Psychogenic non-epileptic seizures in neurosurgical patients with pharmacoresistant epilepsy: epidemiology

Background . Psychogenic non-epileptic seizures (PNES) are common in pharmacoresistant epilepsy (PRE), especially in neurosurgical patients. Objective . To assess the epidemiology and classify variants of PNES in neurosurgical patients with PRE. Design and Methods . A single-centre uncontrolled open observational study was conducted (2017–2023) at Polenov Neurosurgical Institute within the framework of state assignment No. 123021000127-7. An epidemiological analysis was performed and a classification of PNES was developed. The study was approved by the LEC (protocol No.: 2304-22 of 18/04/2022). Descriptive statistics were used (SPSS 29.0.10; p = 0.05). Results . The study included 369 neurosurgical patients with PRE (cohort 1); PNES were identified in 29 patients (cohort 2). The PNES rate was 8 %. Preoperative PNES occurred in 5.4 % of cohort 1 and 70 % of cohort 2; postoperative PNES — in 2.4 % and 30 %, respectively. The proposed PNES classification includes four variants: isolated PNES, PNES during epilepsy remission, comorbidity of seizures and PNES, and de novo PNES. Conclusion . Psychogenic non-epileptic seizures are reported in about one in thirteen neurosurgical patients with pharmacoresistant epilepsy. De novo psychogenic non-epileptic seizures as psychopathological complications after surgery occur in 2.8 % of patients with epilepsy. The classification of psychogenic non-epileptic seizures includes 4 variants of the combination with epilepsy. The practical applica tion of the data on the epidemiology of psychogenic non-epileptic seizures in pharmacoresistant epilepsy will help to avoid irrational use of antiepileptic drugs and surgical treatment methods.