Resective surgery for medically refractory epilepsy using intraoperative MRI and functional neuronavigation: the Erlangen experience of 415 patients

OBJECTIVE Intraoperative overestimation of resection volume in epilepsy surgery is a well-known problem that can lead to an unfavorable seizure outcome. Intraoperative MRI (iMRI) combined with neuronavigation may help surgeons avoid this pitfall and facilitate visualization and targeting of sometimes ill-defined heterogeneous lesions or epileptogenic zones and may increase the number of complete resections and improve seizure outcome. METHODS To investigate this hypothesis, the authors conducted a retrospective clinical study of consecutive surgical procedures performed during a 10-year period for epilepsy in which they used neuronavigation combined with iMRI and functional imaging (functional MRI for speech and motor areas; diffusion tensor imaging for pyramidal, speech, and visual tracts; and magnetoencephalography and electrocorticography for spike detection). Altogether, there were 415 patients (192 female and 223 male, mean age 37.2 years; 41% left-sided lesions and 84.9% temporal epileptogenic zones). The mean preoperative duration of epilepsy was 17.5 years. The most common epilepsy-associated pathologies included hippocampal sclerosis (n = 146 [35.2%]), long-term epilepsy-associated tumor (LEAT) (n = 67 [16.1%]), cavernoma (n = 45 [10.8%]), focal cortical dysplasia (n = 31 [7.5%]), and epilepsy caused by scar tissue (n = 23 [5.5%]). RESULTS In 11.8% (n = 49) of the surgeries, an intraoperative second-look surgery (SLS) after incomplete resection verified by iMRI had to be performed. Of those incomplete resections, LEATs were involved most often (40.8% of intraoperative SLSs, 29.9% of patients with LEAT). In addition, 37.5% (6 of 16) of patients in the diffuse glioma group and 12.9% of the patients with focal cortical dysplasia underwent an SLS. Moreover, iMRI provided additional advantages during implantation of grid, strip, and depth electrodes and enabled intraoperative correction of electrode position in 13.0% (3 of 23) of the cases. Altogether, an excellent seizure outcome (Engel Class I) was found in 72.7% of the patients during a mean follow-up of 36 months (range 3 months to 10.8 years). The greatest likelihood of an Engel Class I outcome was found in patients with cavernoma (83.7%), hippocampal sclerosis (78.8%), and LEAT (75.8%). Operative revisions that resulted from infection occurred in 0.3% of the patients, from hematomas in 1.6%, and from hydrocephalus in 0.8%. Severe visual field defects were found in 5.2% of the patients, aphasia in 5.7%, and hemiparesis in 2.7%, and the total mortality rate was 0%. CONCLUSIONS Neuronavigation combined with iMRI was beneficial during surgical procedures for epilepsy and led to favorable seizure outcome with few specific complications. A significantly higher resection volume associated with a higher chance of favorable seizure outcome was found, especially in lesional epilepsy involving LEAT or diffuse glioma.

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Focal Cortical Dysplasia IIIa in Hippocampal Sclerosis-Associated Epilepsy: Anatomo-Electro-Clinical Profile and Surgical Results From a Multicentric Retrospective Study

Neurosurgery ◽

10.1093/neuros/nyaa369 ◽

2020 ◽

Author(s):

Massimo Cossu ◽

Piergiorgio d'Orio ◽

Carmen Barba ◽

Sofia Asioli ◽

Francesco Cardinale ◽

...

Keyword(s):

Focal Cortical Dysplasia ◽

Hippocampal Sclerosis ◽

Cortical Dysplasia ◽

Clinical Profile ◽

Class I ◽

Seizure Outcome ◽

Surgical Results ◽

Postoperative Control ◽

Postoperative Seizure

Abstract BACKGROUND Hippocampal sclerosis (HS) may be associated with focal cortical dysplasia IIIa (FCD IIIa) in patients undergoing surgery for temporal lobe epilepsy (TLE). OBJECTIVE To investigate whether the anatomo-electro-clinical profile and surgical outcome in patients with HS-related TLE are affected by coexisting FCD IIIa. METHODS A total of 220 patients, operated in 5 centers, with at least 24 mo follow-up (FU), were retrospectively studied. Preliminary univariate and subsequent multivariate analyses were performed to investigate possible associations between several potential presurgical, surgical, and postsurgical predictors and different variables (Engel's class I and Engel's class Ia, co-occurrence of FCD IIIa). RESULTS At last available postoperative control (FU: range 24-95 mo, median 47 mo), 182 (82.7%) patients were classified as Engel's class I and 142 (64.5%) as Engel's class Ia. At multivariate analysis, extension of neocortical resection and postoperative electroencephalogram were significantly associated with Engel's class I, whereas length of FU had a significant impact on class Ia in the whole cohort and in isolated HS (iHS) patients, but not in the FCD IIIa group. No differences emerged in the anatomo-electro-clinical profile and surgical results between patients with FCD IIIa and with iHS. CONCLUSION Coexistence of FCD IIIa did not confer a distinct anatomo-electro-clinical profile to patients with HS-related epilepsy. Postoperative seizure outcome was similar in FCD IIIa and iHS cases. These findings indicate limited clinical relevance of FCD IIIa in HS-related epilepsy and might be useful for refining future FCD classifications. Further studies are needed to clarify the correlation of class Ia outcome with the duration of FU.

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The Impact of Intraoperative Electrocorticography on Seizure Outcome After Resection of Pediatric Brain Tumors: A Cohort Study

Neurosurgery ◽

10.1093/neuros/nyy342 ◽

2018 ◽

Vol 85 (3) ◽

pp. 375-383 ◽

Cited By ~ 1

Author(s):

Faith C Robertson ◽

Nicole J Ullrich ◽

Peter E Manley ◽

Hasan Al-Sayegh ◽

Clement Ma ◽

...

Keyword(s):

Pediatric Patients ◽

Focal Cortical Dysplasia ◽

Tumor Resection ◽

Cortical Dysplasia ◽

Class I ◽

Gross Total Resection ◽

Seizure Outcome ◽

Seizure Freedom ◽

Total Resection ◽

The Impact

AbstractBACKGROUNDIntraoperative electrocorticography (ECoG) has been utilized in patients with tumor-associated seizures; however, its effectiveness for seizure control remains controversial.OBJECTIVETo evaluate clinical outcomes in pediatric patients undergoing lesionectomy with or without ECoG.METHODSPatients undergoing brain tumor resection at Boston Children's Hospital were examined retrospectively (2005-2014). Inclusion criteria involved diagnosis of a supratentorial tumor, ≥2 unequivocal seizures, and ≥6 mo follow-up. Patients with isolated cortical dysplasia or posterior fossa tumors were excluded. Logistic regression models evaluated predictors of ECoG use, and the impact of ECoG, gross total resection, and focal cortical dysplasia with tumors on seizure freedom by Engel Class and anti-epileptic drug use (AED).RESULTSA total of 119 pediatric patients were included (n = 69 males, 58%; median age, 11.3 yr). Forty-one patients (34.5%) had ECoG-guided surgery. Preoperative seizure duration and number and duration of AED use were significant predictors for undergoing ECoG. There were no differences in seizure freedom (Engel Class I) or improved Engel Score (Class I-II vs III-IV) in patients who did or did not have ECoG at 30 d, 6 mo, and 1, 2, or 5 yr. Patients undergoing ECoG required a greater number of AEDs at 6 mo (P = .01), although this difference disappeared at subsequent time intervals. Gross total resection predicted seizure freedom at 30 d and 6 mo postsurgery (P = .045).CONCLUSIONThis retrospective study, one of the largest evaluating the use of ECoG during tumor resection, suggests that ECoG does not provide improved seizure freedom compared to lesionectomy alone for children.

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Surgical strategy for focal cortical dysplasia based on the analysis of the spike onset and peak zones on magnetoencephalography

Journal of Neurosurgery ◽

10.3171/2019.6.jns191058 ◽

2020 ◽

Vol 133 (6) ◽

pp. 1850-1862 ◽

Cited By ~ 1

Author(s):

Hiroshi Shirozu ◽

Akira Hashizume ◽

Hiroshi Masuda ◽

Akiyoshi Kakita ◽

Hiroshi Otsubo ◽

...

Keyword(s):

Focal Cortical Dysplasia ◽

Cortical Dysplasia ◽

Complete Resection ◽

Surgical Strategy ◽

Class I ◽

Type I ◽

Incomplete Resection ◽

Epileptogenic Zone ◽

Current Dipole ◽

Significant Difference

OBJECTIVEThe aim of this study was to elucidate the surgical strategy for focal cortical dysplasia (FCD) based on the interictal analysis on magnetoencephalography (MEG). For this purpose, the correlation between the spike onset zone (Sp-OZ) and the spike peak zone (Sp-PZ) on MEG was evaluated to clarify the differences in the Sp-OZ and its correlation with Sp-PZ in FCD subtypes to develop an appropriate surgical strategy.METHODSForty-one FCD patients (n = 17 type I, n = 13 type IIa, and n = 11 type IIb) were included. The Sp-OZ was identified by the summation of gradient magnetic-field topography (GMFT) magnitudes at interictal MEG spike onset, and Sp-PZ was defined as the distribution of the equivalent current dipole (ECD) at spike peak. Correlations between Sp-OZ and Sp-PZ distributions were evaluated and compared with clinical factors and seizure outcomes retrospectively.RESULTSGood seizure outcomes (Engel class I) were obtained significantly more often in patients with FCD type IIb (10/11, 90.9%) than those with type IIa (4/13, 30.8%; p = 0.003) and type I (6/17, 35.3%; p = 0.004). The Sp-OZ was significantly smaller (1 or 2 gyri) in type IIb (10, 90.9%) than in type IIa (4, 30.8%; p = 0.003) or type I (9, 53.0%; p = 0.036). Concordant correlations between the Sp-OZ and Sp-PZ were significantly more frequent in type IIb (7, 63.6%) than in type IIa (1, 7.7%; p = 0.015) or type I (1, 5.8%; p = 0.004). Complete resection of the Sp-OZ achieved significantly better seizure outcomes (Engel class I: 9/10, 90%) than incomplete resection (11/31, 35.5%) (p = 0.003). In contrast, complete resection of the Sp-PZ showed no significant difference in good seizure outcomes (9/13, 69.2%) compared with incomplete resection (11/28, 39.3%).CONCLUSIONSThe Sp-OZ detected by MEG using GMFT and its correlation with Sp-PZ were related to FCD subtypes. A discordant distribution between Sp-OZ and Sp-PZ in type I and IIa FCD indicated an extensive epileptogenic zone and a complex epileptic network. Type IIb showed a restricted epileptogenic zone with the smaller Sp-OZ and concordance between Sp-OZ and Sp-PZ. Complete resection of the Sp-OZ provided significantly better seizure outcomes than incomplete resection. Complete resection of the Sp-PZ was not related to seizure outcomes. There was a definite difference in the epileptogenic zone among FCD subtypes; hence, an individual surgical strategy taking into account the correlation between the Sp-OZ and Sp-PZ should be considered.

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Focal Cortical Dysplasia Type Ⅲ Related Medically Refractory Epilepsy: MRI Findings and Potential Predictors of Surgery Outcome

Diagnostics ◽

10.3390/diagnostics11122225 ◽

2021 ◽

Vol 11 (12) ◽

pp. 2225

Author(s):

Xiaozhuan Wang ◽

Dabiao Deng ◽

Chengqian Zhou ◽

Honglin Li ◽

Xueqin Guan ◽

...

Keyword(s):

Refractory Epilepsy ◽

Focal Cortical Dysplasia ◽

Febrile Seizures ◽

Cortical Dysplasia ◽

Seizure Outcome ◽

Incomplete Resection ◽

Negative Finding ◽

Number Of Patients ◽

Medically Refractory Epilepsy

This study aims to explore the relationship between neuropathologic and the post-surgical prognosis of focal cortical dysplasia (FCD) typed-Ⅲ-related medically refractory epilepsy. A total of 266 patients with FCD typed-Ⅲ-related medically refractory epilepsy were retrospectively studied. Presurgical clinical data, type of surgery, and postsurgical seizure outcome were analyzed. The minimum post-surgical follow-up was 1 year. A total of 266 patients of FCD type Ⅲ were included in this study and the median follow-up time was 30 months (range, 12~48 months). Age at onset ranged from 1.0 years to 58.0 years, with a median age of 12.5 years. The number of patients under 12 years old was 133 (50%) in patients with FCD type Ⅲ. A history of febrile seizures was present in 42 (15.8%) cases. In the entire postoperative period, 179 (67.3%) patients were seizure-free. Factors with p < 0.15 in univariate analysis, such as age of onset of epilepsy (p = 0.145), duration of epilepsy (p = 0.004), febrile seizures (p = 0.150), being MRI-negative (p = 0.056), seizure type (p = 0.145) and incomplete resection, were included in multivariate analysis. Multivariate analyses revealed that MRI-negative findings of FCD (OR 0.34, 95% CI 0.45–0.81, p = 0.015) and incomplete resection (OR 0.12, 95% CI 0.05–0.29, p < 0.001) are independent predictors of unfavorable seizure outcomes. MRI-negative finding of FCD lesions and incomplete resection were the most important predictive factors for poor seizure outcome in patients with FCD type Ⅲ.

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Occult focal cortical dysplasia may predict poor outcome of surgery for drug-resistant mesial temporal lobe epilepsy

PLoS ONE ◽

10.1371/journal.pone.0257678 ◽

2021 ◽

Vol 16 (9) ◽

pp. e0257678

Author(s):

Arkadiusz Nowak ◽

Aleksandra Bala

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Focal Cortical Dysplasia ◽

Mesial Temporal Lobe Epilepsy ◽

Cortical Dysplasia ◽

Class I ◽

Seizure Outcome ◽

Epileptogenic Zone ◽

Dual Pathology ◽

Mesial Temporal Lobe

Purpose The results of surgery in patients with mesial temporal lobe epilepsy (MTLE) associated with hippocampal sclerosis (HS) are favorable, with a success rate over 70% following resection. An association of HS with focal cortical dysplasia (FCD) in the temporal lobe is one of the potential causes for poor surgical outcome in MTLE. We aimed to analyzed seizure outcome in a population of MTLE patients and recognize the role of occult FCD in achieving postoperative seizure control. Methods We retrospectively analyzed postoperative outcomes for 82 consecutive adult patients with the syndrome of MTLE due to HS, who had no concomitant lesions within temporal lobe in MRI and who underwent surgical treatment in the years 2005–2016, and correlated factors associated with seizure relapse. Results At the latest follow-up evaluation after surgery, 59 (72%) were free of disabling seizures (Engel Class I) and 48 (58,5%) had an Engel Class Ia. HS associated with FCD in neocortical structures were noted in 33 patients (40%). Analyzes have shown that dual pathology was the most significant negative predictive factor for Engel class I and Engel class Ia outcome. Conclusions The incidence of dual pathology in patients with temporal lobe epilepsy seems to be underestimated. An incomplete epileptogenic zone resection of occult focal temporal dysplasia within temporal lobe is supposed to be the most important negative prognostic factor for seizure freedom after epilepsy surgery in MTLE-HS patients. The study indicates the need to improve diagnostics for other temporal lobe pathologies, despite the typical clinical and radiological picture of MTLE-HS.

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Electroclinical and Multimodality Neuroimaging Characteristics and Predictors of Post-Surgical Outcome in Focal Cortical Dysplasia Type IIIa

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.810897 ◽

2022 ◽

Vol 9 ◽

Author(s):

Lingling Zhang ◽

Hailing Zhou ◽

Wei Zhang ◽

Xueying Ling ◽

Chunyuan Zeng ◽

...

Keyword(s):

Epilepsy Surgery ◽

Focal Cortical Dysplasia ◽

Univariate Analysis ◽

Postoperative Outcome ◽

Cortical Dysplasia ◽

Seizure Outcome ◽

Seizure Freedom ◽

Incomplete Resection ◽

Type Iiia ◽

Imaging Characteristics

Focal cortical dysplasia (FCD) type IIIa is an easily ignored cause of intractable temporal lobe epilepsy. This study aimed to analyze the clinical, electrophysiological, and imaging characteristics in FCD type IIIa and to search for predictors associated with postoperative outcome in order to identify potential candidates for epilepsy surgery. We performed a retrospective review including sixty-six patients with FCD type IIIa who underwent resection for drug-resistant epilepsy. We evaluated the clinical, electrophysiological, and neuroimaging features for potential association with seizure outcome. Univariate and multivariate analyses were conducted to explore their predictive role on the seizure outcome. We demonstrated that thirty-nine (59.1%) patients had seizure freedom outcomes (Engel class Ia) with a median postsurgical follow-up lasting 29.5 months. By univariate analysis, duration of epilepsy (less than 12 years) (p = 0.044), absence of contralateral insular lobe hypometabolism on PET/MRI (pLog-rank = 0.025), and complete resection of epileptogenic area (pLog-rank = 0.004) were associated with seizure outcome. The incomplete resection of the epileptogenic area (hazard ratio = 2.977, 95% CI 1.218–7.277, p = 0.017) was the only independent predictor for seizure recurrence after surgery by multivariate analysis. The results of past history, semiology, electrophysiological, and MRI were not associated with seizure outcomes. Carefully included patients with FCD type IIIa through a comprehensive evaluation of their clinical, electrophysiological, and neuroimaging characteristics can be good candidates for resection. Several preoperative factors appear to be predictive of the postoperative outcome and may help in optimizing the selection of ideal candidates to benefit from epilepsy surgery.

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The influence of lesion volume, perilesion resection volume, and completeness of resection on seizure outcome after resective epilepsy surgery for cortical dysplasia in children

Journal of Neurosurgery Pediatrics ◽

10.3171/2014.10.peds14282 ◽

2015 ◽

Vol 15 (6) ◽

pp. 644-650 ◽

Cited By ~ 30

Author(s):

Chima O. Oluigbo ◽

Jichuan Wang ◽

Matthew T. Whitehead ◽

Suresh Magge ◽

John S. Myseros ◽

...

Keyword(s):

Epilepsy Surgery ◽

Seizure Control ◽

Brain Mri ◽

Age At Onset ◽

Cortical Dysplasia ◽

Complete Resection ◽

Seizure Outcome ◽

Seizure Freedom ◽

Lesion Volume ◽

Resection Volume

OBJECT Focal cortical dysplasia (FCD) is one of the most common causes of intractable epilepsy leading to surgery in children. The predictors of seizure freedom after surgical management for FCD are still unclear. The objective of this study was to perform a volumetric analysis of factors shown on the preresection and postresection brain MRI scans of patients who had undergone resective epilepsy surgery for cortical dysplasia and to determine the influence of these factors on seizure outcome. METHODS The authors reviewed the medical records and brain images of 43 consecutive patients with focal MRI-documented abnormalities and a pathological diagnosis of FCD who had undergone surgical treatment for refractory epilepsy. Preoperative lesion volume and postoperative resection volume were calculated by manual segmentation using OsiriX PRO software. RESULTS Forty-three patients underwent first-time surgery for resection of an FCD. The age range of these patients at the time of surgery ranged from 2 months to 21.8 years (mean age 7.3 years). The median duration of follow-up was 20 months. The mean age at onset was 31.6 months (range 1 day to 168 months). Complete resection of the area of an FCD, as adjudged from the postoperative brain MR images, was significantly associated with seizure control (p = 0.0005). The odds of having good seizure control among those who underwent complete resection were about 6 times higher than those among the patients who did not undergo complete resection. Seizure control was not significantly associated with lesion volume (p = 0.46) or perilesion resection volume (p = 0.86). CONCLUSIONS The completeness of FCD resection in children is a significant predictor of seizure freedom. Neither lesion volume nor the further resection of perilesional tissue is predictive of seizure freedom.

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