .73-.86). At last follow-up, 42 (33%) patients had favorable treatment outcome. No difference in treatment response was observed between acquired and nonacquired etiologies. Among patients with nonacquired etiologies, developmental delay prior to spasms onset increased the odds of unfavorable treatment outcome (p = .014), whereas a clearly recognizable dysmorphic/syndromic etiology was associated with a lower risk for treatment failure (p = .034). In nonacquired etiology without a recognizable dysmorphic/syndrome but with a genetic etiology, unfavorable treatment outcome was more likely (p = .043). SIGNIFICANCE: Rigorous evaluation with neuroimaging and genetic testing yields an etiological diagnosis in most patients with IS. Among patients with a nonacquired etiology, those with recognizable dysmorphic/syndromic diagnosis had a higher likelihood of a favorable treatment outcome, whereas the absence of such a finding, when associated with an identifiable genetic diagnosis, was associated with unfavorable treatment outcomes.

Keto-Sleuths - An Unusual Cause of Loss of Ketosis?

Ketogenic diets provide a non-pharmaceutical alternative for treatment of refractory epilepsy. When successful in reducing or eliminating seizures, medication numbers or doses may be reduced. Unexpected loss of ketosis is a common problem in management of patients on ketogenic diets and, especially when the diet is an effective treatment, loss of ketosis may be associated with an exacerbation in seizures. Identification of the cause of loss of ketosis is critical to allow rapid resumption of seizure control, and prevention of unnecessarily increased diet restriction or increased medication doses. Here an unusual environmental cause of loss of ketosis is described (contamination with starch-containing drywall dust), illustrating the extent of investigation sometimes necessary to understand the clinical scenario.

Hippocampal Involvement With Vigabatrin-Related MRI Signal Abnormalities in Patients With Infantile Spasms: A Novel Finding.

BACKGROUND: In a subset of infants exhibiting typical vigabatrin-related magnetic resonance imaging (MRI) changes, the authors observed additional hippocampal signal abnormalities. The authors investigated occurrence and significance of additional signal abnormalities. METHODS: A retrospective review of infantile spasms patients with typical vigabatrin-related MRI abnormalities was performed. Atypical features included signal changes unilaterally or at previously unreported sites. Comparisons were made between patients with and without atypical features. RESULTS: In all, 26/55 (47%) exhibited typical vigabatrin-related MRI changes, with additional signal abnormalities in the hippocampi in 6 of 26. On follow-up, evolution of hippocampal signal changes paralleled changes at typical locations in 4 patients. Two patients, clinically well, without follow-up MRI. Patients with and without additional hippocampal signal changes did not differ with respect to clinical factors, including seizure status. One patient had unilateral thalamic/cerebral peduncle signal abnormality along with typical vigabatrin changes. CONCLUSIONS: Hippocampal changes seen in subset of patients with typical vigabatrin-related changes may be attributable to vigabatrin exposure in the appropriate circumstance.

Cost-effectiveness of adrenocorticotropic hormone versus oral steroids for infantile spasms.

OBJECTIVE: To compare the effectiveness and cost-effectiveness of adrenocorticotropic hormone (ACTH) and oral steroids as first-line treatment for infantile spasm resolution, we performed a systematic review, meta-analysis, and cost-effectiveness study. METHODS: A decision analysis model was populated with effectiveness data from a systematic review and meta-analysis of existing literature and cost data from publicly available prices. Effectiveness was defined as the probability of clinical spasm resolution 14 days after treatment initiation. RESULTS: We included 21 studies with a total of 968 patients. The effectiveness of ACTH was not statistically significantly different from that of oral steroids (.70, 95% confidence interval [CI] = .60-.79 vs. .63, 95% CI = .56-.70; p = .28). Considering only the three available randomized trials with a total of 185 patients, the odds ratio of spasm resolution at 14 days with ACTH compared to high-dose prednisolone (4-8 mg/kg/day) was .92 (95% CI = .34-2.52, p = .87). Adjusting for potential publication bias, estimates became even more favorable to high-dose prednisolone. Using US prices, the more cost-effective treatment was high-dose prednisolone, with an incremental cost-effectiveness ratio (ICER) of $333 per case of spasms resolved, followed by ACTH, with an ICER of $1 432 200 per case of spasms resolved. These results were robust to multiple sensitivity analyses and different assumptions. Prednisolone at 4-8 mg/kg/day was more cost-effective than ACTH under a wide range of assumptions. SIGNIFICANCE: For infantile spasm resolution 2 weeks after treatment initiation, current evidence does not support the preeminence of ACTH in terms of effectiveness and, especially, cost-effectiveness.

A Pilot Randomized, Controlled, Double-Blind Trial of Bumetanide to Treat Neonatal Seizures.

OBJECTIVE: In the absence of controlled trials, treatment of neonatal seizures has changed minimally despite poor drug efficacy. We tested bumetanide added to phenobarbital to treat neonatal seizures in the first trial to include a standard-therapy control group. METHODS: A randomized, double-blind, dose-escalation design was employed. Neonates with postmenstrual age 33 to 44 weeks at risk of or with seizures were eligible. Subjects with electroencephalography (EEG)-confirmed seizures after ≥20 and <40mg/kg phenobarbital were randomized to receive additional phenobarbital with either placebo (control) or 0.1, 0.2, or 0.3mg/kg bumetanide (treatment). Continuous EEG monitoring data from ≥2 hours before to ≥48 hours after study drug administration (SDA) were analyzed for seizures. RESULTS: Subjects were randomized to treatment (n = 27) and control (n = 16) groups. Pharmacokinetics were highly variable among subjects and altered by hypothermia. The only statistically significant adverse event was diuresis in treated subjects (48% vs 13%, p = 0.02). One treated (4%) and 3 control subjects died (19%, p = 0.14). Among survivors, 2 of 26 treated subjects (8%) and 0 of 13 control subjects had hearing impairment, as did 1 nonrandomized subject. Total seizure burden varied widely, with much higher seizure burden in treatment versus control groups (median = 3.1 vs 1.2 min/h, p = 0.006). There was significantly greater reduction in seizure burden 0 to 4 hours and 2 to 4 hours post-SDA (both p < 0.01) compared with 2-hour baseline in treatment versus control groups with adjustment for seizure burden. INTERPRETATION: Although definitive proof of efficacy awaits an appropriately powered phase 3 trial, this randomized, controlled, multicenter trial demonstrated an additional reduction in seizure burden attributable to bumetanide over phenobarbital without increased serious adverse effects. Future trials of bumetanide and other drugs should include a control group and balance seizure severity. ANN NEUROL 2021;89:327-340.

Pediatric and adult neurologist perspectives on the challenges of sustaining a transfer clinic.

We present a novel epilepsy fellow-driven transfer clinic model and discuss the challenges experienced in finding sustainability; this is timely as many pioneering transition clinics are dissolving across North America. The goal of this clinic was to improve patient care and satisfaction, as measured by a post-visit telephone survey. Unfortunately, our transfer clinic model proved unsustainable due to several factors, broadly categorized as (1) cultural-societal differences between the pediatric and adult health care environments, (2) staffing issues, (3) lack of an established standardized process for transfer of care, and (4) financial and administrative barriers. We suggest potential solutions to these challenges, but the fate of transition and transfer of care clinics may ultimately depend on implementation of practice, policy, and/or financial guidelines.

Ketogenic diet in Zambia: Managing drug-resistant epilepsy in a low and middle income country.

Globally, drug-resistant epilepsy affects one third of people living with epilepsy. With limitations in treatment options for refractory epilepsy in resource-limited regions, ketogenic diet therapy is an important option to consider. Utilizing the 2015 International League Against Epilepsy recommended minimum requirements for ketogenic diet therapy, three male children with refractory epilepsy, aged 2.5, 6.5 and 10 years, were initiated on the classical ketogenic diet using locally available food in August 2017 at University Teaching Hospitals-Children's Hospital in Lusaka, Zambia, through partnership with the Epilepsy Program at Boston Children's Hospital in the United States. Following successful initiation in all three children, the diet was discontinued in the 10-year-old due to difficulties complying with the diet. The youngest child demonstrated an over 50% seizure reduction and gained developmental milestones. The third child achieved seizure freedom and showed marked improvement in behaviour. This pilot demonstrates the feasibility of ketogenic diet as an important therapeutic option for refractory epilepsy in Zambia. Given the limitations in treatment choices and medication accessibility, dietary therapy offers an alternative management strategy in our setting. Collaboration with an established ketogenic diet centre contributes to a successful program.

Mortality in infantile spasms: A hospital-based study.

OBJECTIVE: To determine risk factors and causes for mortality during childhood in patients with infantile spasms (IS). We describe the overall goals of care for those who died. METHODS: This is a retrospective chart review of IS patients born between 2000 and 2011. We examined potential risk factors for mortality, including etiology, neurologic impairment, medication use, persistence of epileptic spasms, and comorbid systemic involvement (requirement for G-tube feedings, respiratory interventions). For patients who died, we describe cause of death and resuscitation status or end-of-life care measures. RESULTS: We identified 150 IS patients with median follow-up of 12 years. During the study period, 25 (17%) patients died, 13 before 5 years of age. Univariate analysis demonstrated that developmental delay, identifiable etiology, hormonal use for IS, persistence of epileptic spasms, polypharmacy with antiseizure medications, refractory epilepsy, respiratory system comorbidity, and the need for a G-tube were significant risk factors for mortality. In a multivariate analysis, mortality was predicted by persistence of epileptic spasms (odds ratio [OR] = 4.30, 95% confidence interval [CI] = 1.11-16.67, P = .035) and significant respiratory system comorbidity (OR = 12.75, 95% CI = 2.88-56.32, P = .001). Mortality was epilepsy-related in one-third of patients who died with sudden unexpected death in epilepsy (SUDEP), accounting for 88% of epilepsy-related deaths. Most deaths before age 5 years were related to respiratory failure, and SUDEP was less common (17%) whereas SUDEP was more common (45%) with deaths after 5 years. For the majority (67%) of patients with early mortality, an end-of-life care plan was in place (based on documentation of resuscitation status, comfort measures, or decision not to escalate medical care). SIGNIFICANCE: Mortality at our single-center IS cohort was 17%, and persistence of epileptic spasms and comorbid respiratory system disorders were the most important determinants of mortality. Early deaths were related to neurological impairments/comorbidities. SUDEP was more common in children who died after 5 years of age than in those who died younger than 5 years.

A novel null mutation in the pyruvate dehydrogenase phosphatase catalytic subunit gene (PDP1) causing pyruvate dehydrogenase complex deficiency.

Congenital lactic acidosis due to pyruvate dehydrogenase phosphatase (PDP) deficiency is very rare. PDP regulates pyruvate dehydrogenase complex (PDC) and defective PDP leads to PDC deficiency. We report a case with functional PDC deficiency with low activated (+dichloroacetate) and inactivated (+fluoride) PDC activities in lymphocytes and fibroblasts, normal activity of other mitochondrial enzymes in fibroblasts, and novel biallelic frameshift mutation in the PDP1 gene, c.575dupT (p.L192FfsX5), with absent PDP1 product in fibroblasts. Unexpectedly, the patient also had low branched-chain 2-ketoacid dehydrogenase (BCKDH) activity in fibroblasts with slight elevation of branched-chain amino acids in plasma and ketoacids in urine but with no pathogenic mutations in the enzymes of BCKDH, which could suggest shared regulatory function of PDC and BCKDH in fibroblasts, potentially in other tissues or cell types as well, but this remains to be determined. The clinical presentation of this patient overlaps that of other patients with primary-specific PDC deficiency, with neonatal/infantile and childhood lactic acidosis, normal lactate to pyruvate ratio, elevated plasma alanine, delayed psychomotor development, epileptic encephalopathy, feeding difficulties, and hypotonia. This patient exhibited marked improvement of overall development following initiation of ketogenic diet at 31 months of age. To the best of our knowledge, this is the fourth case of functional PDC deficiency with a defined mutation in PDP1. SYNOPSIS: Pyruvate dehydrogenase phosphatase (PDP) regulates pyruvate dehydrogenase complex (PDC) and defective PDP due to PDP1 mutations leads to PDC deficiency and congenital lactic acidosis.

The Evolution of Subclinical Seizures in Children With Tuberous Sclerosis Complex.

BACKGROUND: Subclinical seizures are electrographic seizures that present without subjective or objective clinical symptoms. In tuberous sclerosis complex, it is not known whether subclinical seizures occur alone, forewarn, or coexist with clinical seizures. To address this knowledge gap, we studied the prevalence and evolution of subclinical seizures in tuberous sclerosis complex. METHODS: We retrospectively reviewed electroencephalography (EEG) data from our tuberous sclerosis complex clinic with subclinical seizures and clinical seizures in a blinded fashion. Based on EEG location and ictal pattern, subclinical seizures were classified as having a clinical counterpart from the same epileptogenic region (match) or not (no match). RESULTS: Of 208 children with tuberous sclerosis complex, 138 had epilepsy and available EEG data. Subclinical seizures were detected in 26 of 138 (19%) children. Twenty-four children had both subclinical seizures and clinical seizures captured on EEG. In 13 of 24, subclinical seizures were detected as a novel, not previously recorded seizure type. In these children, subclinical seizures preceded matching clinical seizures in 4 (31%) within a median time of 4.5 months (range 2-14), whereas 9 (69%) never had any matching clinical seizure. In 11 of 24 children, subclinical seizures were not novel and could be matched to a previously recorded clinical seizure. Matching seizure types were focal (n = 10, 67%), tonic (n = 2), epileptic spasms (n = 2), and status epilepticus (n = 1). CONCLUSIONS: Subclinical seizures occur in one-fifth of children with tuberous sclerosis complex and epilepsy, and match with clinical seizures in a small majority. In a third of patients presenting with a novel subclinical seizure, matching clinical seizures follow.

Recurrent SLC1A2 variants cause epilepsy via a dominant negative mechanism.

SLC1A2 is a trimeric transporter essential for clearing glutamate from neuronal synapses. Recurrent de novo SLC1A2 missense variants cause a severe, early onset developmental and epileptic encephalopathy via an unclear mechanism. We demonstrate that all 3 variants implicated in this condition localize to the trimerization domain of SLC1A2, and that the Leu85Pro variant acts via a dominant negative mechanism to reduce, but not eliminate, wild-type SLC1A2 protein localization and function. Finally, we demonstrate that treatment of a 20-month-old SLC1A2-related epilepsy patient with the SLC1A2-modulating agent ceftriaxone did not result in a significant change in daily spasm count. ANN NEUROL 2019;85:921-926.

Cannabis for refractory epilepsy in children: A review focusing on CDKL5 Deficiency Disorder.

Severe paediatric epilepsies such as CDKL5 Deficiency Disorder (CDD) are extremely debilitating, largely due to the early-onset and refractory nature of the seizures. Existing treatment options are often ineffective and associated with a host of adverse effects, causing those that are affected to seek alternative treatments. Cannabis based products have attracted significant attention over recent years, primarily driven by reports of miraculous cures and a renewed public preference for 'natural' therapies, thus placing intense pressure on health professionals and the government for regulatory change. This study provides a comprehensive overview of the potential role for cannabis in the treatment of CDD. Key areas discussed include the history, mechanism of action, efficacy and safety of cannabis based preparations as well as the burden related to CDD. The evidence supports the use of cannabinoids, especially cannabidiol, in similar forms of refractory epilepsy including Dravet and Lennox-Gastaut syndromes. Evidence for cannabinoids specifically in CDD is limited but growing, with multiple anecdotal reports and an open-label trial showing cannabidiol to be associated with a significant reduction in seizure activity. This review provides the first comprehensive overview of the potential role for cannabis based preparations in the treatment of CDD and provides justification for further clinical and observational research.

Efficacy and safety of ketogenic diet for treatment of pediatric convulsive refractory status epilepticus.

PURPOSE: To describe the efficacy and safety of ketogenic diet (KD) for convulsive refractory status epilepticus (RSE). METHODS: RSE patients treated with KD at the 6/11 participating institutions of the pediatric Status Epilepticus Research Group from January-2011 to December-2016 were included. Patients receiving KD prior to the index RSE episode were excluded. RSE was defined as failure of ≥2 anti-seizure medications, including at least one non-benzodiazepine drug. Ketosis was defined as serum beta-hydroxybutyrate levels >20 mg/dl (1.9 mmol/l). Outcomes included proportion of patients with electrographic (EEG) seizure resolution within 7 days of starting KD, defined as absence of seizures and ≥50% suppression below 10 µV on longitudinal bipolar montage (suppression-burst ratio ≥50%); time to start KD after onset of RSE; time to achieve ketosis after starting KD; and the proportion of patients weaned off continuous infusions 2 weeks after KD initiation. Treatment-emergent adverse effects (TEAEs) were also recorded. RESULTS: Fourteen patients received KD for treatment of RSE (median age 4.7 years, interquartile range [IQR] 5.6). KD was started via enteral route in 11/14 (78.6%) patients. KD was initiated a median of 13 days (IQR 12.5) after the onset of RSE, at 4:1 ratio in 8/14 (57.1%) patients. Ketosis was achieved within a median of 2 days (IQR 2.0) after starting KD. EEG seizure resolution was achieved within 7 days of starting KD in 10/14 (71.4%) patients. Also, 11/14 (78.6%) patients were weaned off their continuous infusions within 2 weeks of starting KD. TEAEs, potentially attributable to KD, occurred in 3/14 (21.4%) patients, including gastro-intestinal paresis and hypertriglyceridemia. Three month outcomes were available for 12/14 (85.7%) patients, with 4 patients being seizure-free, and 3 others with decreased seizure frequency compared to pre-RSE baseline. CONCLUSIONS: This series suggests efficacy and safety of KD for treatment of pediatric RSE.

Somatic SLC35A2 variants in the brain are associated with intractable neocortical epilepsy.

OBJECTIVE: Somatic variants are a recognized cause of epilepsy-associated focal malformations of cortical development (MCD). We hypothesized that somatic variants may underlie a wider range of focal epilepsy, including nonlesional focal epilepsy (NLFE). Through genetic analysis of brain tissue, we evaluated the role of somatic variation in focal epilepsy with and without MCD. METHODS: We identified somatic variants through high-depth exome and ultra-high-depth candidate gene sequencing of DNA from epilepsy surgery specimens and leukocytes from 18 individuals with NLFE and 38 with focal MCD. RESULTS: We observed somatic variants in 5 cases in SLC35A2, a gene associated with glycosylation defects and rare X-linked epileptic encephalopathies. Nonsynonymous variants in SLC35A2 were detected in resected brain, and absent from leukocytes, in 3 of 18 individuals (17%) with NLFE, 1 female and 2 males, with variant allele frequencies (VAFs) in brain-derived DNA of 2 to 14%. Pathologic evaluation revealed focal cortical dysplasia type Ia (FCD1a) in 2 of the 3 NLFE cases. In the MCD cohort, nonsynonymous variants in SCL35A2 were detected in the brains of 2 males with intractable epilepsy, developmental delay, and magnetic resonance imaging suggesting FCD, with VAFs of 19 to 53%; Evidence for FCD was not observed in either brain tissue specimen. INTERPRETATION: We report somatic variants in SLC35A2 as an explanation for a substantial fraction of NLFE, a largely unexplained condition, as well as focal MCD, previously shown to result from somatic mutation but until now only in PI3K-AKT-mTOR pathway genes. Collectively, our findings suggest a larger role than previously recognized for glycosylation defects in the intractable epilepsies. Ann Neurol 2018.

Detailed Magnetic Resonance Imaging (MRI) Analysis in Infantile Spasms.

PURPOSE: To evaluate initial magnetic resonance imaging (MRI) abnormalities in infantile spasms, correlate them to clinical characteristics, and describe repeat imaging findings. METHODS: A retrospective review of infantile spasm patients was conducted, classifying abnormal MRI into developmental, acquired, and nonspecific subgroups. RESULTS: MRIs were abnormal in 52 of 71 infantile spasm patients (23 developmental, 23 acquired, and 6 nonspecific) with no correlation to the clinical infantile spasm characteristics. Both developmental and acquired subgroups exhibited cortical gray and/or white matter abnormalities. Additional abnormalities of deep gray structures, brain stem, callosum, and volume loss occurred in the structural acquired subgroup. Repeat MRI showed better definition of the extent of existing malformations. CONCLUSION: In structural infantile spasms, developmental/acquired subgroups showed differences in pattern of MRI abnormalities but did not correlate with clinical characteristics.

Seizure clustering during presurgical electroencephalographic monitoring in children.

BACKGROUND: Presurgical evaluation with antiseizure medication tapering in patients with refractory epilepsy places them at risk for seizure clustering or prolonged seizures. We looked at the occurrence of seizure clustering (3 or more seizures within 24h) and prolonged seizures and the factors that influence seizure clustering and affect length of stay (LOS) in pediatric patients during presurgical monitoring. METHODS: We retrospectively reviewed the medical records of all consecutive admissions to the epilepsy monitoring unit (EMU) and included patients undergoing noninvasive presurgical evaluation. Data were extracted regarding demographics, seizure history, details of the EMU admission including occurrence of seizure clusters, prolonged seizures, status epilepticus, treatment, and LOS. RESULTS: Sixty-nine patients met our inclusion criteria. Seizure clustering during monitoring was observed in 33 patients (48%). Prolonged seizures lasting >5min was observed in 14 (20%) patients including 2 with status epilepticus (3%). Seizure clusters necessitated rescue treatment in around 30%. History of seizure clustering at home was the only factor associated with the occurrence of seizure clustering during the EMU stay (p<0.0001). The LOS did not differ significantly between patients who had seizure clustering during monitoring versus those who did not (p=0.369). CONCLUSIONS: Seizure clustering was common in children undergoing presurgical monitoring and seen especially in those with a history of seizure clustering at home. Occurrence of seizure clustering did not prolong the LOS but necessitated the use of rescue medications in about a third of the patients with seizure clusters due to multiple seizures.