Efficacy of intraoperative electrocorticography for assessing seizure outcomes in intractable epilepsy patients with temporal-lobe-mass lesions.

PURPOSE: The findings of previous studies have been controversial regarding the optimal surgical procedures required for effective seizure control. In particular, there are varying views as to whether or not lesionectomy of a temporal-lobe-mass lesion is a satisfactory process or whether removal of additional seizure foci is necessary. In this study, we evaluated the efficacy of additional removal of electrically positive foci using intraoperative electrocorticography on mass lesions related to temporal lobe epilepsy. METHODS: Thirty-five medically intractable epilepsy patients with temporal-lobe benign mass lesions, who had been surgically treated, were assessed. The relationship between resection of the epilepsy focus using intraoperative electrocorticography and seizure outcome was analyzed. In addition, the sites of residual spikes after lesion removal were evaluated. RESULTS: In this study, the benign mass lesions consisted of 21 gangliogliomas, 8 cavernous angiomas and 6 dysembryoplastic neuroepithelial tumors. The number of 3-year postoperative seizure-free incidences for the group that underwent lesionectomy plus additional spike-positive site resection equated to 90.9%. In contrast, in the group that underwent a lesionectomy only, 76.9% were seizure-free for 3-years postoperatively. After complete removal of mass lesions, 86.4% of the residual spikes were detected over the hippocampus. CONCLUSION: Even after the complete removal of temporal-lobe-mass lesions, a high frequency of residual spikes was obtained from the hippocampus. Effective surgical seizure control was achieved by carrying out additional procedures on the affected hippocampus. To detect seizure foci surrounding the lesion, especially over the hippocampus, intraoperative electrocorticogram monitoring was shown to be an effective technique.     

Parietal Lobe Lesional Epilepsy: Electroclinical Correlation and Operative Outcome

Summary: We retrospectively studied ictal behavior, extracranial EEG, and operative outcome in 10 consecutive patients with intractable partial epilepsy of presumed parietal lobe origin who received a lesionectomy, i.e., resection of the neuroimaging-identified abnormality, at the Mayo Clinic. Nine patients had a pathologically verified foreign-tissue lesion, e.g., tumor or vascular malformation, and 1 patient had gliosis. All patients with foreign-tissue lesions were rendered seizure-free. The patient with gliosis experienced a reduction in seizure tendency. There were no operative complications. The most common seizure type was a simple partial seizure with visual, motor, or sensory symptoms (n = 8). Complex partial seizures (n = 5) and secondarily generalized tonic-clonic seizures (GTC, n = 2) were also observed. The ictal behavior was often nonspecific although useful in identifying lateralization of the epileptogenic zone. Extracranial interictal and ictal EEG changes were unreliable markers of the parietal lobe origin of seizure activity. Lesionectomy without chronic intracranial monitoring or functional mapping may be an effective and safe alternative surgical procedure in patients with partial epilepsy related to parietal lobe lesions.     

Long-Term Follow-Up of Stereotactic Lesionectomy in Partial Epilepsy: Predictive Factors and Electroencephalographic Results

We performed an extended follow-up study assessing the efficacy of stereotactic lesionectomy in 23 patients with foreign-tissue lesions and intractable partial epilepsy. Sixteen lesions involved functional or eloquent cortex as determined by anatomic localization. By definition, the surgical objective in these patients was excision of the lesion, and not the surrounding cerebral cortex. The mean duration of follow-up was 48.5 months (range 26-69 months). Seventeen patients (74%) had a significant reduction in seizures (greater than or equal to 90%) after lesionectomy. Thirteen patients (56%) had a class I operative outcome (seizure-free, single seizure episode, or auras only). Five of these patients were successfully discontinued from antiepileptic drug (AED) therapy. Patients with temporal lobe lesions were statistically less likely to be rendered seizure-free (p less than 0.05). Age at operation, duration of epilepsy, and underlying pathology were not significant predictors of seizure outcome. The anatomic distribution of extracranial EEG recorded epileptiform activity did not appear to be an important determinant of outcome. The absence of interictal epileptiform activity in the 3-month postoperative EEG correlated with a significant reduction in seizures. Long-term follow-up indicates that lesionectomy may be effective in select patients with medically refractory partial seizure disorders.     

Patients with Epileptic Seizures and Cerebral Lesions Who Underwent Lesionectomy Restricted to or Associated with the Adjacent Irritative Area

PURPOSE: To analyze the best surgical procedure for patients with epileptic seizures and cerebral lesions-i.e., resection restricted to the lesion or resection associated with the adjacent irritative area-based on the clinical evolution of patients' seizure outcome and electroencephalographic (EEG) and electrocorticographic (ECoG) findings. METHODS: This study comprised 37 patients with epileptic seizures and cerebral lesions, ranging in age from 9 to 66 years. Patients were divided into two groups: Group 1 consisted of 21 patients with medically intractable epilepsy, Group 2 of 16 patients with medically controlled epilepsy. Eleven of the 21 patients in Group 1 (Subgroup A) underwent surgical resection of the cerebral lesion and adjacent irritative area as shown by ECoG. For the remaining 10 patients in Group 1 (Subgroup B), the resection was restricted to the lesion. The 16 patients in Group 2 all underwent lesionectomies. RESULTS: Of the 11 patients in group 1 who underwent resection of the cerebral lesion and adjacent irritative area, 91% became seizure free. Sixty percent of the remaining patients in group I whose resections were restricted to the lesion also became seizure free, as did all the patients in group 2. An overall analysis of the EEGs for all patients showed a statistically significant decrease in paroxysmal activity. CONCLUSIONS: In patients with uncontrolled seizures, resection of the cerebral lesion associated with the irritative area shows a tendency to obtain better seizure-outcome results than restricted lesionectomy.     

Seizure outcome after resection of cavernous malformations is better when surrounding hemosiderin-stained brain also is removed

PURPOSE: Considering the epileptogenic effect of cavernoma-surrounding hemosiderin, assumptions are made that resection only of the cavernoma itself may not be sufficient as treatment of symptomatic epilepsy in patients with cavernous malformations. The purpose of this study was to test the hypothesis whether seizure outcome after removal of cavernous malformations may be related to the extent of resection of surrounding hemosiderin-stained brain tissue. METHODS: In this retrospective study, 31 consecutive patients with pharmacotherapy-refractory epilepsy due to a cavernous malformation were included. In all patients, cavernomas were resected, and all patients underwent pre- and postoperative magnetic resonance imaging (MRI). We grouped patients according to MRI findings (hemosiderin completely removed versus not/partially removed) and compared seizure outcome (as assessed by the Engel Outcome Classification score) between the two groups. RESULTS: Three years after resection of cavernomas, patients in whom hemosiderin-stained brain tissue had been removed completely had a better chance for a favorable long-term seizure outcome compared with those with detectable postoperative hemosiderin (p=0.037). CONCLUSIONS: Our study suggests that complete removal of cavernoma-surrounding hemosiderin-stained brain tissue may improve epileptic outcome after resection of cavernous malformations.     

A comparative study of lesionectomy versus corticectomy in patients with temporal lobe lesional epilepsy

We performed a retrospective study comparing surgical outcome of anterior temporal lobectomy (n = 20) and stereotactic lesionectomy (n = 14) in 34 consecutive patients with intractable partial epilepsy evaluated at this institution between June 1986 and June 1992. All patients had medically refractory partial seizures and a neuroimaging-identified temporal lobe foreign-tissue lesion. Patients underwent a pre- and postoperative comprehensive evaluation. In all patients, postoperative neuroimaging studies indicated complete lesion resection. Seventy-one percent of lesionectomy patients and 90% of lobectomy patients, respectively, experienced a worthwhile reduction in seizure tendency. Forty-three percent of lesionectomy patients and 85% of lobectomy patients, respectively, were seizure-free postoperatively. Mean duration of follow-up was 51 months (range, 21–83 months). Morbidity occurred in three patients who underwent corticectomy: complete homonymous hemianopsia (1) and dysphasia (2). No significant morbidity was associated with lesionectomy. Results of this study have altered the surgical strategy at this institution for patients with temporal lobe lesional epilepsy and have proved useful in counseling patients regarding neurologic outcome.     

Electro-clinical characteristics and postoperative outcome of medically refractory tumoral temporal lobe epilepsy

BACKGROUND: Very few studies have specifically addressed surgical treatment and outcome of patients with tumor-related temporal lobe epilepsy (TLE). AIM: To define the postoperative seizure outcome and the factors that influenced the outcome of patients with tumor-related TLE. MATERIALS AND METHODS: We selected patients whose surgical pathology revealed a temporal lobe neoplasm and who had completed > 1 year of postoperative follow-up. We reviewed the clinical, EEG, radiological and pathological data, and the seizure outcome of these patients and assessed the factors that influenced the outcome. RESULTS: Out of the 409 patients who underwent surgery for refractory TLE during the 8-year study period, there were 34 (8.3%) patients with temporal lobe neoplasms. The median age at surgery was 20 years and the median duration of epilepsy prior to surgery was 9.0 years. MRI revealed tumor in the mesial location in 21 (61.8%) patients. Interictal and ictal epileptiform EEG abnormalities were localized to the side of th lesion in the majority. Mesial temporal lobe structures were included in the resection, if they were involved by the tumor; otherwise, lesionectomy alone was performed. During a median follow-up of 4 years, 27 (79%) patients were completely seizure-free. The only factor that predicted long-term seizure-free outcome was being seizure-free during the first two postoperative years. CONCLUSIONS: Our results emphasize the fact that in patients with tumoral TLE, when the seizures are medically refractory, surgery offers potential for cure of epilepsy in the majority.     

Supratentorielle Kavernome und epileptische Anfälle

For cavernous haemangiomas, it is the aim of surgical treatment to control epilepsy and eliminate potential sources of intracerebral haematomas. In the following investigation, it was attempted to find indicators for seizure freedom after surgery. Success of therapy was assessed according to three patterns of classification. Thirty patients underwent tailored resection based on findings from preoperative investigations and intraoperative electrocorticography. Follow-up averaged 4 years. Lesionectomy, extended lesionectomy, and modified lobe resection were carried out in 13, 11, and six patients, respectively. For all procedures, including microsurgical lesionectomy, the firm gliotic layer unequivocally differed in colour and consistency from normal brain and was removed. Further tissue resection was carried out only if the electrocortical course suggested persistent spike activity around the resection cavity or if presurgical MRI evaluation (e.g. hippocampal atrophy) or electrophysiology also pointed to pathology distant from the lesion. Of the patients, 53.3% became completely seizure-free (Engel I), and one additional patient had only occasional isolated auras. Dramatic reductions in seizure frequency and severity were exhibited by 26.7%. Outcome in respect to seizure control was not associated with resection procedure, comparing pure lesionectomy with lesionectomy plus cortectomy. In the group of patients with epilepsy surgery, those with hippocampectomy had significantly better outcome than those without. Important prognostic factors were early operation after seizure manifestation (91.7% operated upon within 2 years of seizure onset became seizure-free). Another prognostic factor was unifocal seizure onset (bilateral or multifocal seizure onset was found in care of the ten patients with unfavourable outcome). None of the four patients harbouring multiple cavernomas became seizure-free after resection of one lesion, which was believed to be mostly attributable to the epileptic focus that was removed.     

Multiple Subpial Transection for Control of Epileptic Seizures: Effectiveness and Safety

Summary: Purpose: To assess the efficacy and safety of multiple subpial transection (MST), a new technique in epilepsy surgery, alone and in combination with resection.
Methods: MST was performed in 22 patients with intractable epilepsy, 10 of whom were treated with a combination of a resection and MST in functionally important cortex, 6 of whom were treated with a combination of a resection and MST performed outside functionally important cortex, and 6 of whom were treated with MST alone.
Results: Of the 6 patients who received MST alone, none became seizure free and 4 showed > 50% reduction of all seizure types. In 2 patients, including 1 with Rasmussen's encephalitis, no change in seizure frequency or intensity occurred. Of the 16 patients in whom MST was combined with a resection, 9 (56%) became seizure free. Six of the remaining 7 patients showed > 95% reduction of all seizure types. Disappearance of epileptiform potentials in the postoperative EEG correlated significantly with complete relief from seizures. Subtle, permanent neurological deficits remained in 5 of 14 patients who received MST in functionally important brain areas.
Conclusions: Reduction of the seizure frequency was substantial in 4 of 6 patients who received MST alone, but complete seizure control was not observed. MST surrounding a lesionectomy may be a new surgical approach which would minimize the excised volume and improve seizure control.     

Predictors of outcome and pathological considerations in the surgical treatment of intractable epilepsy associated with temporal lobe lesions

OBJECTIVES: To evaluate the influence of clinical, investigative, and pathological factors on seizure remission after temporal lobectomy for medically intractable epilepsy associated with focal lesions other than hippocampal sclerosis. METHODS: From a series of 234 consecutive "en bloc" temporal resections for medically intractable epilepsy performed between 1976 and 1995, neuropathological examination disclosed a focal lesion in 80. The preoperative clinical, neuropsychological, interictal EEG, and neuroimaging characteristics of these patients were assembled in a computerised database. The original neuropathological material was re-examined for lesion classification and completeness of removal. The presence of additional cortical dysplasia and mesial temporal sclerosis was also noted. Survival analysis was performed using Kaplan-Meier curves and actuarial statistics. Logistic regression analysis was used to establish the independent significance of the clinical variables. RESULTS: The probability of achieving a 1 year seizure remission was 71% by 5 years of follow up. Factors predicting a poor outcome on multivariate analysis included the need for special schooling and a long duration of epilepsy. Generalised tonic-clonic seizures, interictal EEG discharges confined to the resected lobe, demonstration of the lesion preoperatively on CT, and complete histological resection of the lesion were not predictive of outcome. Neuropsychological tests correctly predicted outcome in left sided cases but apparently congruent findings in right sided resections were associated with a poor outcome. Pathological reclassification established the dysembryoplastic neuroepithelial tumour as the commonest neoplasm (87%) in this series, with a significantly better seizure outcome than for developmental lesions, such as focal cortical dysplasia. CONCLUSIONS: The findings highlight the importance of dysembryoplastic neuroepithelial tumour in the pathogenesis of medically refractory lesional temporal lobe epilepsy and the prognostic significance of preoperative duration of epilepsy emphasises the need for early recognition and surgical treatment. Cognitive and behavioural dysfunction, however, is associated with a lower seizure remission rate, independent of duration of epilepsy.     

A longitudinal study of surgical outcome and its determinants following posterior cortex epilepsy surgery

Purpose:   To investigate the longitudinal seizure outcome and identify potential prognostic indicators following posterior cortex epilepsy (PCE) surgery.
Methods:   We reviewed patients who underwent a parietal, occipital, or parietooccipital resections between 1994 and 2006, using survival analysis and multivariate regression with Cox proportional hazard modeling. A favorable outcome was defined as Engel Class I at last follow-up.
Results:   Fifty-seven patients were identified with a mean follow-up of 3.3 years (range 1–12 years). The estimated chance of seizure freedom (SF) was 73.1% at 6 postoperative months, 68.5% at 1 year, 65.8% at between 2 and 5 years, and 54.8% at 6 years and beyond. Most recurrences (75%) occurred within the first 6 postoperative months. Parietal resections had a worse outcome than occipital or parietooccipital resections (52% SF vs. 89% and 93%, respectively, at 5 years). Independent predictors of recurrence included an epilepsy etiology other than tumor or dysplasia [risk ratio (RR) 2.29], limiting resection to a lesionectomy (RR 2.10), having ipsilateral temporal spiking on preoperative scalp electroencephalography (EEG) (RR 2.06), or any ipsilateral spiking on postoperative EEG (RR 2.70) (Log likelihood-ratio test p < 0.0001). Only 40–50% of patients with a poor outcome predictor were SF at 5 postoperative years as opposed to about 80% otherwise. In surgical failures, recurrent seizure frequency was related directly to baseline seizure frequency and to the presence of ipsilateral spiking on postoperative EEG.
Discussion:   These data highlight favorable long-term outcomes following PCE surgery. Limited surgical resection and diffuse baseline epileptogenicity may be important predictors of seizure recurrence.     

Epileptogenic temporal cavernous malformations: Operative strategies and postoperative seizure outcomes

Operative treatment of epileptogenic cavernous malformations (CM) continues under debate. Most studies focus on surgery for supratentorial CM in general. For temporal lobe CM, surgical decision-making concerns in particular whether to perform lesionectomy alone or the additional excision of mesial temporal structures. The purpose of this case series was to evaluate operative strategies used to treat epileptogenic temporal CM and to report resultant postoperative seizure outcomes.Twelve consecutive cases of patients with medically intractable epilepsy who underwent operation for temporal CM between 1996 and 2006 were retrospectively reviewed. When the temporal CM directly invaded the hippocampus or amygdala, the affected structures were resected in addition to the lesion; when the CM was located in the superficial temporal cortex, and there was no radiographic evidence of hippocampal sclerosis, lesionectomy alone was done; with CM located between the superficial temporal cortex and the mesial temporal region, other factors were considered in decision-making, such as lesion proximity to the deep mesiotemporal structures and preoperative epilepsy duration.For six of the twelve patients, extended lesionectomy (EL) alone was done; for the other six, tailored anteromedial temporal resection with hippocampectomy and/or amygdalectomy was performed in addition to EL. Postoperatively, 11 patients – all with preoperative VEM demonstrating electroclinical seizure patterns concordant with lesion location – were seizure-free. We conclude that epileptogenic temporal CM are surgically remediable, when approached with the above operative strategies and presurgical VEM. On the basis of these postoperative seizure control results, we recommend consideration of concurrent resection of mesial temporal structures with EL for certain temporal CM.     

Epilepsy surgery in the first months of life: a large type IIb focal cortical dysplasia causing neonatal drug‐resistant epilepsy

Focal cortical dysplasia is a common cause of medically refractory epilepsy in infancy and childhood. We report a neonate with seizures occurring within the first day of life. Continuous video‐EEG monitoring led to detection of left motor seizures and a right frontal EEG seizure pattern. Brain MRI revealed a lesion within the right frontal lobe without contrast enhancement. The patient was referred for epilepsy surgery due to drug resistance to vitamin B6 and four antiepileptic drugs. Lesionectomy was performed at the age of two and a half months, and histopathological evaluation confirmed the diagnosis of focal cortical dysplasia type IIb (FCD IIb). The patient is free of unprovoked seizures without medication (Engel Class I) and is normally developed at 36 months after surgery. The case study demonstrates that FCD IIb may cause seizures within the first day of life and that epilepsy surgery can be successfully performed in medically intractable patients with a clearly identifiable seizure onset zone within the first three months of life. Although radical surgery such as hemispherectomy and multi‐lobar resections are over‐represented in early infancy, this case also illustrates a favourable outcome with a more limited resection in this age group.     

Low-Grade Glial Neoplasms and Intractable Partial Epilepsy: Efficacy of Surgical Treatment

Summary: We performed a retrospective study of 51 consecutive patients who underwent operation for intractable partial epilepsy related to low-grade intracerebral neoplasms between 1984 and 1990. All patients had medically refractory partial seizures and a mass lesion identified on neuroimaging studies. Lesionectomy was performed on 17 patients, and 34 had lesion resection and corticectomy. Mean postoperative follow-up was 4.4 years (range 2–8 years). Sixty-six percent of patients were seizure-free, and 88% experienced a significant reduction in seizure frequency. In 16 patients (31%), antiepileptic drugs (AEDs) were successfully discontinued. Twenty-five of 31 (81%) eligible patients obtained a driver's license after successful operation. Patients with complete tumor resection and no interictal epileptiform activity on postoperative EEG studies had the best operative outcome. Epilepsy surgery can result in long-term improvement in seizure control and quality of life (QOL) in selected patients with intractable tumor-related epilepsy. Our results should be useful to clinicians considering treatment options for patients with intractable seizures related to low-grade intracerebral neoplasms.     

Seizure outcomes of lesionectomy in pediatric lesional epilepsy with brain tumor – Single institute experience

Purpose

To determine the clinical characteristics, surgical strategy, and outcome in pediatric lesional epilepsy patients younger than 5 years of age undergoing surgery in a single institute.

Method

Retrospective data were collected and analyzed on patients younger than 5 years of age who underwent lesionectomy for lesional epilepsy at single institute from January 2001 to August 2010. Fourteen pediatric lesional epilepsy patients were enrolled in this study. Engel classification was used to classify seizure outcome.

Results

Median preoperative seizure period was 1 month (range, 1–21). Median post-operative follow up period was 35 months (range 13–84). Ten patients who underwent gross total resection of tumor showed Engel class Ia seizure outcome without any antiepileptic drug (AED). Subtotal resection was performed in four patients to avoid eloquent area injury. Two of these four patients with subtotal removal became seizure-free (Engel class Ia) without AED, while two were in Engel class Ib with AED medication. There was no significant surgical morbidity or mortality.

Conclusion

Lesionectomy in children younger than 5 years of age is relatively safe and effective in controlling seizures. Short preoperative seizure periods and total removal of tumor might be associated with good outcome. Therefore, early and complete lesionectomy alone may help allow for seizure freedom and optimal brain development in pediatric patients.     

Medically refractory epilepsy associated with temporal lobe ganglioglioma: characteristics and postoperative outcome

OBJECTIVES: To define the postoperative seizure outcome and its predictors in patients with ganglioglioma-related temporal lobe epilepsy (TLE). PATIENTS AND METHODS: We reviewed the pre- and post-surgical evaluation data of 23 patients with temporal lobe ganglioglioma, who had completed >or=1 year of postoperative follow-up. They comprised 4.9% of the patients with TLE and 67.6% of the tumoral TLE operated in a developing country epilepsy center during an 8-year period. RESULTS: Median age at surgery was 20 years; median duration of epilepsy prior to surgery was 9 years. Magnetic resonance imaging (MRI) revealed tumor in mesial temporal location in 18 patients (78.3%) and in the lateral location in 2; in the remaining 3, involved both mesial and lateral regions. EEG abnormalities were localized to the side of lesion in the majority. Mesial temporal lobe structures were included in the resection, if they were involved by the tumor; otherwise, lesionectomy alone was performed. During a median follow-up of 4 years, 19 (82.6%) patients were completely seizure-free. Epileptiform abnormalities persisting in the 1-year postoperative EEG predicted unfavorable seizure outcome. CONCLUSION: We emphasize that, in patients with temporal lobe ganglioglioma, when the seizures are medically refractory, surgery offers potential for cure of epilepsy in the majority.     

Significance of postoperative electroencephalograms in patients with extratemporal lesional epilepsy

We retrospectively studied EEGs performed 1 week, 3 months, and 1 year after surgery (lesionectomy or lesion resection with corticectomy) in 24 patients with extratemporal lesional epilepsy who had a mean duration of follow-up of 2.5 years. All patients had intractable partial seizures and underwent a comprehensive presurgical evaluation including long-term EEG monitoring. Twenty of the 24 patients had interictal epileptiform activity (IEA) identified on the preoperative sleep and awake EEG recordings. The presence of IEA 1 year after surgery was associated with recurrent seizure activity (p < 0.05). The postoperative EEG recordings, however, revealed no IEA in the two patients with persistent seizures who had no epileptiform abnormality on the preoperative study. The extent of cortical resection appeared to have no significant effect on the recording of IEA after surgery. One-year postoperative EEG recordings are prognostically useful in patients with extratemporal lesional epilepsy who undergo surgical treatment.     

Chronic Intracranial EEG Monitoring for Localizing the Epileptogenic Zone: An Electroclinical Correlation

Summary: Purpose: To evaluate the diagnostic yield and identify predictive factors of the surgical outcome in patients with intractable partial epilepsy undergoing chronic intracranial EEG monitoring (CIEM).
Methods: The clinical, magnetic resonance imaging (MRI) and electrophysiologic data of 108 patients that underwent CIEM were retrospectively reviewed. The discharge pattern and spatial extent of the initial ictal discharge were determined by blinded visual inspection and computerized analysis.
Results: The main predictive indicator for epilepsy surgery outcome in patients that underwent CIEM was the presurgical MRI findings. Most patients with hippocampal atrophy or complete lesionectomy were rendered seizure free after epilepsy surgery (83 and 80%, respectively), whereas only a small minority of patients with partial lesipectomy or no detected MRI lesion had seizure–free operative outcomes (21 and 22%, respectively). Multifocal independent initiation of the initial ictal discharge was associated with a poor surgical outcome. In contrast, the pattern and local spatial extent of the initial ictal discharge observed with CIEM failed to predict the surgical outcome.
Conclusions: The main predictor of the surgical outcome in patients that underwent CIEM was the MRI findings, whereas CIEM had only limited use in localizing the epileptogenic zone in the absence of an MRI lesion. The reported findings indicate a low specificity of CIEM in defining the site of seizure onset, which in turn significantly impairs the reliability of CIEM in delineating the epileptogenic zone for epilepsy surgery. Further studies are required to define the indications and patient sub–populations who can benefit from CIEM before epilepsy surgery.     

Surgical implications of neuromagnetic spike localization in temporal lobe epilepsy

PURPOSE: To investigate the clinical usefulness of magnetoencephalography (MEG) as a guide to the surgical treatment of temporal lobe epilepsy (TLE). METHODS: Preoperative spike localization by MEG was compared with seizure outcome and postoperative spike localization at 12 months after resective surgery in 16 patients with TLE. Spike localization was classified into anterior temporal (AT) and non-AT localization in 11 patients without neocortical lesion treated with anterior temporal lobectomy (ATL); and lesion and lobar localization in five patients with neocortical lesion treated with lesionectomy (n = 3) or lesionectomy with medial temporal resection (n = 2). RESULTS: All five patients with AT localization became seizure free and spike free after surgery. Among the six patients with non-AT localization, two became seizure free and spike free, two became seizure free with residual spikes, one had residual seizures but no spikes, and one had both residual seizures and spikes. All three patients with lesion localization and two with lobar localization had favorable seizure outcome and became spike free after surgery. CONCLUSIONS: MEG spike localization can identify neocortical sources remote from the presumed epileptogenic area. Favorable seizure outcome can be expected in patients with AT localization after ATL and patients with lesion localization after lesionectomy. In contrast, non-AT localization indicates either nonmedial TLE or spike propagation to the posterior and extratemporal neocortex. Similarly, lobar localization indicates spike propagation from an epileptogenic lesion or extensive epileptogenicity. Patients with non-AT localization or lobar localization should undergo intensive evaluations, such as intracranial EEG, for improved seizure outcome.     

病灶切除辅以皮质癎灶热灼术治疗顽固性癫癎

目的　观察病灶切除辅以皮质灶横纤维热灼术治疗顽固性癫的临床效果。方法　将病灶切除辅以皮质灶热灼术 2 91例病人和单纯病灶切除术 78例病人的疗效进行分析比较。结果　病灶切除辅以皮质灶热灼组效果优于单纯病灶切除组 ,两者的临床效果存在显著性差异 (P <0 0 5 ) ;同时 ,病灶切除辅以皮质灶热灼术组无永久性的术后并发症。结论　病灶切除辅以皮质灶热灼术是治疗顽固性癫安全有效的方法 ,长期疗效有待进一步观察。