scholarly journals Use of an intraventricular strip electrode for mesial temporal monitoring in children with medically intractable epilepsy

2017 ◽  
Vol 19 (4) ◽  
pp. 495-501
Author(s):  
Hyunmi Kim ◽  
Ahyuda Oh ◽  
Larry Olson ◽  
Joshua J. Chern
Keyword(s):  
Intractable Epilepsy ◽  
Median Number ◽  
Seizure Onset ◽  
Strip Electrode ◽  
Subdural Electrodes ◽  
Seizure Onset Zone ◽  
Subdural Electrode ◽  
Temporal Structures ◽  
Seizure Onset Zones

OBJECTIVE The objective of this study was to evaluate mesial temporal electroencephalographic (EEG) monitoring, using an intraventricular strip electrode (IVSE) along the ventricular surface of the hippocampus, in children with medically intractable epilepsy. METHODS The authors reviewed 10 consecutive cases in which subdural electrode placements and mesial temporal monitoring were recommended. The median age of the patients was 12.7 years (range 4.5–19.3 years). Both grids and IVSE were placed in all patients. The 4-contact IVSE was used in 5 cases, and the 6-contact IVSE in the other 5 cases. The median number of contacts, including IVSE contacts, was 122 (range 66–181). A total of 182 seizures were analyzed. RESULTS The IVSE localized seizure-onset zones in 8 patients. The seizure-onset zone was identified exclusively by IVSE in 3 patients and was simultaneous in IVSE and subdural electrodes in 5 patients. Among the 5 patients with simultaneous onset on both IVSE and subdural electrodes, 4 had basal temporal onset and one had orbitofrontal and lateral midtemporal onset. In the remaining 2 patients, the absence of IVSE seizure onset permitted sparing of mesial temporal structures. An Engel Class Ia outcome was achieved in 9 of 10 cases. No complication was associated with IVSE placement. CONCLUSIONS Intracranial monitoring using IVSE offers an alternative in terms of quality of EEG recording. IVSE was useful in children who already required open craniotomy for intracranial monitoring over an extensive network of hyper-excitability.

Palliative hemispherotomy in children with bilateral seizure onset

2012 ◽  
Vol 9 (4) ◽  
pp. 381-388 ◽  
Author(s):  
Michael Anthony Ciliberto ◽  
David Limbrick ◽  
Alexander Powers ◽  
Jeffrey B. Titus ◽  
Rebecca Munro ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Mr Imaging ◽  
Seizure Control ◽  
Epileptiform Activity ◽  
Intractable Epilepsy ◽  
Retrospective Chart Review ◽  
Seizure Onset ◽  
Significant Burden

Object Intractable epilepsy is a significant burden on families and on the cognitive development and quality of life (QOL) of patients. Periinsular hemispherotomy (PIH) for medically intractable epilepsy can benefit patients who qualify for this procedure. The ideal hemispherotomy candidate has ipsilateral ictal and interictal epileptiform activity, unilateral MR imaging abnormalities, contralateral hemiplegia, and a normal contralateral hemisphere. However, certain patients present with a mixed picture of bilateral electroencephalography (EEG) findings and severe intractable epilepsy, prompting consideration of a more aggressive treatment approach. This report introduces the possibility of surgery for patients who normally would not meet criteria for this treatment modality. Methods In this retrospective chart review, the authors report on 7 patients with bilateral seizure onset noted on routine or video-EEG monitoring. A QOL phone questionnaire, based on the Quality of Life in Childhood Epilepsy tool, was administered to a parent. The authors reviewed each patient's chart for surgical complications, changes in examination, QOL, limited neuropsychological outcomes, and seizure outcomes. They also investigated each chart for MR imaging and EEG findings as well as the patient's epilepsy clinic notes for seizure semiology and frequency. Results All patients enjoyed a decrease in seizure frequency and a subjective increase in QOL after PIH. Five patients (71%) achieved Engel Class I or II seizure control. The mean follow-up was 3.64 years (2–5.3 years). One patient is now off all antiseizure medication. No patient had a decrement in Full Scale IQ on postsurgical testing, and 2 (28.5%) of 7 individuals had increased adaptive and social functioning. Postsurgical examination changes included hemiplegia and homonymous hemianopia. Conclusions Hemispherotomy in patients with intractable epilepsy is generally reserved for individuals with unilateral epileptiform abnormalities or lesions on MR imaging. Seven patients in this study benefited from surgery despite bilateral seizure onset with improvement in seizure control and overall QOL. Thus, bilateral ictal onset does not necessarily preclude consideration for hemispherotomy in selected patients with severe medically refractory epilepsy.

scholarly journals Surgery for Heterotopia: A Second Look

2005 ◽  
Vol 5 (5) ◽  
pp. 197-199
Author(s):  
Paul A. Garcia
Keyword(s):  
Surgical Outcomes ◽  
Grey Matter ◽  
Epileptiform Activity ◽  
Intractable Epilepsy ◽  
Epileptogenic Zone ◽  
Seizure Onset ◽  
Periventricular Nodular Heterotopia ◽  
Nodular Heterotopia ◽  
Temporal Structures

Electroclinical, MRI, and Neuropathological Study of 10 Patients with Nodular Heterotopia, with Surgical Outcomes Tassi L, Colombo N, Cossu M, Mai R, Francione S, Lo Russo G, Galli C, Bramerio M, Battaglia G, Garbelli R, Meroni A, Spreafico R Brain 2005;128:321–337 We present the results of a retrospective study on 10 patients operated on for intractable epilepsy associated with nodular heterotopia, as identified by high-resolution MRI. Seven patients had unilateral heterotopia, one patient had symmetrical bilateral heterotopia, and two patients had asymmetrical bilateral heterotopia. By stereoelectroencephalogram (SEEG; nine patients), interictal activity within nodules was similar in all cases, and ictal activity never started from nodules alone but from the overlying cortex or simultaneously in nodules and cortex. Excellent outcomes (Engel class Ia, 1987) were achieved in the seven patients with unilateral heterotopia, showing that surgery can be highly beneficial in such cases when the epileptogenic zone is carefully located before surgery by MRI and particularly SEEG. For the bilateral cases, surgical outcomes were Engel IIa (one patient) or Engel IIIa (two patients). Histologic/immunohistochemical studies of resected specimens showed that all nodules had similar microscopic organization, even though their extent and location varied markedly. The overlying cortex was dysplastic in nine patients, but of normal thickness. We suggest that nodule formation may be the result of a dual mechanism: ( 1 ) failure of a stop signal in the germinal periventricular region leading to cell overproduction; and ( 2 ) early transformation of radial glial cells into astrocytes, resulting in defective neuronal migration. The intrinsic interictal epileptiform activity of nodules may be due to an impaired intranodular GABAergic system. The Role of Periventricular Nodular Heterotopia in Epileptogenesis Aghakhani Y, Kinay D, Gotman J, Soualmi L, Andermann F, Olivier A, Dubeau F Brain 2005;128:641–651 A temporal resection in patients with periventricular nodular heterotopia (PNH) and intractable focal seizures yields poor results. To define the role of heterotopic grey matter tissue in epileptogenesis and to improve outcome, we performed stereoencephalography (SEEG) recordings in eight patients with uni- or bilateral PNH and intractable focal epilepsy. The SEEG studies aimed to evaluate the most epileptogenic areas and included the allo- and neocortex and at least one nodule of grey matter. Interictal spiking activity was found in ectopic grey matter in three patients, in the cortex overlying the nodules in five, and in the mesial temporal structures in all. At least one heterotopion was involved at seizure onset in six patients, synchronous with the overlying neocortex or ipsilateral hippocampus. Two patients had their seizures originating in the mesial temporal structures only. Six patients had surgery, and the resected areas included the seizure onset, with follow-up from 1 to 8 years. An amygdalohippocampectomy was performed in two (Engel classes Id and III), an amygdalohippocampectomy plus removal of an adjacent heterotopion in two (class Ia), and a resection of two contiguous nodules plus a small rim of overlying occipital cortex in one patient (class Id). One patient with bilateral PNH had three adjacent nodules resected and an ipsilateral amygdalohippocampectomy, resulting in a reduction of the number of seizures by 25 to 50%. The best predictor of surgical outcome is the presence of a focal epileptic generator; this generator may or may not include the PNH. Invasive recording is required in patients with PNH; it improves localization and is the key to better outcome.

Minimally Invasive, Endoscopic-Assisted Device for Subdural Electrode Implantation in Epilepsy

2019 ◽  
Vol 18 (1) ◽  
pp. 92-97
Author(s):  
Sanjeet S Grewal ◽  
Mark Benscoter ◽  
Stephen Kuehn ◽  
Brian N Lundstrom ◽  
Matthew Stead ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Direct Visualization ◽  
Invasive Approach ◽  
Novel Device ◽  
Subdural Electrodes ◽  
Seizure Onset Zone ◽  
Visual Damage ◽  
Subdural Electrode ◽  
Subdural Hemorrhages ◽  
Keyhole Craniotomy

Abstract BACKGROUND Subdural grids and strip electrodes provide wide coverage of the cerebral cortex, precise delineation of the extent of the seizure onset zone, and improved spatial sampling to perform functional mapping for eloquent cortex. OBJECTIVE To describe a novel device that allows for a minimally invasive approach to implantation of subdural grid and strip electrodes. METHODS A skull mounted device was created to allow for implantation of subdural electrodes through a keyhole craniotomy with direct visualization using the aid of a flexible neurovideoscope. The initial studies in preparation for grid development performed on cadaveric skulls were analyzed to determine the size of craniotomy required for deployment, maximal distance of strip electrode deployment from center of craniotomy, and visual inspection of the cortex was performed for any underlying damage. RESULTS The device allowed for the placement of subdural electrodes through a 40-mm craniotomy. Subdural electrodes were deployed in multiple directions to a distance of a 70-mm radius from the center of the craniotomy. There was no visual damage to the underlying cortex after the procedures were completed. CONCLUSION Large craniotomies are typically desired to provide direct visualization of the implantation of subdural electrodes, but can increase the risk of subdural hemorrhages and infections. This study describes a novel minimally invasive endoscopically assisted device for the implantation of subdural strip electrodes under direct visualization. With this device, we are able to limit the size of the craniotomy, avoid incision through the temporalis muscle, and implant subdural electrodes with visualization of the cortex.

Seizure Outcomes After Corpus Callosotomy for Drop Attacks

Neurosurgery ◽  
2013 ◽  
Vol 73 (6) ◽  
pp. 993-1000 ◽  
Author(s):  
Regina S. Bower ◽  
Elaine Wirrell ◽  
Macaulay Nwojo ◽  
Nicholas M. Wetjen ◽  
W. Richard Marsh ◽  
...  
Keyword(s):  
Pediatric Population ◽  
Intractable Epilepsy ◽  
Seizure Outcome ◽  
Seizure Onset ◽  
Corpus Callosotomy ◽  
Drop Attacks ◽  
Younger Age ◽  
Age At Surgery ◽  
Adults And Children

Abstract BACKGROUND: Medically intractable epilepsy involving drop attacks can be difficult to manage and negatively affect quality of life. Most studies investigating the effect of corpus callosotomy (CC) on seizures have been limited, focusing on the pediatric population or drop seizures alone, with little attention to other factors influencing seizure outcome. OBJECTIVE: To assess seizure outcomes after CC in adults and children. METHODS: Retrospective analysis was performed on all patients who underwent CC (anterior two thirds, 1- or 2-stage complete) at our institution between 1990 and 2011. Change in frequency after CC was assessed for drop seizures and other seizure types. Multiple factors were evaluated for impact on seizure outcome. RESULTS: Fifty patients met inclusion criteria. The median age was 1.5 years at seizure onset and 17 years at time of surgery. Anterior two-thirds CC was performed in 28 patients, 1-stage complete in 17, and 2-stage complete in 5. All 3 groups experienced a significant decrease in drop seizures (P < .001, P < .001, and P = .020, respectively), with 40% experiencing complete resolution, and 64% dropping at least 1 frequency category. Other seizure types significantly decreased in anterior two-thirds CC and 1-stage complete (P = .0035, P = .001, respectively). Younger age at surgery correlated with better seizure outcomes (P = .043). CONCLUSION: CC for medically refractory generalizing epilepsy is effective for both drop seizures and other seizure types. CC should be considered soon after a patient has been deemed medically refractory because earlier age at surgery results in lower risk and better outcome.

scholarly journals Temporal Lobe Epilepsy Semiology

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Robert D. G. Blair
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Focal Epilepsy ◽  
Intractable Epilepsy ◽  
Febrile Seizures ◽  
Mesial Temporal Sclerosis ◽  
Careful Study ◽  
Seizure Onset ◽  
Seizure Semiology ◽  
Seizure Onset Zone

Epilepsy represents a multifaceted group of disorders divided into two broad categories, partial and generalized, based on the seizure onset zone. The identification of the neuroanatomic site of seizure onset depends on delineation of seizure semiology by a careful history together with video-EEG, and a variety of neuroimaging technologies such as MRI, fMRI, FDG-PET, MEG, or invasive intracranial EEG recording. Temporal lobe epilepsy (TLE) is the commonest form of focal epilepsy and represents almost 2/3 of cases of intractable epilepsy managed surgically. A history of febrile seizures (especially complex febrile seizures) is common in TLE and is frequently associated with mesial temporal sclerosis (the commonest form of TLE). Seizure auras occur in many TLE patients and often exhibit features that are relatively specific for TLE but few are of lateralizing value. Automatisms, however, often have lateralizing significance. Careful study of seizure semiology remains invaluable in addressing the search for the seizure onset zone.

LOCALIZATION OF EPILEPTIC FOCI USING MULTIMODALITY NEUROIMAGING

2012 ◽  
Vol 23 (01) ◽  
pp. 1230001 ◽  
Author(s):  
LARRY D. OLSON ◽  
M. SCOTT PERRY
Keyword(s):  
Drug Delivery ◽  
Epilepsy Surgery ◽  
Successful Treatment ◽  
Intractable Epilepsy ◽  
Targeted Treatment ◽  
Seizure Onset ◽  
Noninvasive Techniques ◽  
Multimodal Analysis ◽  
Iatrogenic Disability ◽  
Seizure Onset Zones

Approximately 30% of epilepsy patients are medically intractable. Epilepsy surgery may offer cure or palliation, and neuromodulation and direct drug delivery are being developed as alternatives. Successful treatment requires correct localization of seizure onset zones and understanding surrounding functional cortex to avoid iatrogenic disability. Several neurophysiologic and imaging localization techniques have inherent individual weaknesses which can be overcome by multimodal analysis. We review common noninvasive techniques, then illustrate the value of multimodal analysis to localize seizure onset for targeted treatment.

scholarly journals Resting-state functional MRI connectivity impact on epilepsy surgery plan and surgical candidacy: prospective clinical work

2020 ◽  
Vol 25 (6) ◽  
pp. 574-581 ◽  
Author(s):  
Varina L. Boerwinkle ◽  
Lucia Mirea ◽  
William D. Gaillard ◽  
Bethany L. Sussman ◽  
Diana Larocque ◽  
...  
Keyword(s):  
Functional Mri ◽  
Epilepsy Surgery ◽  
Resting State ◽  
Intractable Epilepsy ◽  
Pediatric Epilepsy ◽  
Seizure Onset ◽  
Surgery Planning ◽  
Seizure Onset Zone ◽  
Pediatric Epilepsy Surgery ◽  
The Impact

OBJECTIVEThe authors’ goal was to prospectively quantify the impact of resting-state functional MRI (rs-fMRI) on pediatric epilepsy surgery planning.METHODSFifty-one consecutive patients (3 months to 20 years old) with intractable epilepsy underwent rs-fMRI for presurgical evaluation. The team reviewed the following available diagnostic data: video-electroencephalography (n = 51), structural MRI (n = 51), FDG-PET (n = 42), magnetoencephalography (n = 5), and neuropsychological testing (n = 51) results to formulate an initial surgery plan blinded to the rs-fMRI findings. Subsequent to this discussion, the connectivity results were revealed and final recommendations were established. Changes between pre– and post–rs-fMRI treatment plans were determined, and changes in surgery recommendation were compared using McNemar’s test.RESULTSResting-state fMRI was successfully performed in 50 (98%) of 51 cases and changed the seizure onset zone localization in 44 (88%) of 50 patients. The connectivity results prompted 6 additional studies, eliminated the ordering of 11 further diagnostic studies, and changed the intracranial monitoring plan in 10 cases. The connectivity results significantly altered surgery planning with the addition of 13 surgeries, but it did not eliminate planned surgeries (p = 0.003). Among the 38 epilepsy surgeries performed, the final surgical approach changed due to rs-fMRI findings in 22 cases (58%), including 8 (28%) of 29 in which extraoperative direct electrical stimulation mapping was averted.CONCLUSIONSThis study demonstrates the impact of rs-fMRI connectivity results on the decision-making for pediatric epilepsy surgery by providing new information about the location of eloquent cortex and the seizure onset zone. Additionally, connectivity results may increase the proportion of patients considered eligible for surgery while optimizing the need for further testing.

scholarly journals Electrical Stimulation Mapping of Brain Function: A Comparison of Subdural Electrodes and Stereo-EEG

2020 ◽  
Vol 14 ◽  
Author(s):  
Krista M. Grande ◽  
Sarah K. Z. Ihnen ◽  
Ravindra Arya
Keyword(s):  
Electrical Stimulation ◽  
Clinical Decision Making ◽  
Cerebral Hemispheres ◽  
Cortical Surface ◽  
Functional Neuroanatomy ◽  
Functional Responses ◽  
Seizure Onset ◽  
Subdural Electrodes ◽  
Depth Electrodes ◽  
Seizure Onset Zone

Despite technological and interpretative advances, the non-invasive modalities used for pre-surgical evaluation of patients with drug-resistant epilepsy (DRE), fail to generate a concordant anatomo-electroclinical hypothesis for the location of the seizure onset zone in many patients. This requires chronic monitoring with intracranial electroencephalography (EEG), which facilitates better localization of the seizure onset zone, and allows evaluation of the functional significance of cortical regions-of-interest by electrical stimulation mapping (ESM). There are two principal modalities for intracranial EEG, namely subdural electrodes and stereotactic depth electrodes (stereo-EEG). Although ESM is considered the gold standard for functional mapping with subdural electrodes, there have been concerns about its utility with stereo-EEG. This is mainly because subdural electrodes allow contiguous sampling of the dorsolateral convexity of cerebral hemispheres, and permit delineation of the extent of eloquent functional areas on the cortical surface. Stereo-EEG, while having relatively sparse sampling on the cortical surface, offers the ability to access the depth of sulci, mesial and basal surfaces of cerebral hemispheres, and deep structures such as the insula, which are largely inaccessible to subdural electrodes. As stereo-EEG is increasingly the preferred modality for intracranial monitoring, we find it opportune to summarize the literature for ESM with stereo-EEG in this narrative review. Emerging evidence shows that ESM for defining functional neuroanatomy is feasible with stereo-EEG, but probably requires a different approach for interpretation and clinical decision making compared to ESM with subdural electrodes. We have also compared ESM with stereo-EEG and subdural electrodes, for current thresholds required to evoke desired functional responses vs. unwanted after-discharges. In this regard, there is preliminary evidence that ESM with stereo-EEG may be safer than ESM with subdural grids. Finally, we have highlighted important unanswered clinical and scientific questions for ESM with stereo-EEG in the hope to encourage future research and collaborative efforts.

MULTI-MODALITY IMAGE REGISTRATION FOR SUBDURAL ELECTRODE LOCALIZATION

2014 ◽  
Vol 26 (05) ◽  
pp. 1450051
Author(s):  
Shuo Dong ◽  
Yuan Liu ◽  
Lixin Cai ◽  
Mei Bai ◽  
Hanmin Yan
Keyword(s):  
Image Registration ◽  
Intractable Epilepsy ◽  
Rigid Registration ◽  
Multimodal Image Registration ◽  
Subdural Electrodes ◽  
Subdural Electrode ◽  
Information Metric ◽  
Electrode Localization ◽  
Image Pairs

Surgical treatment has been proved to be an effective way to control seizures for some kinds of intractable epilepsy. The electrocorticogram (ECoG) recorded from subdural electrodes has become an important technique for defining epileptogenic zones before surgery in clinical practice. The exact location of subdural electrodes has to be determined to establish the connection between electrodes and epileptogenic zones. Artifacts caused by the electrodes can severely affect the quality of CT imaging and sequentially image registration. In this paper, we discussed the performance of mean squares and the Mattes mutual information metric methods in multimodal image registration for subdural electrode localization. Since the skull can be regarded as a rigid body, rigid registration is sufficient for the purpose of subdural electrode localization. The vital parameter for the rigid registration is rotation. The translation result depends on the result of rotation. Both the methods performed well in the determination of the rotation center. Rotation angles of different image pairs of the same volume pair fluctuated a lot. Based on the image acquisition process, we assume that the images within the same volume pair should have the same transformation parameters for registration. Results show that the mean rotation angles of images within one dataset are approximate to the manual results that are considered to be the actual result for registration despite their fluctuation range.

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