Prognostic factors for the surgery for mesial temporal lobe epilepsy: longitudinal analysis

PURPOSE: Determining long-term prognostic factors of surgery for mesial temporal lobe epilepsy (MTLE) is important for identifying ideal candidates and predicting the prognosis for individual patients. We tried to identify the prognostic factors of anterior temporal lobectomy (ATL) for MTLE with longitudinal multivariate analysis. METHODS: Two hundred twenty-seven patients with MTLE were included in this study. The primary outcome variable was patient status 1-5 years after surgery: seizure free, or not. Clinical characteristics and recent diagnostic modalities were considered as prognostic factors. Univariate and standard multiple logistic-regression analysis for outcome at 1 and 5 years after surgery and the generalized estimation equation (GEE) model for longitudinal multiple logistic regression of the 5-year follow-up period were used. RESULTS: The seizure-free rate at 1 year was 81.1% and decreased to 75.2% at 5 years after surgery. By the univariate or standard multiple logistic-regression analysis, age at surgery or hippocampal sclerosis on magnetic resonance imaging (MRI) ipsilateral to surgery was significant for the postsurgical outcome. However, the longitudinal analysis by the GEE model revealed that younger age at surgery [odds ratio (OR), 0.59; 95% confidence interval (CI), 0.43-0.81], absence of secondarily generalized tonic-clonic seizure (2 degrees GTCS; OR, 0.45; 95% CI, 0.26-0.79), and hippocampal sclerosis on MRI (OR, 2.44; 95% CI, 1.11-5.26) were significant predictors of a good surgical outcome. CONCLUSIONS: Age at surgery, presence of 2 degrees GTCS, and hippocampal sclerosis on MRI are independent prognostic factors for ATL in MTLE. These findings suggest that MTLE is a progressive disorder, and surgical outcome is better when early ATL is performed.     

Dual pathology in a patient with temporal lobe epilepsy associated with neocortical glial scar after brain abscess and end folium sclerosis/hippocampal sclerosis type 3

End folium sclerosis or hippocampal sclerosis (HS) type 3 is often associated with another coexisting epileptogenic lesion (dual pathology); however, the pathogenesis of HS type 3 remains elusive. A 46‐year‐old man presented with medically intractable focal aware seizures and focal impaired awareness seizures (FIAS) with occasional focal to bilateral tonic–clonic seizures (FBTCS) two years after surgical treatment with extensive cranial reconstruction for a brain abscess in the right temporal lobe associated with intracranial extension of ipsilateral cholesteatoma. Head magnetic resonance imaging (MRI) at age 49 revealed atrophy of the right cerebral hemisphere including the hippocampus and amygdala. The patient's first epilepsy surgery was a lateral temporal lobectomy, in which the mesial temporal structures were preserved because no epileptiform discharge was detected on the intraoperative electrocorticogram. However, FIAS with FBTCS started 15 months after the operation. The second surgery, amygdalohippocampectomy, at age 52, resulted in the patient being seizure‐free again for one year before seizures of the right lateral temporal origin recurred. He underwent a third surgery, resection of the Heschl's and supramarginal gyri, at age 53, but he continued to have drug‐resistant epilepsy over two years after that. Histopathological examination revealed dual pathology consisting of glial scar in the lateral temporal lobe and ipsilateral HS type 3 with an unusually severe lesion in the subiculum. No significant inflammatory change was observed. The clinicopathological features in the present case indicate that HS developed secondarily in the context of neocortical epilepsy due to glial scar, suggesting a role of repetitive abnormal electrical input from neocortical epileptogenic lesions into the hippocampus finally via the perforant pathway in the pathogenesis of HS type 3. Severe hippocampal atrophy on preoperative MRI together with its silent electrocorticogram recording at initial epilepsy surgery may represent clinically pre‐epileptogenic HS in a seizure‐free “silent or latent period” before completion of hippocampal epileptogenesis to the extent that clinical epileptic seizures occur.     

The seizure outcome after amygdalohippocampectomy and temporal lobectomy

The aim of this study was to compare the seizure outcome of two different types of epilepsy surgery, selective amydalohippocampectomy (AHE) and anterior temporal lobectomy (ATLE) in patients with temporal lobe epilepsy. We included 114 patients who had mesio-temporal lobe epilepsy and hippocampal sclerosis or gliosis on histology. Patients had ATLE if the non-dominant hemisphere was affected or if the whole temporal lobe was atrophic. Patients had AHE if the dominant hemisphere was affected. Standardized seizure outcome at 1 year following surgery was used. Overall 40% of the 114 patients who had temporal lobe epilepsy surgery were seizure-free at 1-year (Engel's class Ia). A good outcome (Engel's classes I and II) was significantly more frequent in ATLE than in AHE. (66% and 44%, respectively, P  = 0.03). ATLE had a better seizure outcome than AHE.     

Outcome after temporal lobectomy in bilateral temporal lobe epilepsy

We determined how noninvasive presurgical data relate to prognosis after temporal lobectomy in patients with independent bilateral temporal lobe (IBTL) complex partial seizures on the intracranial electroencephalogram (EEG). Between 1986 and 1994, 28 patients had IBTL seizures on intracranial EEG. Fifteen of these 28 patients underwent temporal lobectomy and 13 were not offered surgery. Of the 15 patients who had surgery, 10 patients became seizure-free. Magnetic resonance imaging (MRI) and the Wada test were the only variables associated with a seizure-free outcome. Seven of 10 seizure-free patients had a lateralized Wada result or the presence of unilateral hippocampal sclerosis, whereas none of the patients with persistent seizures had either of these findings. Variables not found to be predictive of a seizure-free outcome included location of scalp interictal spikes, degree of seizure-onset laterality, presence of early epilepsy risk factor, duration of epilepsy, and full-scale intelligence quotient. We conclude that MRI and the Wada test provide information of prognostic value in patients with bilateral temporal seizures independent of intracranial EEG data.     

Ganglioglioma and Intractable Epilepsy: Clinical and Neurophysiologic Features and Predictors of Outcome After Surgery

Summary: Purpose: To review the clinical, neurophysiologic, and radiological data of patients with ganglioglioma who had undergone evaluation and surgery in our Epilepsy Program.
Methods: The medical and neurophysiologic records of 38 patients with intractable epilepsy and ganglioglioma were re- viewed. Data underwent statistical analysis.
Results: There were 28 temporal and 10 extratemporal resections, with a mean age at seizure onset of 10.5 years and mean age at surgery of 22 years. Five tumor resections performed earlier were recorded. Twenty-nine patients had auras and 20 had secondarily generalized seizures. All 28 patients with temporal tumor had complex partial seizures. Preoperative MRI demonstrated the tumor in 36 of 36 patients: 17 of 29 demonstrated gadolinium enhancement, and 17 of 36 had mass effect. Scalp interictal sharp waves were present in 32 patients, and in 15 they were multiregional. In two patients, scalp EEG seizure onset was from the hemisphere contralateral to the tumor. Postoperatively, 79% of patients (30 of 38) were seizure-free (Engel's class I) at 6 months, 72% at 1 year (26 of 36), and 63% at 2 years (20 of 32). Excellent outcome was associated with a lower age at operation (p = 0.008), shorter duration of epilepsy (p = <0.01), absence of generalized seizures (p = <0.01), and no epileptiform discharges on a postoperative EEG (p = 0.01).
Conclusions: Good surgical outcome is expected in patients with ganglioglioma despite years of medically resistant seizures. Good outcome may be achieved despite EEG findings that may conflict with tumor location, and is more likely when surgery is performed relatively soon after epilepsy onset.     

Prognosis after temporal lobe epilepsy surgery: the value of combining predictors

Purpose: Although several independent predictors of seizure freedom after temporal lobe epilepsy surgery have been identified, their combined predictive value is largely unknown. Using a large database of operated patients, we assessed the combined predictive value of previously reported predictors included in a single multivariable model.
Methods: The database comprised a cohort of 484 patients who underwent temporal lobe surgery for drug-resistant epilepsy. Good outcome was defined as Engel class 1, one year after surgery. Previously reported independent predictors were tested in this cohort. To be included in our final prediction model, predictors had to show a multivariable p-value of <0.20.
Results: The final multivariable model included predictors obtained from the patient's history (absence of tonic–clonic seizures, absence of status epilepticus), magnetic resonance imaging [MRI; ipsilateral mesial temporal sclerosis (MTS), space occupying lesion], video electroencephalography (EEG; absence of ictal dystonic posturing, concordance between MRI and ictal EEG), and fluorodeoxyglucose positron emission tomography (FDG-PET; unilateral temporal abnormalities), that were related to seizure freedom in our data. The model showed an expected receiver-operating characteristic curve (ROC) area of 0.63 [95% confidence interval (CI) 0.57–0.68] for new patient populations. Intracranial monitoring and surgery-related parameters (including histology) were not important predictors of seizure freedom. Among patients with a high probability of seizure freedom, 85% were seizure-free one year after surgery; however, among patients with a high risk of not becoming seizure-free, still 40% were seizure-free one year after surgery.
Conclusion: We could only moderately predict seizure freedom after temporal lobe epilepsy surgery. It is particularly difficult to predict who will not become seizure-free after surgery.     

Outcome predictors for surgical treatment of temporal lobe epilepsy with hippocampal sclerosis

Purpose: To study long-term postoperative course and identify predictors for postoperative seizure control in patients with medically intractable temporal lobe epilepsy (TLE) associated with hippocampal sclerosis (HS), diagnosed by magnetic resonance imaging (MRI), and ascertained histopathologically. To compare patients becoming seizure-free (i.e., cured from epilepsy) and patients experiencing prolonged seizure-free periods interposed with recurring seizures.
Methods: One hundred thirty-five patients (74 women) underwent complete evaluation for epilepsy surgery. The predictive value of duration of epilepsy, age at onset, age at surgery, gender, febrile convulsion history, ictal dystonic posturing, unilateral interictal electroencephalography (EEG) discharges (IED), preoperative secondarily generalized tonic–clonic seizures (SGTCS), and preoperative seizure frequency for short- and long-term postoperative seizure control were evaluated with two classification systems: Classification 1 (seizure-freedom with or without auras during 12-months before observation points) and the stringent classification 2 [International League Against Epilepsy (ILAE) Ia; absolute absence of seizures and auras after operation].
Results: Unilateral IED at year 1 and 2 (p = 0.037 and p = 0.034), male gender and low seizure frequency at year 2 (p = 0.013 and p = 0.046) were significant predictors for seizure freedom using classification 1. All variables (except male gender at year 2; p = 0.035) lost their predictive power, applying classification 2. The proportion of seizure-free patients remained stable between 70% to 79% with classification 1, but decreased from 64.4% at year 1 to 45.8% at year 5 with classification 2.
Discussion: Positive predictors of short-term outcome do not predict long-term outcome in patients with TLE associated with HS. Absolute freedom of seizures and auras cannot be predicted by conventional preoperative variables.     

儿童和青少年颞叶癫癎的术后长期疗效观察

目的总结儿童和青少年颞叶癫癎手术后的长期疗效和生活质量。方法回顾性分析31例儿童和青少年颞叶癫癎病人的临床资料,行标准前颞叶切除术26例,扩大前颞叶切除术2例,前颞叶切除术＋软化灶切除术2例,颞后顶下致癎灶切除术1例。评估术后癫癎发作改善情况及认知、生活质量等。结果术后随访5年以上,其中癫癎发作消失、达到EngelⅠ级26例,EngelⅡ级1例,EngelⅢ级2例,EngelⅣ级2例。术后病理示：海马组织硬化13例,皮质发育异常伴胶质增生9例,皮质发育异常伴海马组织硬化6例,神经元胶质肿瘤2例,继发性瘢痕脑回形成1例。术后并发症多数可恢复。结论儿童和青少年颞叶癫癎术后长期疗效良好,生活质量提高。     

Long-term prognosis and psychosocial outcomes after surgery for MTLE

PURPOSE: To assess the seizure-freedom rates and self-perceived psychosocial changes associated with the long-term outcome of epilepsy surgery in patients with refractory medial temporal lobe epilepsy associated with hippocampal sclerosis. METHODS: A standard questionnaire was given to 183 patients who underwent surgery between 1988 and 2004, and 110 were completed. RESULTS: The mean duration of follow-up after surgery was 7 years, with a maximum of 17 years. The probability that patients were seizure-free after surgery was dependent on the definition of the seizure freedom. For the patients who were seizure-free since surgery (Engel's class Ia), the probability was 97.6% at 1 year after surgery, 85.2% at 2 years after surgery, 59.5% at 5 years after surgery, and 42.6% at 10 years after surgery. For the patients who still experienced rare disabling seizures after surgery but were seizure-free at least 1 year before the time of assessment, the probability was of 97.6% at 1 year after surgery, 95% at 2 years after surgery, 82.8% at 5 years after surgery, and 71.1% at 10 years after surgery. The psychosocial long-term outcome, as measured by indices of driving, employment, familial and social relationships, and marital status, was similar to the psychosocial short-term outcome. It did not depend on seizure freedom or on follow-up time interval and was not influenced statistically by seizure frequency in cases of persisting seizures. Most but not all patients noticed a substantial overall improvement in their psychosocial condition; 48% drove (increased by 7%), 47% improved (14% worsened) in their employment status, and 68% improved (5% worsened) in their familial and social relationships. Overall, 91% of patients were satisfied with the surgery, and 92% did not regret their decision. CONCLUSIONS: The results of this study suggest that temporal lobe surgery has real long-term benefits. Two specific conclusions emerge: (a) the long-term rates of freedom from seizure depend on how seizure freedom is defined, and (b) the psychosocial long-term outcome does not change dramatically over years and does not depend on seizure freedom.     

Temporal lobe epilepsy due to hippocampal sclerosis in pediatric candidates for epilepsy surgery.

OBJECTIVE: To characterize the clinical, EEG, MRI, and histopathologic features and explore seizure outcome in pediatric candidates for epilepsy surgery who have temporal lobe epilepsy (TLE) caused by hippocampal sclerosis (HS). METHODS: The authors studied 17 children (4 to 12 years of age) and 17 adolescents (13 to 20 years of age) who had anteromesial temporal resection between 1990 and 1998. RESULTS: All patients had seizures characterized by decreased awareness and responsiveness. Automatisms were typically mild to moderate in children and moderate to marked in adolescents. Among adolescents, interictal spikes were almost exclusively unilateral anterior temporal, as opposed to children in whom anterior temporal spikes were associated with mid/posterior temporal, bilateral temporal, extratemporal, or generalized spikes in 60% of cases. MRI showed hippocampal sclerosis on the side of EEG seizure onset in all patients. Fifty-four percent of children and 56% of adolescents had significant asymmetry of total hippocampal volumes, whereas the remaining patients had only focal atrophy of the hippocampal head or body. Subtle MRI abnormalities of ipsilateral temporal neocortex were seen in all children and 60% of adolescents studied with FLAIR images. On histopathology, there was an unexpectedly high frequency of dual pathology with mild to moderate cortical dysplasia as well as HS, seen in 79% of children and adolescents. Seventy-eight percent of patients were free of seizures at follow-up (mean, 2.6 years). A tendency for lower seizure-free outcome was observed in patients with bilateral temporal interictal sharp waves or bilateral HS on MRI. The presence of dual pathology did not portend poor postsurgical outcome. CONCLUSIONS: TLE caused by HS similar to those in adults were seen in children as young as 4 years of age. Focal hippocampal atrophy seen on MRI often was not reflected in total hippocampal volumetry. Children may have an especially high frequency of dual pathology, with mild to moderate cortical dysplasia as well as HS, and MRI usually, but not always, predicts this finding. Postsurgical seizure outcome is similar to that in adult series.     

Is anterior temporal lobectomy a precipitating factor for transient global amnesia?

Little is known about the pathophysiology of transient global amnesia (TGA) and how it is related to epilepsy. We report here five typical episodes of TGA, each occurring several years after surgery for epilepsy. In all cases, patients were seizure-free after a surgery consisting of anterior temporal lobectomy for refractory medial temporal lobe epilepsy associated with hippocampal sclerosis (n = 4) or linked with a dysembryoplastic neuroepithelial tumour (n = 1). Investigations, including MRI or CT scan, angio-MRI or echocardiogram or vascular echo Doppler, excluded a vascular origin. Using accepted criteria to distinguish between TGA and epileptic amnesic attacks--the typical clinical presentation, the long duration of the episode, the absence of other symptoms associated with seizures and the absence of recurrence--it is evident that these patients suffered a TGA. These studies suggest that hippocampal resection carried out therapeutically in some epileptic patients may be a precipitating factor for TGA.     

Prognostic factors in anterior temporal lobe resections for mesial temporal lobe epilepsy: multivariate analysis

PURPOSE: Even though there have been several studies on the prognostic factors of temporal lobe epilepsy (TLE) after lobectomy, no studies have been performed for homogeneous mesial TLE. Furthermore, most studies on the predictors of outcome of epileptic surgery were based on univariate analyses and did not consider modern epileptic surgery investigation modalities such as brain magnetic resonance imaging (MRI) and positron emission tomography (PET). We attempted to identify the prognostic factors in anterior temporal lobectomy (ATL) for mesial TLE with multivariate analysis. METHODS: Ninety-three patients with mesial TLE (54 men and 39 women, mean age at surgery, 28.3 +/- 8.2 years) were included in the study. The primary outcome variable was the status of patients in the second postoperative year, classified as either seizure free (except aura), or not seizure free. Clinical, electroencephalographic, MRI, PET, Wada test, and pathological data were considered. RESULTS: Seventy-eight (84.0%) patients had remission of seizures. With univariate analysis, age at surgery (p < 0.001), epilepsy duration before surgery (p = 0.04), and ipsilateral hippocampal sclerosis on MRI (p = 0.02) were found to be significant. By using multivariate analysis, age at surgery (p = 0.001) and ipsilateral hippocampal sclerosis on MRI (p = 0.03) were found to be the most significant prognostic factors. CONCLUSIONS: Age at surgery and hippocampal sclerosis are independent prognostic factors for ATL in mesial TLE. These findings suggest that mesial TLE may be a progressive disorder, and surgical outcome is better when early ATL is performed.     

Outcome after surgery in patients with refractory temporal lobe epilepsy and normal MRI.

Our purpose is to determine predictors of outcome in patients with refractory temporal lobe epilepsy and normal high resolution magnetic resonance imaging (MRI) who undergo surgical therapy. We identified 23 patients who underwent temporal lobectomy and had normal pre-operative MRI, including surface coil phased array temporal lobe imaging. All were followed at least 2 years after surgery. We graded outcome as seizure-free, > 75% reduction in seizures, or < 75% reduction in seizures. We examined pre-operative interictal and ictal electroencephalographic (EEG) findings, age of onset, gender, duration of epilepsy, risk factors, family history, physical findings, age at operation, side of operation, and pathology of resected tissue in order to determine if any of these factors were associated with outcome. Overall, 48% (11/23) of patients were seizure-free, 39% (9/23) had > 75% reduction in seizures, while 13% (3/23) had < 75% reduction in seizures. Only the EEG findings were useful in predicting outcome. When ictal onsets arose from basal-temporal regions, 61% (11/18) of patients were seizure-free, while none (0/5) were seizure-free when seizures arose from mid-posterior temporal regions (P = 0.04). Interictally, if all epileptiform patterns were localized exclusively to one basal-temporal region, a finding that invariably correlated with ictal onsets, 78% (7/9) of patients were seizure-free, while only 29% (4/14) were seizure-free if discharges were bilateral or multifocal (P = 0.04). We conclude that surgery may be a reasonable treatment for some patients with intractable temporal lobe seizures and normal MRI. The best outcomes occur when seizure onsets and interictal epileptiform patterns are exclusive to one basal-temporal region. Unfavorable outcomes are most likely to occur when ictal origins are from mid-posterior temporal regions and when interictal discharges are bitemporal or multifocal in distribution.     

Benign epileptiform discharges in Rolandic region with mesial temporal lobe epilepsy: MEG, scalp and intracranial EEG features

AIM OF THE STUDY: To report benign epileptiform discharges (BEDs) in the Rolandic region, coexisting in a pediatric patient with intractable localization-related epilepsy, secondary to hippocampal sclerosis. METHODS: We describe the clinical features, MRI, scalp video EEG, magnetoencephalography (MEG) and intracranial video EEG findings, and surgical outcome in a 9-year-old boy with BEDs and intractable complex partial seizures. RESULTS: MRI showed left hippocampal sclerosis. Scalp video EEG interictally demonstrated left temporal spike and sharply contoured slow waves, and right fronto-centro-temporal spike and waves. Ictal scalp video EEG showed left temporal rhythmic sharp waves after the clinical onset of epigastric aura, followed by staring. MEG showed interictal dipoles in the bilateral Rolandic regions with a uniform orientation and right hemispheric predominance. Intracranial video EEG, with bilateral mesial temporal depth and fronto-temporo-parietal strip electrodes, interictally showed polyspikes and slow waves with superimposed low-amplitude fast waves in the left mesial and posterior lateral temporal regions, and spike and waves in the bilateral fronto-parietal regions. Ictal onset was marked by low-amplitude fast waves in the left mesial and posterior lateral temporal regions. He underwent left anterior temporal lobectomy with hippocampectomy. Pathology was hippocampal sclerosis. Predominant right fronto-centro-temporal spike and waves and MEG right Rolandic dipoles persisted after surgery. He was seizure-free 14 months after surgery. CONCLUSION: This is the first report on MEG and intracranial video EEG features of BEDs in the Rolandic region, coexisting with hippocampal sclerosis. Persistence of contralateral benign MEG Rolandic dipoles after surgery indicates that BEDs are coincidental in mesial temporal lobe epilepsy. MEG identified Rolandic dipoles, although was unable to localize the deep and focal epileptogenic dipoles from the hippocampal sclerosis.     

Significance of fornix atrophy in temporal lobe epilepsy surgery outcome

BACKGROUND: Previous magnetic resonance imaging (MRI) studies have shown concurrent fornix atrophy in a large proportion of patients with hippocampal atrophy. The contribution of the fornix as an independent preoperative determinant of surgical outcome is unknown. OBJECTIVE: To evaluate the contribution of the fornix as a determinant of surgical outcome in patients with preoperatively determined temporal lobe epilepsy. METHODS: We selected 78 patients who had undergone anterior temporal lobectomy for intractable temporal lobe epilepsy at the University of Alabama at Birmingham Epilepsy Center during a 24-month period. All patients underwent standard presurgical investigations and intracranial investigations when needed. Magnetic resonance imaging volumetric studies were performed prior to surgery using previously published techniques. Patients were assessed regularly for postoperative seizure control. Outcome after at least 3 years was evaluated using Engel's classification for epilepsy. The chi2 test was used to compare categorical data. RESULTS: Seventy-eight patients were included in this study. Eight patients were excluded because of inadequate follow-up. Thirty-five patients (44.9%) had unilateral isolated hippocampal atrophy exclusively on MRI volumetry, 29 (37.2%) had unilateral hippocampal atrophy with ipsilateral fornix atrophy, and 6 (7.7%) had isolated fornix atrophy without hippocampal atrophy. Twenty-eight patients (80%) in the unilateral hippocampal atrophy group were seizure free (ie, Engel class 1: patients who are completely seizure free with no aura and who do not receive antiepileptic drugs) compared with 21 patients (73%) in the fornix and hippocampal atrophy group (P =.57). All 6 patients with isolated fornix atrophy achieved an Engel's class 1 outcome. CONCLUSIONS: These findings suggest that identification of fornix atrophy with or without associated hippocampal atrophy is not an important preoperative determinant of surgical outcome. However, in the presence of a normal hippocampus, fornix atrophy may be valuable in predicting seizure-free outcome.     

Orbito-frontal epilepsy masquerading as temporal lobe epilepsy-a case report.

Temporal lobectomy fails to control seizures in a considerable percentage of patients who do not have hippocampal sclerosis. One theoretical reason for failure of surgery is that some of these patients may in fact have extratemporal epilepsy. We present a 28-year-old woman with clinical and scalp electroencephalogram (EEG) evidence of right temporal lobe epilepsy (TLE) supported by functional imaging with interictal positron emission tomography (PET) and ictal single-photon emission computerized tomography (SPECT). An invasive EEG monitoring was prompted by the discovery of a small right orbito-frontal lesion on MRI. Monitoring documented seizure onset at the lesion, with rapid right temporal involvement. The patient was almost seizure-free after a lesionectomy. The index of suspicion of orbito-frontal epilepsy should be high in patients with apparent TLE when the scalp EEG and neuroimaging data are not congruent, or if temporal lobe pathology cannot be identified on structural imaging.     

Temporal Lobe Epilepsy Surgery with Limited Resources: Results and Economic Considerations

Summary: This study evaluates the surgical outcome of patients with medically refractory temporal lobe epilepsy (TLE) who underwent anterior temporal lobe lobectomy (ATL) based on data derived from noninvasive studies and assesses the economic costs entailed at a newly created epilepsy program in Chile. Seventeen ATL candidates underwent a presurgical evaluation. This included outpatient brain MRI and neuropsychological testing and inpatient scalp/sphenoidal prolonged video-EEG monitoring. There were 10 females and 7 males, with a mean age of 23.8 years and a mean duration of seizure disorder of 12 years. Patients with congruent data localizing the seizure focus to one anterotemporal region underwent ATL. Seven patients underwent a left-side ATL and 10 patients a right-side ATL. The histopathological findings showed a lowgrade tumor in six patients, hippocampal sclerosis in five, neuronal migration disorder in four, and cavernous angiomas in two patients. The mean follow-up period was 29·1 months. Seizure outcome was assessed with Engel's classification: class I, no seizures or only auras; class II, rare seizures; class III, >90% seizure reduction; class IV, <90% seizure reduction. Fifteen patients are now in class I, one patient in class II, and one in class IV. The total cost, including evaluation and surgery, was equivalent to US$ 5,020. Thus, well-selected TLE patients can derive maximal benefit from ATL after a noninvasive presurgical evaluation. This finding is of great significance for the creation of epilepsy surgery programs in developing countries.     

Long-term seizure outcome following resective surgery at National Epilepsy Center in Shizuoka, Japan

We analyzed the seizure outcome of 357 patients who were followed for at least 2 years after resective surgeries; 282 underwent temporal lobe resection and 75 had extratemporal lobe resection. This study confirmed that resective surgery provides sustained, positive benefits with a high seizure-free rate of nearly 80% for most medically refractory patients. In patients with no MRI-detectable lesion who underwent extratemporal lobe resection, however, Engel's class I-II (seizure-free or rare seizures) was achieved in less than 50% of patients. High-resolution MRI should be performed at the early stage of disease in all patients with partial epilepsies. The findings would certainly urge clinicians to actively select surgical intervention.     

Extent of Resection in Temporal Lobectomy for Epilepsy. I. Interobserver Analysis and Correlation with Seizure Outcome

The extent of resection was assessed in 45 temporal lobectomies for medically intractable epilepsy with mapped temporal lobe foci. Postoperative magnetic resonance imaging (MRI) in the coronal plane was used to quantify the extent of resection of superior lateral, inferior lateral, basal, and medial structures, including the amygdalohippocampal complex. A new 20-compartment model of the temporal lobe was used for this assessment. Blinded interobserver variability was minimal. Intraoperative measurements and maps routinely overestimated the actual extent of resection, especially of medial structures. One year after surgery, 70% of patients remained seizure-free (except for auras). Seizure-free outcome was accomplished despite varying degrees of resection, but was more likely achieved with more extensive resections in all compartments. Among patients with mesiobasal foci, seizure-free outcome correlated significantly with extent of resection of amygdalohippocampal complex. We conclude that assessment of extent of resection by postoperative MRI provides an objective basis of evaluating outcome after temporal lobectomy. It allows a rational approach to understanding of operative failures and is potentially useful in comparing efficacy of various surgical approaches.     

Hypersalivation in temporal lobe epilepsy

PURPOSE: We sought to determine whether hypersalivation helps lateralize seizure onset during complex partial seizures of temporal lobe origin. Several clinical signs, which help lateralize seizure onset, have been reported in temporal lobe epilepsy (TLE). Increased salivation only occasionally has been reported as a manifestation of partial epilepsy. METHODS: Of 590 consecutive patients admitted for video-EEG monitoring, either as a part of a presurgical evaluation of medically intractable epilepsy or for diagnosis and clarification of their paroxysmal symptoms, we identified 10 patients with ictal hypersalivation as a prominent manifestation of complex partial seizures. We reviewed the clinical features, scalp-sphenoidal video-EEG monitoring, intracarotid amytal (Wada) testing, hippocampal volumetric magnetic resonance imaging (MRI), and fluorodeoxyglucose-positron emission tomography (FDG-PET) scans of these patients. RESULTS: Of the 10 patients with ictal hypersalivation, seven patients had nondominant/right TLE, and three patients had dominant/left TLE. All patients had hippocampal atrophy on volumetric MRI. Eight of the 10 patients underwent standard temporal lobectomy with amygdalohippocampectomy (six right, two left). All of the operated-on patients had a seizure-free (Engel class I) outcome, and their increased salivation resolved. Two patients, who did not undergo surgical treatment, continue to have complex partial seizures with increased salivation. CONCLUSIONS: We conclude that increased salivation as a prominent ictal finding in complex partial seizures of temporal lobe origin is more likely to be of nondominant temporal lobe origin. Further studies with larger numbers of patients are needed to replicate this finding.