Authors :
Presenting Author: John duncan, DM FRCP FMedSci – NHNN, UCL
Davide Giampiccolo, MD – NHNN, UCL
Amrita Gupta, MSc – NHNN, UCL
Jane de Tisi, BSc – NHNN, UCL
Giorgio Fiore, MD – NHNN, UCL
Aidan O'keefe, PhD – University of Nottingham
shahidul mannan, MD – NHNN, UCL
jackson cheung, BSc – NHNN, UCL
andrew mcevoy, FRCS – NHNN, UCL
anna miserocchi, MD – NHNN, UCL
Ley Sander, MD – NHNN, UCL
Rationale:
t is important to clarify rates of long-term seizure freedom and seizure reduction after epilepsy surgery and the factors predicting permanent seizure freedom. Methods:
We reviewed seizure outcomes in 1024 patients operated for drug-resistant focal epilepsy with a follow-up to 35 years after surgery. We undertook prospective follow up with annual contact with patients, primary care and local hospitals through NHS records. Seizure status (ILAE outcome 1-6) was determined annually. Kaplan-Meier survival analysis, univariate and multivariate analyses to identify factors associated with stable freedom of seizures impairing awareness (ILAE 1-2 against 3-6) and/or seizure reduction over 50% (ILAE 1-4). We also calculated the percentage of seizure-free years, and years with >50% seizure reduction per person.Results:
702 of the 1024 patients (69%) were free of seizures impairing awareness after 1 year, 45% remained seizure-free after 10 years, 41% remained seizure-free after 20 years and 37% remained seizure-free after 30 years.
Out of 14,209 patient- years of follow-up, 1024 individuals experienced 9872 years of seizure-freedom (69%).
More than 50% seizure reduction was achieved in 981 (96%) patients after 1 year of follow-up. This beneficial outcome was maintained in 902 (88%) patients at 10 years and 864 (84%) patients at 20 years post-surgery.
Focal-to-bilateral tonic-clonic seizures (HR:1.57, CI:1.26-1.95), a history of status epilepticus (HR:1.25, CI: 0.99-1.57), normal or non-focal MRI (HR: 1.64, CI: 1.21-2.24), disorders of mood (HR: 1.26, CI: 1.04-1.5), stress-related psychiatric conditions (HR: 1.68, CI: 1.04-2.75), history of substance abuse (HR: 1.70, CI: 1.1-2.62) were independently predictive of increased risk of long-term seizure recurrence.
There was no peri-operative mortality. In the whole cohort, there were 88 deaths (8.2%), 6.16 deaths/1,000 person-years of follow-up. 52 were unrelated to epilepsy or of unknown cause. 36 (41%) were epilepsy-related (12 SUDEP). Epilepsy-related deaths occurred predominantly during the first 15 years follow-up.
Conclusions:
Epilepsy surgery can stop seizures occurring, but efficacy decreases over time. Overall, 69% of post-operative years were seizure free, and 84% years had >50% seizure reduction, superior to neuromodulation. Relapse of epilepsy after early post-operative remission, suggests the presence of a network disorder that is only partially treated by focal resection, further exploration of this topic is needed. Funding: NIHR UCLH/UCL Biomedical Research Centre