Seizure freedom after functional hemispherectomy and a possible role for the insular cortex: the Dutch experience

AbstractBACKGROUNDVarious studies suggest that the insular cortex may play an underappreciated role in pediatric frontotemporal/parietal epilepsy. Here, we report on the postsurgical outcomes in 26 pediatric patients with confirmed insular involvement by depth electrode monitoring.OBJECTIVETo describe one of the largest series of pediatric patients with medically refractory epilepsy undergoing laser interstitial thermal therapy (LITT) or surgical resection of at least some portion of the insular cortex.METHODSPediatric patients in whom invasive insular sampling confirmed insular involvement and who subsequently underwent a second stage surgery (LITT or open resection) were included. Complications and Engel Class outcomes at least 1 yr postsurgery were compiled as well as pathology results in the open surgical cases.RESULTSThe average age in our cohort was 10.3 yr, 58% were male, and the average length of follow-up was 2.43 ± 0.20 (SEM) yr. A total of 14 patients underwent LITT, whereas 12 patients underwent open resection. Complications in patients undergoing either LITT or open resection were mostly minimal and generally transient. Forty-three percent of patients who underwent LITT were Engel Class I, compared to 50% of patients who underwent open insular resection.CONCLUSIONBoth surgical resection and LITT are valid management options in the treatment of medically refractory insular/opercular epilepsy in children. Although LITT may be a less invasive alternative to craniotomy, further studies are needed to determine its noninferiority in terms of complication rates and seizure freedom, especially in cases of cortical dysplasia that may involve extensive regions of the brain.

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Dysphagia after pediatric functional hemispherectomy

Journal of Neurosurgery Pediatrics ◽

10.3171/2013.10.peds13182 ◽

2014 ◽

Vol 13 (1) ◽

pp. 95-100 ◽

Cited By ~ 5

Author(s):

Robert T. Buckley ◽

Tiffany Morgan ◽

Russell P. Saneto ◽

Jason Barber ◽

Richard G. Ellenbogen ◽

...

Keyword(s):

Pediatric Patients ◽

Clinical Symptoms ◽

Intractable Epilepsy ◽

Seizure Freedom ◽

Postoperative Dysphagia ◽

Duration Of Symptoms ◽

Functional Hemispherectomy ◽

Clinical Records ◽

The Impact ◽

New Onset

Object Functional hemispherectomy is a well-recognized surgical option for the treatment of unihemispheric medically intractable epilepsy. While the resultant motor deficits are a well-known and expected consequence of the procedure, the impact on other cortical functions has been less well defined. As the cortical control of swallowing would appear to be threatened after hemispherectomy, the authors retrospectively studied a pediatric population that underwent functional hemispherectomy for medically intractable epilepsy to characterize the incidence and severity of dysphagia after surgery. Methods A retrospective cohort (n = 39) of pediatric patients who underwent hemispherectomy at a single institution was identified, and available clinical records were reviewed. Additionally, the authors examined available MR images for integrity of the thalamus and basal ganglia before and after hemispherectomy. Clinical and video fluoroscopic assessments of speech pathology were reviewed, and the presence, type, and duration of pre- and postoperative dysphagia were recorded. Results New-onset, transient dysphagia occurred in 26% of patients after hemispherectomy along with worsening of preexisting dysphagia noted in an additional 15%. Clinical symptoms lasted a median of 19 days. Increased duration of symptoms was seen with late (> 14 days postoperative) pharyngeal swallow dysfunction when compared with oral dysphagia alone. Neonatal stroke as a cause for seizures decreased the likelihood of postoperative dysphagia. There was no association with seizure freedom or postoperative hydrocephalus. Conclusions New-onset dysphagia is a frequent and clinically significant consequence of hemispherectomy for intractable epilepsy in pediatric patients. This dysphagia was always self-limited except in those patients in whom preexisting dysphagia was noted.

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Reoperative Hemispherectomy for Intractable Epilepsy

Neurosurgery ◽

10.1227/neu.0b013e31825979bb ◽

2012 ◽

Vol 71 (2) ◽

pp. 388-393 ◽

Cited By ~ 28

Author(s):

Sumeet Vadera ◽

Ahsan N.V. Moosa ◽

Lara Jehi ◽

Ajay Gupta ◽

Prakash Kotagal ◽

...

Keyword(s):

Seizure Frequency ◽

Medical Records ◽

Cleveland Clinic ◽

Intractable Epilepsy ◽

Patient Characteristics ◽

Cortical Dysplasia ◽

Seizure Freedom ◽

Management Options ◽

Functional Hemispherectomy

Abstract BACKGROUND: In patients with medically intractable epilepsy and diffuse unilateral hemispheric disease, functional or disconnective hemispherectomy is a widely accepted and successful treatment option. If recurrent seizures develop after disconnective hemispherectomy, management options become more complex and include conversion to anatomic hemispherectomy. OBJECTIVE: To present the outcomes of all patients undergoing reoperative hemispherectomy in 1 institution by 1 surgeon since 1998. METHODS: The medical records, operative reports, and imaging studies for 36 patients undergoing reoperative hemispherectomy for continuing medically intractable epilepsy from 1998 to 2011 at Cleveland Clinic were reviewed. Patient characteristics, cause of seizure, imaging findings, surgery-related complications, and long-term seizure outcomes were evaluated. RESULTS: Patients presented with a variety of seizure origins, including Rasmussen encephalitis, perinatal infarction, cortical dysplasia, and hemimegalencephaly. Overall, 19% of patients were seizure free after conversion to anatomic hemispherectomy, and 45% reported a decrease in seizure frequency by ≥ 90%. An additional 36% reported no improvement. Generalized ictal electroencephalography tended to confer a poorer prognosis, as did cortical dysplasia as the underlying diagnosis. CONCLUSION: The possibility that residual epileptogenic tissue in the operated hemisphere remains connected should be considered after failed functional hemispherectomy because our data suggest that improvement in seizure frequency is possible after reoperative hemispherectomy, although the chance of obtaining seizure freedom is relatively low. The decision to proceed with reoperative hemispherectomy should be made after proper discussion with the patient and family and informed consent is given.

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Functional hemispherectomy: can preoperative imaging predict outcome?

Journal of Neurosurgery Pediatrics ◽

10.3171/2019.12.peds19370 ◽

2020 ◽

Vol 25 (6) ◽

pp. 567-573

Author(s):

Alexander G. Weil ◽

Aria Fallah ◽

Shelly Wang ◽

George M. Ibrahim ◽

Lior M. Elkaim ◽

...

Keyword(s):

Postoperative Hemorrhage ◽

Preoperative Imaging ◽

Seizure Freedom ◽

Event Analysis ◽

Seizure Recurrence ◽

Scalp Eeg ◽

Malformation Of Cortical Development ◽

Functional Hemispherectomy ◽

Csf Diversion

OBJECTIVEAlthough hemispherectomy is an effective treatment for children with intractable hemispheric epilepsy syndromes, as many as 40% of patients eventually develop seizure recurrence. The causes of seizure recurrence in these patients are incompletely understood. The authors sought to evaluate the efficacy of hemispherectomy at their center and determine whether contralateral MRI abnormalities can predict seizure recurrence.METHODSA retrospective review of consecutive hemispherectomies performed at Miami Children’s Hospital between January 2000 and June 2014 was performed. Time-to-event analysis was performed. The “event” was defined as any seizures following resective epilepsy surgery (not including seizures in the first postoperative week and auras). Several preoperative variables were analyzed to determine their suitability to predict seizure recurrence following surgery.RESULTSSixty-nine patients (44 boys) with a mean age of 8.2 ± 5.9 years (range 0.1–20.8 years) underwent 72 hemispherectomies; 67 of these were functional hemispherectomies, while another 5 were completion of a previous functional hemispherectomy (2 completions of functional hemispherectomies, 3 anatomical hemispherectomies). The duration of epilepsy was 5.8 ± 5.5 years with 66 cases (91.7%) having daily seizures. Etiology included stroke (n = 28), malformation of cortical development (n = 11), hemimegalencephaly (n = 11), encephalitis (n = 13), and other (n = 7). Engel class I outcome was achieved in 59 (86%) and 56 (81%) patients at 1 and 2 years of follow-up, respectively. The mean time to seizure recurrence was 33.5 ± 31.1 months. In univariate analyses, the absence of contralateral abnormalities on MRI (HR 4.09, 95% CI 1.41–11.89, p = 0.009) was associated with a longer duration of seizure freedom. The presence of contralateral MRI abnormalities was associated with contralateral ictal seizures on preoperative scalp EEG (p = 0.002). Fifteen patients experienced 20 complications (20/72, 27.8%), including the development of hydrocephalus necessitating CSF diversion in 9 cases (13%), hygroma in 1, hemispheric edema in 1, aseptic meningitis in 2, postoperative hemorrhage in 2, infection in 2, ischemic stroke in 2, and blood transfusion–contracted hepatitis C in 1 case.CONCLUSIONSPatients with bihemispheric abnormalities, as evidenced by contralateral MRI abnormalities, have a higher risk of earlier seizure recurrence following functional hemispherectomy.

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Epilepsy surgery for Rasmussen encephalitis: the UCLA experience

Journal of Neurosurgery Pediatrics ◽

10.3171/2020.4.peds2098 ◽

2020 ◽

Vol 26 (4) ◽

pp. 389-397

Author(s):

Nikhil Bellamkonda ◽

H. Westley Phillips ◽

Jia-Shu Chen ◽

Alexander M. Tucker ◽

Cassia Maniquis ◽

...

Keyword(s):

Epilepsy Surgery ◽

Outcome Data ◽

Seizure Freedom ◽

Rasmussen Encephalitis ◽

Seizure Recurrence ◽

Functional Hemispherectomy ◽

Significant Difference ◽

Seizure Relapse ◽

Drug Resistant Epilepsy ◽

Postoperative Seizure

OBJECTIVERasmussen encephalitis (RE) is a rare inflammatory neurological disorder typically involving one hemisphere and resulting in drug-resistant epilepsy and progressive neurological decline. Here, the authors present seizure outcomes in children who underwent epilepsy surgery for RE at a single institution.METHODSThe records of consecutive patients who had undergone epilepsy surgery for RE at the UCLA Mattel Children’s Hospital between 1982 and 2018 were retrospectively reviewed. Basic demographic information, seizure history, procedural notes, and postoperative seizure and functional outcome data were analyzed.RESULTSThe cohort included 44 patients, 41 of whom had sufficient data for analysis. Seizure freedom was achieved in 68%, 48%, and 22% of the patients at 1, 5, and 10 years, respectively. The median time to the first seizure for those who experienced seizure recurrence after surgery was 39 weeks (IQR 11–355 weeks). Anatomical hemispherectomy, as compared to functional hemispherectomy, was independently associated with a longer time to postoperative seizure recurrence (HR 0.078, p = 0.03). There was no statistically significant difference in postoperative seizure recurrence between patients with complete hemispherectomy and those who had less-than-hemispheric surgery. Following surgery, 68% of the patients could ambulate and 84% could speak regardless of operative intervention.CONCLUSIONSA large proportion of RE patients will have seizure relapse after surgery, though patients with anatomical hemispherectomies may have a longer time to postoperative seizure recurrence. Overall, the long-term data in this study suggest that hemispheric surgery can be seen as palliative treatment for seizures rather than a cure for RE.

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Surgery for Nontumoral Insular Epilepsy Explored by Stereoelectroencephalography

Neurosurgery ◽

10.1227/neu.0000000000001257 ◽

2016 ◽

Vol 79 (4) ◽

pp. 578-588 ◽

Cited By ~ 27

Author(s):

Guillaume Gras-Combe ◽

Lorella Minotti ◽

Dominique Hoffmann ◽

Alexandre Krainik ◽

Philippe Kahane ◽

...

Keyword(s):

Focal Cortical Dysplasia ◽

Intractable Epilepsy ◽

Insular Cortex ◽

Cavernous Angioma ◽

Cortical Dysplasia ◽

Electrode Placement ◽

Seizure Freedom ◽

Epileptogenic Zone ◽

Pharmacoresistant Epilepsy ◽

The Right

Abstract BACKGROUND Hidden by the perisylvian operculi, insular cortex has long been underexplored in the context of epilepsy surgery. Recent studies advocated stereoelectroencephalography (SEEG) as a reliable tool to explore insular cortex and its involvement in intractable epilepsy and suggested that insular seizures could be an underestimated entity. However, the results of insular resection to treat pharmacoresistant epilepsy are rarely reported. OBJECTIVE We report 6 consecutive cases of right insular resection performed based on anatomoelectroclinical correlations provided by SEEG. METHODS Six right-handed patients (3 male, 3 female) with drug-resistant epilepsy underwent comprehensive presurgical evaluation. Based on video electroencephalographic recordings, they all underwent SEEG evaluation with bilateral (n = 4) or unilateral right (n = 2) insular depth electrode placement. All patients had both orthogonal and oblique (1 anterior, 1 posterior) insular electrodes (n = 4-6 electrodes). Preoperative magnetic resonance imaging findings were normal in 4 patients, 1 patient had right insular focal cortical dysplasia, and 1 patient had a right opercular postoperative scar (cavernous angioma). All patients underwent right partial insular corticectomy via the subpial transopercular approach. RESULTS Intracerebral recordings demonstrated an epileptogenic zone confined to the right insula in all patients. After selective insular resection, 5 of 6 patients were seizure free (Engel class I) with a mean follow-up of 36.2 months (range, 18-68 months). Histological findings revealed focal cortical dysplasia in 5 patients and a gliosis scar in 1 patient. All patients had minor transient neurological deficit (eg, facial paresis, dysarthria). CONCLUSION Insular resection based on SEEG findings can be performed safely with a significant chance of seizure freedom.

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Indications, technique, and safety profile of insular stereoelectroencephalography electrode implantation in medically intractable epilepsy

Journal of Neurosurgery ◽

10.3171/2017.1.jns161070 ◽

2018 ◽

Vol 128 (4) ◽

pp. 1147-1157 ◽

Cited By ~ 10

Author(s):

Soha Alomar ◽

Jeffrey P. Mullin ◽

Saksith Smithason ◽

Jorge Gonzalez-Martinez

Keyword(s):

Sampling Rate ◽

Intractable Epilepsy ◽

Insular Cortex ◽

Preoperative Imaging ◽

Seizure Freedom ◽

Epileptogenic Zone ◽

Class Iii ◽

Electrode Implantation ◽

Accurate Localization ◽

Depth Electrodes

OBJECTIVEInsular epilepsy is relatively rare; however, exploring the insular cortex when preoperative workup raises the suspicion of insular epilepsy is of paramount importance for accurate localization of the epileptogenic zone and achievement of seizure freedom. The authors review their clinical experience with stereoelectroencephalography (SEEG) electrode implantation in patients with medically intractable epilepsy and suspected insular involvement.METHODSA total of 198 consecutive cases in which patients underwent SEEG implantation with a total of 1556 electrodes between June 2009 and April 2013 were reviewed. The authors identified patients with suspected insular involvement based on seizure semiology, scalp EEG data, and preoperative imaging (MRI, PET, and SPECT or magnetoencephalography [MEG]). Patients with at least 1 insular electrode based on the postoperative 3D reconstruction of CT fused with the preoperative MRI were included.RESULTSOne hundred thirty-five patients with suspected insular epilepsy underwent insular implantation of a total of 303 electrodes (1–6 insular electrodes per patient) with a total of 562 contacts. Two hundred sixty-eight electrodes (88.5%) were implanted orthogonally through the frontoparietal or temporal operculum (420 contacts). Thirty-five electrodes (11.5%) were implanted by means of an oblique trajectory either through a frontal or a parietal entry point (142 contacts). Nineteen patients (14.07%) had insular electrodes placed bilaterally. Twenty-three patients (17.04% of the insular implantation group and 11.6% of the whole SEEG cohort) were confirmed by SEEG to have ictal onset zones in the insula. None of the patients experienced any intracerebral hemorrhage related to the insular electrodes. After insular resection, 5 patients (33.3%) had Engel Class I outcomes, 6 patients (40%) had Engel Class II, 3 patients (20%) had Engel Class III, and 1 patient (6.66%) had Engel Class IV.CONCLUSIONSInsula exploration with stereotactically placed depth electrodes is a safe technique. Orthogonal electrodes are implanted when the hypothesis suggests opercular involvement; however, oblique electrodes allow a higher insular sampling rate.

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Functional hemispherectomy for patients with adult-onset Rasmussen’s encephalitis

Acta Epileptologica ◽

10.1186/s42494-021-00045-1 ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Hong Xue ◽

Cuiping Xu ◽

Xiaoxia Zhou ◽

Duanyu Ni ◽

Xueyuan Wang ◽

...

Keyword(s):

Surgical Treatment ◽

Clinical Manifestations ◽

Neurological Deficits ◽

Seizure Freedom ◽

Adult Onset ◽

Rasmussen’S Encephalitis ◽

Functional Hemispherectomy ◽

Clonic Seizures

Abstract Background Surgical treatment for patients with adult-onset Rasmussen’s encephalitis (A-RE) is rarely reported. We investigated the clinical and surgical features of two patients with A-RE who underwent functional hemispherectomy. Case presentation The data of clinical manifestations, neuroimaging, surgical treatment and surgical outcomes of two patients with A-RE was reviewed. The two patients initially presented with recurrent partial seizures or secondly generalized tonic clonic seizures. Gradually, the patients showed unilateral limb paralysis as well as chronic focal epileptic status. Both patients underwent functional hemispherectomy and achieved seizure freedom in the follow-up. The contralateral neurological deficits improved gradually after rehabilitation and were acceptable for the self-care of daily living. The living quality improved prominently after surgery. Conclusions Despite the risk of hemiplegia, functional hemispherectomy may be a choice for patients with A-RE for favorable seizure control and improved quality of life in selected patients.

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Intractable epilepsy after a functional hemispherectomy: important lessons from an unusual case

Journal of Neurosurgery ◽

10.3171/jns.2001.94.3.0510 ◽

2001 ◽

Vol 94 (3) ◽

pp. 510-514 ◽

Cited By ~ 17

Author(s):

Sandeep Mittal ◽

Jean-Pierre Farmer ◽

Bernard Rosenblatt ◽

Frederick Andermann ◽

José L. Montes ◽

...

Keyword(s):

Single Photon ◽

Anterior Commissure ◽

Photon Emission ◽

Intractable Epilepsy ◽

Insular Cortex ◽

Cortical Dysplasia ◽

Content Type ◽

Functional Hemispherectomy ◽

The Right ◽

Fine Print

✓ Residual seizures after functional hemispherectomy occur in approximately 20% of patients with catastrophic epilepsy. These episodes are traditionally attributed to incomplete disconnection, persistent epileptogenic activity in the ipsilateral insular cortex, or bilateral independent epileptogenic activity. The authors report on the case of an 8-year-old boy with an intractable seizure disorder who had classic frontal adversive seizures related to extensive unilateral left hemispheric cortical dysplasia. The initial intervention consisted of extensive removal of the epileptic frontal and precentral dysplastic tissue and multiple subpial transections of the dysplastic motor strip, guided by intraoperative electrocorticography. Subsequently, functional hemispherectomy including insular cortex resection was performed for persistent attacks. After a seizure-free period of 6 months, a new pattern ensued, consisting of an aura of fear, dystonic posturing of the right arm, and unusual postictal hyperphagia coupled with an interictal diencephalic-like syndrome. Electroencephalography and ictal/interictal single-photon emission computerized tomography were used to localize the residual epileptic discharges to deep ipsilateral structures. Results of magnetic resonance imaging indicated a complete disconnection except for a strip of residual frontobasal tissue. Therefore, a volumetric resection of the epileptogenic frontal basal tissue up to the anterior commissure was completed. The child has remained free of seizures during 21 months of follow-up review. Standard hemispherectomy methods provide extensive disconnection, despite the presence of residual frontal basal cortex. However, rarely, and especially if it is dysplastic, this tissue can represent a focus for refractory seizures. This is an important consideration in determining the source of ongoing seizures posthemispherectomy in patients with extensive cortical dysplasia. It remains important to assess them fully before considering their disease refractory to surgical treatment.

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