Efficacy of limited hippocampal radiofrequency thermocoagulation for mesial temporal lobe epilepsy

Abstract

OBJECTIVERadiofrequency thermocoagulation (RFTC), which has been developed for drug-resistant epilepsy patients, involves less brain tissue loss due to surgery, fewer surgical adverse effects, and generally good seizure control. This study demonstrates the effectiveness of RFTC performed at limited hippocampal locations.METHODSDaily seizure diaries were prospectively maintained for at least 6 months by 9 patients (ages 30–59 years) with drug-resistant mesial temporal lobe epilepsy (MTLE) before treatment with RFTC. The limited target for stereotactic RFTC was chosen based on intraoperative electroencephalography (EEG) recording and was initially tested with a Radionics electrode at a low temperature, 45°C, for 60 seconds. The therapeutic RFTC heating parameters were 78°C–80°C for 90 seconds. All patients who received the RFTC treatment underwent both MRI and EEG recording immediately postoperatively and at the 3-month follow-up. Monthly outpatient clinic visits were arranged over 6 months to document seizure frequency and severity to clarify the changes noted in imaging studies and EEG patterns.RESULTSTwo patients were excluded from our analysis because one had undergone multiple seizure surgeries and the other had a poor recording of seizure frequency, before the RFTC surgery. Five and two patients underwent left-sided and right-sided RFTC, respectively. None of the patients had generalized tonic-clonic attacks postoperatively, and no adverse effects or complications occurred. According to MRI data, the effect of coagulation was limited to less than 1.0 cm in diameter and perifocal edema was also in limited range. The seizure frequency within 6 months decreased postoperatively with a mean reduction in seizures of 78% (range 36%–100%). Only two patients had a temporary increase in seizure frequency within 2 weeks of the surgery, and over 50% of all patients showed a decrease in average seizure frequency.CONCLUSIONSThe study results confirm that limited RFTC provides a more effective surgery with similar seizure control but fewer complications than resective surgery for drug-resistant MTLE patients.

Comparison of minimally invasive and traditional surgical approaches for refractory mesial temporal lobe epilepsy: A systematic review and meta‐analysis of outcomes

“…Zhao et al reported on 12 patients with bilateral ablation of the temporal lobes and could demonstrate a significant improvement at the group level in all scales of the Wechsler Adult Intelligence Scale–Revised (WAIS‐R) as well as the Wechsler Memory Scale–Revised, except the delayed recall 32 . In contrast, Lee et al could not detect a significant difference in WAIS‐R at 6 months after RFA 61 …”

“…32 In contrast, Lee et al could not detect a significant difference in WAIS-R at 6 months after RFA. 61 Neuropsychological data at an individual level were found in six of the open surgery studies and were summarized. 4,37,38,40,44,45 Postoperative visual memory decline was reported in 24.8% (35/141) and 25.7% (45/175) after ATL and sAHE, respectively, whereas an improvement in visual memory function was found in 31.2% (44/141) after ATL and in 33.1% (58/175) after sAHE.…”

Optimized SEEG-guided radiofrequency thermocoagulation for mesial temporal lobe epilepsy with hippocampal sclerosis

“…Specifically, a controlled study in TLE found that SEEG-guided RF-TC was significantly inferior to anterior-temporal lobectomy (ATL) [21]. But, interestingly, a recent study in 9 patients with drug-resistant mesial temporal lobe epilepsy (MTLE) reported that the short-term outcome of seizure control of limited RF-TC with a Radionics electrode was similar to that of surgical resection [32]. The duration of follow-up and study size might contribute to the difference in results.…”

Stereo-crossed ablation guided by stereoelectroencephalography for epilepsy: comprehensive coagulations via a network of multi-electrodes

“…As an approach to ablate the intracranial lesions, traditional stereotactic radiofrequency thermocoagulation (RF-TC) was introduced more than half a century ago, 1 and it has long been used to treat epileptic patients. [2][3][4][5] When the limitations of the canonical stereotactic radiofrequency apparatus, that is, its inability to record electrical information, became apparent, stereoelectroencephalography (SEEG) electrodes were introduced to facilitate the radiofrequency procedure in the past two decades. [6][7][8][9] However, through either the traditional approach or the novel SEEG-guided approach, the clinical outcome was consistently shown to be unsatisfactory due to the relatively small lesioning size.…”