Stereoelectroencephalography in epilepsy, cognitive neurophysiology, and psychiatric disease: safety, efficacy, and place in therapy

Neuropsychiatric Disease and Treatment Dovepress open access to scientific and medical research Neuropsychiatric Disease and Treatment downloaded from https://www.dovepress.com/ by 124.219.154.141 on 19-Jun-2020 For personal use only. Open Access Full Text Article REVIEW Stereoelectroencephalography in epilepsy, cognitive neurophysiology, and psychiatric disease: safety, efficacy, and place in therapy This article was published in the following Dove Press journal: Neuropsychiatric Disease and Treatment Brett E Youngerman Farhan A Khan Guy M McKhann Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA Abstract: For patients with drug-resistant epilepsy, surgical intervention may be an effective treatment option if the epileptogenic zone (EZ) can be well localized. Subdural strip and grid electrode (SDE) implantations have long been used as the mainstay of intracranial seizure localization in the United States. Stereoelectroencephalography (SEEG) is an alternative approach in which depth electrodes are placed through percutaneous drill holes to stereotactically defined coordinates in the brain. Long used in certain centers in Europe, SEEG is gaining wider popularity in North America, bolstered by the advent of stereotactic robotic assistance and mounting evidence of safety, without the need for catheter-based angiography. Rates of clinically significant hemorrhage, infection, and other complications appear lower with SEEG than with SDE implants. SEEG also avoids unnecessary craniotomies when seizures are localized to unresectable eloquent cortex, found to be multifocal or nonfocal, or ultimately treated with stereotactic procedures such as laser interstitial thermal therapy (LITT), radiofrequency thermocoagulation (RF-TC), responsive neurostimulation (RNS), or deep brain stimulation (DBS). While SDE allows for excellent localization and functional mapping on the cortical surface, SEEG offers a less invasive option for sampling disparate brain areas, bilateral investigations, and deep or medial targets. SEEG has shown efficacy for seizure localization in the temporal lobe, the insula, lesional and nonlesional extra-temporal epilepsy, hypothalamic hamartomas, periventricular nodular heterotopias, and patients who have had prior craniotomies for resections or grids. SEEG offers a valuable opportunity for cognitive neurophysiology research and may have an important role in the study of dysfunctional networks in psychiatric disease and understanding the effects of neuromodulation. Keywords: stereoelectroencephalography, SEEG, epilepsy surgery, cognitive neurophysiology, psychiatric neurosurgery History Correspondence: Brett E Youngerman Department of Neurological Surgery, Columbia University Medical Center, 710 West 168th Street, New York, NY 10032, USA Tel +1 516 964 2145 Email 1701 submit your manuscript | www.dovepress.com Neuropsychiatric Disease and Treatment 2019:15 1701–1716 DovePress © 2019 Youngerman et al. This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/ terms.php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms (https://www.dovepress.com/terms.php). http://doi.org/10.2147/NDT.S177804 Powered by TCPDF (www.tcpdf.org) Approximately 30% of the patients with epilepsy have seizures refractory to antiepileptic drugs despite optimal management.1,2 After unsuccessful trials of two medications, the likelihood of achieving seizure freedom with a third is less than 4%. In such patients with drug-resistant epilepsy,3 surgical intervention may be an effective treatment option if the seizure onset zone can be well localized. In some cases, where seizure semiology, noninvasive scalp EEG, and imaging concordantly suggests a clear epileptogenic zone (EZ) in a surgically accessible region, a resection or other targeted procedure can be performed with reasonable confidence. However, when there is discordant information, multiple potential foci, or Neuropsychiatric Disease and Treatment downloaded from https://www.dovepress.com/ by 124.219.154.141 on 19-Jun-2020 For personal use only. Youngerman et al nearby eloquent cortex, intracranial implantation of electrodes and extra-operative mapping of the seizure onset zone can aid in further treatment planning.4 Subdural electrodes (SDE) have been the seizure mapping approach of choice for decades in the United States. Strips and grids of electrodes are placed in the subdural space through a craniotomy or burr holes, allowing for electrocorticography and localization of seizure onsets on the cortical surface. Otfrid Foerster and Hans Altenburger introduced SDE in 1935 and were the first to describe an ictal seizure pattern.5 Wilder Penfield and Herbert Jasper built upon these findings two years later by incorporating neural stimulation.6 This development allowed for the identification and preservation of functionally critical cortical areas. Since then, procedural standards have evolved to include extensive preoperative planning, tailored craniotomies or burr-holes, and focused placement of modernized strips and/or grids.7 The technique has frequently been combined with the use of select depth electrodes to sample deeper brain structures such as the hippocampus, but SDE remained the foundation of intracranial seizure monitoring in the United States. Stereoelectroencephalography (SEEG) is an alternative approach to intracranial monitoring in which depth electrodes are placed through percutaneous twist drill holes to stereotactically defined coordinates in the brain and secured at the skull. Jean Talairach and Jean Bancaud developed SEEG between 1957 and the early 1970s at Hospital Saint Anne, Paris.8 Early SEEG innovators placed the electrodes using frame-based stereotactic systems. A Talairach stereotactic frame and double-grid system were applied under anesthesia.9 To avoid damage to vascular structures, diagraming trajectories initially involved a fusion of angiography and ventriculography within the Talairach atlas.10 Ventriculography was replaced with CT and MRI for co-registration as those techniques became available, allowing for improved visualization and planning.11 SEEG offered several potential advantages over SDE for certain types of intracranial investigations. While SDE allowed for excellent localization on the cortical surface, SEEG facilitated direct recording from virtually every cerebral structure and three-dimensional seizure localization. SEEG also offered a less invasive option for sampling disparate (...truncated)