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Hagiwara K. [Insular lobe epilepsy. Part 2: presurgical evaluation & surgical interventions with stereo-electroencephalography]. Rinsho Shinkeigaku 2024; 64:540-549. [PMID: 39069490 DOI: 10.5692/clinicalneurol.cn-001930-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Identification of insular lobe epilepsy (ILE) presents a major clinical challenge in the diagnosis and treatment of drug-resistant focal epilepsies. ILE has diverse clinical presentations due to the multifaceted functions of the insula. Surface EEG findings do not provide straightforward information to predict this deeply-situated origin of seizures; they are even misleading, masquerading as those of other focal epilepsies, such as temporal and frontal ones. Non-invasive imagings may disclose insular abnormalities, but extra-insular abnormalities can coexist or even stand out. Careful reading and a second-look guided by other clinical information are crucial in order not to miss subtle insulo-opercular abnormalities. Furthermore, a possible insular origin of seizures should be considered in MRI-negative frontal/temporal/parietal epilepsies. Therefore, exploration/exclusion of insular-origin seizures is necessary for a great majority of surgical candidates. As for the stereo-electroencephalography, considered as the gold standard method for intra-cranial EEG investigations with suspicion of ILE, planning of electrode positions/trajectories require sufficient knowledge of the functional localization and anatomo-functional connectivity of the insula. Dense sampling within the insula is required in patients with probable ILE, because the seizure-onset zone can be restricted to a single insular gyrus or even a part of it. It is also crucial to explore extra-insular regions on the basis of non-invasive investigation results while considering their anatomo-functional relationships with the insula. From a surgical perspective, differentiating seizures strictly confined to the insula from those extending to the opercula is of particular importance. Pure insular seizures can be treated with less invasive measures, such as radiofrequency thermocoagulation. To conclude, close attention must be paid to the possibility of ILE throughout the diagnostic workup. The precise identification/exclusion of ILE is a prerequisite to provide appropriate and effective surgical treatment in pharmaco-resistant focal epilepsies.
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Chaudhari DM, . P, Renjen PN, Ahmad K. A Case of Hypermotor Seizures in Posterior Insular Cortex Epilepsy. Cureus 2023; 15:e36280. [PMID: 37075168 PMCID: PMC10105905 DOI: 10.7759/cureus.36280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2023] [Indexed: 03/19/2023] Open
Abstract
Insular seizure is a rare entity. Insular spikes spread to the temporal, parietal, and frontal lobes and clinically manifest with seizure semiology specific to these areas. We report the case of a 19-year-old male patient who presented with complaints of left-sided hemimotor tonic-clonic focal seizures of the limbs occurring three times per day. Neuroimaging showed cortical-subcortical right posterior insular cortex hyperintensities on fluid-attenuated inversion recovery (FLAIR) sequence and T2-weighted MRI with no significant diffusion restriction on apparent diffusion coefficient (ADC) and no post-contrast enhancement, suggesting focal cortical dysplasia of right posterior insular cortex. Electroencephalogram (EEG) showed right frontal epileptiform activity with secondary bilateral synchrony. The patient's atypical hemimotor tonic-clonic focal seizure, the conventional video EEG showing right frontal spikes synchronizing with bilateral temporal ictal spikes, and insular cortical dysplasia on MRI led us to a diagnosis of insular epilepsy.
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Jayapaul P, Gopinath S, Pillai A. Outcome following surgery for insulo-opercular epilepsies. J Neurosurg 2022; 137:1226-1236. [PMID: 35276652 DOI: 10.3171/2021.12.jns212220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/20/2021] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate the clinical outcome in patients with medically refractory epilepsy who had undergone resective or ablative surgery for suspected insulo-opercular epileptogenic foci. METHODS The prospectively maintained database of patients undergoing epilepsy surgery was reviewed, and all patients who underwent insulo-opercular surgery for medically refractory epilepsy with a minimum of 12 months of postoperative follow-up were identified, excluding those who had insulo-opercular resection in combination with temporal lobectomy. The presurgical electroclinicoradiological data, stereo-EEG (SEEG) findings, resection/ablation patterns, surgical pathology, postoperative seizure outcome, and neurological complications were analyzed. RESULTS Of 407 patients undergoing epilepsy surgery in a 5-year period at the Amrita Advanced Centre for Epilepsy, 24 patients (5.9%) who underwent exclusive insulo-opercular interventions were included in the study. Eleven (46%) underwent surgery on the right side, 12 (50%) on the left side, and the operation was bilateral in 1 (4%). The mean age at surgery was 24.5 ± 12.75 years. Onset of seizures occurred on average at 10.6 ± 9.7 years of life. Characteristic auras were identified in 66% and predominant seizure type was hypermotor (15.4%), automotor (15.4%), hypomotor (11.5%), or a mixed pattern. Seventy-five percent of the seizures recorded on scalp video-EEG occurred during sleep. The 3T MRI results were normal in 12 patients (50%). Direct single-stage surgery was undertaken in 5 patients, and SEEG followed by intervention in 19. Eighteen patients (75%) underwent exclusive resective surgery, 4 (16.7%) underwent exclusive volumetric radiofrequency ablation, and 2 (8.3%) underwent staged radiofrequency ablation and resective surgery. Immediate postoperative neurological deficits occurred in 10/24 (42%), which persisted beyond 12 postoperative months in 3 (12.5%). With a mean follow-up of 25.9 ± 14.6 months, 18 patients (75%) had Engel class I outcome, 3 (12.5%) had Engel class II, and 3 (12.5%) had Engel class III or IV. There was no statistically significant difference in outcomes between MRI-positive versus MRI-negative cases. CONCLUSIONS Surgery for medically refractory epilepsy in insulo-opercular foci is less common and remains a challenge to epilepsy surgery centers. Localization is aided significantly by a careful study of auras and semiology followed by EEG and imaging. The requirement for SEEG is generally high. Satisfactory rates of seizure freedom were achievable independent of the MRI lesional/nonlesional status. Morbidity is higher for insulo-opercular epilepsy surgery compared to other focal epilepsies; hence, the practice and development of minimally invasive strategies for this subgroup of patients undergoing epilepsy surgery is perhaps most important.
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Affiliation(s)
| | - Siby Gopinath
- 2Department of Neurology, Amrita Advanced Centre for Epilepsy, Amrita Institute of Medical Sciences & Research Centre, Kochi, India
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Passos GAR, Silvado CES, Borba LAB. Drug resistant epilepsy of the insular lobe: A review and update article. Surg Neurol Int 2022; 13:197. [PMID: 35673654 PMCID: PMC9168288 DOI: 10.25259/sni_58_2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 03/24/2022] [Indexed: 12/02/2022] Open
Abstract
Background: Epilepsy is a chronic disease that affects millions of people around the world generating great expenses and psychosocial problems burdening the public health in different ways. A considerable number of patients are refractory to the drug treatment requiring a more detailed and specialized investigation to establish the most appropriate therapeutic option. Insular epilepsy is a rare form of focal epilepsy commonly drug resistant and has much of its investigation and treatment involved with the surgical management at some point. The insula or the insular lobe is a portion of the cerebral cortex located in the depth of the lateral sulcus of the brain; its triangular in shape and connects with the other adjacent lobes. The insular lobe is a very interesting and complex portion of the brain related with different functions. Insula in Latin means Island and was initially described in the 18th century but its relation with epilepsy was first reported in the 1940–1950s. Insular lobe epilepsy is generally difficult to identify and confirm due to its depth and interconnections. Initial non-invasive studies generally demonstrate frustrating or incoherent information about the origin of the ictal event. Technological evolution made this pathology to be progressively better recognized and understood enabling professionals to perform the correct diagnosis and choose the ideal treatment for the affected population. Methods: A literature review was performed using MEDLINE/PubMed, Scopus, and Web of Science databases. The terms epilepsy/epileptic seizure of the insula and surgical treatment was used in various combinations. We included studies that were published in English, French, or Portuguese; performed in humans with insular epilepsy who underwent some surgical treatment (microsurgery, laser ablation, or radiofrequency thermocoagulation). Results: Initial search results in 1267 articles. After removing the duplicates 710 remaining articles were analyzed for titles and abstracts applying the inclusion and exclusion criteria. 70 studies met all inclusion criteria and were selected. Conclusion: At present, the main interests and efforts are in the attempt to achieve and standardize the adequate management of the patient with refractory epilepsy of the insular lobe and for that purpose several forms of investigation and treatment were developed. In this paper, we will discuss the characteristics and information regarding the pathology and gather data to identify and choose the best therapeutic option for each case.
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Affiliation(s)
- Gustavo A. R. Passos
- UFPR Post Graduate Program in Internal Medicine, Department of Neurosurgery, Mackenzie University Hospital,
| | - Carlos E. S. Silvado
- UFPR Post Graduate Program in Internal Medicine, Department of Neurology, Hospital de Clínicas da Universidade Federal do Paraná,
| | - Luis Alencar B. Borba
- Department of Neurosurgery, Hospital de Clínicas da Universidade Federal do Paraná/Mackenzie University Hospital, Curitiba, Brazil
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Aljafen BN. Insular epilepsy, an under-recognized seizure semiology. A review for general neurologist. NEUROSCIENCES (RIYADH, SAUDI ARABIA) 2020; 25:262-268. [PMID: 33130806 PMCID: PMC8015617 DOI: 10.17712/nsj.2020.4.20200063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Understanding seizure semiology is one of the most important and crucial steps in diagnosing a seizure disorder. Insular epilepsy may mimic other focal seizure semiologies, leading to misdiagnosis and failed epilepsy surgery. Insular seizures may begin as brief ictal symptoms, such as laryngeal discomfort and unpleasant throat sensations, and spread rapidly to the temporal or frontal regions, causing prominent ictal symptoms different to the initial insular ictal manifestation. Moreover, insular seizures are associated with complex epileptogenic networks and multiple connections. For this reason, accurate seizure semiology helps to lateralize and localize the seizure onset. The insular cortex is deep, and thus scalp electroencephalography is not always beneficial as the epileptic discharges will not be easily recorded, or they will be seen over other cortical regions like the temporal or frontal areas. Insular surgical resection is generally safe, but it requires extensive presurgical workup and surgical precautions in order to minimize mortality.
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Affiliation(s)
- Bandar N Aljafen
- College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia. E-mail:
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Bouthillier A, Weil AG, Martineau L, Létourneau-Guillon L, Nguyen DK. Operculoinsular cortectomy for refractory epilepsy. Part 1: Is it effective? J Neurosurg 2020; 133:950-959. [PMID: 31629321 DOI: 10.3171/2019.4.jns1912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 04/19/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Patients with refractory epilepsy of operculoinsular origin are often denied potentially effective surgical treatment with operculoinsular cortectomy (also termed operculoinsulectomy) because of feared complications and the paucity of surgical series with a significant number of cases documenting seizure control outcome. The goal of this study was to document seizure control outcome after operculoinsular cortectomy in a group of patients investigated and treated by an epilepsy team with 20 years of experience with this specific technique. METHODS Clinical, imaging, surgical, and seizure control outcome data of all patients who underwent surgery for refractory epilepsy requiring an operculoinsular cortectomy were retrospectively reviewed. Tumors and progressive encephalitis cases were excluded. Descriptive and uni- and multivariate analyses were done to determine seizure control outcome and predictors. RESULTS Forty-three patients with 44 operculoinsular cortectomies were studied. Kaplan-Meier estimates of complete seizure freedom (first seizure recurrence excluding auras) for years 0.5, 1, 2, and 5 were 70.2%, 70.2%, 65.0%, and 65.0%, respectively. With patients with more than 1 year of follow-up, seizure control outcome Engel class I was achieved in 76.9% (mean follow-up duration 5.8 years; range 1.25-20 years). With multivariate analysis, unfavorable seizure outcome predictors were frontal lobe-like seizure semiology, shorter duration of epilepsy, and the use of intracranial electrodes for invasive monitoring. Suspected causes of recurrent seizures were sparing of the language cortex part of the focus, subtotal resection of cortical dysplasia/polymicrogyria, bilateral epilepsy, and residual epileptic cortex with normal preoperative MRI studies (insula, frontal lobe, posterior parieto-temporal, orbitofrontal). CONCLUSIONS The surgical treatment of operculoinsular refractory epilepsy is as effective as epilepsy surgeries in other brain areas. These patients should be referred to centers with appropriate experience. A frontal lobe-like seizure semiology should command more sampling with invasive monitoring. Recordings with intracranial electrodes are not always required if the noninvasive investigation is conclusive. The complete resection of the epileptic zone is crucial to achieve good seizure control outcome.
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Affiliation(s)
| | - Alexander G Weil
- 1Divisions of Neurosurgery
- 4Division of Neurosurgery, Sainte-Justine University Hospital Center, Montreal, Quebec, Canada
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Bouthillier A, Weil AG, Martineau L, Létourneau-Guillon L, Nguyen DK. Operculoinsular cortectomy for refractory epilepsy. Part 2: Is it safe? J Neurosurg 2020; 133:960-970. [PMID: 31597116 DOI: 10.3171/2019.6.jns191126] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Accepted: 06/18/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Operculoinsular cortectomy (also termed operculoinsulectomy) is increasingly recognized as a therapeutic option for perisylvian refractory epilepsy. However, most neurosurgeons are reluctant to perform the technique because of previously experienced or feared neurological complications. The goal of this study was to quantify the incidence of basic neurological complications (loss of primary nonneuropsychological functions) associated with operculoinsular cortectomies for refractory epilepsy, and to identify factors predicting these complications. METHODS Clinical, imaging, and surgical data of all patients investigated and surgically treated by our team for refractory epilepsy requiring an operculoinsular cortectomy were retrospectively reviewed. Patients with tumors and encephalitis were excluded. Logistic regression analysis was used for uni- and multivariate statistical analyses. RESULTS Forty-four operculoinsular cortectomies were performed in 43 patients. Although postoperative neurological deficits were frequent (54.5% of procedures), only 3 procedures were associated with a permanent significant neurological deficit. Out of the 3 permanent deficits, only 1 (2.3%; a sensorimotor hemisyndrome) was related to the technique of operculoinsular cortectomy (injury to a middle cerebral artery branch), while the other 2 (arm hypoesthesia and hemianopia) were attributed to cortical resection beyond the operculoinsular area. With multivariate analysis, a postoperative neurological deficit was associated with preoperative insular hypometabolism on PET scan. Postoperative motor deficit (29.6% of procedures) was correlated with fewer years of neurosurgical experience and frontal operculectomies, but not with corona radiata ischemic lesions. Ischemic lesions in the posterior two-thirds of the corona radiata (40.9% of procedures) were associated with parietal operculectomies, but not with posterior insulectomies. CONCLUSIONS Operculoinsular cortectomy for refractory epilepsy is a relatively safe therapeutic option but temporary neurological deficits after surgery are frequent. This study highlights the role of frontal/parietal opercula resections in postoperative complications. Corona radiata ischemic lesions are not clearly related to motor deficits. There were no obvious permanent neurological consequences of losing a part of an epileptic insula, including on the dominant side for language. A low complication rate can be achieved if the following conditions are met: 1) microsurgical technique is applied to spare cortical branches of the middle cerebral artery; 2) the resection of an opercula is done only if the opercula is part of the epileptic focus; and 3) the neurosurgeon involved has proper training and experience.
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Affiliation(s)
| | - Alexander G Weil
- 1Divisions of Neurosurgery
- 4Division of Neurosurgery, Sainte-Justine University Hospital Center, Montreal, Quebec, Canada
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Kappen P, Eltze C, Tisdall M, Cross JH, Thornton R, Moeller F. Stereo-EEG exploration in the insula/operculum in paediatric patients with refractory epilepsy. Seizure 2020; 78:63-70. [PMID: 32203882 DOI: 10.1016/j.seizure.2020.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 02/09/2020] [Accepted: 02/12/2020] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Failure to recognise involvement of the insula / opercula (I/O) region is associated with poor outcome in epilepsy surgery. Recognition is challenging due to high connectivity with adjacent structures resulting in variable and misleading semiology, often subjective and therefore likely to be underreported by children. In this study we explored prevalence and characteristics of I/O involvement in paediatric patients undergoing sEEG exploration. METHOD We retrospectively included all consecutive patients undergoing sEEG at our centre between 11/2014 and 01/2018 with at least three contacts within I/O and excluded those with undetermined seizure onset zone (SOZ) by sEEG. We divided patients into three groups: 1) SOZ in I/O, 2) spread to I/O and 3) no I/O involvement. We compared pre-invasive characteristics, sEEG results, surgery and outcome for each group. RESULTS 29 of all 53 consecutive patients had an identified SOZ by sEEG and at least three contacts within the I/O and were included. 41% had I/O SOZ, 38% had I/O spread and 21% had no I/O involvement. Insula associated symptoms described in adult literature were not statistically different between the three groups. Complications due to sEEG were low (2 of 53 patients). Following I/O surgery, 63% were seizure free while an additional 26% of patients achieved seizure reduction. Postoperative deficits were seen in 75% of the patients but completely resolved in all but one patient. CONCLUSIONS Our data suggest an important role of the I/O region with frequent onset or propagation to the I/O region (at least 64% of all 53 sEEG cases). Semiology appears less specific than in adults. Insula depth electrode insertion is safe with subsequent good surgical outcomes albeit common transient deficits.
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Affiliation(s)
- Pablo Kappen
- Department of Neurophysiology, Great Ormond Street Hospital for Children, London, United Kingdom; Department of (Child) Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
| | - Christin Eltze
- Department of Neurophysiology, Great Ormond Street Hospital for Children, London, United Kingdom
| | - Martin Tisdall
- Department of Neurophysiology, Great Ormond Street Hospital for Children, London, United Kingdom
| | - J Helen Cross
- Department of Neurophysiology, Great Ormond Street Hospital for Children, London, United Kingdom; University College London Institute of Child Health, London, United Kingdom
| | - Rachel Thornton
- Department of Neurophysiology, Great Ormond Street Hospital for Children, London, United Kingdom
| | - Friederike Moeller
- Department of Neurophysiology, Great Ormond Street Hospital for Children, London, United Kingdom
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Türk BG, Metin B, Tekeli H, Sayman ÖA, Kızılkılıç O, Uzan M, Özkara Ç. Evaluation of olfactory and gustatory changes in patients with mesial temporal lobe epilepsy. Seizure 2020; 75:110-114. [DOI: 10.1016/j.seizure.2020.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 12/07/2019] [Accepted: 01/01/2020] [Indexed: 11/29/2022] Open
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Stefan H, Gollwitzer S. Ictal semiology, functional anatomy and multimodal diagnostic in patients with insular epilepsies. ACTA EPILEPTOLOGICA 2019. [DOI: 10.1186/s42494-019-0006-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Abstract
Background
The insula is a hidden part in the cerebral cortex. Insular epilepsy is underrecognized and it bears a special risk for misdiagnosis with regard to nonepileptic seizures or wrong localization of epileptic seizures.
Case presentations
The manuscript describes 2 cases with ictal semiology of paresthesia and pain followed by hyperkinetic movements, noninvasive findings of source localization and/or invasive SEEG exploration.
Conclusion
Magnetic source imaging, ictal SPECT as noninvasive and invasive recordings with depth electrodes (SEEG) can provide important preoperative information for the involvement of insular and periinsular regions in focal pharmacoresistant epilepsies. The optimal use of these methods presupposes extensive knowledge of ictal semiology and other clinical characteristics. The clinical localization hypothesis can be optimally proofed by SEEG exploration.
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Das KK, Singh S, Deora H, Khatri D, Mehrotra A, Srivastava AK, Jaiswal AK, Behari S. Microsurgical excision of giant dominant lobe insular cavernoma presenting acutely: Sometimes you win, sometimes you learn. INTERDISCIPLINARY NEUROSURGERY-ADVANCED TECHNIQUES AND CASE MANAGEMENT 2019. [DOI: 10.1016/j.inat.2019.100475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Jobst BC, Gonzalez-Martinez J, Isnard J, Kahane P, Lacuey N, Lahtoo SD, Nguyen DK, Wu C, Lado F. The Insula and Its Epilepsies. Epilepsy Curr 2019; 19:11-21. [PMID: 30838920 PMCID: PMC6610377 DOI: 10.1177/1535759718822847] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Insular seizures are great mimickers of seizures originating elsewhere in the
brain. The insula is a highly connected brain structure. Seizures may only
become clinically evident after ictal activity propagates out of the insula with
semiology that reflects the propagation pattern. Insular seizures with
perisylvian spread, for example, manifest first as throat constriction, followed
next by perioral and hemisensory symptoms, and then by unilateral motor
symptoms. On the other hand, insular seizures may spread instead to the temporal
and frontal lobes and present like seizures originating from these regions. Due
to the location of the insula deep in the brain, interictal and ictal scalp
electroencephalogram (EEG) changes can be variable and misleading. Magnetic
resonance imaging, magnetic resonance spectroscopy, magnetoencephalography,
positron emission tomography, and single-photon computed tomography imaging may
assist in establishing a diagnosis of insular epilepsy. Intracranial EEG
recordings from within the insula, using stereo-EEG or depth electrode
techniques, can prove insular seizure origin. Seizure onset, most commonly seen
as low-voltage, fast gamma activity, however, can be highly localized and easily
missed if the insula is only sparsely sampled. Moreover, seizure spread to the
contralateral insula and other brain regions may occur rapidly. Extensive
sampling of the insula with multiple electrode trajectories is necessary to
avoid these pitfalls. Understanding the functional organization of the insula is
helpful when interpreting the semiology produced by insular seizures. Electrical
stimulation mapping around the central sulcus of the insula results in
paresthesias, while stimulation of the posterior insula typically produces
painful sensations. Visceral sensations are the next most common result of
insular stimulation. Treatment of insular epilepsy is evolving, but poses
challenges. Surgical resections of the insula are effective but risk significant
morbidity if not carefully planned. Neurostimulation is an emerging option for
treatment, especially for seizures with onset in the posterior insula. The close
association of the insula with marked autonomic changes has led to interest in
the role of the insula in sudden unexpected death in epilepsy and warrants
additional study with larger patient cohorts.
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Affiliation(s)
| | | | - Jean Isnard
- 3 Hospices Civils de Lyon, Hospital for Neurology and Neurosurgery, Lyon, France
| | | | - Nuria Lacuey
- 5 University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Samden D Lahtoo
- 5 University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | | | - Chengyuan Wu
- 7 Thomas Jefferson University, Philadelphia, PA, USA
| | - Fred Lado
- 8 Northwell Health, Great Neck, NY, USA
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The role of magnetoencephalography in the presurgical evaluation of patients with MRI-negative operculo-insular epilepsy. Seizure 2018; 61:104-110. [DOI: 10.1016/j.seizure.2018.07.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 06/30/2018] [Accepted: 07/08/2018] [Indexed: 10/28/2022] Open
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Bouthillier A, Nguyen DK. Epilepsy Surgeries Requiring an Operculoinsular Cortectomy: Operative Technique and Results. Neurosurgery 2018; 81:602-612. [PMID: 28419327 DOI: 10.1093/neuros/nyx080] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 02/04/2017] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Epilepsy surgeries requiring an operculoinsulectomy pose significant difficulties because the perisylvian area is highly vascular, deep, and functional. OBJECTIVE To report the operative technique and results of epilepsy surgeries requiring an operculoinsular cortectomy at our institution. METHODS The data of all consecutive patients who had undergone an epilepsy surgery requiring an operculoinsular cortectomy with a minimum follow-up of 1 yr were reviewed. Tumor and vascular malformation cases were excluded. Surgical techniques are described based on findings during surgery. RESULTS Twenty-five patients underwent an epilepsy surgery requiring an operculoinsular cortectomy: mean age at surgery was 35 y (9-51), mean duration of epilepsy was 19 y (5-36), 14 were female, and mean duration of follow-up was 4.7 y (1-16). Magnetic resonance imaging of the operculoinsular area was normal or revealed questionable nonspecific findings in 72% of cases. Investigation with intracranial EEG electrodes was done in 17 patients. Surgery was performed on the dominant side for language in 7 patients. An opercular resection was performed in all but 2 patients who only had an insulectomy. Engel class I seizure control was achieved in 80% of patients. Postoperative neurological deficits (paresis, dysphasia, alteration of taste, smell, hearing, pain, and thermal perceptions) were frequent (75%) but always transient except for 1 patient with persistent mild alteration of thermal and pain perception. CONCLUSION Surgical treatment of operculoinsular epilepsy is effective in achieving seizure control and is associated with an acceptable long-term complication rate.
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Affiliation(s)
- Alain Bouthillier
- Division of Neurosurgery, Hôpital Notre-Dame (CHUM), Université de Montréal, Quebec, Canada
| | - Dang Khoa Nguyen
- Division of Neurology, Hôpital Notre-Dame (CHUM), Université de Montréal, Quebec, Canada
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The Value of Regional Cerebral Blood Flow SPECT and FDG PET in Operculoinsular Epilepsy. Clin Nucl Med 2018; 43:e67-e73. [DOI: 10.1097/rlu.0000000000001949] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Tomycz LD, Hale AT, Haider AS, Clarke DF, Lee MR. Invasive Insular Sampling in Pediatric Epilepsy: A Single-Institution Experience. Oper Neurosurg (Hagerstown) 2017; 15:310-317. [DOI: 10.1093/ons/opx253] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
BACKGROUND
It has been increasingly recognized that the insular cortex plays an important role in frontotemporal-parietal epilepsy in children. The insula, however, cannot be properly interrogated with conventional subdural grids, and its anatomy makes it difficult to implicate the insula with semiology or noninvasive modalities. Frame-based, stereotactic placement of insular depth electrodes for direct extraoperative monitoring is a relatively low-risk maneuver that allows for conclusive interrogation of this region, and, in select cases, can easily be replaced with a laser applicator for minimally invasive treatment via thermoablation.
OBJECTIVE
To describe the largest reported series of pediatric patients with refractory epilepsy undergoing insular depth electrode placement.
METHODS
We used current procedural terminology billing records to identify cases of depth electrode insertion performed at our institution. Clinical information from patients undergoing invasive insular sampling was then retrospectively collected.
RESULTS
Seventy-four insular depth electrodes were placed in 49 patients for extraoperative, inpatient monitoring. The decision to place insular depth electrodes was determined by a multidisciplinary epilepsy team. In 65.3% of cases, direct invasive sampling implicated the insula in seizure onset and prompted either thermoablation or surgical resection of some portion of the insula. There were no serious adverse effects or complications associated with the placement of insular depth electrodes.
CONCLUSION
Given the low morbidity of insular depth electrode insertion and the high proportion of patients who exhibited insular involvement, it is worth considering whether insular depth electrodes should be part of the standard presurgical evaluation in children with treatment-refractory frontotemporal-parietal epilepsy.
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Affiliation(s)
- Luke D Tomycz
- Department of Neurological Surgery, Dell Children's Medical Center, Austin, Texas
| | - Andrew T Hale
- Medical Scientist Training Program, Vanderbilt University School of Medicine, Nashville, Tennessee
| | | | - Dave F Clarke
- Department of Pediatric Neurology, Dell Children's Medical Center, Austin, Texas
| | - Mark R Lee
- Department of Neurological Surgery, Dell Children's Medical Center, Austin, Texas
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Laoprasert P, Ojemann JG, Handler MH. Insular epilepsy surgery. Epilepsia 2017; 58 Suppl 1:35-45. [PMID: 28386920 DOI: 10.1111/epi.13682] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2016] [Indexed: 11/29/2022]
Abstract
Since it was originally described nearly 70 years ago, insular epilepsy has been increasingly recognized and may explain failures after apparently well-planned operations. We review the history of awareness of the phenomenon, techniques for its assessment, and its surgical management. Insular epilepsy can mimic features of frontal, parietal, or temporal seizures. It should be considered when a combination of somatosensory, visceral, and motor symptoms is observed early in a seizure. Extraoperative intracranial recordings are required to accurately diagnose insular seizures. Stereo-electroencephalography (EEG) or craniotomy with implantation of surface and depth electrodes have been used successfully to identify insular onset of seizures. Surgical resection of an insular focus may be performed with good success and acceptable risk.
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Affiliation(s)
- Pramote Laoprasert
- Division of Neurology, Department of Pediatrics, University of Colorado Denver School of Medicine and Children's Hospital Colorado, Aurora, Colorado, U.S.A
| | - Jeffrey G Ojemann
- Department of Neurosurgery, University of Washington School of Medicine and Seattle Children's Hospital, Seattle, Washington, U.S.A
| | - Michael H Handler
- Department of Neurosurgery, University of Colorado Denver School of Medicine and Children's Hospital Colorado, Aurora, Colorado, U.S.A
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Aitouche Y, Gibbs SA, Gilbert G, Boucher O, Bouthillier A, Nguyen DK. Proton MR Spectroscopy in Patients with Nonlesional Insular Cortex Epilepsy Confirmed by Invasive EEG Recordings. J Neuroimaging 2017; 27:517-523. [PMID: 28318128 DOI: 10.1111/jon.12436] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 02/10/2017] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Recent studies suggest that a nonnegligible proportion of drug-resistant epilepsy surgery candidates have an epileptogenic zone that involves the insula. We aimed to examine the value of proton magnetic resonance spectroscopy (1 H-MRS) in identifying patients with insular cortex epilepsy. METHODS Patients with possible nonlesional drug-refractory insular epilepsy underwent a voxel-based 1 H-MRS study prior to an intracranial electroencephalographic (EEG) study. Patients were then divided into two groups based on invasive EEG findings: the insular group with evidence of insular seizures and the noninsular group with no evidence of insular seizures. Sixteen age-matched healthy controls were also scanned for normative data. RESULTS Twenty-two epileptic patients were recruited, 12 with insular seizures and 10 with extra-insular seizures. Ipsilateral and contralateral insular N-acetyl-aspartate concentrations ([NAA]) and NAA/Cr ratios were found to be similar in both patient groups. No significant differences in [NAA] or NAA/Cr ratios were found between the insular group, noninsular group, and healthy controls. [NAA] and NAA/Cr asymmetry indices correctly lateralized the seizure focus in only 16.7% and 0% of patients, respectively. CONCLUSIONS Our preliminary findings suggest that 1 H-MRS fares poorly in identifying patients with nonlesional insular epilepsy.
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Affiliation(s)
| | - Steve A Gibbs
- Department of Neurosciences, Université de Montréal, Canada.,Division of Neurology, Hôpital du Sacré-Cœur de Montréal, Université de Montréal, Canada
| | - Guillaume Gilbert
- MR Clinical Science, Philips Healthcare, Canada.,Department of Radiology, CHUM Notre-Dame, Université de Montréal, Canada
| | | | - Alain Bouthillier
- Division of Neurosurgery, CHUM Notre-Dame, Université de Montréal, Canada
| | - Dang Khoa Nguyen
- Department of Neurosciences, Université de Montréal, Canada.,Division of Neurology, CHUM Notre-Dame, Université de Montréal, Canada
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