Subdural electrode analysis in focal cortical dysplasia

Widdess‐Walsh, Peter; Jeha, Lara E.; Nair, Dileep; Kotagal, Prakash; Bingaman, William; Najm, Imad

doi:10.1212/01.wnl.0000267427.91987.21

Cited by 152 publications

(114 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Despite the efficacy and spatial accuracy in mapping the superficial cortex provided by the subdural methodology, relatively deep epileptic foci cannot be sampled adequately, and exploration is generally limited to one hemisphere. Moreover, patients with a normal MRI and electroclinical features suggestive of functional network involvement may need sampling from several nodes of the epileptic network (Widdess-Walsh, 2007). In cases like these, the stereo-electroencephalography (SEEG) methodology may be more suited for invasive evaluation (Bancaud et al, 1970;Kahane et al, 2006;GonzalezMartinez et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Correlating magnetoencephalography to stereo-electroencephalography in patients undergoing epilepsy surgery

Murakami

Wang

Marashly

et al. 2016

Brain

135

103

View full text Add to dashboard Cite

) for a scientific commentary on this article.Magnetoencephalography and stereo-electroencephalography are often necessary in the course of the non-invasive and invasive presurgical evaluation of challenging patients with medically intractable focal epilepsies. In this study, we aim to examine the significance of magnetoencephalography dipole clusters and their relationship to stereo-electroencephalography findings, area of surgical resection, and seizure outcome. We also aim to define the positive and negative predictors based on magnetoencephalography dipole cluster characteristics pertaining to seizure-freedom. Included in this retrospective study were a consecutive series of 50 patients who underwent magnetoencephalography and stereo-electroencephalography at the Cleveland Clinic Epilepsy Center. Interictal magnetoencephalography localization was performed using a single equivalent current dipole model. Magnetoencephalography dipole clusters were classified based on tightness and orientation criteria. Magnetoencephalography dipole clusters, stereo-electroencephalography findings and area of resection were reconstructed and examined in the same space using the patient's own magnetic resonance imaging scan. Seizure outcomes at 1 year postoperative were dichotomized into seizurefree or not seizure-free. We found that patients in whom the magnetoencephalography clusters were completely resected had a much higher chance of seizure-freedom compared to the partial and no resection groups (P = 0.007). Furthermore, patients had a significantly higher chance of being seizure-free when stereo-electroencephalography completely sampled the area identified by magnetoencephalography as compared to those with incomplete or no sampling of magnetoencephalography results (P = 0.012). Partial concordance between magnetoencephalography and interictal or ictal stereo-electroencephalography was associated with a much lower chance of seizure freedom as compared to the concordant group (P = 0.0075). Patients with one single tight cluster on magnetoencephalography were more likely to become seizure-free compared to patients with a tight cluster plus scatter (P = 0.0049) or patients with loose clusters (P = 0.018). Patients whose magnetoencephalography clusters had a stable orientation perpendicular to the nearest major sulcus had a better chance of seizure-freedom as compared to other orientations (P = 0.042). Our data demonstrate that stereo-electroencephalography exploration and subsequent resection are more likely to succeed, when guided by positive magnetoencephalography findings. As a corollary, magnetoencephalography clusters should not be ignored when planning the stereo-electroencephalography strategy. Magnetoencephalography tight cluster and stable orientation are positive predictors for a good seizure outcome after resective surgery, whereas the presence of scattered sources diminishes the probability of favourable outcomes. The concordance pattern between magnetoencephalography and stereo-electroencephalography is a strong...

show abstract

Section: Introductionmentioning

confidence: 99%

Correlating magnetoencephalography to stereo-electroencephalography in patients undergoing epilepsy surgery

Murakami

Wang

Marashly

et al. 2016

Brain

135

103

View full text Add to dashboard Cite

show abstract

“…5,8 Other series reporting complications across invasive monitoring procedures (subdural grids and depth electrodes) have rates ranging from 0% to 26%. 3,12,17,28,21 Interestingly, subdural monitoring with grid electrodes has historically been shown to have a low permanent morbidity rate (range 0%-3%) compared with depth electrodes (range 3%-6%) since there is no intraparenchymal passage. 18 Although it is difficult to compare morbidity rates between subdural grids and SEEG depth electrodes due to the variability in patient selection, different institutions, and variable number of implanted electrodes, it is our preliminary impression that the SEEG method provides at least a similar degree of safety when compared with subdural grids or strips.…”

Section: Discussionmentioning

confidence: 99%

“…In addition to the general criteria used for invasive extraoperative monitoring, 6,7,13,15,21 additional specific criteria were considered in choosing SEEG instead of other methods of invasive monitoring. 9 These criteria included: 1) the possibility of a deep-seated or difficult-to-cover location of the epileptogenic zone in areas such as the mesial structures of the temporal lobe, opercular areas, cingulate gyrus, interhemispheric regions, posterior orbitofrontal areas, insula, and depths of sulci; 2) the failure of a previous subdural invasive study to clearly outline the exact location of the seizure-onset zone; 3) the need for extensive bihemispheric explorations; and 4) a presurgical evaluation suggestive of a functional network involvement (for example, the limbic system) in the setting of normal MRI findings.…”

mentioning

confidence: 99%

Stereotactic placement of depth electrodes in medically intractable epilepsy

González-Martínez

Mullin²,

Vadera³

et al. 2014

JNS

178

146

View full text Add to dashboard Cite

Object Despite its long-reported successful record, with almost 60 years of clinical use, the technical complexity regarding the placement of stereoelectroencephalography (SEEG) depth electrodes may have contributed to the limited widespread application of the technique in centers outside Europe. The authors report on a simplified and novel SEEG surgical technique in the extraoperative mapping of refractory focal epilepsy. Methods The proposed technique was applied in patients with medically refractory focal epilepsy. Data regarding general demographic information, method of electrode implantation, time of implantation, number of implanted electrodes, seizure outcome after SEEG-guided resections, and complications were prospectively collected. Results From March 2009 to April 2012, 122 patients underwent SEEG depth electrode implantation at the Cleveland Clinic Epilepsy Center in which the authors' technique was used. There were 65 male and 57 female patients whose mean age was 33 years (range 5–68 years). The group included 21 pediatric patients (younger than 18 years). Planning and implantations were performed in a single stage. The time for planning was, on average, 33 minutes (range 20–47 minutes), and the time for implantation was, on average, 107 minutes (range 47–150 minutes). Complications related to the SEEG technique were observed in 3 patients. The calculated risk of complications per electrode was 0.18%. The seizure-free rate after SEEG-guided resections was 62% in a mean follow-up period of 12 months. Conclusions The authors report on a safe, simplified, and less time-consuming method of SEEG depth electrode implantation, using standard and widely available surgical tools, making the technique a reasonable option for extraoperative monitoring of patients with medically intractable epilepsy in centers lacking the Talairach stereotactic armamentarium.

show abstract

“…[7][8][9][10] However, patients with type I CD are a challenge in that they often have negative MRI scans, making surgical treatment difficult without knowing the exact location and borders necessary for complete lesion removal. [11][12][13][14][15][16] Supplemental data at www.neurology. org Our center has recently focused on exploring newer neuroimaging methods to detect cortical lesions in the multimodality presurgery evaluation of patients with refractory epilepsy.…”

mentioning

confidence: 99%

FDG-PET/MRI coregistration improves detection of cortical dysplasia in patients with epilepsy

Salamon¹,

et al. 2008

View full text Add to dashboard Cite

Objective: Patients with cortical dysplasia (CD) are difficult to treat because the MRI abnormality may be undetectable. This study determined whether fluorodeoxyglucose (FDG)-PET/MRI coregistration enhanced the recognition of CD in epilepsy surgery patients. UCLA MRI identified CD in 78% of patients, and 37% of type I CD cases had normal UCLA scans. EEG and neuroimaging findings were concordant in 52% of type I CD patients, compared with 89% of type II CD patients. FDG-PET scans were positive in 71% of CD cases, and type I CD patients had less hypometabolism compared with type II CD patients. Postoperative seizure freedom occurred in 82% of patients, without differences between type I and type II CD cases. Cortical dysplasia (CD), first described in 1971, 1 is the most common malformation of cortical development identified in surgically treated patients with therapy-resistant epilepsy. Methods: Conclusions:2,3 The histopathology of CD is classified into mild Palmini type I and severe Palmini type II.4,5 Type I CD is characterized by cortical dyslamination and columnar disorganization often associated with excessive subcortical white matter neurons. Type II CD shows cortical disorganization plus abnormal dysmorphic or cytomegalic neurons with or without balloon cells. 6 In the past decade, improvements in MRI have increased awareness that CD is a frequent substrate causing epilepsy. This is especially true for patients with type II CD in whom structural MRI and functional neuroimaging often identify the lesion. 7-10 However, patients with type I CD are a challenge in that they often have negative MRI scans, making surgical treatment difficult without knowing the exact location and borders necessary for complete lesion removal.

show abstract

Subdural electrode analysis in focal cortical dysplasia

Abstract: We have identified specific predictive factors that may guide the surgical evaluation of patients with focal cortical dysplasia and intractable epilepsy requiring subdural EEG monitoring. Successful surgical results can be obtained utilizing subdural EEG in carefully selected patients.

Cited by 152 publications

References 30 publications

Correlating magnetoencephalography to stereo-electroencephalography in patients undergoing epilepsy surgery

Correlating magnetoencephalography to stereo-electroencephalography in patients undergoing epilepsy surgery

Stereotactic placement of depth electrodes in medically intractable epilepsy

FDG-PET/MRI coregistration improves detection of cortical dysplasia in patients with epilepsy

Contact Info

Product

Resources

About