- [Show abstract] [Hide abstract] ABSTRACT: OBJECTIVE The purpose of this study was to assess the positive predictive value of postresection outcomes obtained by presurgical subtracted ictal SPECT in patients with lesional (MRI positive) and nonlesional (MRI negative) refractory extratemporal lobe epilepsy (ETLE) and temporal lobe epilepsy (TLE). Specifically, outcomes were compared between partial versus complete resection of the regions of transient hyperperfusion identified using subtraction ictal SPECT coregistered to MRI (SISCOM) in relation to the ictal onset zone (IOZ) that was confirmed by electrocorticography (ECoG). That is, SISCOM was used to understand the long-term postsurgical outcomes following resection of the IOZ that overlapped with 1 or more regions of ictal onset-associated transient hyperperfusion. METHODS The study cohort included 44 consecutive patients with refractory ETLE or TLE who were treated between 2002 and 2013 and underwent presurgical evaluation using SISCOM. Concordance was determined between SISCOM localization and the IOZ on the basis of ECoG monitoring. In addition, the association between the extent of the resection site overlapping with the SISCOM signal and postresection outcomes were assessed. Postsurgical follow-up was longer than 24 months in 39 of 44 patients. RESULTS The dominant SISCOM signals were concordant with ECoG and overlapped the resection site in 32 of 44 (73%) patients (19 ETLE and 13 TLE patients), and 20 of 32 (63%) patients became seizure free. In all 19 ETLE patients with concordant SISCOM and ECoG results, the indicated location of ictal onset on ECoG was completely resected; 11 of 19 patients (58%) became seizure free (Engel Class I). In all 13 TLE patients with concordant SISCOM and ECoG results, the indicated ECoG focus was completely resected; 9 of 13 patients (69%) became seizure free (Engel Class I). Complete resection of the SISCOM signal was found in 7 of 34 patients (21%). Of these 7 patients, 5 patients (72%) were seizure free (Engel Class I). Partial resection of the SISCOM signal was found in 16 of 34 patients (47%), and 10 of these 16 patients (63%) were seizure free (Engel Class I) after more than 24 months of follow-up. CONCLUSIONS Concordance between 1 or more SISCOM regions of hyperperfusion with ECoG and at least partial resection of the dominant SISCOM signal in this refractory epilepsy cohort provided additional useful information for predicting long-term postresection outcomes. Such regions are likely critical nodes in more extensive, active, epileptogenic circuits. In addition, SPECT scanner technology may limit the sensitivity of meaningful SISCOM signals for identifying the maximal extent of the localizable epileptogenic network.
- [Show abstract] [Hide abstract] ABSTRACT: Objective: To review the clinical features and surgical outcome in patients with temporal lobe gangliogliomas associated with intractable chronic epilepsy. Methods: The Rush University Surgical Epilepsy Database was queried to identify patients with chronic intractable epilepsy who underwent resection of temporal lobe gangliogliomas at Rush University Medical Center. Medical records were reviewed for age of seizure onset, delay to referral for surgery, seizure frequency and characteristics, pre-operative MRI results, extent of resection, pathological diagnosis, complications, length of follow-up, and seizure improvement. Results: Fifteen patients were identified. Average duration between seizure onset and surgery was 14.3 years. Complex partial seizures were the most common presenting symptom. Detailed operative data was available for 11 patients - of these, 90.9% underwent complete resection of the amygdala and either partial or complete resection of the hippocampus, in addition to lesionectomy. Average follow-up was 10.4 years (range 1.6-27.5 years), with 14 patients improving to Engel's class I and one patient to Engel's class III. There were no recurrences, and permanent complications were noted in one patient. Conclusions: Long-term follow-up of patients with temporal lobe gangliogliomas associated with chronic intractable epilepsy demonstrates excellent results in seizure improvement with surgery and increasingly low incidence of complications with improvements in microsurgical techniques.
- [Show abstract] [Hide abstract] ABSTRACT: There have been only a few large series that have used a tailored temporal lobectomy. To clarify whether tailoring a temporal lobe resection will lead to equivalent epilepsy outcomes or have the same predictive factors for success when compared with standard resections. Retrospective analysis of 222 patients undergoing a tailored temporal lobe resection. Demographic measures and typical factors influencing outcome were evaluated. Pathology included 222 cases. With a mean follow-up of 5.4 years, 70% of patients achieved Engel class I outcome. A significant factor predicting Engel class I outcome on multivariate analysis was lesional pathology (P = .04). Among patients with hippocampal sclerosis, extent of lateral neocortical resection and hippocampal resection were not statistically associated with Engel class I outcome (P = .93 and P = .24). However, an analysis of Engel class subgroups a to d showed that patients who had a complete hippocampectomy in the total series were more likely to achieve an Engel class Ia outcome (P = .04). This was also true among patients with hippocampal sclerosis (P = .03). Secondarily, generalized seizure (P = .01) predicted outcome less than Engel class I. Predictive of poor outcome was the need for preoperative electrodes (P = .02). Complications included superior quadrant visual field defects, 2 cases of permanent dysphasia, and 3 wound infections. Predictors of successful seizure outcome for a tailored temporal lobectomy are similar to standard lobectomy. Patients with secondarily generalized epilepsy and cases in which preoperative subdural electrodes were thought necessary were less likely to achieve class I outcome. Among Engel class I cases, those who had a complete hippocampectomy were more likely to achieve Engel class Ia outcome.
- [Show abstract] [Hide abstract] ABSTRACT: Abnormal MRI findings localizing to the mesial temporal lobe predict a favorable outcome in temporal lobe epilepsy surgery. The purpose of this study is to summarize the surgical outcome of patients who underwent a tailored antero-temporal lobectomy (ATL) with normal 1.5 T MRI. Specifically, factors that may be associated with favorable post-surgical seizure outcome are evaluated. A retrospective analysis of the Rush University Medical Center surgical epilepsy database between 1992 and 2003 was performed. Patients who underwent an ATL and had a normal MRI study documented with normal volumetric measurements of hippocampal formations and the absence of any other MRI abnormality were selected for this study. Demographic information was collected on all patients. Seizure outcomes were evaluated using Engel's classification. A two-sided Fisher exact test with Bonferroni correction was performed in statistical analyses. Twenty-one (21) patients met the inclusion criteria of normal 1.5 T MRI and underwent a tailored temporal lobectomy. Mean age at time of surgery was 28 years (SD=8.1, range 11-44) and mean duration of the seizure disorder was 13.4 years (range 2-36). Risk factors for epilepsy included head injury (n=4), encephalitis (n=3), febrile seizures (n=2), and 12 patients had no risk factors. Pathological evaluation of resected tissue revealed no abnormal pathology in 12/21 patients (57%). After a mean 4.8 years follow-up post-surgical period, 15/21 (71%) patients were free of disabling seizures (Engel I outcome). At 8.3 years follow-up, 13/21 (62%) patients had similar results. Absence of prior epilepsy risk factors was the only statistically significant predictor of an Engel class I outcome (p<0.0022). Patients with medically intractable epilepsy and normal MRI appear to benefit from epilepsy surgery. Absence of prior epilepsy risk factors may be a positive prognostic factor.
- [Show abstract] [Hide abstract] ABSTRACT: The authors undertook a study to review the clinical features and outcome in patients who underwent surgery for intractable chronic epilepsy caused by temporal lobe tumors. The Rush Surgical Epilepsy Database was queried to identify patients with chronic intractable epilepsy who underwent resection of temporal lobe tumors between 1981 and 2005 at Rush University Medical Center. Medical records were reviewed for age of the patient at seizure onset, delay to referral for surgery, seizure frequency and characteristics, preoperative MR imaging results, extent of resection, pathological diagnosis, complications, duration of follow-up period, and seizure improvement. Thirty-eight patients were identified, all with low-grade tumors. Gangliogliomas were the most common (36.8%), followed in descending order by dysembryoplastic neuroepithelial tumors (26.3%) and low-grade diffuse astrocytoma (10.5%). The mean duration between seizure onset and surgery was 15.4 years. Complex partial seizures were the most common presenting symptom. Detailed operative data were available for 28 patients; of these, 89.3% underwent complete resection of the amygdala, and 82.1% underwent partial or complete resection of hippocampus, in addition to lesionectomy. The mean follow-up duration was 7.7 years (range 1.0-23.1 years), with 78.9% of patients having seizure status that improved to Engel Class I, 15.8% to Engel Class II, and 5.3% to Engel Class III. Permanent complications were noted in 2.6% of patients. The authors' examination of the long-term follow-up data in patients with temporal lobe tumors causing chronic intractable epilepsy demonstrated excellent results in seizure improvement after surgery.
Conference Paper: Complications of subdural electrode epilepsy recording
- [Show abstract] [Hide abstract] ABSTRACT: Twenty-three patients had magnetic resonance imaging (MRI) and computed tomography (CT) of the head prior to surgery for medically intractable epilepsy. Eleven patients had neoplasms, mostly astrocytomas. Six of the 11 tumors were seen on CT. In five of the six cases, the MRI showed a focal area of increased signal on T2-weighted images. All 11 tumors were detected by MRI. None of the non-neoplastic lesions produced an abnormal T2-weighted signal area on MRI. Only one of the non-neoplastic lesions was seen on both CT and on MRI. MRI allowed clear discrimination between tumors and non-neoplastic lesions in patients coming to surgery for intractable epilepsy.
- [Show abstract] [Hide abstract] ABSTRACT: To the Editor. —In their recent report on electroencephalographic and clinical changes in seizure patients with slowly growing brain tumors, Hughes and Zak1 provide interesting and useful data. However, they assert that "the yield from CT (computed tomography) at all ages can be expected to be only 5% to 7%, and in these days of cost containment... this yield would not seem to justify performing one of these expensive procedures on every patient (especially the indigent) with chronic seizures." We believe that this conclusion is misleading and, in addition, raises serious ethical and moral questions. A few examples may help illuminate these points.Our current series of 87 patients who have undergone resective surgery for chronic partial epilepsy includes 14 (16%) with low-grade primary brain tumors (12 of glial origin and two gangliogliomata). Eleven (79%) had abnormal CT scans, of which only three (27% ) were thought to suggest a