Epilepsy surgery for children with epileptic spasms: A systematic review and meta-analysis with focus on predictors and outcomes.

To conduct a systematic review of the literature regarding rates and predictors of favorable seizure outcome after resective surgery for epileptic spasms (ES) in pediatric patients. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards were followed. We searched PubMed, EMBASE, and Cochrane CENTRAL for articles published on the prevalence or incidence of epileptic spasm since 1985. Abstract, full-text review, and data extraction were conducted by two independent reviewers. Meta-analysis was performed to assess overall seizure freedom rate. Subject-level analysis was performed on a subset of studies to identify prognostic indicators. A total of 21 retrospective studies (n = 531) were included. Meta-analysis of all studies demonstrated a pooled seizure freedom rate of 68.8%. Subject-level analysis on 18 studies (n = 360) demonstrated a significant association between duration of spasms and recurrence of spasms after surgery, with an estimated increased risk of 7% per additional year of spasms prior to operation. Patients who underwent resective surgery that was not a hemispherectomy (i.e., lobectomy, lesionectomy, etc.) had an increased recurrence risk of 57% compared to patients who had undergone hemispherectomy. Resective surgery results in seizure freedom for the majority of pediatric patients with epileptic spasms. Patients who undergo hemispherectomy have lower risk of recurrence than patients who undergo other types of surgical resection. Increased duration of spasms prior to surgery is associated with increased recurrence risk after surgery. PLAIN LANGUAGE SUMMARY: Children with epileptic spasms (ES) that do not respond to medications may benefit from surgical treatment. Our study reviewed existing research to understand how effective surgery is in treating ES in children and what factors predict better outcomes. Researchers followed strict guidelines to search for and analyze studies published since 1985, finding 21 studies with a total of 531 patients. They found that, on average, nearly 70% of children became seizure-free after surgery. Further individual analysis of 360 patients showed that longer duration of spasms before surgery increased the risk of spasms returning by 7% per year. Additionally, children who had less extensive surgeries, such as removal of only a specific part of the brain, had a 57% higher risk of seizure recurrence compared to those who had a hemispherectomy, which removed or disconnected half of the brain. Overall, the study concludes that surgery can often stop seizures, especially when more extensive surgery is performed and when the surgery is done sooner rather than later.

Pupillary constriction on stimulation of the parietal cortex-A novel finding.

Pupillary changes can be an important semiologic feature in focal epilepsy. Though the subcortical networks involving pupillomotor function have been described, cortical generators of pupillary dilation and constriction in humans are not well known. In this report, we describe a case of pupillary constriction occurring during seizures in a patient with drug resistant focal epilepsy. On stereoelectroencephalography, onset was noted within the posterior segment of the right intraparietal sulcus and direct cortical electrical stimulation of these electrode contacts reproduced pupillary constriction associated with habitual seizures. This is the first case report to describe ictal pupillary constriction during SEEG with confirmation of the cortical localization by direct cortical electrical stimulation. The posterior segment of the right intraparietal sulcus localization of pupillary constriction may aid in surgical evaluation patients with drug resistant focal epilepsy.

Electroclinical Features of Infantile Epileptic Spasms Syndrome.

Epileptic spasms are a unique, age-dependent manifestation of epilepsies in infancy and early childhood, commonly occurring as part of infantile epileptic spasms syndrome. Developmental stagnation and subsequent decline may occur in children with epileptic spasms, partly due to the abundant high-amplitude interictal epileptiform and slow wave abnormalities. Early recognition and treatment of epileptic spasms, along with the reversal of the electroencephalography (EEG) findings, are critical for improving outcomes. Recognizing hypsarrhythmia and its variations is key to confirming the diagnosis. The various patterns of hypsarrhythmia are not etiology specific, but could indicate the severity of the disease. Several scoring systems have been proposed to improve the inter-rater reliability of recognizing hypsarrhythmia and to assess EEG progress in response to treatment. Ictal patterns during spasms are brief and composed of slow waves, sharp transients, fast activity, and voltage attenuation, either in isolation or more commonly as a combination of these waveforms. Ictal patterns are commonly diffuse, but may be lateralized to one hemisphere in children with structural etiology. A subset of patients with epileptic spasms has a surgically remediable etiology, with readily identifiable lesions on neuroimaging in most cases. Asymmetry in epileptic spasms, concurrent focal seizures, and asymmetric interictal and ictal EEG findings may be present, but a lack of focality in electrophysiological findings is not uncommon. Intracranial EEG features of epileptic spasms have been described, but the utility of intracranial EEG monitoring in surgical candidates with overt focal epileptogenic lesions on magnetic resonance imaging is questionable, and surgery could be performed using noninvasive data.

Postoperative shunt failure following hemispherectomy in pediatric patients with pre-existing hydrocephalus.

OBJECTIVE: The risk of hydrocephalus following hemispherectomy for drug resistant epilepsy (DRE) remains high. Patients with pre-existing hydrocephalus pose a postoperative challenge, as maintaining existing shunt patency is necessary but lacks a clearly defined strategy. This study examines the incidence and predictors of shunt failure in pediatric hemispherectomy patients with pre-existing ventricular shunts. METHODS: We performed a retrospective chart review at our center to identify pediatric patients diagnosed with DRE who were treated with ventricular shunt prior to their first hemispherectomy surgery. Demographic and perioperative data were obtained including shunt history, hydrocephalus etiology, epilepsy duration, surgical technique, and postoperative outcomes. Univariate analysis was performed using Fisher's exact test and Pearson correlation, with Bonferroni correction to a = 0.00625 and a = 0.01, respectively. RESULTS: Five of nineteen (26.3%) patients identified with ventriculoperitoneal shunting prior to hemispherectomy experienced postoperative shunt malfunction. All 5 of these patients underwent at least 1 shunt revision prior to hemispherectomy, with a significant association between pre- and post-hemispherectomy shunt revisions. There was no significant association between post-hemispherectomy shunt failure and valve type, intraoperative shunt alteration, postoperative external ventricular drain placement, hemispherectomy revision, lateralization of shunt relative to resection, postoperative complications, or postoperative aseptic meningitis. There was no significant correlation between number of post-hemispherectomy shunt revisions and age at shunt placement, age at hemispherectomy, epilepsy duration, or shunt duration prior to hemispherectomy. CONCLUSIONS: Earlier shunt revision surgery may portend a subsequent need for shunt revision following hemispherectomy. These findings may guide neurosurgeons in counseling patients with pre-existing ventricular shunts prior to hemispherectomy surgery.

Predictive factors of hydrocephalus development in pediatric patients undergoing hemispherectomy for intractable epilepsy.

OBJECTIVE: Hemispherectomy surgery is an effective procedure for pediatric patients with intractable hemispheric epilepsy. Hydrocephalus is a well-documented complication of hemispherectomy contributing substantially to patient morbidity. Despite some clinical and operative factors demonstrating an association with hydrocephalus development, the true mechanism of disease is incompletely understood. The aim of this study was to investigate a range of clinical and surgical factors that may contribute to hydrocephalus to enhance understanding of the development of this complication and to aid the clinician in optimizing peri- and postoperative surgical management. METHODS: A retrospective chart review was conducted on all pediatric patients younger than 21 years who underwent hemispherectomy surgery at the Cleveland Clinic between 2002 and 2016. Data collected for each patient included general demographic information, neurological and surgical history, surgical technique, pathological analysis, presence and duration of perioperative CSF diversion, CSF laboratory values obtained while an external ventricular drain (EVD) was in place, length of hospital stay, postoperative aseptic meningitis, and in-hospital surgical complications (including perioperative stroke, hematoma formation, wound breakdown, and/or infection). Outcomes data included hemispherectomy revision and Engel grade at last follow-up (based on the Engel Epilepsy Surgery Outcome Scale). RESULTS: Data were collected for 204 pediatric patients who underwent hemispherectomy at the authors' institution. Twenty-eight patients (14%) developed hydrocephalus requiring CSF diversion. Of these 28 patients, 13 patients (46%) presented with hydrocephalus during the postoperative period (within 90 days), while the remaining 15 patients (54%) presented later (beyond 90 days after surgery). Multivariate analysis revealed postoperative aseptic meningitis (OR 7.0, p = 0.001), anatomical hemispherectomy surgical technique (OR 16.3 for functional/disconnective hemispherectomy and OR 7.6 for modified anatomical, p = 0.004), male sex (OR 4.2, p = 0.012), and surgical complications (OR 3.8, p = 0.031) were associated with an increased risk of hydrocephalus development, while seizure freedom (OR 0.3, p = 0.038) was associated with a decreased risk of hydrocephalus. CONCLUSIONS: Hydrocephalus remains a prominent complication following hemispherectomy, presenting both in the postoperative period and months to years after surgery. Aseptic meningitis, anatomical hemispherectomy surgical technique, male sex, and surgical complications show an association with an increased rate of hydrocephalus development while seizure freedom postsurgery is associated with a decreased risk of subsequent hydrocephalus. These findings speak to the multifactorial nature of hydrocephalus development and should be considered in the management of pediatric patients undergoing hemispherectomy for medically intractable epilepsy.

Determinants of epileptogenic zone identification and seizure outcome in children with refractory epilepsy undergoing stereoelectroencephalography.

OBJECTIVE: The objective of this paper was to investigate the factors associated with successful epileptogenic zone (EZ) identification and postsurgical seizure freedom in pediatric patients with drug-resistant epilepsy who underwent first-time stereoelectroencephalography (SEEG). METHODS: The authors conducted a retrospective cohort study of all consecutive patients younger than 18 years of age at the time of recommendation for invasive evaluation with SEEG who were treated from July 2009 to June 2020. The authors excluded patients who had undergone failed prior resective epilepsy surgery or prior intracranial electrode evaluation for seizure localization. For their primary outcome, the authors evaluated the relationship between clinical and radiographic factors and successful identification of a putative EZ. For their secondary outcome, the authors investigated whether these factors had a significant relationship with seizure freedom (according to the Engel classification) at last follow-up. RESULTS: The authors included 101 patients in this study. SEEG was safe, with no major morbidity or mortality experienced. The population was complex, with an MRI lesion present in less than 40% of patients and patients as young as 2.9 years included. A proposed EZ was identified in 88 (87%) patients. Patients with an older onset of epilepsy (OR 1.20/year, p = 0.04) or epilepsy etiology suspected to be due to a developmental lesion (OR 8.38, p = 0.02) were more likely to have proposed EZ identification. Patients with a preimplantation bilateral seizure-onset hypothesis (OR 0.29, p = 0.047) and those who underwent longer periods of monitoring (OR 0.86/day, p = 0.006) were somewhat less likely to have proposed EZ identification. The presence of an MRI lesion was a positive factor on secondary analyses (OR 4.18, p = 0.049; 1-tailed test). Fifty percent of patients who underwent surgical treatment with resection or laser ablation achieved Engel class I outcomes, in contrast to 0% of patients who underwent neuromodulation. Patients with a preimplantation hypothesis in the frontal/parietal lobes had increased odds of seizure freedom compared with patients with a hypothesis in other locations (OR 3.64, p = 0.01). CONCLUSIONS: Pediatric SEEG is safe and often identifies a proposed resectable EZ. These results suggest that SEEG is effective in patients with frontal/parietal preimplantation hypothesis, with or without identified lesions on MRI.

Pediatric anti-NMDA-receptor autoimmune encephalitis in siblings: Developmental, Electrophysiologic, and Genetic Implications.

BACKGROUND: Anti-NMDAR encephalitis is a leading cause of autoimmune encephalitis in children. Untreated disease can lead to long-term neurological disability. CASE REPORT: We present siblings with pediatric-onset anti-NMDAR encephalitis. One was treated early, while the other's diagnosis and treatment were delayed by several years. Developmental, electrophysiologic, and genetic implications are discussed. CONCLUSION: Anti-NMDAR encephalitis is a severely debilitating disease that often requires prompt initiation and early escalation in treatment. Delayed treatment may lead to irreversible neurological sequalae. Further studies exploring associations between timing and tier of treatment initiation and longitudinal outcomes are needed.

Epileptic spasms in CDKL5 deficiency disorder: Delayed treatment and poor response to first-line therapies.

OBJECTIVE: We aimed to assess the treatment response of infantile-onset epileptic spasms (ES) in CDKL5 deficiency disorder (CDD) vs other etiologies. METHODS: We evaluated patients with ES from the CDKL5 Centers of Excellence and the National Infantile Spasms Consortium (NISC), with onset from 2 months to 2 years, treated with adrenocorticotropic hormone (ACTH), oral corticosteroids, vigabatrin, and/or the ketogenic diet. We excluded children with tuberous sclerosis complex, trisomy 21, or unknown etiology with normal development because of known differential treatment responses. We compared the two cohorts for time to treatment and ES remission at 14 days and 3 months. RESULTS: We evaluated 59 individuals with CDD (79% female, median ES onset 6 months) and 232 individuals from the NISC database (46% female, median onset 7 months). In the CDD cohort, seizures prior to ES were common (88%), and hypsarrhythmia and its variants were present at ES onset in 34%. Initial treatment with ACTH, oral corticosteroids, or vigabatrin started within 1 month of ES onset in 27 of 59 (46%) of the CDD cohort and 182 of 232 (78%) of the NISC cohort (p < .0001). Fourteen-day clinical remission of ES was lower for the CDD group (26%, 7/27) than for the NISC cohort (58%, 106/182, p = .0002). Sustained ES remission at 3 months occurred in 1 of 27 (4%) of CDD patients vs 96 of 182 (53%) of the NISC cohort (p < .0001). Comparable results were observed with longer lead time (≥1 month) or prior treatment. Ketogenic diet, used within 3 months of ES onset, resulted in ES remission at 1 month, sustained at 3 months, in at least 2 of 13 (15%) individuals with CDD. SIGNIFICANCE: Compared to the broad group of infants with ES, children with ES in the setting of CDD often experience longer lead time to treatment and respond poorly to standard treatments. Development of alternative treatments for ES in CDD is needed.

Beyond seizure freedom: Dissecting long-term seizure control after surgical resection for drug-resistant epilepsy.

OBJECTIVE: This study was undertaken to better understand the long-term palliative and disease-modifying effects of surgical resection beyond seizure freedom, including frequency reduction and both late recurrence and remission, in patients with drug-resistant epilepsy. METHODS: This retrospective database-driven cohort study included all patients with >9 years of follow-up at a single high-volume epilepsy center. We included patients who underwent lobectomy, multilobar resection, or lesionectomies for drug-resistant epilepsy; we excluded patients who underwent hemispherectomies. Our main outcomes were (1) reduction in frequency of disabling seizures (at 6 months, each year up to 9 years postoperatively, and at last follow-up), (2) achievement of seizure remission (>6 months, >1 year, and longest duration), and (3) seizure freedom at last follow-up. RESULTS: We included 251 patients; 234 (93.2%) achieved 6 months and 232 (92.4%) experienced 1 year of seizure freedom. Of these, the average period of seizure freedom was 10.3 years. A total of 182 (72.5%) patients were seizure-free at last follow-up (defined as >1 year without seizures), with a median 11.9 years since remission. For patients not completely seizure-free, the mean seizure frequency reduction at each time point was 76.2%, and ranged from 66.6% to 85.0%. Patients decreased their number of antiseizure medications on average by .58, and 53 (21.2%) patients were on no antiseizure medication at last follow-up. Nearly half (47.1%) of those seizure-free at last follow-up were not seizure-free immediately postoperatively. SIGNIFICANCE: Patients who continue to have seizures after resection often have considerable reductions in seizure frequency, and many are able to achieve seizure freedom in a delayed manner.

Epileptiform abnormalities in the disconnected hemisphere are common in seizure-free patients after hemispherectomy

Objective: The spectrum of EEG abnormalities in the disconnected hemisphere in seizure-free patients after hemispherectomy has not been well characterized. Methods: Fifty consecutive patients who were seizure-free following hemispheric disconnection were identified. Data on preoperative clinical, EEG and neuroimaging findings and postoperative EEG findings and antiseizure medication status were collected. Results: Forty-seven patients (94%) had functional hemispherectomy, and three (6%) had more extensive tissue resection of the posterior quadrant or frontal region along with hemispheric disconnection. Etiologies included: residual effects from vascular lesions including perinatal stroke in 35 patients, Rasmussen encephalitis in six, malformation of cortical development in seven, and Sturge-Weber syndrome in two. Pre-operative EEG showed focal epileptiform discharges in the affected hemisphere in 26 patients and in both hemispheres in 19. Eleven patients had diffuse bisynchronous epileptiform discharges. Postoperative EEGs at six to 12 months after surgery showed slowing and attenuation of physiological rhythms on the operated side in all patients. Thirty-four patients (68%) had epileptiform discharges exclusively from the operated hemisphere, six (12%) had bilateral independent epileptiform discharges, nine (18%) had no epileptiform discharges on either side, and one (2%) had epileptiform discharges from the contralateral hemisphere only. Lateralized periodic discharges from the operated hemisphere were noted in three patients (6%). EEG seizures from the operated hemisphere without clinical signs were noted in four patients (8%). After a median follow-up of three years, 30 patients (60%) were off all antiseizure medications, including 8/9 (89%) patients with no epileptiform discharges, 20/34 (59%) patients with postoperative epileptiform discharges from the operated hemisphere, and 2/7 (28%) patients with contralateral discharges. Significance: The majority of patients who are seizure-free after disconnective hemispherectomy will continue to show epileptiform discharges in the operated hemisphere. The presence of such discharges should not preclude tapering, nor prompt restarting of antiseizure medication in seizure-free patients.

Electroclinical Features in Epilepsy Surgery Candidates With Epileptic Spasms.

SUMMARY: Electroclinical features in surgical candidates with epileptic spasms differ significantly from the other focal epilepsy phenotypes. EEG findings tend to be more diffuse and less localizing in children with epileptic spasms. These are illustrated with five case studies to highlight three different categories of findings on interictal and ictal EEG: lateralizing , nonlateralizing , and false lateralizing . Hemihypsarrhythmia on interictal EEG is the most striking lateralizing abnormality that occurs in a minority of surgical candidates. Persistent focal epileptiform discharges in one region or asymmetric physiologic rhythms decreased over the abnormal hemisphere may provide localization clues. Ictal EEG patterns are diffuse and nonlocalizing in over half of the patients. Ictal patterns are best expressed in the posterior head regions even in patients with epileptogenic zone in anterior regions. Semiologically, epileptic spasms tend to be symmetrical in majority of surgical candidates. Asymmetric spasms and coexisting focal seizures (concurrent or remote), when present, may provide localization findings. False lateralizing interictal or ictal EEG abnormalities, paradoxically higher over the healthier hemisphere, occur in the setting of large encephaloclastic/volume loss lesions. In these patients, the diffuse discharges are less expressed over the abnormal hemisphere with less cerebral tissue. Recognition of such false lateralizing findings is important to avoid excluding appropriate surgical candidates based on the EEG findings alone. Epileptogenic lesions are visible on brain MRI in majority of surgical candidates with epileptic spasms. Electroclinical findings are often concordant with the lesion, but discordant findings are not uncommon in children with epileptic spasms.

The Efficacy and Use of a Pocket Card Algorithm in Status Epilepticus Treatment.

OBJECTIVE: To determine whether a pocket card treatment algorithm improves the early treatment of status epilepticus and to assess its utilization and retention in clinical practice. METHODS: Multidisciplinary care teams participated in video-recorded status epilepticus simulation sessions from 2015 to 2019. In this longitudinal cohort study, we examined the sessions recorded before and after introducing an internally developed, guideline-derived pocket card to determine differences in the adequacy or timeliness of rescue benzodiazepine. Simulation participants were queried 9 months later for submission of a differentiating identification number on each card to assess ongoing availability and utilization. RESULTS: Forty-four teams were included (22 before and 22 after the introduction of the pocket card). The time to rescue therapy was shorter for teams with the pocket card available (84 seconds [64-132]) compared with teams before introduction (144 seconds [100-162]) (U = 94; median difference = -46.9, 95% confidence interval [CI]: -75.9 to -21.9). The adequate dosing did not differ with card availability (odds ratio 1.48, 95% CI: 0.43-5.1). At the 9-month follow-up, 32 participants (65%) completed the survey, with 26 (81%) self-reporting having the pocket card available and 11 (34%) confirming ready access with the identification number. All identification numbers submitted corresponded to the hard copy laminated pocket card, and none to the electronic version. CONCLUSIONS: A pocket card is a feasible, effective, and worthwhile educational tool to improve the implementation of updated guidelines for the treatment of status epilepticus.

Current neurologic treatment and emerging therapies in CDKL5 deficiency disorder.

BACKGROUND: CDKL5 deficiency disorder (CDD) is associated with refractory infantile onset epilepsy, global developmental delay, and variable features that include sleep, behavioral disturbances, and movement disorders. Current treatment is primarily symptom-based and informed by experience in caring for this population. METHODS: We describe medication and non-medication approaches to treatment of epilepsy and additional key neurologic symptoms (sleep disturbances, behavioral issues, movement disorders, and swallowing dysfunction) in a cohort of 177 individuals meeting criteria for CDD, 154 evaluated at 4 CDKL5 Centers of Excellence in the USA and 40 identified through the NIH Natural History Study of Rett and Related Disorders. RESULTS: The four most frequently prescribed anti-seizure medications were broad spectrum, prescribed in over 50% of individuals. While the goal was not to ascertain efficacy, we obtained data from 86 individuals regarding response to treatment, with 2-week response achieved in 14-48% and sustained 3-month response in 5-36%, of those with known response. Additional treatments for seizures included cannabis derivatives, tried in over one-third of individuals, and clinical trial medications. In combination with pharmacological treatment, 50% of individuals were treated with ketogenic diet for attempted seizure control. Surgical approaches included vagus nerve stimulators, functional hemispherectomy, and corpus callosotomy, but numbers were too limited to assess response. Nearly one-third of individuals received pharmacologic treatment for sleep disturbances, 13% for behavioral dysregulation and movement disorders, and 43% had gastrostomy tubes. CONCLUSIONS: Treatment for neurologic features of CDD is currently symptom-based and empiric rather than CDD-specific, though clinical trials for CDD are emerging. Epilepsy in this population is highly refractory, and no specific anti-seizure medication was associated with improved seizure control. Ketogenic diet is commonly used in patients with CDD. While behavioral interventions are commonly instituted, information on the use of medications for sleep, behavioral management, and movement disorders is sparse and would benefit from further characterization and optimization of treatment approaches. The heterogeneity in treatment approaches highlights the need for systematic review and guidelines for CDD. Additional disease-specific and disease-modifying treatments are in development.

Surgical candidates in children with epileptic spasms can be selected without invasive monitoring: A report of 70 cases.

OBJECTIVE: Prior surgical series in children with drug-resistant epileptic spasms have reported use of intracranial EEG monitoring in up to two-third of patients. We report outcome after epilepsy surgery for drug-resistant epileptic spasms in a cohort of children without the use of intracranial EEG monitoring in any of the patients. METHODS: Medical records of all consecutive children aged 5 years or under who had epilepsy surgery for epileptic spasms at Cleveland Clinic between 2000 and 2018 were reviewed. Post-operative seizure outcome and predictors of prognosis of seizure outcome were analyzed. RESULTS: Seventy children with active epileptic spasms underwent surgical resections during the study period. Mean age at seizure onset was 6.8 (+9.31) months and median age at surgery was 18.5 months. An epileptogenic lesion was identified on brain MRI in all patients; 17 (24%) had bilateral abnormalities. Etiologies included malformations of cortical development (58%), perinatal infarct/encephalomalacia (39%), and tumor (3%). None of the patients had intracranial EEG. Surgical procedures included hemispherectomy (44%), lobectomy/ lesionectomy (33%), and multilobar resections (23%). Twelve children needed repeat surgery; six (50%) became seizure free after the second surgery. At six months follow-up, 73% (51/70) were seizure-free since surgery. At a mean follow-up of 4.7 years, 60% (42/70) had Engel 1 outcome. In those with seizure recurrence, 17 (60%) reported improvement. Shorter epilepsy duration (p = 0.05) and lobar or sub-lobar epileptogenic lesions (p = 0.02) predicted favorable seizure outcome at 6 months after surgery. For long term outcome, patients with bilateral abnormalities on MRI (p = 0.001), and multilobar extent on MRI (p = 0.02) were at higher risk for recurrence. SIGNIFICANCE: Children with drug-resistant epileptic spasms secondary to an epileptogenic lesion detected on MRI could be selected for epilepsy surgery without undergoing intracranial EEG monitoring. A surgical selection paradigm without intracranial monitoring may allow early surgery without the risks of invasive monitoring.

Characterizing the phenotype of drug-resistant childhood epilepsy associated with leukemia: A case series.

Children with leukemia are at risk for epilepsy due to primary disease or neurotoxic therapies. We describe the phenotypes of drug-resistant epilepsy in 10 children with history of leukemia. Of 10 cases, 6 had features of Lennox-Gastaut syndrome, and 4 had focal epilepsy. Mean age of epilepsy onset was 5 years in Lennox-Gastaut cases and 6.5 years in focal epilepsy cases. Mean latency between leukemia diagnosis and seizure onset was about 3 years. Brain MRI of 2 patients with epileptic encephalopathy had structural abnormalities - unclear if causative for epilepsy, and 4 had no overt structural abnormalities. In focal epilepsy group, 3 had temporal lobe epilepsy and one had fronto-temporal localization. All 10 patients had received intrathecal chemotherapy; 2 also had received whole brain irradiation. Seizures were poorly controlled in the epileptic encephalopathy group. Three underwent corpus callosotomy with variable response. Two patients with temporal lobe epilepsy had temporal lobectomy with Engel 1 outcome at 2 year follow-up in both. Two phenotypes of refractory epilepsy were observed in children with previous history of leukemia, focal epilepsy and epileptic encephalopathy. Children with temporal lobe epilepsy had good response to temporal lobectomy; response to palliative surgery was variable.

Brain morphological abnormalities in children with cyclin-dependent kinase-like 5 deficiency disorder.

BACKGROUND: To quantitatively evaluate the brain MRI morphological abnormalities in patients with cyclin-dependent kinase-like 5 deficiency disorder (CDD) on a group level and longitudinally. METHODS: We performed surface-based MRI analysis on high-resolution T1-weighted images on three CDD patients scanned at age of three years, and compared with 12 age- and gender-matched healthy controls. We further examined the longitudinal morphological changes in one patient with a follow-up of 5 years. RESULTS: CDD patients presented significant reductions in total intracranial volume, total gray matter (GM) volume and subcortical GM volume compared to controls. For subcortical regions, significant GM volume reductions were seen in the brain stem, bilateral thalamus, bilateral hippocampus, bilateral cerebellum and left amygdala. Although GM volume of cortical mantle did not show statistical differences overall, significant reduction was detected in bilateral parietal, left occipital and right temporal lobes. Cortical thickness exhibited significant decreases in bilateral occipital, parietal and temporal lobes, while surface area did not show any significant differences. Longitudinal follow-up in one patient revealed a monotonic downward trend of relative volume in the majority of brain regions. The relative surface area appeared to gain age-related growth, whereas the relative cortical thickness exhibited a striking progressive decline over time. CONCLUSIONS: Quantitative morphology analysis in children with CDD showed global volume loss in the cortex and more notably in the subcortical gray matter, with a progressive trend along with the disease course. Cortical thickness is a more sensitive measure to disclose cortical atrophy and disease progression than surface area.

Perisylvian vulnerability to postencephalitic epilepsy.

OBJECTIVE: Postencephalitic epilepsy is often resistant to antiseizure medications, leading to evaluation for epilepsy surgery. Characterizing its localization carries implications for optimal surgical approach. We aimed to determine whether a prior history of encephalitis is associated with specific epileptogenic networks among patients with drug resistant epilepsy undergoing stereotactic EEG (SEEG). METHODS: We conducted a retrospective cohort study of drug resistant epilepsy, with and without a prior history of encephalitis. We analyzed SEEG recordings to identify patterns of seizure onset and organization. Seventeen patients with a history of encephalitis (of infectious etiology in two subjects) were identified from a database of patients undergoing SEEG and were compared to seventeen drug-resistant epilepsy controls without a history of encephalitis matched for confounding variables including pre-implantation hypotheses, epilepsy duration, age, and sex. RESULTS: Independent bilateral seizures were noted in 65% of the postencephalitic epilepsy cohort. We identified four SEEG-ictal patterns in patients with a prior history of encephalitis: (1) anteromesial temporal onset (24%), (2) anteromesial temporal onset with early spread to the perisylvian region (29%), (3) perisylvian (59%) and (4) synchronized anteromesial temporal and perisylvian (29%) onsets. Patterns 3 and 4, with perisylvian involvement at onset, were unique to the encephalitis group (p = 0.0003 and 0.04 respectively) and exhibited a "patchwork" organization. None of the encephalitis patients vs 5/7 matched controls had Engel I outcome (p = 0.0048). CONCLUSIONS: Postencephalitic epilepsies involve anteromesial temporal and perisylvian networks, often in a bilateral independent manner. Unique ictal patterns involving the perisylvian regions was identified in the encephalitis group, but not in the matched control group. SIGNIFICANCE: These findings may reflect a selective vulnerability of the perisylvian regions to epilepsy resulting from encephalitis, significantly mitigating the chances of success with SEEG-guided temporal resections.

Vasospasm Following Hemispherectomy: A Case Report of a Novel Complication.

BACKGROUND: Hemispherectomy has been shown to be successful in treating medically intractable epilepsy, with favorable seizure-free outcomes. However, the procedure is technically challenging with high rates of in-hospital complications. We present a unique case of functional hemispherectomy complicated by diffuse cerebral vasospasm and subsequent death in a patient with COL4A1 gene mutation. CASE DESCRIPTION: A 17-year-old boy presented with right hemispheric epilepsy and a previously diagnosed autosomal dominant heterozygous COL4A1 gene mutation (c.4380T>G;p.Cys1460Trp). Functional hemispherectomy was performed without complications. On postoperative day 8, he developed an acute decline in neurologic status requiring urgent intubation for airway protection. Magnetic resonance imaging revealed areas of restricted diffusion throughout bilateral hemispheres that was explained by severe vasospasm and minimal cerebral blood flow seen on cerebral angiography. Intra-arterial calcium channel blocker infusion and balloon angioplasty were attempted without improvement in perfusion. With a worsening clinical picture, he was transitioned to comfort care and died. CONCLUSIONS: This is the first report in the literature describing global vasospasm and delayed cerebral ischemia following hemispherectomy in a patient carrying COL4A1 gene mutation. We postulate that his COL4A1 gene mutation might have resulted in this exaggerated vasospasm despite minimal residual postoperative subarachnoid hemorrhage burden. This hypothesis needs to be studied in animal models of this genetic disorder.

Antiepileptic Drug Treatment of Epilepsy in Children.

PURPOSE OF REVIEW: The treatment of epilepsy in children is highly individualized at each and every major step in the management. This review examines various factors that modify the treatment from the point of initiation of therapy to the decision to stop an antiepileptic drug (AED). RECENT FINDINGS: AED therapy leads to seizure freedom in about 70% of all children with epilepsy. AED initiation could be delayed until a second seizure in most children and may be avoided altogether in many children with self-limited childhood focal epilepsies. Three key factors influence the choice of AED: seizure type(s), efficacy of the drug for the seizure type, and the side effect profile of the drug(s). For epileptic spasms, steroids and vigabatrin are the most effective treatment options. For absence seizures, ethosuximide and valproic acid are superior to lamotrigine. For focal seizures, many newer AEDs have favorable side effect profiles with efficacy comparable to older-generation drugs. For generalized epilepsies, valproic acid remains the most effective drug for a broad range of seizure types. Genetic and metabolic etiologies may guide unique treatment choices in some children. After 2 years or more of seizure freedom, if the recurrence risk after AED withdrawal is acceptable, slow weaning of AEDs should be done over the span of 6 weeks or longer. After discontinuation, about 70% of patients remain seizure free, and of those with recurrence, the majority achieve seizure control with restarting an AED. When treatment with two or more AEDs fails, other treatment opportunities for drug-resistant epilepsy, including epilepsy surgery, vagal nerve stimulation, and dietary therapies should be considered. SUMMARY: Carefully selected medical therapy guided by seizure type and AED characteristics is effective in more than two-thirds of children with epilepsy.