SummaryElectrical status epilepticus in slow‐wave sleep (ESES) is characterized by nearly continuous spike–wave discharges during non–rapid eye movement (REM) sleep. ESES is present in Landau‐Kleffner syndrome (LKS) and continuous spike and wave in slow‐wave sleep (CSWS). Sulthiame has demonstrated reduction in spike–wave index (SWI) in ESES, but is not available in the United States. Acetazolamide (AZM) is readily available and has similar pharmacologic properties. Our aims were to assess the effect of AZM on SWI and clinical response in children with LKS and CSWS. Children with LKS or CSWS treated with AZM at our institution were identified retrospectively. Pre‐ and posttherapy electroencephalography (EEG) studies were evaluated for SWI. Parental and teacher report of clinical improvement was recorded. Six children met criteria for inclusion. Three children (50%) demonstrated complete resolution or SWI <5% after AZM. All children had improvement in clinical seizures and subjective improvement in communication skills and school performance. Five of six children had subjective improvement in hyperactivity and attention. AZM is a potentially effective therapy for children with LKS and CSWS. This study lends to the knowledge of potential therapies that can be used for these disorders, which can be challenging for families and providers.
Seizure and Psychosocial Outcomes of Childhood and Juvenile Onset Generalized Epilepsies: Wolf in Sheep's Clothing, or Well-Dressed Wolf?
Studies of generalized electroclinical syndromes can provide guidance regarding long-term seizure, cognitive, and psychosocial outcomes. Childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and idiopathic generalized epilepsy with generalized tonic–clonic seizures alone are electroclinical syndromes typically associated with normal intellect and good response to antiseizure medications. However, studies have demonstrated significantly poorer psychosocial outcomes than expected for these syndromes, regardless of seizure control. Potential causes for this include underlying abnormalities in social skills, social stigma, and underlying abnormalities in brain development and maturation.
Repeat resective surgery in complex pediatric refractory epilepsy: lessons learned
OBJECT Resection can sometimes offer the best chance of meaningful seizure reduction in children with medically intractable epilepsy. However, when surgery fails to achieve the desired outcome, reoperation may be an option. The authors sought to investigate outcomes following resective reoperation in pediatric patients with refractory epilepsy, excluding tumoral epilepsies. Differences in preoperative workup between surgeries are analyzed to identify factors influencing outcomes and complications in this complex group. METHODS Medical records were reviewed for all pediatric patients undergoing a repeat resective surgery for refractory epilepsy at the authors' institution between 2005 and 2012. Tumor and vascular etiologies were excluded. Preoperative evaluation and outcomes were analyzed for each surgery and compared. RESULTS Ten patients met all inclusion criteria. The median age at seizure onset was 4.5 months. Preoperative MRI revealed no lesion in 30%. Nonspecific gliosis and cortical dysplasia were the most common pathologies. The majority of preoperative workups included MRI, video-electroencephalography (EEG), and SISCOM. Intracranial EEG was performed for 60% for the first presurgical evaluation and 70% for the second evaluation. The goal of surgery was palliative in 4 patients with widespread cortical dysplasia. The final Engel outcome was Class I in 50%. The rate of favorable outcome (Engel Class I–II) was 70%. The complication rate for the initial surgery was 10%. However, the rate increased to 50% with the second surgery, and 3 of these 5 complications were pseudomeningoceles requiring shunt placement (2 of the 3 patients underwent hemispherotomy). CONCLUSIONS Resective reoperation for pediatric refractory epilepsy has a high rate of favorable outcome and should be considered in appropriate candidates, even as a palliative measure. Intracranial EEG monitoring should be considered on initial workup in cases where the results of imaging or EEG studies are ambiguous or conflicting. Epilepsy secondary to cortical dysplasia, especially if the dysplasia is not seen clearly on MRI, can be difficult to cure surgically. Therefore, in these cases, as large a resection as can be safely accomplished should be done, particularly when the goal is palliative. The rate of complications, particularly pseudomeningocele ultimately requiring shunt placement, is much higher following reoperation, and patients should be counseled accordingly.
How should children with West syndrome be efficiently and accurately investigated? Results from the National Infantile Spasms Consortium
Summary Objective To prospectively evaluate the etiology of new‐onset infantile spasms and evaluate the yield of genetic and metabolic investigations in those without obvious cause after initial clinical evaluation and magnetic resonance imaging ( MRI ). Methods Twenty‐one U.S. pediatric epilepsy centers prospectively enrolled infants with newly diagnosed West syndrome in a central database. Etiology and investigations performed within 3 months of diagnosis were documented. Results From June 2012 to June 2014, a total of 251 infants were enrolled (53% male). A cause was identified in 161 (64.4%) of 250 cases (genetic,14.4%; genetic‐structural, 10.0%; structural‐congenital, 10.8%; structural‐acquired, 22.4%; metabolic, 4.8%; and infectious, 2.0%). An obvious cause was found after initial clinical assessment (history and physical examination) and/or MRI in 138 of 161, whereas further genetic and metabolic studies were revealing in another 23 cases. Of 112 subjects without an obvious cause after initial evaluation and MRI , 81 (72.3%) had undergone genetic testing, which showed a causal abnormality in 23.5% and a variant of unknown significance in 14.8%. Although metabolic studies were done in the majority (serum, 79.5%; urine, 69.6%; and cerebrospinal fluid [ CSF ], 38.4%), these revealed an etiology in only five cases (4.5%). No correlation was found between type of health insurance (public vs. private) and either genetic or metabolic testing. Significance Clinical evaluation and MRI provide a specific diagnosis in 55% of children presenting with West syndrome. We propose that a cost‐effective workup for those without obvious cause after initial clinical evaluation and MRI includes an array comparative genomic hybridization ( aCGH ) followed by an epilepsy gene panel if the microarray is not definitive, serum lactate, serum amino acids, and urine organic acids.
Utility of an immunotherapy trial in evaluating patients with presumed autoimmune epilepsy
SummaryMedically refractory epilepsy remains a major medical problem worldwide. Although some patients are eligible for surgical resection of seizure foci, a proportion of patients are ineligible for a variety of reasons. One such reason is that the foci reside in eloquent cortex of the brain and therefore resection would result in significant morbidity. This retrospective study reports our experience with a novel neurostimulation technique for the treatment of these patients. We identified three patients who were ineligible for surgical resection of the intracranially identified seizure focus because it resided in eloquent cortex, who underwent therapeutic trial of focal cortical stimulation delivered through the subdural monitoring grid. All three patients had a significant reduction in seizures, and two went on to permanent implantation, which resulted in long‐term reduction in seizure frequency. In conclusion, this small case report provides some evidence of proof of concept of the role of targeted continuous neocortical neurostimulation in the treatment of medically refractory focal epilepsy, and provides support for ongoing investigations into this treatment modality.A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.
Evidence-Based Guideline Update: Vagus Nerve Stimulation for the Treatment of Epilepsy
OBJECTIVE: To evaluate the evidence since the 1999 assessment regarding efficacy and safety of vagus nerve stimulation (VNS) for epilepsy, currently approved as adjunctive therapy for partial-onset seizures in patients >12 years. METHODS: We reviewed the literature and identified relevant published studies. We classified these studies according to the American Academy of Neurology evidence-based methodology. RESULTS: VNS is associated with a >50% seizure reduction in 55% (95% confidence interval [CI] 50%–59%) of 470 children with partial or generalized epilepsy (13 Class III studies). VNS is associated with a >50% seizure reduction in 55% (95% CI 46%–64%) of 113 patients with Lennox-Gastaut syndrome (LGS) (4 Class III studies). VNS is associated with an increase in ≥50% seizure frequency reduction rates of ~7% from 1 to 5 years postim-plantation (2 Class III studies). VNS is associated with a significant improvement in standard mood scales in 31 adults with epilepsy (2 Class III studies). Infection risk at the VNS implantation site in children is increased relative to that in adults (odds ratio 3.4, 95% CI 1.0–11.2). VNS is possibly effective for seizures (both partial and generalized) in children, for LGS-associated seizures, and for mood problems in adults with epilepsy. VNS may have improved efficacy over time. RECOMMENDATIONS: VNS may be considered for seizures in children, for LGS-associated seizures, and for improving mood in adults with epilepsy (Level C). VNS may be considered to have improved efficacy over time (Level C). Children should be carefully monitored for site infection after VNS implantation. Neurology® 2013;81:1–7
Evidence-based guideline update: Vagus nerve stimulation for the treatment of epilepsy
OBJECTIVES: Estimate the causes and risk of death, specifically seizure related, in children followed from onset of epilepsy and to contrast the risk of seizure-related death with other common causes of death in the population. METHODS: Mortality experiences from 4 pediatric cohorts of newly diagnosed patients were combined. Causes of death were classified as seizure related (including sudden unexpected death [SUDEP]), natural causes, nonnatural causes, and unknown. RESULTS: Of 2239 subjects followed up for >30 000 person-years, 79 died. Ten subjects with lethal neurometabolic conditions were ultimately excluded. The overall death rate (per 100 000 person-years) was 228; 743 in complicated epilepsy (with associated neurodisability or underlying brain condition) and 36 in uncomplicated epilepsy. Thirteen deaths were seizure-related (10 SUDEP, 3 other), accounting for 19% of all deaths. Seizure-related death rates were 43 overall, 122 for complicated epilepsy, and 14 for uncomplicated epilepsy. Death rates from other natural causes were 159, 561, and 9, respectively. Of 48 deaths from other natural causes, 37 were due to pneumonia or other respiratory complications. CONCLUSIONS: Most excess death in young people with epilepsy is not seizure-related. Mortality is significantly higher compared with the general population in children with complicated epilepsy but not uncomplicated epilepsy. The SUDEP rate was similar to or higher than sudden infant death syndrome rates. In uncomplicated epilepsy, sudden and seizure-related death rates were similar to or higher than rates for other common causes of death in young people (eg, accidents, suicides, homicides). Relating the risk of death in epilepsy to familiar risks may facilitate discussions of seizure-related mortality with patients and families.
What predicts enduring intractability in children who appear medically intractable in the first 2 years after diagnosis?
SummaryPurposeIn a population‐based retrospective cohort of children with newly diagnosed epilepsy, to determine (1) what proportion meet criteria for early medical intractability, and (2) predictors of enduring intractability.MethodsChildren with newly diagnosed epilepsy between 1980 and 2009 while resident in Olmsted County, MN, and followed >36 months, were stratified into groups based on both early medical intractability (“apparent” medical intractability in the first 2 years) and enduring intractability (persisting intractability at final follow‐up or having undergone surgery for intractable epilepsy), and variables predicting these outcomes were evaluated.Key FindingsThree hundred eighty‐one children were included, representing 81% of our cohort with newly diagnosed epilepsy. Seventy five (19.7%) had early medical intractability, and predictors of this outcome on multivariable analysis were neuroimaging abnormality (risk ratio, 2.70; p = 0.0004), abnormal neurologic examination at diagnosis (risk ratio, 1.87; p = 0.015), and mode of onset (association was significant for focal vs. generalized onset [risk ratio, 0.25; p < 0.0001] but not unknown vs. generalized onset [p = 0.065]). After a median follow‐up of 11.7 years, 49% remained intractable, 8% had rare seizures (≤ every 6 months), and the remainder were seizure‐free. The only factor predicting enduring intractability on multivariable analysis was neuroimaging abnormality (risk ratio, 7.0; p = 0.0006).SignificanceAlthough a significant minority of children with early medical intractability ultimately achieved seizure control without surgery, those with an abnormal imaging study did poorly. For this subgroup, early surgical intervention is strongly advised to limit comorbidities of ongoing, intractable seizures. Conversely, a cautious approach is suggested for those with normal imaging, as most will remit with time.