Investigatory pathway and principles of patient selection for epilepsy surgery candidates: a systematic review

Association of Localizing 18F-FDG-PET Hypometabolism and Outcome Following Epilepsy Surgery: Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Although commonly used in the evaluation of patients for epilepsy surgery, the association between the detection of localizing 18fluorine fluorodeoxyglucose PET (18F-FDG-PET) hypometabolism and epilepsy surgery outcome is uncertain. We conducted a systematic review and meta-analysis to determine whether localizing 18F-FDG-PET hypometabolism is associated with favorable outcome after epilepsy surgery.

METHODS

A systematic literature search was undertaken. Eligible publications included evaluation with 18F-FDG-PET before epilepsy surgery, with ≥10 participants, and those that reported surgical outcome at ≥12 months. Random-effects meta-analysis was used to calculate the odds of achieving a favorable outcome, defined as Engel class I, International League Against Epilepsy class 1-2, or seizure-free, with localizing 18F-FDG-PET hypometabolism, defined as concordant with the epilepsy surgery resection zone. Meta-regression was used to characterize sources of heterogeneity.

RESULTS

The database search identified 8,916 studies, of which 98 were included (total patients n = 4,104). Localizing 18F-FDG-PET hypometabolism was associated with favorable outcome after epilepsy surgery for all patients with odds ratio (OR) 2.68 (95% CI 2.08-3.45). Subgroup analysis yielded similar findings for those with (OR 2.64, 95% CI 1.54-4.52) and without epileptogenic lesion detected on MRI (OR 2.49, 95% CI 1.80-3.44). Concordance with EEG (OR 2.34, 95% CI 1.43-3.83), MRI (OR 1.69, 95% CI 1.19-2.40), and triple concordance with both (OR 2.20, 95% CI 1.32-3.64) was associated with higher odds of favorable outcome. By contrast, diffuse 18F-FDG-PET hypometabolism was associated with worse outcomes compared with focal hypometabolism (OR 0.34, 95% CI 0.22-0.54).

DISCUSSION

Localizing 18F-FDG-PET hypometabolism is associated with favorable outcome after epilepsy surgery, irrespective of the presence of an epileptogenic lesion on MRI. The extent of 18F-FDG-PET hypometabolism provides additional information, with diffuse hypometabolism associated with worse surgical outcome than focal 18F-FDG-PET hypometabolism. These findings support the incorporation of 18F-FDG-PET into routine noninvasive investigations for patients being evaluated for epilepsy surgery to improve epileptogenic zone localization and to aid patient selection for surgery.

Health Care System Costs Associated With Surgery and Medical Therapy for Children With Drug-Resistant Epilepsy in Ontario

BACKGROUND AND OBJECTIVES

Improvement in seizure control after epilepsy surgery could lead to lower health care resource use and costs, but it is uncertain whether this could offset the high costs related to surgery. This study aimed to evaluate phase-specific and cumulative long-term health care costs of surgery compared to medical therapy in children with drug-resistant epilepsy from the health care payer perspective.

METHODS

Children who were evaluated for epilepsy surgery and treated with surgery or medical therapy from 2003 to 2018 at the Hospital for Sick Children in Toronto were identified from chart review and linked to their health administrative databases in Ontario, Canada. Inverse probability of treatment weighting with stabilized weights was used to balance the baseline covariates between the 2 groups. Patients were assigned to presurgery, surgery, short-term (first 2 years), intermediate-term (2-5 years), and long-term (>5 years) postsurgery care phases on the basis of treatment trajectory. Phase-specific and cumulative long-term health care costs were evaluated. Costs were converted from Canadian to US dollars year 2018 value.

RESULTS

There were 372 surgical and 258 medical patients. Costs were higher in surgical than medical patients for presurgery (3 and 39 weeks), surgery, and short-term care phase, and the attributable costs of surgery per 7 patient-days were $1,602 (95% CI $1,438-$1,785), $172 (95% CI $147-$185), $19,819 (95% CI $18,822-$20,932), and $28 (95% CI $22-$32), respectively. Costs were lower in surgical patients for intermediate- and long-term care phase, and the attributable costs were -$72 (95% CI -$124 to -$35) and -$94 (95% CI -$129 to -$63), respectively. In surgical patients, costs were highest for surgery followed by presurgery care phase, with hospitalizations accounting for the highest cost component. In medical patients, costs increased gradually from presurgery to long-term care phase. Cumulative costs were higher for surgical than medical patients in the first 7 years after surgery, but from 8 years on, costs were lower for surgical patients.

DISCUSSION

This study demonstrated the long-term economic benefits of epilepsy surgery compared to medical therapy for the health care system with the use of real-world data, which would justify the high costs of surgery. The results will support future economic evaluation comparing minimally invasive treatment such as laser therapy to surgery.

Educational needs of physicians (in training) for management of patients with epilepsy

OBJECTIVES

To investigate the opinions of medical students, residents in different disciplines, and clinical attendings in various disciplines on the educational needs and learning objectives about epilepsy at the basic and intermediate levels of medical education.

METHODS

On July 15th, 2021, we posted an online invitation including a questionnaire to all the medical students, residents, and attendings of Shiraz University of Medical Sciences, Iran. The survey anonymously collected data about the participants [sex, age, educational level, and their disciplines (attendings)], and answers to the questions about their opinions about the educational needs and learning objectives of the medical students and residents about epilepsy.

RESULTS

Five hundred and seventy-eight trainees and 53 attendings participated in the study. Trainees at different educational levels and in various disciplines had significantly different opinions on their educational needs and learning objectives about epilepsy. At the undergraduate level, the opinions of the trainees and their attendings were similar and the most reported needs by both groups included: Terminology and definitions, Physiopathology and etiology, Semiology and clinical characteristics, Medical treatment, Comorbidities. For the residents in neurology, psychiatry, and neurosurgery, the most reported needs included: all aspects of epilepsy.

SIGNIFICANCE

Trainees at various educational levels/disciplines in medicine have different educational needs and learning objectives with regard to epilepsy and management of PWE. Policy makers in medical education should consider the observations of this study in order to design tailored and targeted educational curricula about epilepsy for various educational levels/disciplines in medicine.

The role of preoperative diffusion tensor imaging in predicting and improving functional outcome in pediatric patients undergoing epilepsy surgery: a systematic review

OBJECTIVE

Diffusion tensor imaging (DTI) is a useful neuroimaging technique for surgical planning in adult patients. However, no systematic review has been conducted to determine its utility for pre-operative analysis and planning of Pediatric Epilepsy surgery. We sought to determine the benefit of pre-operative DTI in predicting and improving neurological functional outcome after epilepsy surgery in children with intractable epilepsy.

METHODS

A systematic review of articles in English using PubMed, EMBASE and Scopus databases, from inception to January 10, 2020 was conducted. All studies that used DTI as either predictor or direct influencer of functional neurological outcome (motor, sensory, language and/or visual) in pediatric epilepsy surgical candidates were included. Data extraction was performed by two blinded reviewers. Risk of bias of each study was determined using the QUADAS 2 Scoring System.

RESULTS

13 studies were included (6 case reports/series, 5 retrospective cohorts, and 2 prospective cohorts) with a total of 229 patients. Seven studies reported motor outcome; three reported motor outcome prediction with a sensitivity and specificity ranging from 80 to 85.7 and 69.6 to 100%, respectively; four studies reported visual outcome. In general, the use of DTI was associated with a high degree of favorable neurological outcomes after epilepsy surgery.

CONCLUSION

Multiple studies show that DTI helps to create a tailored plan that results in improved functional outcome. However, more studies are required in order to fully assess its utility in pediatric patients. This is a desirable field of study because DTI offers a non-invasive technique more suitable for children.

ADVANCES IN KNOWLEDGE

This systematic review analyses, exclusively, studies of pediatric patients with drug-resistant epilepsy and provides an update of the evidence regarding the role of DTI, as part of the pre-operative armamentarium, in improving post-surgical neurological sequels and its potential for outcome prediction.

Comparative economic outcomes in patients with focal seizures initiating eslicarbazepine acetate versus brivaracetam as their first adjunctive ASD

AIMS

To study the association between initiation of first adjunctive therapy with eslicarbazepine acetate (ESL) vs. brivaracetam (BRV) on healthcare resource utilization (HCRU) and charges among patients with treated focal seizures (FS).

MATERIALS AND METHODS

Symphony Health's Integrated Dataverse (IDV) claims data (1 April 2015 to 30 June 2018) were used to identify two cohorts as first adjunctive therapy with ESL or BRV following a generic anti-seizure drug (ASD). The index date was the earliest claim for a new ESL or BRV prescription. Key inclusion criteria were only 1 generic ASD in the 12 months before the index date; ≥1 medical claim with an FS diagnosis. Unit of analysis was the 90-day person-time-block. Changes in HCRU and charges were assessed using a difference-in-differences framework. Both unadjusted and adjusted analyses were performed. The adjusted model utilized person-specific fixed effects and propensity score-based weighting to control for differences in baseline covariates. Bias-corrected bootstrap confidence intervals (CIs) were calculated for charge outcomes.

RESULTS

208 and 137 patients initiated first adjunctive therapy with ESL (43.7 years, 51.9% female) or BRV (39.3 years, 51.8% female). Patients in the ESL cohort had numerically larger reductions in all-cause and FS-related inpatient hospitalizations and outpatient visits and FS-related emergency department visits. Compared to patients initiating BRV, patients treated with ESL had significantly larger reductions in total charges (-$3,446, CI: -$13,716, -$425), all-cause (-$3,166, CI: -$13,991, -$323) and FS-related (-$2,969, CI: -$21,547, -$842) medical charges, all-cause (-$3,397, CI: -$15,676, -$818) and FS-related (-$2,863, CI: -$19,707, -$787) outpatient charges, and non-ASD-related prescription charges (-$420, CI: -$1,058, -$78).

LIMITATIONS

Claims may be missing, or miscoded; outcomes may be influenced by variables not accounted for in the analysis; only information on submitted charges was included.

CONCLUSIONS

Among patients with FS, initiation of first adjunctive therapy with ESL was associated with significantly larger reductions in medical and non-ASD-related prescriptions charges compared to BRV.

Response to antiepileptic drugs after unsuccessful epilepsy surgery: A multivariate analysis of 103 patients

OBJECT

Epilepsy patients may still have seizures after surgery, and there have been few studies on the response to antiepileptic drugs (AEDs) after surgery failure. The purpose of this study was to analyze the response to AEDs after unsuccessful epilepsy surgery.

METHODS

Patients who underwent unsuccessful epilepsy surgery between January 1999 and January 2019 were evaluated. Patient demographics, etiology, factors related to surgery and AED use patterns were assessed.

RESULTS

After excluding the 5 patients who were lost to follow-up and the 2 patients who died, the records of 103 consecutive patients were analyzed. Ninety patients (87.4 %) had seizure recurrence within one year after surgery, 2 (1.9 %) patients had recurrence from one year to two years after surgery, and 11 (10.7 %) patients had recurrence two or more years after surgery (2-10 years). After surgery failure, the patients tried at least 2 kinds of AEDs with different mechanisms for more than 2 years. The average total number of AEDs used was 5.97, the average number of AEDs used before surgery was 3.21, and the average number of AEDs used after surgery was 4.02. After retreatment with AEDs, 10 patients (9.7 %) were seizure-free, 18 patients' (17.5 %) seizures were alleviated, and 75 patients (72.8 %) had seizures as they did prior to the adjustments. The number of AEDs used before and after surgery and the total number of AEDs were not significantly different among the seizure free group, alleviated seizure group and no change group. There were no significant differences in seizure onset age, surgery age, etiology, time between seizure onset and surgery, magnetic resonance imaging, seizure type, localization and lateralization of the surgery site among the three groups.

CONCLUSIONS

The results showed that a small percentage of patients (27.2 %) who undergo unsuccessful epilepsy surgery benefit from AED adjustments; however, the vast majority of patients (72.8 %) do not benefit from AED adjustments.