Stereoelectroencephalography in the presurgical evaluation of focal epilepsy in infancy and early childhood

2012 ◽  
Vol 9 (3) ◽  
pp. 290-300 ◽  
Author(s):  
Massimo Cossu ◽  
Marco Schiariti ◽  
Stefano Francione ◽  
Dalila Fuschillo ◽  
Francesca Gozzo ◽  
...  
Keyword(s):  
Focal Epilepsy ◽  
Brain Mri ◽  
Electrode Placement ◽  
Motor Deficit ◽  
Epileptogenic Zone ◽  
Drug Resistant ◽  
Presurgical Evaluation ◽  
Intracranial Surgery ◽  
Eloquent Areas ◽  
Drug Resistant Epilepsy

Object The authors report on the use of stereoelectroencephalography (stereo-EEG) in the presurgical electroclinical evaluation of infants and very young children with focal drug-resistant epilepsy. Methods Fifteen patients (9 girls and 6 boys, mean age 34.1 ± 7.3 months, range 21–45 months), potentially candidates to receive surgical treatment for their focal drug-resistant epilepsy, were evaluated using stereo-EEG recording for a detailed definition of the epileptogenic zone. Stereoelectroencephalography was indicated because neuroradiological (brain MRI) and video-EEG data failed to adequately localize the epileptogenic zone. Stereotactic placement of multicontact intracerebral electrodes was preceded by the acquisition of all pertinent anatomical information from structural and functional MRI and from brain angiography, enabling the accurate targeting of desired structures through avascular trajectories. Stereoelectroencephalography monitoring attempted to record habitual seizures; electrical stimulations were performed to induce seizures and for the functional mapping of eloquent areas. Stereoelectroencephalography-guided microsurgery, when indicated, pointed to removal of the epileptogenic zone and seizure control. Results Brain MRI revealed an anatomical lesion in 13 patients (lobar in 2 cases, multilobar or hemispheric in 11 cases) and was unremarkable in 2 patients. One patient underwent 2 stereo-EEG studies. The arrangement of the intracerebral electrodes was unilateral in all but 1 case. One patient died the day following electrode placement due to massive brain edema and profound hyponatremia of undetermined cause. In 8 cases intracerebral electrical stimulations allowed mapping of functionally critical areas; in 3 other cases that received purposeful placement of electrodes in presumably eloquent areas, no functional response was obtained. Of the 14 patients who completed stereo-EEG monitoring, 1 was excluded from surgery for multifocality of seizures and 13 underwent operations. Postoperatively, 2 patients exhibited an anticipated, permanent motor deficit, 3 experienced a transient motor deficit, and 2 experienced transient worsening of a preexisting motor deficit. Three patients developed a permanent homonymous hemianopia after posterior resections. Histological analysis revealed cortical malformations in 10 cases. Of the 10 patients with a postoperative follow-up of at least 12 months, 6 (60%) were seizure-free (Engel Class Ia), 2 (20%) experienced a significant reduction of seizures (Engel Class II), and 2 (20%) were unchanged (Engel Class IV). Conclusions The present study indicates that stereo-EEG plays a prominent role in the presurgical evaluation of focal epilepsies also in the first years of life and that it may offer a surgical option in particularly complex cases that would have scarcely benefitted from further medical treatment. Results of stereo-EEG–guided resective surgery were excellent, with 80% of patients exhibiting a substantial improvement in seizures. In consideration of the potentially life-threatening risks of major intracranial surgery in this specific age group, the authors recommend reserving stereo-EEG evaluations for infants with realistic chances of benefiting from surgery.

scholarly journals Medically resistant pediatric insular-opercular/perisylvian epilepsy. Part 1: invasive monitoring using the parasagittal transinsular apex depth electrode

2016 ◽  
Vol 18 (5) ◽  
pp. 511-522 ◽  
Author(s):  
Alexander G. Weil ◽  
Aria Fallah ◽  
Evan C. Lewis ◽  
Sanjiv Bhatia
Keyword(s):  
Epilepsy Surgery ◽  
Electrode Placement ◽  
Epileptogenic Zone ◽  
Drug Resistant ◽  
Depth Electrodes ◽  
Depth Electrode ◽  
Age At Surgery ◽  
Feasible Alternative ◽  
The Mean ◽  
Drug Resistant Epilepsy

OBJECTIVE Insular lobe epilepsy (ILE) is an under-recognized cause of extratemporal epilepsy and explains some epilepsy surgery failures in children with drug-resistant epilepsy. The diagnosis of ILE usually requires invasive investigation with insular sampling; however, the location of the insula below the opercula and the dense middle cerebral artery vasculature renders its sampling challenging. Several techniques have been described, ranging from open direct placement of orthogonal subpial depth and strip electrodes through a craniotomy to frame-based stereotactic placement of orthogonal or oblique electrodes using stereo-electroencephalography principles. The authors describe an alternative method for sampling the insula, which involves placing insular depth electrodes along the long axis of the insula through the insular apex following dissection of the sylvian fissure in conjunction with subdural electrodes over the lateral hemispheric/opercular region. The authors report the feasibility, advantages, disadvantages, and role of this approach in investigating pediatric insular-opercular refractory epilepsy. METHODS The authors performed a retrospective analysis of all children (< 18 years old) who underwent invasive intracranial studies involving the insula between 2002 and 2015. RESULTS Eleven patients were included in the study (5 boys). The mean age at surgery was 7.6 years (range 0.5–16 years). All patients had drug-resistant epilepsy as defined by the International League Against Epilepsy and underwent comprehensive noninvasive epilepsy surgery workup. Intracranial monitoring was performed in all patients using 1 parasagittal insular electrode (1 patient had 2 electrodes) in addition to subdural grids and strips tailored to the suspected epileptogenic zone. In 10 patients, extraoperative monitoring was used; in 1 patient, intraoperative electrocorticography was used alone without extraoperative monitoring. The mean number of insular contacts was 6.8 (range 4–8), and the mean number of fronto-parieto-temporal hemispheric contacts was 61.7 (range 40–92). There were no complications related to placement of these depth electrodes. All 11 patients underwent subsequent resective surgery involving the insula. CONCLUSIONS Parasagittal transinsular apex depth electrode placement is a feasible alternative to orthogonally placed open or oblique-placed stereotactic methodologies. This method is safe and best suited for suspected unilateral cases with a possible extensive insular-opercular epileptogenic zone.

scholarly journals Stereoelectroencephalography-Guided Radiofrequency Thermocoagulation (SEEG-Guided RF-TC) in Patients with Drug-Resistant Focal Epilepsy

2017 ◽  
Vol 3 (1) ◽  
pp. 40-47
Author(s):  
Chengwei Xu ◽  
Wenjing Zhou
Keyword(s):  
Radio Frequency ◽  
Surgical Resection ◽  
Seizure Frequency ◽  
Palliative Treatment ◽  
Focal Epilepsy ◽  
Epileptogenic Zone ◽  
Drug Resistant ◽  
Functional Area ◽  
Presurgical Evaluation ◽  
Epileptic Patients

For some patients with drug-resistant focal epilepsy, we usually select conventional surgical resection, which has brought better outcomes. However, others are not eligible for a conventional open surgical resection of the epileptogenic zone because of the proximity of a functional area or the implication of a larger epileptogenic network. Initially, stereoelectroencephalography (SEEG) exploration was a method of electroencephalography recording that was used in the presurgical evaluation of epileptic patients with complex epilepsy. Later, intracerebral electrodes used for SEEG were applied to produce radio frequency thermocoagulation (RF-TC) in epileptic patients. SEEG-guided RF-TC has produced some promising results, especially in the last dacade. Now, it has become popular as a palliative treatment to reduce seizure frequency in patients with drug-resistant focal epilepsy. This article presents a review of SEEG-guided RF-TC.

scholarly journals P.042 Safety and efficacy of stereoelectroencephalography in pediatric epilepsy surgery

2019 ◽  
Vol 46 (s1) ◽  
pp. S25
Author(s):  
CA Elliott ◽  
K Narvacan ◽  
J Kassiri ◽  
S Carline ◽  
B Wheatley ◽  
...  
Keyword(s):  
Pediatric Epilepsy ◽  
Seizure Outcome ◽  
Neurogenic Pulmonary Edema ◽  
Epileptogenic Zone ◽  
Drug Resistant ◽  
Presurgical Evaluation ◽  
Pediatric Drug ◽  
Safety And Efficacy ◽  
Drug Resistant Epilepsy

Background: There are few published reports on the safety and efficacy of stereoelectroencephalography (SEEG) in the presurgical evaluation of pediatric drug-resistant epilepsy. Our objective was to describe institutional experience with pediatric SEEG in terms of (1) insertional complications, (2) identification of the epileptogenic zone and (3) seizure outcome following SEEG-tailored resections. Methods: Retrospective review of 29 patients pediatric drug resistant epilepsy patients who underwent presurgical SEEG between 2005 – 2018. Results: 29 pediatric SEEG patients (15 male; 12.4 ± 4.6 years old) were included in this study with mean follow-up of 6.0 ± 4.1 years. SEEG-related complications occurred in 1/29 (3%)—neurogenic pulmonary edema. A total of 190 multi-contact electrodes (mean of 7.0 ± 2.5per patient) were implanted across 30 insertions which captured 437 electrographic seizures (mean 17.5 ± 27.6 per patient). The most common rationale for SEEG was normal MRI with surface EEG that failed to identify the EZ (16/29; 55%). SEEG-tailored resections were performed in 24/29 (83%). Engel I outcome was achieved following resections in 19/24 cases (79%) with 5.9 ± 4.0 years of post-operative follow-up. Conclusions: Stereoelectroencephalography in presurgical evaluation of pediatric drug-resistant epilepsy is a safe and effective way to identify the epileptogenic zone permitting SEEG-tailored resection.

scholarly journals Stereoelectroencephalography-guided radiofrequency thermocoagulation in the epileptogenic zone: a retrospective study on 89 cases

2015 ◽  
Vol 123 (6) ◽  
pp. 1358-1367 ◽  
Author(s):  
Massimo Cossu ◽  
Dalila Fuschillo ◽  
Giuseppe Casaceli ◽  
Veronica Pelliccia ◽  
Laura Castana ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Treatment Option ◽  
Focal Epilepsy ◽  
Motor Deficit ◽  
Seizure Freedom ◽  
Epileptogenic Zone ◽  
Drug Resistant ◽  
Radiofrequency Thermocoagulation ◽  
Group 2 ◽  
Group 1

OBJECT Radiofrequency thermocoagulation (RF-TC) of presumed epileptogenic lesions and/or structures has gained new popularity as a treatment option for drug-resistant focal epilepsy, mainly in patients with mesial temporal lobe epilepsy. The role of this minimally invasive procedure in more complex cases of drug-resistant epilepsy, which may require intracranial electroencephalographic evaluation, has not been fully assessed. This retrospective study reports on a case series of patients with particularly complex focal epilepsy who underwent stereoelectroencephalography (SEEG) evaluation with stereotactically implanted multicontact intracerebral electrodes for the detailed identification of the epileptogenic zone (EZ) and who received RF-TC in their supposed EZ (according to SEEG findings). METHODS Eighty-nine patients (49 male and 40 female; age range 2–49 years) who underwent SEEG evaluation and subsequent RF-TC of the presumed EZ at the authors' institution between January 2008 and December 2013 were selected. Brain MRI revealed structural abnormalities in 43 cases and no lesions in 46 cases. After SEEG, 67 patients were judged suitable for resective surgery (Group 1), whereas surgery was excluded for 22 patients (Group 2). Thermocoagulation was performed in each of these patients by using the previously implanted multicontact recording electrodes and delivering RF-generated currents to adjacent electrode contacts. RESULTS The mean number of TC sites per patient was 10.6 ± 7.2 (range 1–33). Sustained seizure freedom occurred after TC in 16 patients (18.0%) (13 in Group 1 and 3 in Group 2). A sustained worthwhile improvement was reported by 9 additional patients (10.1%) (3 in Group 1 and 6 in Group 2). As a whole, 25 patients (28.1%) exhibited a persistent significant improvement in their seizures. More favorable results were observed in patients with nodular heterotopy (p = 0.0001389), those with a lesion found on MRI (not significant), and those with hippocampal sclerosis (not significant). Other variables significantly correlated to seizure freedom were the patient's age (p = 0.02885) and number of intralesional TC sites (p = 0.0271). The patients in Group 1 who did not benefit at all (21 patients) or who experienced only a transient benefit (30 patients) from TC underwent microsurgical resection of their EZ. Thermocoagulation was followed by severe permanent neurological deficits in 2 patients (an unexpected complex neuropsychological syndrome in one patient and an expected and anticipated permanent motor deficit in the other). CONCLUSIONS This study provides evidence that SEEG-guided TC in the EZ may be a treatment option for particularly complex drug-resistant focal epilepsy that requires invasive evaluation. A small subset of patients who achieve seizure freedom or worthwhile improvement may avoid open surgery or take advantage of an otherwise unexpected treatment if resection is not an option. Patients with epileptogenic nodular heterotopy are probably ideal candidates for this treatment.

scholarly journals Neurocysticercosis as a probable risk factor for hippocampal sclerosis

2018 ◽  
Vol 76 (11) ◽  
pp. 783-790 ◽  
Author(s):  
Gagandeep Singh ◽  
Josemir W. Sander
Keyword(s):  
Hippocampal Sclerosis ◽  
Taenia Solium ◽  
Population Based ◽  
Temporal Lobectomy ◽  
Epileptogenic Zone ◽  
Drug Resistant ◽  
Common Risk Factors ◽  
Longitudinal Imaging ◽  
Drug Resistant Epilepsy ◽  
Pathology Reports

ABSTRACT Neurocysticercosis is one of the most common risk factors for epilepsy but its association with drug-resistant epilepsy remains uncertain. Conjectures of an association with drug-resistant epilepsy have been fueled by reports of an association between calcific neurocysticercosis lesions (CNL) and hippocampal sclerosis (HS) from specialized epilepsy centers in Taenia solium-endemic regions. The debate arising from these reports is whether the association is causal. Evidence for the association is not high quality but sufficiently persuasive to merit further investigation with longitudinal imaging studies in population-based samples from geographically-diverse regions. The other controversial point is the choice of a surgical approach for drug-resistant epilepsy associated with CNL-HS. Three approaches have been described: standard anteromesial temporal lobectomy, lesionectomy involving a CNL alone and lesionectomy with anteromesial temporal lobectomy (for dual pathology); reports of the latter two approaches are limited. Presurgical evaluation should consider possibilities of delineating the epileptogenic zone/s in accordance with all three approaches.

How to Inject Ictal SPECT? From Manual to Automated Injection

2021 ◽  
Author(s):  
Xavier Setoain ◽  
Francisco Campos ◽  
Antonio Donaire ◽  
Maria Mayoral ◽  
Andres Perissinotti ◽  
...  
Keyword(s):  
Injection System ◽  
Control Group ◽  
Epileptogenic Zone ◽  
Drug Resistant ◽  
Injection Time ◽  
Tracer Injection ◽  
Ictal Spect ◽  
Seizure Focus ◽  
Drug Resistant Epilepsy ◽  
Automated Injection

Abstract BackgroundSuccessful surgery depends on the accurate localization of epileptogenic zone before surgery. Ictal SPECT is the only imaging modality that allows identification of the ictal onset zone by measuring the regional cerebral blood flow at the time of injection. The main limitations of ictal SPECT in epilepsy are the complex methodology of the tracer injection during a seizure. To overcome these limitations, we present the main features of the first automated injector for ictal SPECT (epijet, LemerPax; La Chapelle -sur-Erdre; France). In this study we compared traditional manual injection with automated injection for ictal SPECT in122 patients with drug-resistant epilepsy. MethodsThe study included 55 consecutive prospective patients with drug-resistant epilepsy undergoing injection with the automated injector. The control group was our retrospective database of a historic pool of 67 patients, injected manually from 2014-2016. Calculated annual exposure/radioactive dose for operators was measured. Injection time, seizure focus localization with ictal SPECT, as well as repeated hospitalizations related to fails injections were compared in these two groups of patients. ResultsThere were no differences in the average injection time with epijet (13 s) compared with the traditional manual injection (14s). The seizure focus was successfully localized with ictal SPECT with epijet in 44/55 (80%) patients and with manual injection in 46/67 (68%) patients (p=0.694). Repeated studies were required in 16/67 (23%) patients in the manual injection group compared to 4 patients (7%) in the epijet group (p=0.022). Calculated annual exposure/dose for operators of 0.39 mSv/year and administered dose error inferior to 5% are other advantages of epijet. ConclusionThe first results using epijet are promising in adjustment of the injection dose, reducing the rate of radiation exposure for patients and nurses, maintaining the same injection time and allowing high SPECT accuracy. These preliminary results support the use of an automated injection system to inject radioactive ictal SPECT doses in epilepsy units.

Stereoencephalography Electrode Placement Accuracy and Utility Using a Frameless Insertion Platform Without a Rigid Cannula

2019 ◽  
Author(s):  
Erin D’Agostino ◽  
John Kanter ◽  
Yinchen Song ◽  
Joshua P Aronson
Keyword(s):  
Electrode Placement ◽  
Target Point ◽  
Localization Error ◽  
Drug Resistant ◽  
Guide Cannula ◽  
Lateral Entry ◽  
Accurate Localization ◽  
Depth Electrodes ◽  
Rigid Frame ◽  
Drug Resistant Epilepsy

Abstract BACKGROUND Implantation of depth electrodes to localize epileptogenic foci in patients with drug-resistant epilepsy can be accomplished using traditional rigid frame-based, custom frameless, and robotic stereotactic systems. OBJECTIVE To evaluate the accuracy of electrode implantation using the FHC microTargeting platform, a custom frameless platform, without a rigid insertion cannula. METHODS A total of 182 depth electrodes were implanted in 13 consecutive patients who underwent stereoelectroencephalography (SEEG) for drug-resistant epilepsy using the microTargeting platform and depth electrodes without a rigid guide cannula. MATLAB was utilized to evaluate targeting accuracy. Three manual coordinate measurements with high inter-rater reliability were averaged. RESULTS Patients were predominantly male (77%) with average age 35.62 (SD 11.0, range 21-57) and average age of epilepsy onset at 13.4 (SD 7.2, range 3-26). A mean of 14 electrodes were implanted (range 10-18). Mean operative time was 144 min (range 104-176). Implantation of 3 out of 182 electrodes resulted in nonoperative hemorrhage (2 small subdural hematomas and one small subarachnoid hemorrhage). Putative location of onset was identified in all patients. We demonstrated a median lateral target point localization error (LTPLE) of 3.95 mm (IQR 2.18-6.23), a lateral entry point localization error (LEPLE) of 1.98 mm (IQR 1.2-2.85), a target depth error of 1.71 mm (IQR 1.03-2.33), and total target point localization error (TPLE) of 4.95 mm (IQR 2.98-6.85). CONCLUSION Utilization of the FHC microTargeting platform without the use of insertion cannulae is safe, effective, and accurate. Localization of seizure foci was accomplished in all patients and accuracy of depth electrode placement was satisfactory.

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