Early resective surgery causes favorable seizure outcome in malformations of cortical development

Patient, parent and carer perspectives surrounding expedited paediatric epilepsy surgery

OBJECTIVE

Most paediatric epilepsies with MRI visible lesions do not respond to antiseizure pharmacotherapy. Such medication resistance, which often takes years to become formally defined, is commonly required for surgical candidacy. Expedited surgical referral at lesional epilepsy diagnosis may result in better seizure, cognitive and developmental prognoses. This study explored the views of patients, parents and carers regarding epilepsy surgery, treatment priorities, and participation in a proposed expedited surgery trial.

METHODS

205 patients, parents and carers (61% UK-based, 26% North American) responded to electronic surveys from February to May 2022. Participants were recruited through social media sites, epilepsy charities and societies. Categorical choice and free-text questions were used to investigate participant perspectives, and Pearson's chi-squared test was utilised to detect meaningful differences amongst respondent subgroups.

RESULTS

Almost 90% of respondents who had experienced epilepsy surgery (either themselves or their child) reported seizure cessation or reduction. Postoperative outcome measures prioritised most frequently were seizure freedom (66%), quality of life (47%), seizure severity (30%), seizure frequency (28%) and independence (27%). Most participants support expedited surgery in suitable patients (65%), with just over half (51%) willing to participate in the proposed trial. Many participants (37%) were undecided, often due to fears surrounding neurosurgery. Subgroup perspectives were broadly similar, with more parents and caregivers favouring expedited surgery compared to patients (p = .016) and more UK-based participants willing to take part in an expedited surgery trial compared to those from North America (p = .01).

CONCLUSIONS

Patients, parents and carers are open to considering expedited surgery for lesional epilepsies and would support a trial exploring this approach. Priorities from treatment were largely similar between participant subgroups, with seizure, quality of life and neuropsychological outcomes ranked highly. Accounting for these preferences will facilitate the delivery of a trial that is patient- and caregiver-focused, enhancing feasibility, satisfaction and benefit for prospective participants.

Surgical treatment for drug-resistant epilepsy due to early brain injury in children

BACKGROUND

The study aimed to summarize the indications and clinical features of pediatric drug-resistant epilepsy associated with early brain injury, surgical outcomes, and prognostic factors.

METHODS

We retrospectively analyzed children diagnosed with drug-resistant epilepsy due to early brain injury, who had undergone surgery at the Pediatric Epilepsy Center of Peking University First Hospital from May 2014 to May 2021. Clinical data of vasculogenic and non-vasculogenic injuries from early brain damage were compared and analyzed. The surgical outcomes were assessed using the Engel grading system.

RESULTS

The median ages at acquiring injury, seizure onset, and surgery among 65 children were 19.0 (0-120) days, 8.6 (0-136.5) months, and 62.9 (13.5-234) months, respectively. Of the 14 children with non-vasculogenic injuries, 12 had posterior ulegyria. Unilateral or bilateral synchronous interictal epileptiform discharges were located mainly in the posterior quadrant in 10 children (71 %), and unilateral posterior quadrant or non-lateralized ictal region in eight children (57 %). The surgical approach was mainly temporo-parieto-occipital or parieto-occipital disconnection in nine children. Of 49 children with vasculogenic injuries, magnetic resonance imaging revealed hemispheric abnormalities in 38. Unilaterally hemispheric or bilateral interictal epileptiform discharges were observed in 36 children (73 %), whereas 42 (86 %) had unilateral hemispheric or non-lateralized ictal onset. The surgical procedure involved hemispherotomy in 38 children (78 %) and lobectomy or disconnection, multilobectomy or disconnection and hemispherotomy in 5, 20, and 40 children, respectively. Fifty-five patients (84.6 %) achieved remission from seizure during follow-up at 5.4 years. Age at surgery (odds ratio = 1.022, 95 % confidence interval = 1.003-1.042, P = 0.023) and etiology (odds ratio = 17.25, 95 % confidence interval = 2.778-107.108, P = 0.002) affected the seizure outcomes.

CONCLUSION

Children with drug-resistant epilepsy due to early brain injury can successfully be treated with surgery after rigorous preoperative screening. Good surgical outcomes are associated with an early age at surgery and an etiology of vasculogenic injury.

Long-term Outcome of Epilepsy and Cortical Malformations Due to Abnormal Migration and Postmigrational Development: A Cohort Study

OBJECTIVE

To evaluate the long-term outcome of patients with epilepsy and malformations of cortical development (MCD).

METHODS

We conducted a historical cohort study of patients with epilepsy and MCD due to impaired neuronal migration and postmigration organization, and with a follow-up period of ≥5 years. For each patient, MCD was classified after accurate neuroimaging reappraisal by an expert neuroradiologist. The primary outcome was remission, defined as a period of seizure freedom ≥5 years at any time from epilepsy onset. We used Kaplan-Meier estimates for survival analysis, and univariate and multivariate Cox regression analyses to evaluate baseline variables as possible factors associated with remission.

RESULTS

The cohort included 71 patients (M/F=31/40) with a 17-year median follow-up (1506 person-years). About half (49.3%) had heterotopia, 35.2% polymicrogyria, 7% lissencephaly and 8.5% had the combination of two MCD. The mean age at seizure onset was 12.4±7.2 years. Intellectual disability and neurological deficits were observed in 30.4% and 40.9%, respectively. More than 60% of patients had refractory epilepsy. In three patients who underwent epilepsy surgery, MCD diagnosis was confirmed by histology. At last visit, 44% of patients had been seizure-free during the previous year, however none of them had stopped anti-seizure medication. Thirty patients achieved remission (Remission group, 42.2%) at some point in their disease history, whereas 41 individuals (Non Remission group, 57.8%) had never been in remission for ≥5 years. The cumulative remission rate was 38% by 20 years from inclusion. In the Cox model, unilateral distribution of MCD (HR: 2.68, 95% CI: 1.04-6.92) and a low seizure frequency at onset (HR: 5.01, 95% CI: 1.12-22.5) were significantly associated with remission.

CONCLUSIONS

Patients with epilepsy and MCD showed a remission rate of 38% by 20 years from onset. Unilateral distribution of the MCD is associated with a three-fold probability of achieving remission. About 40% of patients showed a drug-sensitive condition with risk of relapse during their epilepsy course.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that in patients with epilepsy and MCD, unilateral MCD and low seizure frequency at onset are associated with achieving epilepsy remission.

Epilepsy Surgery: Special Circumstances

Epilepsy surgery has proven to be very effective in treating refractory focal epilepsies in children, producing seizure freedom or partial seizure control well beyond any other medical or dietary therapies. While surgery is mostly utilized in certain clinical phenotypes, either based on the location such as temporal lobe epilepsy, or based on the presence of known epileptogenic lesions such as focal cortical dysplasia, tumors or hemimegalencephaly, there is a growing body of evidence to support the role of surgery in other patients' cohorts that were classically not thought of as surgical candidates. These include patients with rare genetic disorders, electrical status epilepticus in sleep, status epilepticus and the very young patients. Furthermore, epilepsy surgery is not considered as a "last resort" as seizure and cognitive outcomes of surgery are considerably better when done earlier rather than later in relation to the time of onset of epilepsy and age of surgery especially in the context of known focal cortical dysplasia. This article examines the accumulating evidence of the utility of epilepsy surgery in these special circumstances.

Predictors of surgical outcome in focal cortical dysplasia and its subtypes

OBJECTIVE

The authors analyzed predictors of surgical outcome in patients with focal cortical dysplasia (FCD) and its ILAE (International League Against Epilepsy) subtypes after noninvasive multimodal evaluation and calculated time to first seizure.

METHODS

Data of 355 patients with refractory epilepsy, confirmed FCD pathology, and 2-13 years of postsurgical follow-up were analyzed to determine the predictive roles of clinical, EEG, imaging, and surgical factors that influence seizure freedom.

RESULTS

The mean ± SD age at surgery was 20.26 ± 12.18 years. In total, 142 (40.0%) patients had daily seizures and 90 (25.3%) had multiple seizure types. MRI showed clear-cut FCD in 289 (81.4%) patients. Pathology suggested type I FCD in 27.3% of patients, type II in 28.4%, and type III in 42.8% of patients. At latest follow-up, 72.1% of patients were seizure free and 11.8% were seizure free and not receiving antiepileptic drugs. Among the subtypes, 88.8% of patients with type III, 69.3% with type II, and 50.5% with type I FCD were seizure free. Multiple seizure types, acute postoperative seizures (APOS), and type I FCD were predictors of persistent seizures, whereas type III FCD was the strongest predictor of seizure freedom. Type I FCD was associated with daily seizures, frontal and multilobar distribution, subtle findings on MRI, incomplete resection, and persistent seizures. Type II and III FCD were associated with clear-cut lesion on MRI, regional interictal and ictal EEG onset pattern, focal pattern on ictal SPECT, complete resection, and seizure freedom. Type III FCD was associated with temporal location, whereas type I and II FCD were associated with extratemporal location. Nearly 80% of patients with persistent seizures, mostly those with type I FCD, had their first seizure within 6 months postsurgery.

CONCLUSIONS

Long-term seizure freedom after surgery can be achieved in more than two-thirds of patients with FCD after noninvasive multimodal evaluation. Multiple seizure types, type I FCD, and APOS were predictors of persistent seizures. Seizures recurred in about 80% of patients within 6 months postsurgery.

Resistant Temporal Lobe Epilepsy: Initial Steps into a Bigger Epilepsy Surgery Program

Background  Among the patients of drug-resistant epilepsy, a subset which has focal impaired seizures localizes to the temporal lobe region (TLE). A majority of these cases are surgically amenable with anterior-medial temporal lobe resection or “lesionectomy.”

Objective  In India, there is scarcity of “specialized centers” providing “comprehensive epilepsy care” and this dearth is further worse in populous states. In this article, we share our single center, observational, and retrospective experience of TLE in background of limited resources and utmost requirement.

Methodology  Our study is a retrospective analysis medically refractory epilepsy patients (2016–2019). Patients with medically refractory epilepsy were selected based upon our noninvasive protocol (clinical semiology, interictal scalp electroencephalography (EEG), long-term video EEG monitoring data, and magnetic resonance injury [MRI]). The follow-up was noted from the last out-patient visit record or through telephonic conversation (International League Against Epilepsy score).

Results  Of 23 cases of TLE ( n = 7, mesial temporal sclerosis; n = 16 temporal lobe like cavernomas, tumors, or arterio-venous malformations). Single photon emission computed tomography/positron emission tomography (SPECT/PET) was performed in five cases (three cases of ictal/interictal SPECT and two cases of PET scan) where there was discordance between EEG/clinical and MRI. The median follow-up was of 19 months with 18 cases being seizure free. Five cases were fully off the antiepileptic drug (AEDs) while in 15 cases, the AEDs dosages or the number were reduced. Average number of AEDs reduced from 2.9 in preoperative period to 1.2 postoperatively. Two cases had quadrantanopia and one case of cerebrospinal fluid leak.

Conclusion  A multidisciplinary and holistic approach is required for best patient care. The results of our initial surgical experience are encouraging.

Seizure outcome and its predictors after frontal lobe epilepsy surgery

OBJECTIVES

Frontal lobe epilepsy (FLE) surgery is the second most common focal resective surgery for drug-resistant epilepsy. Not many studies are available regarding the long-term surgical outcome of FLE. We studied the longitudinal outcome and predictors of seizure outcome following FLE surgery in a sizeable cohort of patients.

MATERIALS & METHODS

A total of 73 consecutive patients who underwent FLE surgery between January 1997 and May 2015 with a minimum follow-up of 1 year (range 1-16 years) were studied. Primary outcome was seizure freedom at last follow-up (Engel Class IA). "Seizure freedom" separately was defined as absence of seizures till last follow-up. Outcome predictors were subjected to multivariate analysis. Using Kaplan-Meier curve, we assessed the post-operative seizure freedom over time.

RESULTS

Twenty-five patients (34%) were seizure-free till last follow-up. The seizure freedom was 45%, 34%, 26%, 20% and 14% at the end of 1st, 2nd, 3rd, 4th and 5th post-operative year, respectively. Engel class I outcomes were 48%, 41%, 56%, 57% and 53% at end of 1st, 2nd, 3rd, 4th and 5th post-operative year, respectively. Predictors of seizure recurrence on multivariate analysis were older age at surgery (P = 0.032), longer duration of epilepsy (P = 0.031), presence of interictal epileptiform discharges in post-operative EEG on 7th day (P = 0.005), 3 months (P = 0.005) and 1 year (P = 0.0179). In subgroup analysis, duration of epilepsy of less than 2 years before surgery was a significant predictor for achieving seizure freedom (P = 0.029).

CONCLUSIONS

These results emphasize early surgery for better outcome in frontal lobe epilepsy. Post-operative EEG remained a good predictor for long-term outcome.

Surgical outcomes in two different age groups with Focal Cortical Dysplasia type II: Any real difference?

OBJECTIVE

Focal Cortical Dysplasias (FCDs) represent a common architectural cortical disorder underlying drug-resistant focal epilepsy. So far, studies aimed at evaluating whether age at surgery is a factor influencing surgical outcome are lacking, so that data on the comparison between patients harboring Type II FCD operated at younger age and those operated at adult age are still scarce. We compared presurgical clinical features and surgical outcomes of patients with histopathologically diagnosed Type II FCD undergoing surgery at an earlier age with those operated after 20 years of age.

METHODS

We retrospectively analyzed 1660 consecutive patients operated at the "Claudio Munari" Epilepsy Surgery Centre. There were 289 patients (17.4%) with a neuropathological diagnosis of Type II FCD. We included two different groups of patients, the first one including patients operated on at less than 6years, the second sharing the same seizure onset age but with delayed surgery, carried out after the age of 20. Seizure characteristics and, neuropsychological and postoperative seizure outcomes were evaluated by study group.

RESULTS

Forty patients underwent surgery before the age of 6 and 66 patients after the age of 20. Surgical outcome was favorable in the whole population (72.6% were classified in Engel's Class Ia+Ic), independently from age at surgery. In the children group, 32 patients were classified in Class I, including 30 (75%) children in classes Ia and Ic. In the adult group, 53 belonged to Class I of whom 47 (71%) were in classes Ia and Ic. The percentage of permanent complications, the surgical outcomes, and AED withdrawal did not significantly differ by study group.

CONCLUSION

Our results indicate that there is no difference between the groups, suggesting that outcome depends mainly on the histological findings and not on timing of surgery.

A longitudinal study of surgical outcome of pharmacoresistant epilepsy caused by focal cortical dysplasia

This study aimed to determine the long-term surgical outcome of pharmacoresistant epilepsy caused by focal cortical dysplasia (FCD) and to identify the important predictors of the favorable surgical outcome. The study retrospectively analyzed the data of pharmacoresistant epilepsy patients with histologically proven FCD in our epilepsy center from May 2010 to December 2014. It included 120 patients with a mean follow-up of 34.6 months. Survival analysis and multivariate regression with Cox proportional hazards model were used to evaluate the rate, stability, and predictors of seizure freedom. The estimated chance of seizure freedom was 73.0 % [95 % confidence intervals (CI), 65.2-80.8 %] at 1 year after surgery, 70.0 % (95 % CI, 62.2-77.8 %) at 2 years, and 65 % (95 % CI, 53.2-76.7 %) at 5 years and beyond. Most seizure recurrences (85.7 %) happened within 12 months after surgery. The incomplete resection of FCD, presence of interictal epileptiform discharges (IEDs) on 3-6 months postoperative electroencephalography (EEG), and presence of habitual acute postoperative seizure (APOS) were independent predictors of seizure recurrence. However, other factors, such as the FCD type and sleep-related epilepsy, did not significantly influence the surgical outcome. Before becoming pharmacoresistant epilepsy, 30 (25 %) patients responded to antiepileptic drugs with a seizure-free duration of more than 1 year. The surgical outcome is favorable in patients with FCD, which is comparable to that reported in developed countries. The incomplete resection of FCD, presence of IEDs on 3-6 months postoperative EEG, and presence of habitual APOS are powerful predictive factors for seizure recurrence after surgery.