Assessing the outcome of drug therapy in adult patients with epilepsy who have experienced seizure recurrence after remission

Background. Remission in general sense means disappearance of signs and symptoms of the disease. The risk of recurrence of seizures is usually evaluated only in terms of the risk of a second unprovoked seizure after the first one or the risk of recurrence of seizures after discontinuation of therapy. There are no studies that assess the probability of achieving a second remission in patients with recurrent seizures.
Aim. To develop a tool for assessing the probability of favorable and unfavorable treatment outcomes after recurrent seizures in adult patients with different forms of epilepsy.
Materials and methods. We analyzed data from 215 patients with recurrent seizures after achieving remission, followed up for 12 or more months, and analyzed disease outcomes.
Results and conclusion. At the end of the study, repeat remission was observed in 67 patients, improvement in 48, and no effect in 100. Patients with remission and improvement were combined into a “favorable outcome” group (n = 115), while patients with no effect from therapy formed an “unfavorable outcome” group (n = 100).
Patients with an unfavorable outcome were statistically significantly more likely to have factors such as longer disease duration, coexisting serious somatic diseases, structural etiology of epilepsy, bilateral tonic-clonic seizures with focal onset, focal forms of epilepsy, daily seizures, epileptogenic changes on neuroimaging, and regional epileptiform activity on EEG (p <0.05). In turn, patients with a favorable outcome were statistically significantly more likely to have factors such as genetic etiology of epilepsy, generalized tonic-clonic seizures, absences, myoclonic seizures, generalized forms of epilepsy, no pathology on neuroimaging, diffuse epileptiform activity on electroencephalogram, and no pathology on electroencephalogram (p <0.05).
Based on the obtained data using the results of constructing contingency tables, a scale for assessing the probability of achieving repeat remission in patients with recurrent epileptic seizures was developed, consisting of 9 sections. To assess the effectiveness of the model, ROC analysis was performed, confirming statistically significant sensitivity and specificity of the obtained scale.
Further research is needed to develop more accurate predictors of epilepsy outcomes to understand the peculiarities of the disease pathogenesis.

1. Avakyan G.N., Ayvazyan S.O., Brutyan A.G. et al. Recommendations of the expert council on neurophysiology of the Russian Antiepileptic League for conducting routine EEG. Epilepsiya i paroksizmalnye sostoyaniya = Epilepsy and Paroxysmal Conditions 2016;8(4):99–108. (In Russ.)

2. Avakyan G.N., Blinov D.V., Alikhanov A.A. et al. Recommendations of the Russian Antiepileptic League (RAL) on the use of magnetic resonance imaging in the diagnosis of epilepsy. Epilepsiya i paroksizmalnye sostoyaniya = Epilepsy and Paroxysmal Conditions 2019;11(3):208–32. (In Russ.)

3. Abimbola S., Martiniuk A.L., Hackett M.L. et al. Early predictors of remission in newly diagnosed epilepsy: A systematic approach to reviewing prognostic factor studies. Neurol Res 2014;36(1):1–12. DOI: 10.1179/1743132813Y.0000000257

4. Beghi E., Beretta S., Carone D. et al. Prognostic patterns and predictors in epilepsy: A multicentre study (PRO-LONG). J Neurol Neurosurg Psychiatry 2019;90(11):1276–85. DOI: 10.1136/jnnp-2019-320883

5. Beghi E., Giussani G., Sander J.W. The natural history and prognosis of epilepsy. Epileptic Disord 2015;17(3):243–53. DOI: 10.1684/epd.2015.0751

6. Fisher R.S., Acevedo C., Arzimanoglou A. et al. ILAE official report: A practical clinical definition of epilepsy. Epilepsia 2014;55(4):475–82. DOI: 10.1111/epi.12550

7. Kwan P., Arzimanoglou A., Berg A.T. et al. Definition of drug resistant epilepsy: Consensus proposal by the ad hoc Task Force of the ILAE Commission on Therapeutic Strategies. Epilepsia 2010;51(6):1069–77. DOI: 10.1111/j.1528-1167.2009.02397.x

8. Pellino G., Faggioli R., Madrassi L. et al. Operational diagnosis of epilepsy in children at undetermined risk: A meta-analysis of prognostic factors for seizure recurrence. Epilepsy Behav 2022;127:108498. DOI: 10.1016/j.yebeh.2021.108498

9. Wirrell E.C., Nabbout R., Scheffer I.E. et al. Methodology for classification and definition of epilepsy syndromes with list of syndromes: Report of the ILAE Task Force on nosology and definitions. Epilepsia 2022;63(6):1333–48. DOI: 10.1111/epi.17237