Abstracts

Rationale: Radiofrequency thermocoagulation (RF-TC) is a minimal intervention method to treat patients with mesial temporal lobe epilepsy (MTLE). Current study reports results of six-month follow-up in six patients of drug-resistant MTLE receiving RF-TC therapy. Methods: The patients underwent stereotactic implantation of the four-contact depth electrode in the hippocampus. Intracranial electroencephalogram was recorded from of the electrode, accompanied with simultaneously extracranial bi-temporal leads. Low-frequency, low-temperature test thermocoagulation was done for evaluation of safety and immediate adverse event. High-frequency high-temperature thermocoagulation was then applied to the identified epileptogenic area. The frequency of seizure and EEG findings, and procedure-related adverse events were followed post-operatively six month, and compared with those of baseline period. Patients were divided into responder and non-responder groups. Regression model (recruiting seizure onset age, seizure duration, aura during RF-TC, immediate seizure after RF-TC, EEG pattern changes, neuropsychological changes, hippocampal volume changes) was done for positive predictors of responder. Results: Three man and three women, aged 38.5 ± 10.4 years (range­ 30–59 years) were studied. The baseline monthly seizure frequency was 3.3 ± 1.5 times (range­ 1.1–5.7 times), with a mean seizure duration of 24 ± 12.8 years (range­ 6–41 years). The general characteristics of RF-TC protocol in every patient were demonstrated in Table 1. The average thermocoagulation lesion size was 0.41 ± 0.23cm3. Seizure frequency had an average reduction of 49% after RF-TC (Figure 1). Favorable predictors of seizure control were provoked aura during RF-TC, whereas immediate seizure after RF-TC and longer seizure duration being an unfavorable one. No procedure-related adverse event was observed throughout the observation period. Mental status evaluation and psychiatric conditions remained stable before and after RC-TC. Conclusions: The RF-TC of hippocampus is a relatively simple and safety method with favorable seizure control within six months in patients with MTLE. Funding: This study received no potential funding.