When Should a Brain MRI Be Performed in Children with New-Onset Seizures? Results of a Large Prospective Trial

Predictors of drug-resistant epilepsy in childhood epilepsy syndromes: A subgroup analysis from a prospective cohort study

OBJECTIVE

Previous studies assessing factors associated with drug-resistant epilepsy (DRE) were constrained by their amalgamation of all epilepsy syndromes in their analyses and the absence of uniform criteria for defining DRE. Our objective was to identify predictors of DRE among the four primary childhood epilepsy syndrome groups within a cohort of children with new onset seizures, using the International League Against Epilepsy (ILAE) definition of DRE and the recent classification of epilepsies.

METHODS

This is a prospective study of 676 children with new onset seizures initiated on antiseizure medication. Patients were monitored for the occurrence of DRE according to the ILAE criteria and were categorized into one of four epilepsy groups: self-limited focal epilepsies (SeLFEs), genetic generalized epilepsies (GGEs), developmental epileptic encephalopathies (DEEs), and focal epilepsies. Cox regression analysis was performed to identify predictors of DRE within each epilepsy group.

RESULTS

Overall, 29.3% of children were classified as having DRE, with the highest incidence observed among children diagnosed with DEEs (77.7%), followed by focal epilepsies (31.5%). Across the entire cohort, predictors of DRE included the presence of an epileptogenic lesion, a higher pretreatment number of seizures, experiencing multiple seizure types, presence and severity of intellectual and developmental delay, myoclonus, and younger age at epilepsy onset. Within the GGEs, only a younger age at seizure onset and experiencing multiple seizure types predicted DRE. Among focal epilepsies, predictors of DRE included the presence of an epileptogenic lesion, experiencing multiple seizure types, and having a greater number of pretreatment seizures. Within the DEEs, predictors of DRE were the occurrence of tonic seizures. Predictors of DRE within SeLFEs could not be identified.

SIGNIFICANCE

This study indicates that different epilepsy syndromes are associated with distinct predictors of drug resistance. Anticipation of drug resistance within various groups is feasible using accessible clinical variables throughout the disease course.

Utility of Gadolinium-Based Contrast in Initial Evaluation of Seizures in Children Presenting Emergently

BACKGROUND AND PURPOSE

The frequency and utility of gadolinium in evaluation of acute pediatric seizure presentation is not well known. The purpose of this study was to assess the utility of gadolinium-based contrast agents in MR imaging performed for the evaluation of acute pediatric seizure presentation.

MATERIALS AND METHODS

We identified consecutive pediatric patients with new-onset seizures from October 1, 2016, to September 30, 2021, who presented to the emergency department and/or were admitted to the inpatient unit and had an MR imaging of the brain for the evaluation of seizures. The clinical and imaging data were recorded, including the patient's age and sex, the use of IV gadolinium, and the underlying cause of epilepsy when available.

RESULTS

A total of 1884 patients were identified for inclusion. Five hundred twenty-four (28%) patients had potential epileptogenic findings on brain MR imaging, while 1153 (61%) patients had studies with normal findings and 207 (11%) patients had nonspecific signal changes. Epileptogenic findings were subclassified as the following: neurodevelopmental lesions, 142 (27%); intracranial hemorrhage (traumatic or germinal matrix), 89 (17%); ischemic/hypoxic, 62 (12%); hippocampal sclerosis, 44 (8%); neoplastic, 38 (7%); immune/infectious, 20 (4%); phakomatoses, 19 (4%); vascular anomalies, 17 (3%); metabolic, 3 (<1%); and other, 90 (17%). Eight hundred seventy-four (46%) patients received IV gadolinium. Of those, only 48 (5%) cases were retrospectively deemed to have necessitated the use of IV gadolinium: Fifteen of 48 (31%) cases were subclassified as immune/infectious, while 33 (69%) were neoplastic. Of the 1010 patients with an initial noncontrast study, 15 (1.5%) required repeat MR imaging with IV contrast to further evaluate the findings.

CONCLUSIONS

Gadolinium contrast is of limited additive benefit in the imaging of patients with an acute onset of pediatric seizures in most instances.

Risk of recurrence in patients with an unprovoked tonic-clonic seizure and generalized epileptiform discharges on EEG

OBJECTIVE

The decision to initiate treatment in patients with a first unprovoked seizure remains controversial. Studies have reported a recurrence rate ranging from 21%-50%, but most have included patients with different etiologies, electroencephalography (EEG) findings, and seizure types. This study aimed to determine the risk of recurrence in patients with a first unprovoked generalized tonic-clonic (GTC) seizure with evidence of generalized spike-wave discharges (GSWDs) on EEG and compare the efficacy of antiseizure medications (ASMs) in preventing recurrence.

METHODS

This prospective study included consecutive patients who presented with a single GTC seizure, evidence of GSWDs on EEG, and a follow-up period of at least 1 year. All patients underwent extensive evaluation, including a 3-hour sleep-deprived video-EEG recording and an epilepsy protocol brain magnetic resonance imaging (MRI). Treatment with ASMs was recommended for all patients. The decision regarding the specific ASM to be used was left to the treating physician's discretion.

RESULTS

A total of 57 patients with a median age of 19 years were included. A total of 41 patients agreed to be started on an ASM while 16 declined. Seizure recurred in 6 of 41 patients (14.6%) in the treated group compared to 11 of 16 (68.8%) in the untreated group (p = .00006). Valproate was significantly more efficacious than levetiracetam or lamotrigine (p = .04). Of the 15 patients who discontinued ASM treatment after remaining seizure-free for an average of 30 months, 6 (40%) experienced a seizure recurrence.

SIGNIFICANCE

Patients with a first unprovoked GTC seizure and evidence of GSWDs on EEG have a high risk of recurrence if left untreated. Valproate is the most efficacious ASM for preventing recurrence in this population. A sizeable proportion of patients can be successfully tapered off medication after a period of seizure freedom. This study provides valuable information for guiding treatment decisions in this patient population.

Early predictors of remission in children and adolescents with new-onset epilepsy: A prospective study

PURPOSE

This study aims to identify predictive factors of a two-year remission (2YR) in a cohort of children and adolescents with new-onset seizures based on baseline clinical characteristics, initial EEG and brain MRI findings.

METHODS

A prospective cohort of 688 patients with new onset seizures, initiated on treatment with antiseizure medication was evaluated. 2YR was defined as achieving at least two years of seizure freedom during the follow-up period. Multivariable analysis was performed and recursive partition analysis was utilized to develop a decision tree.

RESULTS

The median age at seizure onset was 6.7 years, and the median follow-up was 7.4 years. 548 (79.7%) patients achieved a 2YR during the follow up period. Multivariable analysis found that presence and degree of intellectual and developmental delay (IDD), epileptogenic lesion on brain MRI and a higher number of pretreatment seizures were significantly associated with a lower probability of achieving a 2YR. Recursive partition analysis showed that the absence of IDD was the most important predictor of remission. An epileptogenic lesion was a significant predictor of non-remission only in patients without evidence of IDD, and a high number of pretreatment seizures was a predictive factor in children without IDD and in the absence of an epileptogenic lesion.

CONCLUSION

Our results indicate that it is possible to identify patients at risk of not achieving a 2YR based on variables obtained at the initial evaluation. This could allow for a timely selection of patients who require close follow-up, consideration for neurosurgical intervention, or investigational treatments trials.

A tale of two cohorts: Differing outcomes in infantile-onset focal epilepsy

OBJECTIVE

Infants with focal-onset epilepsy are an understudied population, requiring additional evaluation for clinical assessment and prognostication. Our goal was to characterize the etiology and natural history of infantile-onset focal epilepsy.

METHODS

We retrospectively identified all infants (0-24 months) with onset of focal epilepsy while resident in Olmsted County, Minnesota, between 1980 and 2018, using the Rochester Epidemiology Project Database. We assessed the impact of etiology on both seizure and neurodevelopmental outcome, and mortality.

RESULTS

Of 686 children with epilepsy onset <18 years, 125 (18.2%) presented with focal-onset seizures in infancy. Median follow-up for this group was 10.9 years (interquartile range [IQR] 6.2, 19.3). Etiology was identified in 65.6% (structural N = 62, genetic N = 13, both structural and genetic N = 3, metabolic N = 4). Of 107 patients followed >2 years, 38 (35.5%) developed drug-resistant epilepsy (DRE). DRE was more likely with younger age at onset, known etiology, and presence of epileptic spasms. Sixty-eight (63.0% of those with follow-up) were developmentally delayed at last follow-up, and known etiology, DRE, and presence of epileptic spasms were significantly associated with delay (p < .001 for all). Fifteen patients (12.0%) died at a median age of 7.1 years (IQR 1.7, 21.7), but only one death was seizure related (suspected sudden unexpected death in epilepsy [SUDEP]). Of 20 infants with normal development at onset and no known etiology with >2 years follow-up, none developed DRE, all were seizure-free at last follow-up (95% off antiseizure medications [ASMs]), and all remained developmentally normal.

SIGNIFICANCE

Infantile-onset focal epilepsy accounts for 18% of all epilepsy in childhood, is frequently due to known etiologies, and has a high rate of DRE. However, developmentally normal infants without a known cause appear to have a very favorable course.