Low IQ predicts worse long-term seizure outcome after resective epilepsy surgery - A propensity score matched analysis.

OBJECTIVE: To describe long-term seizure outcomes in patients with IQ < 70 undergoing resective epilepsy surgery and to analyse whether baseline IQ predicts seizure outcome. METHODS: Patients undergoing focal resective epilepsy surgery 1995-2017 at age ≥ 4 years were identified in the population-based Swedish National Epilepsy Surgery Register. Two-year, five-year and long-term (10-20-year follow-up) outcomes were analysed. Seizure outcomes of patients with IQ ≥ 70 and IQ < 70 at baseline were compared in the full cohort and between propensity score matched groups. RESULTS: Follow-up data were available for 884 patients, 79 of whom had IQ < 70. Matched controls were found for 74 of the IQ < 70 patients. Preoperative MRI pathology was unifocal in 54 % and 79 % of IQ < 70 and IQ ≥ 70 patients before matching compared to 58 % and 62 % after matching, respectively. Patients with IQ < 70 achieved significantly worse seizure outcomes at all time points both when analysing the full cohort and the matched groups. After matching, the proportions of seizure-free patients in the IQ < 70 group were 28 %, 32 % and 32 % at the 2-year, 5-year and long-term follow-ups, respectively. Corresponding figures in the IQ ≥ 70 group were 54 %, 62 % and 60 % (p for difference between IQ groups 0.004, 0.002 and 0.049). In the IQ < 70 group, 36 %, 29 % and 45 % had a ≥ 75 % reduction in seizure frequency at the respective three follow-ups. CONCLUSION: Low preoperative IQ predicts lower chances of seizure freedom after resective epilepsy surgery and few patients with IQ < 70 remain completely seizure-free in the long term. Nevertheless, a significant proportion had a reduction in seizure frequency of at least 75 % at long-term follow-up, indicating an important palliative potential of resective surgery for epilepsy patients with intellectual disability.

Method considerations and study protocol for a Nordic multi-centre prospective study on outcomes in rare paediatric epilepsy surgery subgroups.

Epilepsy surgery is a therapeutic option for selected children with drug-resistant epilepsy. Children who are surgical candidates have a high prevalence of neurodevelopmental comorbidities. There is a lack of adequately sized prospective studies in a number of rare surgical subgroups, especially of outcome domains such as cognitive level and health-related quality-of-life. In this article, we describe method considerations and a study protocol for a Nordic population-based multi-centre follow-up programme covering seizure as well as non-seizure outcomes in children aged <4 years undergoing resective epilepsy surgery and children aged ≤18 years undergoing hemispherotomy, callosotomy or surgery for hypothalamic hamartoma.

Long-term employment outcomes after epilepsy surgery in childhood.

OBJECTIVE: To analyze long-term employment outcomes in a population-based cohort of adults who underwent epilepsy surgery in childhood or adolescence and to compare the results to general population reference data. METHODS: Prospective data on epilepsy surgery procedures performed on patients <19 years of age between 1995 and 2012 were extracted from the Swedish National Epilepsy Surgery Register. Five-, 10-, 15- and 20-year follow-up data were analyzed. Patients aged ≥19 years at follow-up were eligible for inclusion. Educational attainment and employment status were analyzed in relation to seizure outcome. Education and employment outcomes of seizure-free patients with a preoperative IQ of ≥70 were compared to general population reference data. RESULTS: A total of 203 patients were included. The mean age at surgery was 13.6 years and 66% had IQ ≥70. Of these, a majority had attained at least high school education 5 years after surgery. Employment rates were 44%, 69%, 71%, and 77% at the 5-, 10-, 15-, and 20-year follow-ups, respectively. Seizure-free patients were significantly more likely to work full-time. Educational attainment and rates of full-time employment of seizure-free patients were similar to the general population. A majority of patients with IQ <70 had attended special education and were reliant on social benefits. CONCLUSION: Long-term overall employment rates were higher compared to most previous studies on surgery in adults. Seizure-free patients with a preoperative IQ ≥70 showed rates of full-time employment similar to the general population. Further research is needed to determine whether this also applies for occupational complexity and wages.

Long-term follow-up after epilepsy surgery in infancy and early childhood--a prospective population based observational study.

PURPOSE: To describe 2-year and long-term outcomes (five or ten years) after resective epilepsy surgery in children operated before the age of four years. METHODS: This prospective, population based, longitudinal study is based on data from the Swedish National Epilepsy Surgery Register 1995-2010. The following variables were analysed: seizure frequency, antiepileptic drug treatment (AED), neurological deficits, type of operation, histopathological diagnosis and perioperative complications. RESULTS: During the study period 47 children under four years had resective surgery. A majority had seizure onset within the first year of life, and the median age at surgery was two years and one month. Two thirds had neurodevelopmental abnormalities. Temporal lobe resection, frontal lobe resection and hemispherotomy predominated. A majority had malformations of cortical development. There was one major perioperative complication. At the 2-year follow-up, 21/47 children (45%) were seizure free, eight of whom were off medication. At the long-term follow-up, 16/32 (50%) were seizure-free and 11 of them off medication. Another ten (31%) had ≥75% reduction in seizure frequency. Fourteen children (44%) had sustained seizure freedom from surgery to the long-term follow-up. CONCLUSION: This is the first prospective, population based, longitudinal study to show that a favourable seizure outcome is achievable in a majority of infants and young children undergoing resective epilepsy surgery and that the improvements are consistent over time. Many can also stop taking AEDs. The findings emphasise the importance of early referral to epilepsy surgery evaluation in cases of medically intractable epilepsy in infants and young children.