Candidates for focal cortex stimulation in the outpatient population of an epilepsy reference center

Focal Cortex Stimulation (FCS) is a novel treatment for epilepsy. The patient population that may benefit from FCS has not been identified yet. This study uses data from a clinical trial screening at a tertiary epilepsy center's outpatient clinic to estimate the potential for FCS application OBJECTIVE: To determine the proportion of people with epilepsy (PWE) who could benefit from FCS considering focus localization and extent METHODS: All adult patients at the Freiburg epilepsy center outpatient clinic between October 1, 2019 and January 31, 2020, were screened for FCS eligibility. Suitable candidates needed to have 1) one predominant epileptic focus, 2) focus localization at the dorsolateral convexity, and 3) estimated focus size < 5 cm in diameter RESULTS: Epilepsy was confirmed in 562 of 604 patients. FCS was precluded in 205 patients due to specific epilepsy syndromes (e.g., genetic generalized epilepsies, mesiotemporal, unclassified). Patients with malignant tumors (25) or lesions outside the dorsolateral convexity (21) were excluded. In 16 of 41 multilesional patients and 18 of 35 nonlesional patients, a predominant focus was identified via EEG/semiology. In 40 of 127 patients with a neocortical single lesion, the lesion was deemed too extensive for FCS. Overall, 121 patients (21.5 % of all PWE, 26.5 % of focal epilepsy patients) were suitable for FCS, 56 of whom were drug-resistant CONCLUSIONS: A significant proportion of PWE at a tertiary epilepsy center have a neocortical focus at the dorsolateral convexity, making them potential candidates for FCS. Given its efficacy and tolerability, FCS is a promising treatment for a major subgroup of patients with drug-resistant focal epilepsy.