Ictal spiking patterns recorded from temporal depth electrodes predict good outcome after anterior temporal lobectomy

PURPOSE: Investigators have shown that the presence of ictal spiking (IS) recorded from temporal depth electrodes is associated with mesial temporal sclerosis (MTS). We investigated the relation of IS to seizure control and pathology after anterior temporal lobectomy (ATL). METHODS: All patients undergoing intracranial ictal monitoring from a single institution since 1989 were identified. Those who did not undergo ATL or had postoperative follow-up of <1 year were excluded. All received at a minimum bilateral temporal depth electrodes. Ictal recordings were reviewed for the presence of IS, and the proportion of seizures with IS was determined for each patient. Outcome was determined by using Engel's classification. Surgical specimens were reviewed for pathology. Statistics used were chi2, Fisher exact test, and Wilcoxon rank sum. RESULTS: Forty patients with 571 seizures were reviewed. In 292 seizures from 32 patients, IS was seen. Outcomes were 24 class I (22 with IS), five class II (four with IS), three class III (one with IS), seven class IV (four with IS), and one lost to follow-up (with IS). Pathologic review revealed 25 with MTS, 22 of whom had IS. The presence of IS was associated with class I outcomes (p = 0.04), but not MTS (p = 0.06). Patients with class I outcomes had a significantly greater proportion of seizures with IS (mean, 0.58 +/- 0.3) compared with other outcomes (mean, 0.30 +/- 0.3, p = 0.02). CONCLUSIONS: The presence of IS and higher proportion of seizures with IS correlated with good seizure outcome after ATL. This information may be used in preoperative counseling.     

Presurgical neuropsychological testing predicts cognitive and seizure outcomes after anterior temporal lobectomy

We sought to determine significant predictors of seizure and cognitive outcome following surgery for epilepsy. Participants included 41 patients who had undergone anterior temporal lobectomy (ATL). Higher presurgical verbal/language scores and lower nonverbal memory scores were predictive of seizure-free status following ATL. Overall, the presurgical predictors were 93% accurate in discriminating between seizure-free and non-seizure-free patients postsurgery. Surgery in the nondominant-for-language hemisphere was predictive of higher postsurgical verbal/language and verbal memory scores. Higher presurgical visual/construction, nonverbal memory, and verbal/language scores were predictive of better postsurgical verbal/language functioning. Better presurgical verbal/language functioning was predictive of the same skills postsurgically as well as visual/construction outcomes. Exploratory analyses in a subset of participants (n = 25) revealed that dominant and nondominant intracarotid amobarbital (Wada) memory scores added unique variance only for predicting nonverbal memory following ATL. Presurgical neuropsychological testing provides significant and unique information regarding postsurgical seizure freedom and cognitive outcome in patients who have undergone ATL.     

Lateralized seizure termination: relationship to outcome following anterior temporal lobectomy.

Determination of side of seizure onset is critical for a successful outcome following epilepsy surgery. Little is known about the significance of lateralized seizure termination. Sustained seizure activity contralateral to side of seizure onset, following termination of ictal activity ipsilateral to side of onset, may suggest the presence of an independent focus. Such activity, if present, should predict a poor outcome. We studied side of seizure termination in 13 patients undergoing monitoring with bitemporal depth electrodes and correlated this to outcome following anterior temporal lobectomy (ATL). Side of seizure onset was determined for all seizures during that evaluation. Based on side of final cessation of ictal activity, patients were classified as having ipsilateral final termination or simultaneous termination (Group 1; N=6) or contra-lateral or mixed final termination (Group 2; N=7). The Duke outcome classification system was used. At the end of 2 years follow-up, 6/6 patients in Group 1 and 3/7 patients in Group 2 were seizure free. We conclude that lateralized seizure termination during evaluation with depth electrodes may be useful in predicting outcome following ATL. Continued seizure activity contralateral to side of seizure onset (following termination of ictal activity ipsilateral to side of onset) predicts a poor outcome. This may indicate the presence of an independent seizure focus opposite to the side of surgery.     

Age of meningitis or encephalitis is independently predictive of outcome from anterior temporal lobectomy.

BACKGROUND: The occurrence of meningitis or encephalitis in early childhood, i.e., < or =4 years of age, may be associated with both the development of medial temporal lobe epilepsy (MTLE) and an excellent operative outcome following an anterior temporal lobectomy (ATL). However, whether the predictive value of this risk factor for partial epilepsy is independent of the finding of mesial temporal sclerosis (MTS) on MRI is not known. METHODS: Consecutive patients (n = 39) with a remote history of meningitis or encephalitis who underwent an ATL were compared with 78 sex- and age-matched control subjects who had not experienced a CNS infection before ATL. All patients in both groups had nonlesional temporal lobe epilepsy and were followed up for at least 12 months postoperatively. RESULTS: There was a trend for the patients with a history of meningitis or encephalitis to have a lower frequency of class I postoperative outcome (61.5% vs 73.1%, p = 0.21). In the meningitis or encephalitis group, a class I outcome was more frequent in those with a history of meningitis or encephalitis at a young age (<4 years) (19/23 vs 5/16, p = 0.002), those with MTS detected on a preoperative MRI (22/31 vs 2/8, p = 0.04), and those with a history of meningitis (16/21 vs 8/18, p = 0.05). Multivariate logistic regression analysis found that a history of meningitis or encephalitis at a young age (b = 2.0, O.R. = 7.5, p = 0.048) was predictive of a class I outcome independent of the presence of MRI-identified MTS (b = 2.0, O.R. = 7.3, p = 0.07). CONCLUSION: The age of occurrence of a remote history of meningitis or encephalitis, but not the type of infection, is predictive of outcome after an ATL independent of the finding of MTS on the preoperative MRI.     

Factors predicting seizure outcome of anterior temporal lobectomy for patients with mesial temporal sclerosis.

PURPOSE: To investigate the factors, including those associated with ictal scalp EEG results, related to surgical outcome in patients with pathologically proven mesial temporal sclerosis. METHODS: We studied 51 consecutive patients who underwent anterior temporal lobectomy and had at least 4 years of follow-up. Surgical outcome was classified as being seizure-free or not seizure-free during the first two and the subsequent two postoperative years. Clinical variables and scalp EEG parameters were subjected to statistical analysis. RESULTS: Of the 51 patients, 36 (70.6%) were seizure-free during postoperative years 3 and 4. Logistic regression analysis revealed that seizure remission for the first 2 years (p = 0.002) and contralateral propagated ictal discharges (p = 0.015) were independently related to seizure outcome at 4 years. Patients who were seizure-free at 2 years had an 86.5% chance of remaining seizure-free at 4 years. Of the patients without bitemporal asynchrony or switch of lateralization, 88.9% were seizure free at 4 years, compared with 54.5% of patients with asynchrony or switch of lateralization (p = 0.007). These two factors, however, were not predictive of seizure outcome at 2 years. CONCLUSIONS: Contralateral propagated ictal discharges, including bitemporal asynchrony and switch of lateralization, unfavorably influence long-term seizure outcome. Long-term seizure control is best when the patient has no such propagation patterns of ictal discharges and is seizure-free during the first 2 years after temporal lobectomy.     

Presurgical multimodality neuroimaging in electroencephalographic lateralized temporal lobe epilepsy

The purpose of this study was to compare 2hyphen;[¹⁸F]fluoro-2-deoxy−D −glucose positron emission tomography (FDG-PET), hippocampal volumetry (HV), T2 relaxometry, and proton magnetic resonance spectroscopic imaging (¹H-MRSI) in the presurgical neuroimaging lateralization of patients with nonlesional, electroencephalogram (EEG)-defined unilateral temporal lobe epilepsy (TLE). Twenty-five patients were prospectively studied, along with age-matched controls. T2 relaxometry examinations were performed in 13 patients. Comparison of FDG-PET, HV, and ¹H-MRSI was possible in 23 patients. FDG-PET lateralized 87% of patients, HV 65%, N-acetyl aspartate (NAA)/(choline [Cho] + creatine [Cr]) 61% and [NAA] 57%. Combined HV and NAA/(Cho + Cr) results lateralized 83% of the patients, a value similar to PET. Of 10 patients with normal magnetic resonance imaging (MRI) scans, 2 were lateralized with HV, 6 with FDG-PET, 4 with NAA/(Cho + Cr), and 3 with [NAA]. T2 relaxometry lateralized no patients without hippocampal atrophy. Bilateral abnormality was present in 29 to 33% of patients with ¹H-MRSI measures and 17% with HV. Only hippocampal atrophy correlated with postoperative seizure-free outcome. FDG-PET remains the most sensitive imaging method to correlate with EEG-lateralized TLE. Both FDG-PET and ¹H-MRSI can lateralize patients with normal MRI, but only the presence of relative unilateral hippocampal atrophy is predictive of seizure-free outcome. Bilaterally abnorma; MRI and ¹H-MRSI measures do not preclude good surgical outcome.     

The Wada memory test and prediction of outcome after anterior temporal lobectomy

We reviewed the records of 77 Chinese-speaking adult patients to investigate the relationship between the Wada memory test and outcomes after anterior temporal lobectomy (ATL). The ipsilateral memory scores, contralateral memory scores and Wada asymmetry index (WAI) were calculated to evaluate their relationships with seizure and cognitive outcomes. The seizure outcomes did not correlate with the unilateral memory scores or the WAI. Patients who had a smaller WAI tended to have a post-operative decline in verbal intelligence quotient (VIQ) (odds ratio: 13.54, 95% confidence interval: 1.17–156.11, p = 0.037). The seven patients who failed the Wada memory test after ipsilateral injection had a higher percentage of VIQ deterioration than the 70 who passed (p = 0.039). However, no patient displayed global amnesia after surgery. The Wada memory test was a predictor for post-operative VIQ changes in our study. Patients who failed the Wada memory test still benefitted from the ATL and showed good seizure outcomes.     

Employment after anterior temporal lobectomy

Purpose: To explore the effect of anterior temporal lobectomy on employment and define demographic and clinical predictors of postoperative employment in a large cohort with a prolonged observational period. Methods: Subjects had an anterior temporal lobectomy for refractory epilepsy. All had an assessment period of 4 years or more with documentation of demographic factors, employment status, and seizure frequency prospectively registered in a database at surgery and at each contact after surgery. McNemar chi‐square and a Wilcoxon matched pairs test were used to compare employment status before and after surgery. A multiple logistic regression assessed independent predictors of postoperative employment status based on preoperative employment status. Key Findings: Three hundred sixty‐nine patients were evaluated. Employment levels were higher and unemployment levels were lower after surgery (McNemar χ² = 3.96; p = 0.047). Working before surgery (Wald’s χ² = 22.69, p < 0.0001) and having a greater percent of seizure‐free years (Wald’s χ² = 34.43, p < 0.0001) were associated with being employed after surgery. Of 131 patients who were unemployed or homemakers before surgery, 67 (51.1%) became employed postoperatively, with a younger age at surgery, a younger age of epilepsy onset, and driving a motor vehicle associated with gaining employment. Of 172 patients who were working at baseline, 27 (15.7%) became unemployed or homemakers after surgery. Gender was the only variable associated with loss of employment, with women being more likely to become homemakers (χ² = 14.98, d.f. = 6, p = 0.02). Most students were working after surgery, with seizure control influencing outcome. Significance: Anterior temporal lobectomy is followed by reduced unemployment and underemployment, with elimination of seizures, relative youth, and operating a motor vehicle serving as the main driving forces for improvement. This is important information for patients and physicians who contemplate surgery as it helps define reasonable expectations, and provides further objective evidence for benefits beyond purely medical outcomes after epilepsy surgery.     

A noninvasive protocol for anterior temporal lobectomy.

We report the results of a protocol for choosing candidates for temporal lobectomy using a standard battery of objective tests without intracranial electrodes. We assigned each test a level of importance, and an algorithm was used to determine whether temporal lobectomy could be performed. Fifty-one patients (total pool, 103 patients) met protocol requirements and had an anterior temporal lobectomy with a mean follow-up of 39.4 months (range, 21 to 64 months), most remaining on anticonvulsant therapy. Eighty percent are seizure free, 12% have less than 3 seizures per year or only nocturnal seizures, and 8% have greater than 80% reduction in seizure frequency. One-third of patients who failed protocol criteria did not have temporal lobe seizures when studied with intracranial electrodes. We analyzed and modified the algorithm after comparing these patients with others who were poor candidates for temporal lobectomy. We conclude that this protocol is effective and recommend using such an objective algorithm.     

Preoperative psychological adjustment and surgical outcome are determinants of psychosocial status after anterior temporal lobectomy.

This investigation evaluated the role of preoperative psychological adjustment, degree of postoperative seizure reduction, and other relevant variables (age, education, IQ, age at onset of epilepsy, laterality of resection) in determining emotional/psychosocial outcome following anterior temporal lobectomy. Ninety seven patients with complex partial seizures of temporal lobe origin were administered the Minnesota Multiphasic Personality Inventory (MMPI), Washington Psychosocial Seizure Inventory (WPSI), and the General Health Questionnaire (GHQ) both before and six to eight months after anterior temporal lobectomy. The data were subjected to a nonparametric rank sum technique (O'Brien's procedure) which combined the test scores to form a single outcome index (TOTAL PSYCHOSOCIAL OUTCOME) that was analysed by multiple regression procedures. Results indicated that the most powerful predictors of patients' overall postoperative psychosocial outcome were: 1) The adequacy of their preoperative psychosocial adjustment, and 2) A totally seizure-free outcome. Additional analyses were carried out separately on the MMPI, WPSI, and GHQ to determine whether findings varied as a function of the specific outcome measure. These results were related to the larger literature concerned with the psychological outcome of anterior temporal lobectomy.     

Endogenous potentials after anterior temporal lobectomy

The scalp topography of endogenous potentials was studied in patients who had previously undergone unilateral anterior temporal lobectomy (ATL). These excisions include medial temporal lobe (MTL) structures that have been shown to generate large potentials during tasks that evoke P3 at the scalp. Following right or left ATL, patients showed no differences from unoperated control subjects in overall amplitude of P3 or any other potential measured. The topography of P3 was very similar in both ATL groups and the control subjects, with no differences in laterality. These results suggest that the MTL is not the major generator of the P3 recorded at the scalp in the tasks studied here.     

Patient readmission and support utilization following anterior temporal lobectomy.

The aim of this study was to examine factors precipitating patient readmission, following anterior temporal lobectomy (ATL) for refractory epilepsy. A second aim was to explore the use of hospital outpatient and community support services ('outpatient services') by this patient population. These aims served the more general goal of identifying patients most likely in need of services additional to those routinely provided by our Seizure Surgery Follow-up and Rehabilitation Programme. The medical records of 100 consecutive ATL patients were retrospectively examined for the incidence and diagnoses precipitating acute readmission, and the utilization of additional outpatient services. Twenty-one patients (21%) required readmission post-ATL, totalling 47 readmissions between them. Psychiatric diagnoses were the most prevalent (53%), including anxiety, depression and/or post-ictal psychosis. Epileptological diagnoses were the other main precipitant (28%). Additional outpatient services were predominantly utilized for ongoing psychological support. Of the 21 patients requiring readmission, 10(10%) also needed additional outpatient services. These patients were predominantly female or unemployed, in contrast to male or employed patients who tended to require readmission only. Seventeen patients (17%) were maintained within the community using additional outpatient services only. Characteristics of these patients included disrupted family dynamics, limited social networks, and/or a psychiatric history. These patients were also more frequently beyond the 24-month follow-up period of the programme. A profile of patients most in need of additional support services can be constructed to assist team planning of proactive management strategies for the rehabilitation phase of ATL.     

Olfactory memory in patients with anterior temporal lobectomy.

Right and left temporal lobectomy patients, matched in age and intelligence, made more errors in odor recall than a control group. Patients with right temporal lobe excisions recalled significantly fewer odors correctly than patients with left temporal lobe excisions. Olfactory memory scores were not related to other memory deficits associated with left or right temporal lobe dysfunction or to intelligence or lesion size. However, in patients with right temporal lobectomy, percent of odors recalled correctly correlated positively with a general memory index. The findings presented are consistent with previous reports that the right temporal lobe is more involved with nonverbal memory than the left temporal lobe.     

Memory outcome 2 years after anterior temporal lobectomy in patients with drug-resistant epilepsy

PURPOSE: Memory decline is often observed after anterior temporal lobectomy (ATL), particularly in patients with dominant hemisphere resections. However, the follow-up length has been 1 year or less in most studies. Our aims were to examine postoperative memory changes over a longer period and to identify baseline demographic and clinical predictors of memory outcome. METHODS: We administered material-specific memory tests at baseline, and 1 and 2 years after surgery to 82 consecutive right-handed patients (52% males) who underwent ATL for drug-resistant temporal lobe epilepsy (TLE) (35 left, 47 right) after a non-invasive presurgical protocol. Repeated measures multivariate analysis of variance (RM-MANOVA) was used to examine the relationship between changes in memory tests scores over time and side of TLE and pathology. Also, standardized residual change scores were calculated for each memory test and entered in multiple linear regression models aimed at identifying baseline predictors of better memory outcome. RESULTS: RM-MANOVA revealed a significant change in memory test scores over time, with an interaction between time and side of surgery, as 2 years after surgery patients with RTLE were improved while patients with LTLE were not worse as compared with baseline. Pathology was not associated with changes in memory scores. In multiple regression analysis, significant associations were found between right TLE and greater improvement in verbal memory, younger age and greater improvement in visuospatial memory, and male gender and greater improvement in both verbal and visuospatial memory. CONCLUSIONS: Our results suggest that the long-term memory outcome of TLE patients undergoing ATL without invasive presurgical assessment may be good in most cases not only for right-sided but also for left-sided resections.     

Presurgical evaluation and surgical outcome of temporal lobe epilepsy

The authors analyzed 22 patients younger than 18 years of age with temporal lobe epilepsy (TLE) treated surgically. Patients underwent a comprehensive presurgical evaluation, including video-electroencephalogram. Fifty-five percent had a history of febrile seizures. Eighty-two percent had auraes and most exhibited oroalimentary and gestural automatisms. Contralateral dystonic posturing was present in 36% and postictal dysphasia in 54% of patients with left-sided resections. Cranial magnetic resonance imaging (MRI) was abnormal in 59% of patients. MRI revealed changes consistent with mesial temporal sclerosis in 8 (47%) of 17 patients without lesions. Fluorodeoxyglucose-positron emission tomography (PET) scans revealed ipsilateral temporal hypometabolism (PET-TH) in 12 (85.7%) of 14 patients. The intracarotid amobarbital procedure revealed impaired memory of the epileptogenic side in 59% of patients. Seventeen patients underwent en-bloc resections and five lesionectomies and resection of the epileptogenic area. There was no surgical morbidity or mortality. Forty-three percent had hippocampal sclerosis, 28.5% gliosis, 14% low-grade tumors, 9.5% cavernous angiomas, and 5% had no pathologic findings. Follow-up (6 months to 12 years) was available for 21 patients; 76% became seizure free, 19% had rare seizures, and 5% had a worthwhile improvement. TLE can be safely treated surgically in younger patients with excellent results. The clinical manifestations were similar to adult patients. PET-TH was present even at a younger age, suggesting that the focal functional deficits appear early in patients with medically refractory TLE, which may help in the early identification of these patients.     

顽固性癫痫行前颞叶切除术的并发症

目的报告顽固性颞叶癫痫行前颞叶切除的并发症,探讨术后并发症的发生率、原因和预防措施。方法顽固性颞叶癫痫患者行前颞叶切除,术后出现急性脑梗死伴颅内感染、硬膜外血肿、轻偏瘫等情况,采取抗炎、抗脑水肿、抗凝治疗及清除血肿等治疗。结果首例病人卡马西平治疗随访1年,癫痫发作消失;第2例随访7年,癫痫发作消失;第3例癫痫消失,但残留轻偏瘫,后渐恢复,遗留左手指屈伸力差。结论血肿和感染是术后最频发的并发症,偏瘫(操作性偏瘫)是最严重的神经并发症,手术时损伤脉络膜前动脉是最可能导致偏瘫的原因。     

Short-term neurocognitive outcomes following anterior temporal lobectomy

Changes in cognitive function are a well established risk of anterior temporal lobectomy (ATL). Deficits in verbal memory are a common postoperative finding, though a small proportion of patients may improve. Postoperative evaluation typically occurs after six to 12 months. Patients may benefit from earlier evaluation to identify potential needs; however, the results of a formal neuropsychological assessment at an early postoperative stage are not described in the literature. We compared pre- and postoperative cognitive function for 28 right ATL and 23 left ATL patients using repeated measures ANOVA. Changes in cognitive function were compared to ILAE seizure outcome. The mean time to postoperative neuropsychological testing was 11.1 weeks (SD = 6.7 weeks). There was a side × surgery interaction for the verbal tasks: immediate memory recall (F(1,33) = 20.68, p < 0.001), short delay recall (F(1,29) = 4.99, p = 0.03), long delay recall (F(1,33) = 10.36, p = 0.003), recognition (F(1,33) = 5.69, p = 0.02), and naming (F(1,37) = 15.86, p < 0.001). This indicated that the left ATL group had a significant decrement in verbal memory following surgery, while the right ATL group experienced a small but significant improvement. For the right ATL group, there was a positive correlation between ILAE outcome and improvement in immediate recall (r = − 0.62, p = 0.02) and long delay recall (r = − 0.57, p = 0.03). There was no similar finding for the left ATL group. This study demonstrates that short-interval follow-up is effective in elucidating postoperative cognitive changes. Right ATL was associated with improvement in verbal memory, while left ATL resulted in a decrement in performance. Improvement in the right ATL group was related to improved seizure outcome. Short-interval follow-up may lend itself to the identification of patients who could benefit from early intervention.     

Long-term psychosocial outcomes of anterior temporal lobectomy

PURPOSE: To examine the long-term psychosocial outcomes of a consecutive series of patients who underwent anterior temporal lobectomy (ATL) compared with medically managed patients. This study focused primarily on actual long-term changes (mean, 5 years) in life performance. There are relatively few long-term controlled studies of actual lifetime performance changes. METHODS: The sample consisted of 61 adults who underwent ATL and 23 individuals who were evaluated for surgery but did not proceed to surgery and continued to receive medical management. Participants were interviewed 2-9 years after surgery. A structured clinical interview and review of medical records was conducted to obtain information regarding seizure frequency and psychosocial status, focusing on employment, education, driving status, financial assistance, and independent living. In addition, two questions regarding quality of life were included. Seizure frequency was evaluated for the year before the interview. RESULTS: Significant differences in psychosocial outcome were found between the surgery group and medical management group. Favorable psychosocial outcomes were more common among those who had surgery (46 vs. 4%). Results indicated that 68% of the surgery group exhibited improved psychosocial status compared with 5% of the medical management group. Individuals who had surgery were more likely to be driving, working full-time, living independently, and being financially independent. Remaining seizure free was not a prerequisite for improvements in psychosocial outcomes. CONCLUSIONS: Compared with medical management, surgery has a significant positive impact on psychosocial outcomes in terms of employment, independent living, driving, and financial independence. Additionally, a person does not necessarily have to be seizure free to achieve positive changes in psychosocial outcomes.