关键词: 局灶性癫痫, 致痫区, 立体脑电图, 射频热凝毁损, 皮质电刺激

Abstract: Objective To explore the feasibility and application value of radiofrequency thermocoagulation ablation (RF-TC) guided by stereoencephalogram (SEEG) in patients with drug-refractory focal epilepsy. Methods A retrospective analysis was conducted on the clinical data of 32 patients with drug-resistant focal epilepsy who underwent SEEG-guided RF-TC treatment in the Department of Neurosurgery,No 988th Hospital of the PLA Joint Logistics Support Force from January 2018 to June 2024.Comprehensive analysis of symptomatology,electroencephalography (EEG),and imaging data was performed.Based on the anatomo-electro-clinical correlations,a hypothesis regarding the origin of abnormal discharges and the epileptic propagation network was proposed.SEEG electrodes were implanted into relevant brain regions within the epileptic network.The origin of abnormal discharges was identified through SEEG monitoring,and exploratory RF-TC treatment was performed.Treatment efficacy was evaluated by Engel grade. Results All 32 patients had SEEG electrodes accurately implanted into the intended targets.The first 3 cases were implanted using Leksell stereotactic head frame,while the remaining 29 cases were implanted with the guidance of the Sino-Plan neurosurgical robot.Among them,one patient with two electrode implantation and RF-TC.Unilateral electrode implantation was performed in 8 cases(3 on the left side and 5 on the right side),and bilateral implantation was performed in 24 patients.A total of 168 electrodes were implanted,with an average of (5.25±1.3) electrodes per patient(range:3～8).The average SEEG monitoringduration was (9.5±2.4) days (range:5～14days).during which 3～20 habitual seizures were captured in all patients.Cortical electrical stimulation induced habitual seizures in 17 cases,non-habitual seizures in 6 cases.and failed to induce seizures in 9 cases.The epileptogenic zone was successfully identified in all cases,including 15 in the temporal lobe,12 in the frontal lobe,3 in the occipital lobe,and 1 case in parietal lobe,1 case in insula lobe.RF-TC was performed using 2～5 electrodes,with an average of (3.1±1.6)electrodes,.There are 12～38 radiofrequency thermocoagulation contacts,with an average of (20.1±4.5)contacts.Post-RF-TC complications included headache in 13 cases,severe cerebral edema with encapsulated effusion resulting transient contralateral upper limb weakness and reduced dexterity in 1case,and temporary behavior abnormalities in 1 case.No complications such as intracranial infection,cerebrospinal fluid leakage,or severe neurological deficits occurred.The follow-up period was (12.9±16.6) months (range:5～78 months).After RF-TC,1 patient achieved Engel Class I,while 31 cases experienced recurrences of varying degrees and durations,including 2 cases within 2 weeks,5 cases within 1 month,and 24 cases within 1～3 months.Subsequently,19 cases underwent elective craniotomy for resection of the epileptogenic zone,resulting in 17 cases(89.47%) achieving Engel Class I and 2 cases(10.53%) achieving Engel Class II.At the final follow-up,the overall efficacy assessment showed 18 cases (56.25%) in Engel Class I,8 cases (25%) in Engel Class II,and 6 cases (18.75%) in Engel Class III. Conclusion SEEG-guided RF-TC can promptly and effectively alleviate epileptic seizures to varying degrees,guide subsequent craniotomy for the resection of the epileptogenic zone,and predict surgical outcomes.It holds significant application value in the surgical treatment of drug-resistant focal epilepsy.

Key words: Focal epilepsy, Epileptogenic zone, Stereoelectroencephalography, Radiofrequency thermocoagulation, Electrical cortical stimulation