What predicts enduring intractability in children who appear medically intractable in the first 2 years after diagnosis?

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.

Predictors of medical intractability in children with epilepsy onset during the first two years of life, excluding infantile epileptic spasm syndrome

PURPOSE

Early childhood epilepsy presents a significant challenge, with approximately 30 % of individuals experiencing treatment failure. This study aimed to identify predictors of medical intractability in children with epilepsy onset during the first two years of life, excluding infantile epileptic spasm syndrome.

METHODS

A total of 323 children were retrospectively evaluated. The analyses included a review of medical records for demographic, laboratory, radiological, and electroencephalographic (EEG) findings. Children were diagnosed with drug-resistant epilepsy (DRE) according to the ILAE diagnostic criteria. Twenty-one potential prognostic predictors were examined in relation to medical intractability.

RESULTS

Among the 323 children (56.7 % male), 119 (36.8 %) had unknown epilepsy, 131 (40.6 %) had structural epilepsy, 53 (16.4 %) had genetic epilepsy, and 20 (6.2 %) had metabolic epilepsy. Over a median follow-up of 68 months, 55.4 % of the children achieved ≥6 months of seizure freedom, 33.1 % developed DRE, and the remaining 11.5 % had rare ongoing seizures but did not meet the criteria for DRE because they were only treated with one antiseizure medication at the last follow-up. Univariate logistic regression analyses identified ten risk factors significantly associated with DRE. Multivariate logistic regression analyses revealed that the presence of developmental delay at epilepsy onset (p = 0.000; OR 7.890; 95 %CI 2.713 to 22.945), history of status epilepticus (p = 0.000; OR 8.247; 95 %CI 3.619 to 18.793), number of antiseizure medications (ASMs) at the sixth month of diagnosis (p = 0.000; OR 20.585; 95 %CI 8.993 to 47.117), and initial EEG findings (p = 0.046; OR 2.366; 95 %CI 1.015 to 5.518) were predictors of medical intractability. Nineteen (5.9 %) children died during follow-up for various reasons, including progressive neurogenetic or neurodegenerative disorders.

CONCLUSION

Developmental delay at epilepsy onset, a history of status epilepticus, the use of two or more ASMs in the sixth month of diagnosis, and abnormal initial EEG findings were associated with medical intractability.

Prevalence and Risk Factors for Pharmacoresistance in Children With Focal Cortical Dysplasia-Related Epilepsy

BACKGROUND AND OBJECTIVES

Focal cortical dysplasia (FCD) is the most common cause of surgically remediable epilepsy in children. Little is known about the risk factors for the timing and development of pharmacoresistance in this population. This study sought to evaluate the prevalence and risk factors for pharmacoresistance in pediatric FCD-related epilepsy.

METHODS

In this retrospective single-center cohort design, patients were identified from search of centralized radiology report database and a central epilepsy surgical database. Inclusion criteria consisted of 3T MRI-confirmed FCD from January, 2011, to January, 2020; ages 0 days to 22 years at MRI; and at least 18 months of documented follow-up after MRI, unless had single seizure or incidentally discovered FCD. Records were excluded if there was dual pathology (except for mesial temporal sclerosis), hemimegalencephaly, or tuberous sclerosis complex present in imaging or history.

RESULTS

One hundred forty-three patients with confirmed FCD met the inclusion criteria. One hundred twenty-four children had epilepsy (87% of patients with FCD) with median age at seizure onset 2.7 years (IQR 0.75-6 years, range 0-17 years). Twelve children (8.5%) had a single lifetime seizure (provoked or unprovoked) or recurrent provoked seizures. Seven children (4.9%) had incidental FCD. Ninety-two patients (74%) of those with epilepsy met criteria for pharmacoresistance. Of children with epilepsy of all types, 93 children (75%) were seizure-free at the last visit; 82 patients underwent epilepsy surgery, of whom 59 (72%) achieved seizure freedom. Seven percent (9/124) achieved seizure freedom with a second ASM and 5.6% (7/124) with a third or more ASMs. Failure of only 1 antiseizure medication is associated with enormous increased incidence and earlier development of pharmacoresistance (OR 346; 95% CI 19.6-6,100); Cox regression showed FCD lobar location, pathologic subtype, and age at seizure onset are not.

DISCUSSION

Failure of 1 antiseizure medication is associated with substantial risk of pharmacoresistance. These data support an operational redefinition of pharmacoresistance, for surgical planning, in FCD-related epilepsy to the failure of 1 antiseizure medication and support early, potentially curative surgery to improve outcomes in this patient population.

Risk factors predicting intractability in focal epilepsy in children under 3 years of age: A cohort study

BACKGROUND

Focal onset epilepsy carries a higher risk of intractability than generalized onset epilepsy. Knowledge of the risk factors of intractability will help guide the treatment of children with focal epilepsy. In addition to risk factors present at initial diagnosis, the evolution of clinical and electroencephalographic features may also play a role in predicting intractability.

METHODS

A prospective cohort study was done on children aged one month to three years with newly diagnosed focal epilepsy. Initial treatment of carbamazepine was given according to a standard protocol after assessment of clinical manifestations, neurologic and developmental status, EEG, and brain MRI. Depending on response to therapy, subjects may also receive valproic acid or phenobarbitone following the protocol. Follow-up was done in the second week and every month thereafter. At the end of the study period, seizure type was re-assessed and a repeat neurological and developmental examination and EEG was obtained to evaluate the role of clinical and EEG evolution in predicting intractability.

RESULTS

Out of 71 subjects, 21 (29.6%) had intractable epilepsy at the end of the study period. Age of onset (p = 0.216) and neurological status (p = 0.052) were not associated with intractable epilepsy. On logistic regression analysis, evolution of seizure type (p < 0.001; RR 56.45; 95%CI 6.56 to 485.85) and evolution of background EEG rhythm (p < 0.001; RR 56.51; 95%CI 2.77 to 1152.16) were significantly associated with intractable epilepsy.

CONCLUSIONS

Changes in seizure type and baseline EEG rhythm may predict intractability in children one month to three years of age with focal epilepsy.

The efficacy comparison of classic ketogenic diet and modified Atkins diet in children with refractory epilepsy: a clinical trial

Dietary therapy has an important role in the therapeutic process in children suffering refractory epilepsy. There are two kinds of dietary therapy which are the most common in children with refractory epilepsy: The classic ketogenic diet (KD) and the modified Atkins diet (MAD). The purpose of the present study was to compare the efficacy, tolerability, and compliance of these two dietary therapies in the children who have refractory epilepsy during 6 months of treatment. From March 2017 to November 2018, 45 children aged 2-15 years who had refractory epilepsy were randomly allocated in KD or MAD group. The intervention period was 6 months in both groups. The frequencies of seizures were determined from parental reports and were compared between the groups. The patients with upper than 50% reduction in seizure frequency were deemed as responders to the diets. Twenty-four patients were assigned to the KD and 11 patients to the MAD. Overall, 45.8% of children treated with the KD and 45.5% of children treated with MAD had over than 50% response to the diet therapies. The difference was not statistically significant (P = 0.437). The MAD was more advantageous regarding better tolerability and fewer side effects. There is not much difference regarding the efficacy between the MAD and classic KD. The MAD with fewer side effects may be more suitable as the first line of dietary therapy in children with refractory epilepsy.

Neuroimaging of Childhood Epilepsy: Focal versus Generalized Epilepsy

Neuroimaging plays an increasingly crucial role in delineating the pathophysiology, and guiding the evaluation, management and monitoring of epilepsy. Imaging contributes to adequately categorizing seizure/epilepsy types in complex clinical situations by demonstrating anatomical and functional changes associated with seizure activity. This article reviews the current status of multimodality neuroimaging in the pediatric population, including focal lesions which may result in focal epileptic findings, focal structural abnormalities that may manifest as generalized epileptiform discharges, and generalized epilepsy without evidence of detectable focal abnormalities.

Alterations in the metabolic networks of temporal lobe epilepsy patients: A graph theoretical analysis using FDG-PET

OBJECTIVE

The aim of this study is to investigate changes in metabolic networks based on fluorodeoxyglucose positron emission tomography (FDG-PET) in patients with drug-resistant temporal lobe epilepsy (TLE) (with and without hippocampal sclerosis [HS]) when compared with healthy controls.

METHODS

We retrospectively enrolled 30 patients with drug-resistant temporal lobe epilepsy (17 patients with HS and 13 patients without HS) and 39 healthy controls. All subjects underwent interictal FDG-PET scans, which were analyzed to obtain metabolic connectivity using graph theoretical analysis. We investigated the differences in metabolic connectivity between patients with drug-resistant TLE (with and without HS) and healthy controls.

RESULTS

When compared with healthy controls, TLE patients with HS showed alterations of global and local metabolic connectivity. When considering global connectivity, TLE patients with HS had a decreased average degree with increased modularity. When considering local connectivity, TLE patients with HS displayed alterations of betweeness centrality in widespread regions. However, there were no alterations of global metabolic connectivity in TLE patients without HS when compared with healthy controls. In addition, when compared to TLE patients without HS, TLE patients with HS had increased modularity.

SIGNIFICANCE

Our study demonstrates more severe alterations in metabolic networks based on FDG-PET in TLE patients with HS than in those without HS and healthy controls. This may represent distinct epileptic networks in TLE patients with HS versus those without HS, although both are drug-resistant focal epilepsy.

Seizures in Children

Epilepsy is one of the most common neurologic disorders seen in children, with the highest incidence in the first year of life. Diagnostic accuracy can be challenging because many seizure mimics must be considered. Electroencephalography and neuroimaging can be critical in determining etiology and syndrome. Genetic testing is a high-yield endeavor, particularly in early-life epilepsies. Up to one-fourth of children with epilepsy will develop drug-resistant seizures. Comorbidities are very common in children with epilepsy, including intellectual disability in 25% and learning disability and attention-deficit/hyperactivity disorder in a significant minority. These comorbidities must be recognized and addressed as part of the child's overall care.

Earlier Is Not Always Better: Outcomes When Epilepsy Occurs in Early Life Versus Adolescence

Immediate Outcomes in Early Life Epilepsy: A Contemporary Account

Berg AT, Wusthoff C, Shellhaas RA, et al. Epilepsy Behav. 2019;97:44-50. doi:10.1016/j.yebeh.2019.05.011. Epub 2019 Jun 7. PMID: 31181428

Rationale:

Early-life epilepsies include some of the most challenging forms of epilepsy to manage. Given recent diagnostic and therapeutic advances, a contemporary assessment of the immediate short-term outcomes can provide a valuable framework for identifying priorities and benchmarks for evaluating quality improvement efforts.

Methods:

Children with newly diagnosed epilepsy and onset <3 years were prospectively recruited through 17 US hospitals, from 2012 to 2015 and followed for 1 year after diagnosis. Short-term outcome included mortality, drug resistance, evolution of nonsyndromic epilepsy to infantile spasms (IS) and from IS to other epilepsies, and developmental decline. Multivariable analyses assessed the risk of each outcome.

Results:

Seven hundred seventy-five children were recruited, including 408 (53%) boys. Median age at onset was 7.5 months (interquartile range [IQR]: 4.2-16.5), and 509 (66%) had onset in the first year of life. Of 22 deaths that occurred within 1 year of epilepsy diagnosis, 21 were children with epilepsy onset in infancy (<12 months). Of 680 children followed ≥6 months, 239 (35%) developed drug-resistant seizures; 34/227 (15%) infants with nonsyndromic epilepsy developed IS, and 48/210 (23%) initially presenting with IS developed additional seizure types. One hundred (23%) of 435 with initially typical development or only mild/equivocal delays at seizure onset, had clear developmental impairment within 1 year after initial diagnosis. Each outcome had a different set of predictors; however, younger age and impaired development at seizure onset were broadly indicative of poorer outcomes. Type of epilepsy and early identification of underlying cause were not reliable predictors of these outcomes.

Conclusion:

Early-life epilepsies carry a high risk of poor outcome which is evident shortly after epilepsy diagnosis. Onset in infancy and developmental delay is associated with an especially high risk, regardless of epilepsy type. The likelihood of poor outcomes is worrisome regardless of specific clinical profiles.