Search

Background: Many neonates with hypoxic ischemic encephalopathy and seizures do not respond to the first line antiepileptic drug, phenobarbital. Little is known about what factors are associated with its failure. Objective: To examine factors associated with failure of phenobarbital therapy in neonates with hypoxic ischemic encephalopathy and seizures. Design/Methods: A single-center retrospective review of 50 term (>35 weeks) neonates with hypoxic ischemic encephalopathy and seizures treated with phenobarbital as the first-line antiepileptic. Neonates were classified into either responders (n = 30) or nonresponders (n = 20). Nonresponse was defined as continued seizures after maximum dosing of phenobarbital or an additional antiepileptic. Subjects with acceptable magnetic resonance imaging (MRI) scans obtained within 2 weeks of birth were included in the study and rated using an MRI injury scoring system. Charts were reviewed for demographic, clinical, and laboratory variables. Resuscitation and seizure scores were also calculated. Electroencephalographic (EEG) background activity was reviewed in 2 different time epochs (12-24 hours and 24-36 hours of life) and graded as per ACNS guidelines. Results: There were no significant group differences in demographic, clinical, and laboratory variables except nonresponders, who had higher mean seizure score (P =.01) and significantly more injury on MRI scan for white matter (P =.004), parenchymal cortex (P =.027), and watershed (P =.009) regions. Neonates with moderately abnormal or severely abnormal background EEG responded poorly to phenobarbital. Conclusion: In the presence of above factors, one can anticipate that additional antiepileptic medication may be needed. These data also support that larger studies should be done to look prospectively at using alternative agents first line in patients with severe injury. [ABSTRACT FROM AUTHOR]

Objective: To determine whether common polymorphisms in CACNA1G, CACNA1H, CACNA1I, and ABCB1 are associated with differential short-term seizure outcome in childhood absence epilepsy (CAE).Methods: Four hundred forty-six CAE children in a randomized double-blind trial of ethosuximide, lamotrigine, and valproate had short-term seizure outcome determined. Associations between polymorphisms (minor allele frequency ≥ 15%) in 4 genes and seizure outcomes were assessed. In vitro electrophysiology on transfected CACNA1H channels determined impact of 1 variant on T-type calcium channel responsiveness to ethosuximide.Results: Eighty percent (357 of 446) of subjects had informative short-term seizure status (242 seizure free, 115 not seizure free). In ethosuximide subjects, 2 polymorphisms (CACNA1H rs61734410/P640L, CACNA1I rs3747178) appeared more commonly among not-seizure-free participants (p = 0.011, odds ratio [OR] = 2.63, 95% confidence limits [CL] = 1.25-5.56; p = 0.026, OR = 2.38, 95% CL = 1.11-5.00). In lamotrigine subjects, 1 ABCB1 missense polymorphism (rs2032582/S893A; p = 0.015, OR = 2.22, 95% CL = 1.16-4.17) was more common in not-seizure-free participants, and 2 CACNA1H polymorphisms (rs2753326, rs2753325) were more common in seizure-free participants (p = 0.038, OR = 0.52, 95% CL = 0.28-0.96). In valproate subjects, no common polymorphisms were associated with seizure status. In vitro electrophysiological studies showed no effect of the P640L polymorphism on channel physiology in the absence of ethosuximide. Ethosuximide's effect on rate of decay of CaV 3.2 was significantly less for P640L channel compared to wild-type channel.Interpretation: Four T-type calcium channel variants and 1 ABCB1 transporter variant were associated with differential drug response in CAE. The in vivo P640L variant's ethosuximide effect was confirmed by in vitro electrophysiological studies. This suggests that genetic variation plays a role in differential CAE drug response. Ann Neurol 2017;81:444-453. [ABSTRACT FROM AUTHOR]

The primary objectives of this study were to determine the prevalence of nonconvulsive seizures and nonconvulsive status epilepticus in patients with abusive head trauma who underwent electroencephalography (EEG) monitoring and to describe predictive factors for this population. Children with a diagnosis of abusive head trauma were studied retrospectively to determine the rate of EEG monitoring, the rate of nonconvulsive seizures and nonconvulsive status epilepticus, and the associated neuroimaging findings. Over 11 years, 73 of 199 (36.8%) children with abusive head trauma had electroencephalography monitoring performed. Of these, 20 (27.4%) had nonconvulsive seizures and 3 (4.1%) had nonconvulsive status epilepticus. The presence of subarachnoid hemorrhage and cortical T2 / fluid-attenuated inversion recovery signal abnormalities were both significantly associated with the presence of nonconvulsive seizures / nonconvulsive status epilepticus. Nonconvulsive seizures are relatively common in abusive head trauma and may go unrecognized. Specific neuroimaging characteristics increase the likelihood of nonconvulsive seizures on EEG. [ABSTRACT FROM AUTHOR]

Purpose Implantation of subdural grids and invasive electroencephalography (EEG) monitoring is important to define the ictal-onset zone and eloquent cortex in selected patients with medically refractory epilepsy. The objective of this systematic review is to summarize data about adverse events related to this procedure. Methods English-language studies published up to July 2012, reporting such adverse events were reviewed. Outcome measures included demographic variables; surgical protocol including number of subdural electrodes implanted per patient, duration of monitoring, antibiotic, and steroid prophylaxis; and adverse events. Key Findings Twenty-one studies were identified including a total of 2,542 patients. The reported mean number of electrodes per patient and duration of monitoring varied from 52 to 95 and 5 to 17 days, respectively. There is a trend toward more uniform use of antibiotics and steroids in the perioperative period. Neurologic infections (pooled prevalence 2.3%, 95% confidence interval 1.5-3.1), superficial infections (3.0%, 1.9-4.1), intracranial hemorrhage (4.0%, 3.2-4.8), and elevated intracranial pressure (2.4%, 1.5-3.3) were found to be the most common adverse events. Up to 3.5% of patients required additional surgical procedure(s) for management of these adverse events. Increased number of electrodes (≥67) was found to be independently associated with increased incidence of adverse events. Significance Although providing critical information for patients with medically refractory epilepsy, subdural grids implantation and invasive EEG monitoring entails risks of infection, hemorrhage, and elevated intracranial pressure. The prevalence estimates, likely to be conservative due to selective reporting, are expected to be helpful in counseling patients. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the incidence and describe the factors influencing ictal cardiac arrhythmias in children with epilepsy. A 2-year review within a pediatric epilepsy monitoring unit revealed 2066 electrographically confirmed seizures in 139 patients. Demographic, seizure, and cardiac variables were collected for each patient. Fisher''s exact test, Wilcoxon rank-sum test, and Spearman''s rank correlation coefficient were used to identify significant differences and associations at the seizure and patient levels. In 244 seizures meeting inclusion criteria, ictal cardiac arrhythmias were seen in 45% of the seizures (40% of the patients). The most common arrhythmia was benign respiratory sinus arrhythmia (78% of seizures with arrhythmias, 70% of patients with arrhythmias). Potentially serious arrhythmias included irregular variable arrhythmias, and abnormal QRS intervals were seen in 12% of all the patients. In seizures with ictal arrhythmias, 64% occurred in male patients (P = 0.016) and 78% occurred in white patients (P = 0.013). This study estimates the incidence of ictal arrhythmias within the pediatric population that need further medical attention and management. [Copyright &y& Elsevier]

A letter to the editor is presented in response to the article related to electroencephalography (EEG) monitoring with subdural grid electrodes in a 2013 issue.

Objective: The aim of this study was to quantify the accuracy of 24-hour video electroencephalography (vEEG) for the diagnosis of epilepsy when a patient's typical paroxysmal event was not captured (no-event vEEG).Methods: We performed a retrospective chart review of all first-time 24 hour no-event vEEG studies at Cincinnati Children's Hospital Medical Center. Clinician diagnosis of epilepsy with a minimum of one year follow-up was used as the reference standard to calculate diagnostic accuracy. Sensitivity and specificity of routine EEG (rEEG) and vEEG were compared in patients with both studies, and factors affecting the accuracy of vEEG were explored with a multivariable analysis.Results: No-event vEEG showed sensitivity of 0.54 (95% confidence interval [CI] 0.44 to 0.64) and specificity of 0.88 (95% CI 0.84 to 0.92) respectively, with a diagnostic odds ratio of 7.53 (95% CI 4.45 to 12.76). The sensitivity of vEEG was statistically superior to that of rEEG, whereas specificity was comparable. Age emerged as the only factor that affected the diagnostic accuracy of no-event vEEG.Conclusion: Even in the absence of a typical seizure or spell, video EEG is a useful test for predicting or excluding epilepsy, with diagnostic accuracy that is superior to rEEG and unaffected by the presence of a chronic neurological condition. [ABSTRACT FROM AUTHOR]

Background: Electrographic status epilepticus in slow sleep or continuous spike and waves during slow-wave sleep is an epileptic encephalopathy characterized by seizures, neurocognitive regression, and significant activation of epileptiform discharges during nonrapid eye movement sleep. There is no consensus on the diagnostic criteria and evidence-based optimal treatment algorithm for children with electrographic status epilepticus in slow sleep.Patient Description: We describe a 12-year-old girl with drug-resistant electrographic status epilepticus in slow wave sleep that was successfully treated with vagus nerve stimulation. Her clinical presentation, presurgical evaluation, decision-making, and course after vagus nerve stimulator implantation are described in detail.Findings: After vagus nerve stimulator implantation, the girl remained seizure free for more than a year, resolved the electrographic status epilepticus in slow sleep pattern on electroencephalography, and exhibited significant cognitive improvement.Conclusion: Vagus nerve stimulation may be considered for electrographic status epilepticus in slow sleep. [ABSTRACT FROM AUTHOR]

Purpose There is wide variation in clinical practice regarding the role of electrocorticography immediately after resection (post-resection ECoG) for pediatric epilepsy surgery. Results can guide further resection of potentially epileptogenic tissue. We hypothesized that post-resection ECoG spiking represents a biomarker of the epileptogenic zone and predicts seizure outcome in children undergoing epilepsy surgery. Methods We retrospectively identified 124 children with post-resection ECoG performed on the margins of resection. ECoG records were scored in a blinded fashion based on presence of frequent spiking. For patients identified as having additional resection based on clinical post-resection ECoG interpretation, these “second-look” ECoG results were re-reviewed for ongoing discharges or completeness of resection. Frequent spike populations were grouped using a standard scoring system into three ranges: 0.1–0.5 Hz, 0.5–1 Hz, >1 Hz. Seizure outcomes were determined at minimum 12-month followup. Results Of 124 patients who met inclusion criteria, 60 (48%) had an identified spike population on post-resection ECoG. Thirty (50%) of these had further resection based on clinical interpretation. Overall, good outcome (ILAE 1) was seen in 56/124 (45%). Completeness of resection of spiking (absence of spiking on initial post-resection ECoG or resolution of spiking after further resection) showed a trend toward good outcome (OR 2.03, p = 0.099). Patients with completeness of resection had good outcome in 41/80 (51%) of cases; patients with continued spikes had good outcome in 15/44 (35%) of cases. Conclusions Post-resection ECoG identifies residual epileptogenic tissue in a significant number of children. Lower frequency or absence of discharges on initial recording showed a trend toward good outcome. Completeness of resection demonstrated on final ECoG recording did not show a significant difference in outcome. This suggests that post-resection discharges represent a prognostic marker rather than a remediable biomarker of the epileptogenic zone in all patients. Resecting residual spike-generating cortex may be beneficial in selected patients, including children with tumors. [ABSTRACT FROM AUTHOR]