Vascular consequences of operculoinsular corticectomy for refractory epilepsy

Abstract

OBJECT Surgery in the insular region is considered challenging because of its vascular relationships, the proximity of functional structures, and its deep location in the sylvian fissure. The authors report the incidence and consequences of ischemic lesions after operculoinsular corticectomy for refractory epilepsy. METHODS The authors retrospectively reviewed the data of all patients who underwent an insular resection with or without an opercular resection for refractory epilepsy at their center. All patients underwent postoperative MRI, enabling a radiological analysis of the ischemic lesions as a result of the corticectomies. The resections were classified according to the location and extent of the insular corticectomy and the type of operculectomy. Each patient underwent clinical follow-up. RESULTS Twenty patients underwent surgery. All patients underwent insular corticectomy with or without an operculectomy. Ischemic lesions were identified in 12 patients (60%). In these patients, 11 ischemic lesions (55%) were related to the insular corticectomy, and 1 was related to the associated periinsular resection. The ischemic lesions associated with the insulectomies were typically located in the corona radiata running from the insula to the periventricular region. Nine patients (45%) developed a postoperative neurological deficit, among whom 6 (67%) had an insular corticectomy–related ischemic lesion. All reported neurological deficits were transient. Five patients (25%) had ischemic lesions without neurological deficit. CONCLUSIONS Operculoinsular corticectomies are associated with ischemic lesions in approximately 60% of patients. However, given that no patient had a definitive postoperative deficit, these ischemic lesions have few clinical consequences. Therefore, this surgical procedure can be considered reasonably safe for the treatment of refractory epilepsy.

Stereotactic thermocoagulation for insular epilepsy: Lessons from successes and failures

“…7,36,37 Furthermore, series showed that favorable seizure outcome was obtained in the majority of the patients, with functional risks considered acceptable, despite ischemic lesions being observed in 60% of the cases. 19 The largest series (25 patients) reported that paresis, dysphasia, alteration of taste, smell, hearing, pain, and thermal perceptions were frequent (75%), but always transient except for one patient with persistent mild alteration of thermal and pain perception. 20 In addition, no major cognitive deterioration was reported by this group.…”

“…However, the initial reports included mainly lesionectomies or were limited to few patients and most often in nondominant hemispheres, including pediatric cases . Furthermore, series showed that favorable seizure outcome was obtained in the majority of the patients, with functional risks considered acceptable, despite ischemic lesions being observed in 60% of the cases . The largest series (25 patients) reported that paresis, dysphasia, alteration of taste, smell, hearing, pain, and thermal perceptions were frequent (75%), but always transient except for one patient with persistent mild alteration of thermal and pain perception .…”

“…In the whole population, the main spread pathways involved the frontal lobe (12 cases), including the operculum (four cases) and the cingulum (three cases). The temporal lobe was secondarily involved in four patients (Cases 5, 9,11,19) and the central area in another one (Case 10). Of note, EZ was easier to localize when hypometabolism on PET was focal ( Figure 1).…”

“…However, the insula lies deep in the sylvian fissure, covered by eloquent frontal, temporal, and parietal opercula with a dense network of vessels. This makes open surgical resection of the insula fraught with risk, despite some recent series reporting reasonable outcomes . Stereotactic thermocoagulation is a minimally invasive technique that has been used for half a century to create precise brain lesions and destroy deep epileptogenic structures, when resective surgery was not feasible .…”

“…This makes open surgical resection of the insula fraught with risk, despite some recent series reporting reasonable outcomes. [17][18][19][20] Stereotactic thermocoagulation is a minimally invasive technique that has been used for half a century to create precise brain lesions and destroy deep epileptogenic structures, when resective surgery was not feasible. 21 More recently, stereotactic radiofrequency thermocoagulation (RFTC) was performed in patients investigated for drug-resistant epilepsy, using the already implanted SEEG electrodes, as a treatment option for the disconnection of epileptic networks.…”