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Purpose: To study if one can conceptualize the scalp ictal onset pattern through analysis of interictal spike domain analysis in temporal lobe epilepsy (TLE)., Methods: Seventy-four patients with unilateral mesial temporal sclerosis (MTS) were categorized into "type A" interictal epileptiform discharges (IEDs) with negativity over infero-lateral scalp electrodes over temporal region and contralateral central region showing positivity; all IEDs other than type A were categorized as type B. The ictal electrographic patterns was termed "focal" when confined to side of MTS, was "regional" when lateralized to the ipsilateral hemisphere; "diffuse" if nonlateralized/localized; and ictal onset contralateral to MTS termed as "discordant.", Results: A total of 377 seizures and 5,476 spikes were studied. These were divided into four types: (1) type A IEDs ipsilateral to MTS (44 patients), (2) type A IEDs bitemporally (16 patients), (3) type A IEDs contralaterally (7 patients) and type B IEDs ipsilaterally, and (4) bilateral type B IEDs (7 patients). The ictal pattern was either focal or regional in 51 of 60 patients (85%) with type A IEDs; it was "diffuse" in 9 patients (15%). Diffuse ictal onset was seen in 12 of 14 (86%) with either ipsilateral/bitemporal type B IEDs. Ictal onset on the opposite hemisphere was noted in 2 (14%)., Conclusions: Type A IEDs signify a focal ictal onset and type B IEDs suggest a diffuse ictal onset in patients with MTS on one side., Significance: Interictal spike domain analysis helps predicting ictal patterns in temporal lobe epilepsy., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2020 by the American Clinical Neurophysiology Society.)

Purpose: To compare the seizure outcome following early and late complete antiepileptic drug (AED) withdrawal following anterior temporal lobectomy (ATL) for mesial temporal lobe epilepsy (MTLE)., Method: All the patients who were seizure free for one year following ATL were offered early or late AED withdrawal. AEDs were discontinued starting at one year in those who opted for early withdrawal. Patients who opted for late withdrawal were continued on single AED for three years following surgery before attempting complete discontinuation., Results: Of the 135 study patients, 65 opted for early AED withdrawal and 70 for late withdrawal. The mean postoperative follow-up duration was 10.4 ± 1.3 (Range, 8-12) years. At three years following surgery, seizure recurrence occurred in 23 (35.4 %) patients in the early withdrawal group and in 10 (14.3 %) patients in late withdrawal group (p = 0.005; relative risk [RR], 2.48; 95 % confidence interval [CI], 1.28-4.80). At last follow-up, 27 (41.5 %) patients in the early withdrawal group and 26 (37.1 %) in late withdrawal group had recurrence (p = 0.60; RR, 1.12, 95 % CI, 0.74-1.70). At last followup, 80 (59.3 %) patients were off AEDs. During the terminal one year, 123 (91 %) patients were seizure free, similar in the two groups., Conclusions: This nonrandomized controlled study suggests that early complete AED withdrawal starting one year following ATL is associated with a higher risk of early seizure recurrence. However, long term seizure outcome is similar in early and late AED withdrawal groups., Competing Interests: Declaration of Competing Interest None of the authors have any conflict of interest related to this work., (Copyright © 2019 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Objectives: To explore the effect of duration of epilepsy and delay in surgery on seizure outcome in patients operated for drug-resistant temporal lobe epilepsy (TLE)., Materials & Methods: A total of 664 consecutive patients who underwent anterior temporal lobectomy (ATL) for TLE from 1995 to 2008 formed the study cohort. We divided them into two, one as seizure-free with or without antiepileptic drugs after ATL as "good outcome" (Engel class I a) and seizures of any type, any time after surgery as "poor outcome." The probability of seizure freedom/seizure recurrence based on the duration of epilepsy was compared using Kaplan-Meier curves, univariate Cox regression survival analysis, and multivariate Cox proportional hazards regression model., Results: A total of 136 children and 528 adults underwent ATL during this period. Mean duration of epilepsy pre-ATL was 17.1 + 9.4 years. At mean follow-up of 8.5 years, 331 patients (49.8%) had good outcome and 333 (50.2%) had poor outcome. The hazard of seizure recurrence linearly increased with duration of epilepsy pre-ATL, from 1.5 (duration of epilepsy, 5-10 years) to 1.9 (duration of epilepsy, 10-15 years) to 2 (duration of epilepsy over 15 years). In addition, encephalitis as antecedent, bilateral mesial temporal sclerosis in MRI, normal histopathology, and spikes in postoperative EEG at 3 months and 1 year predicted poor seizure outcome., Conclusions: "Epilepsy duration" independently predicted both short- and long-term seizure outcome after surgery in TLE. "Lost years" translate into poor seizure outcome after ATL. Therefore, all cases of drug-resistant TLE should be referred to a surgical center at the earliest., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: The success of epilepsy surgery lies in identifying the ictal onset zone accurately. The significance of auras has little been explored on surgical outcome in drug-resistant epilepsy. This study focuses on the clinicopathological correlation of aura(s) and its role in predicting surgical outcome in drug-resistant temporal lobe epilepsy (TLE). We compared surgical outcome in TLE between patients with and without aura and identified the clinico-pathological, radiological and surgical differences between the two groups., Methods: Consecutive patients who underwent presurgical evaluation from January 2009 to December 2014 for drug-resistant TLE who underwent anterior temporal lobectomy (ATL) were included. Patients were followed up at 3months, 12 months and then annually., Results: Among 456 patients, 344(75%) had aura. Multivariate logistic regression showed that prototype EEG pattern at ictal onset (OR 2.12, 95% CI 1.18-3.06, p = 0.012) and right sided epileptogenic zone (OR 1.82 95% CI 1.18-3.78, p = 0.007) were significantly associated with presence of aura. There was no difference in surgical outcome between those with and without aura. But patients with auditory aura (OR 7.28, CI 2.80-18.95, p = 0.0002) and vertiginous aura (OR 3.01, CI 1.55-7.85, p = 0.028) had a poor surgical outcome. Bivariate analysis showed that normal MRI (p = 0.028) and normal/indeterminate pathology (p = 0.001) were significantly more common with auditory/vertiginous auras., Conclusions: Mere presence of aura does not affect outcome after TLE surgery. However, auditory and vertiginous auras are predictors of poor surgical outcome. These patients require more extensive screening for an ictal onset zone beyond standard limits of ATL before surgery., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objectives: To validate concurrent utility of within-scanner encoding and delayed recognition-memory paradigms to ascertain hippocampal activations during task-based memory fMRI., Methods: Memory paradigms were designed for faces, word-pairs and abstract designs. A deep-encoding task was designed comprising of a total of 9 cycles run within a 1.5T MRI scanner. A recall session was performed after 1 h within the scanner using an event-related design. Group analysis was done with 'correct-incorrect' responses applied as parametric modulators in Statistical Parametric Mapping version 8 using boot-strap method to enable estimation of laterality indices (LI) using custom anatomical masks involving the medio-basal temporal structures., Results: Twenty seven subjects with drug-resistant mesial temporal lobe epilepsy due to hippocampal sclerosis (MTLE-HS) [17 patients of left-MTLE and 10 patients of right-MTLE] and 21 right handed age-matched healthy controls (HC) were recruited. For the encoding paradigm blood oxygen level dependent (BOLD) responses in HC demonstrated right laterality for faces, left laterality for word pairs, and bilaterality for design encoding over the regions of interest. Both right and left MTLE-HS groups revealed left lateralisation for word-pair encoding, bilateral activation for face encoding, with design encoding in right MTLE-HS demonstrating a left shift. As opposed to lateralization shown in controls, group analysis of cued-recall BOLD signals acquired within scanner in left MTLE-HS demonstrated right lateralization for word-pairs with bilaterality for faces and designs. The right MTLE-HS group demonstrated bilateral activations for faces, word-pairs and designs., Conclusion: Recall-based fMRI paradigms indicate hippocampal plasticity in MTLE-HS, maximal for word-pair associate recall tasks., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objective: To study the long-term outcome following seizure recurrence on antiepileptic drug (AED) withdrawal after anterior temporal lobectomy for mesial temporal lobe epilepsy., Methods: We retrospectively studied the AED profile of patients who had a minimum of 5 years of postoperative follow-up after anterior temporal lobectomy for mesial temporal lobe epilepsy. Only those patients with hippocampal sclerosis or normal MRI were included. AED withdrawal was initiated at 3 months in patients on ≥2 drugs and at 1 year for patients on a single drug., Results: Three hundred eighty-four patients with median postoperative follow-up of 12 years (range, 7-17 years) were included. Of them, 316 patients (82.3%) were seizure-free during the terminal 1 year. AED withdrawal was attempted in 326 patients (84.9%). At last follow-up, AEDs were discontinued in 207 patients (53.9%). Seizure recurrence occurred in 92 patients (28.2%) on attempted withdrawal. After a median postrecurrence follow-up of 7 years, 79 (86%) of them were seizure-free during the terminal 2 years. AEDs could be stopped in 17 patients (18.5%) and doses were reduced in another 57 patients (62%). Patients with febrile seizures, normal postoperative EEG at 1 year, and duration of epilepsy of <20 years (FND20 score) had 17% risk of seizure recurrence on attempted AED withdrawal. We also formulated a score to predict the chances of AED freedom for the whole cohort., Conclusion: Patients with seizure recurrence on AED withdrawal have good outcome with 86% becoming seizure-free and 18% becoming drug-free after initial recurrence. A FND20 score helps in predicting recurrence on AED withdrawal., (© 2018 American Academy of Neurology.)

Purpose: To determine the factors predicting seizure outcome in children who underwent anterior temporal lobectomy (ATL) for drug-resistant temporal lobe epilepsy (TLE)., Methods: Among the 664 patients who underwent ATL for TLE from 1995 to 2008, there were 134 children. "Excellent" outcome in them was defined as seizure freedom during the entire follow-up (Engel class I a); "good outcome", if in remission last 2 years, and the rest as "unfavorable outcome". To identify the potential predictors of seizure recurrence, the attributes of recurred and non-recurred groups was compared by univariate and multivariate analysis., Results: Of the 134 children, at a mean post-operative follow-up of 8.1 years, there were 82 (61.1%) with excellent outcome and 26 (19.4%) with good outcome (category-1; seizure-free, 80.6%). Drugs could be successfully withdrawn in 69 (63.9%). 26 patients (22.4%) had seizure recurrence, (category-2, treatment/surgical failure).Whereas, of the 530 adults who underwent ATL during this time period, only 46.8% never had seizures (category-1) and 53.2% had seizure recurrence in the form of acute post-operative seizures or auras or habitual or non-habitual seizures (category-2).The hazard of seizure recurrence in children increased with positive family history of seizures and /or epilepsy, normal neuroimaging, spikes in post-operative EEG at 3-months, normal histopathology and duration of epilepsy ≥5 years., Conclusions: The information on the predictive factors causing seizure recurrence/freedom in children with drug-resistant TLE is important in surgical selection. Surgery for pediatric TLE results in favorable outcome, hence one should subject children for resective surgery at the earliest especially in lesions known to cause refractoriness., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Aim: To study the clinical, electrophysiological and imaging characteristics of patients with unilateral mesial temporal lobe epilepsy (MTLE) with contralateral ictal onset on scalp EEG, viz. 'burned-out hippocampus' syndrome (MTLE-BHS)., Methods: MTLE-BHS was defined as TLE with unilateral hippocampal sclerosis (HS) without any dual pathology on MRI and contralateral ictal onset on scalp EEG, unlike in classical hippocampal sclerosis (HS). Consecutive "MTLE-BHS" patients evaluated at our Centre for Comprehensive Epilepsy Care from January 2005 to July 2014 were studied. Twenty-five cases of classic MTLE-HS operated during the same period were also analyzed for comparison., Results: Seventeen patients were diagnosed to have MTLE-BHS. Mean age of seizure onset was 9.5±7.7years and the mean duration of epilepsy was18.2±7.3years. Epigastric aura was more common in MTLE-HS and fear, secondary generalized seizures and temporal polar changes on MRI were more prevalent in the MTLE-BHS subgroup. In the latter group, five (29%) exhibited seizure semiology and 2 (12%) had interictal discharges discordant to the side of MTS. Eight (47%) patients in the MTLE-BHS sub-group had normal medial temporal volume on Scheltens scale. Eight patients among MTLE-BHS underwent surgery (4 following intracranial monitoring that localized to the side of HS) with Engel class I outcome at 1year follow-up in 6 and Engel class II outcome in 2., Conclusion: Attenuation of ipsilateral fast ictal rhythms on scalp EEG as well as neocortical changes are likely to be deterministic factors for MTLE-BHS as opposed to the severity of hippocampal atrophy. Considering good post-operative outcomes, intracranial monitoring for surgical selection is not mandatory in MTLE-BHS despite discordant semiology and ictal onset, in the presence of inter-ictal, functional imaging and neuropsychology data concordant to the side of HS., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: This study aimed to compare the memory outcome following left anterior temporal lobectomy (ATL) between patients with a failed Wada test and patients who passed the Wada test., Methods: From 1996 to 2002, we performed the Wada test on all patients with unilateral left mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) and concordant electroclinical data before ATL. We used a 12-item recognition paradigm for memory testing and awarded a score of +1 for each correct response and -0.5 for each incorrect response. No patient was denied surgery on the basis of Wada scores. We assessed cognitive and memory functions using the Wechsler Adult Intelligence Scale and the Wechsler Memory Scale preoperatively and at one year after ATL. We compared the number of patients who showed decline in memory scores, as per the published reliable change indices, between the patients with a failed Wada test and the patients who passed the Wada test., Results: Out of the 116 eligible patients with left MTLE-HS, 88 underwent bilateral Wada test, while 28 underwent ipsilateral Wada test. None of them developed postoperative amnesia. Approximately, one-third of patients with a failed Wada memory test when the failure was defined as a contralateral score of <4, as an ipsilateral score of >8, and as an asymmetry score of <0. The patients with Wada memory failure had a longer pre-ATL duration of epilepsy (p<0.003). The memory and quality-of-life outcomes did not differ between the group with a failed Wada memory test and the group who passed the Wada memory test. The results remained the same when analyses were repeated at various other cutoff points., Conclusion: The patients with left MTLE-HS with concordant electroclinical, MRI, and neuropsychological data should not be denied ATL solely on the basis of Wada memory test results., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Purpose: Whether Meyer's loop (ML) tracking using diffusion tensor imaging tractography (DTIT) can be utilized to avoid post-operative visual field deficits (VFD) after anterior temporal lobectomy (ATL) for drug-resistant temporal lobe epilepsy (TLE) using a large cohort of controls and patients. Also, we wanted to create a normative atlas of ML in normal population., Methods: DTIT was used to study ML in 75 healthy subjects and 25 patients with and without VFD following ATL. 1.5T MRI echo-planar DTI sequences with DTI data were processed in Nordic ICE using a probabilistic method; a multiple region of interest technique was used for reconstruction of optic radiation trajectory. Visual fields were assessed in patients pre- and post-operatively., Results: Results of ANOVA showed that the left ML-TP distance was less than right across all groups (p = 0.01). The average distance of ML from left temporal pole was 37.44 ± 4.7 mm (range: 32.2-46.6 mm) and from right temporal pole 39.08 ± 4.9 mm (range: 34.3-49.7 mm). Average distance of left and right temporal pole to tip of temporal horn was 28.32 ± 2.03 mm (range: 26.4-32.8 mm) and was 28.92 ± 2.09 mm, respectively (range: 25.9-33.3 mm). If the anterior limit of the Meyer's loop was ≤38 mm on the right and ≤35 mm on the left from the temporal pole, they are at a greater risk of developing VFDs., Conclusions: DTIT is a novel technique to delineate ML and plays an important role in planning surgical resection in TLE to predict post-operative visual performance and disability., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Objective: To study the usefulness of the Wada test for predicting seizure outcome following anterior temporal lobectomy (ATL)., Methods: From 1996 to 2002, all patients with left mesial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS) and selected patients with right MTLE-HS underwent the Wada test before ATL at our center. Patients were selected for ATL on the basis of unilateral HS on MRI and concordant electro-clinical data. Twelve-item recognition paradigm was used for Wada memory testing. Score of +1 was awarded for a correct response and -0.5 for an incorrect response. We defined Wada failure as a contralateral score of <5, ipsilateral score of >8, and difference score of <0. No patient was denied surgery based on the Wada results. Means of the three scores were compared between seizure free and non-seizure free patients. Sensitivity, specificity and receiver operator characteristic curves of various scores for predicting seizure outcome were calculated., Results: 151 patients (129 left MTLE; mean age: 27.80±8.72 years) formed the study group. At mean postoperative follow-up of 6.4±2.0 years, 127 patients were seizure free. Mean contralateral score was lower in the seizure-free group (7.15±3.07 vs. 8.71±4.13; p<0.001) while ipsilateral and difference scores were similar between the two seizure outcome groups. Areas under the curves for contralateral, ipsilateral and difference scores for predicting seizure-free outcome were 0.49, 0.58 and 0.59, respectively, suggesting its modest usefulness in individual patients. Results remained same when the analysis was restricted to left MTLE patients., Conclusions: Wada test has limited usefulness for predicting seizure outcome following ATL., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The human major vault protein (MVP) has been implicated in the development of drug resistance in cancer cells. Over expression of MVP has also been reported in brain tissue samples from antiepileptic drug (AED)-resistant human focal epilepsies. To investigate the relationship between single nucleotide polymorphisms (SNPs) involving the MVP gene and AED-resistance, we compared the distribution of three SNPs in the MVP gene, rs4788187, rs3815824 and rs3815823, among 220 patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) (prototype of AED-resistant epilepsy syndrome), 201 patients with juvenile myoclonic epilepsy (JME) (prototype of AED-responsive epilepsy syndrome) and 213 ethnically matched non-epilepsy controls. All the patients and controls were residents of the South Indian state of Kerala for more than three generations. We did not find any significant difference in allele and genotypic frequencies of the studied SNPs between AED-resistant and AED-responsive cohorts, and between AED-resistant and AED-responsive cohorts independently and pooled together when compared with the controls. We conclude that rs4788187, rs3815824, rs3815823 variants of the MVP gene are associated neither with predisposition for epilepsy nor with AED-resistance in the population that we have studied. Our results suggest the need for further research into the link between MVP and AED-resistance., (Copyright © 2013 Elsevier B.V. All rights reserved.)

To critically assess the value of material-specific memory deficits in lateralizing temporal lobe dysfunction preoperatively, we compared the neuropsychological data of 50 consecutive patients with unilateral mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS; right: 31, left: 19) with those of 50 age- and education-matched healthy control subjects. On case-control comparison, both the subcohorts with left and right MTLE-HS performed poorly on intelligence tests, in addition to individual memory tests. However, comparison of the verbal and visual memory functions between subcohorts with right and left MTLE-HS revealed that learning trials and delayed word list recall were the only tests that hypothesized left temporal lobe dysfunction. We conclude that material-specific memory deficits are largely test driven, but there is a lateralizing role for task-specific deficits in left MTLE-HS. Although neuropsychological data help to define baseline neuropsychological impairment, caution should be exercised in interpreting the lateralizing value of material-specific memory deficits prior to surgery., (© 2013.)

Utilizing a questionnaire, we inquired about the self-perceived sexual behavior of 50 married males with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) before and after anterior temporal lobectomy (ATL) and compared the results with those of 50 age-matched healthy married males. The sexual desire and satisfaction of the patients were poor when compared to the controls. Although a majority of the sexual domains improved following ATL, even after a median duration of five years, the sexual status of the patients did not match with that of the controls. Those who, after ATL, were seizure free, had one or no antiepileptic drug (AED) and had an EEG without epileptiform abnormalities achieved a better sexual outcome. We conclude that sexual dysfunction is frequent in male patients with MTLE-HS. They require preoperative assessment to identify their sexual inadequacies as well as counseling about the expected post-ATL sexual outcome. Discontinuation of enzyme-inducing AEDs facilitates post-ATL improvement in sexual function., (Copyright © 2012 Elsevier Inc. All rights reserved.)

We compared the allele and genotype frequencies of SCN1A SNP rs3812718 between patients with MTLE-HS of south Indian ancestry with and without febrile seizures (FS) and with ethnically matched controls. While we observed no significant difference in allele and genotype frequencies of rs3812718 between MTLE-HS patients with and without FS, A allele and AA genotype were overrepresented in MTLE-HS patients when compared to controls. We conclude that in the population studied, although rs3812718 polymorphism increases the susceptibility to MTLE-HS, this is not by increasing the susceptibility to FS., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Objective: The utility of sphenoidal electrodes (SPh) in analyzing interictal epileptiform discharges (IEDs) and ictal electrography remains controversial, despite its widespread use., Methods: One hundred and twenty-two consecutive patients with presumed temporal lobe epilepsy (TLE) who underwent presurgical evaluation were prospectively studied. SPh and Silverman's electrodes were placed, in addition to routine electrodes in 10-20 international system. IEDs and ictal electroencephalography (EEG) were analyzed separately in bipolar and referential montages. The proportion of patients selected for surgery after adjusting for SPh placement based on the earlier ictal onset and IEDs were analyzed., Results: Of the 8701 IEDs in SPh, only 65% were seen over the scalp bipolar montage; 1392 (16%) IEDs were confined to SPh electrodes, and were not seen at scalp bipolar montage (p<0.001). Spike amplitudes were highest at SPh (p<0.001). Of the 592 seizures analyzed, 62 (61%) had simultaneous SPh and scalp onset, while in 26 (25%) SPh onset preceded the scalp., Conclusions: Out of the 35 patients with unilateral mesial temporal sclerosis (MTS) with additional neocortical changes and/or non-lateralized bitemporal IEDs and/or diffuse ictal onset (group 1), 27 were selected for surgery (77%). About 7% was selected for surgery in this group by SPh placement. Also, in patients with bilateral MTS (group 2), 25% (5/20) were chosen for anterior temporal lobectomy, SPh provided an additional benefit in 11% (p<0.001). Patients with normal magnetic resonance imaging (group 3) and temporal plus epilepsy (group 4) had a lower surgical yield, only 12% and 9.5% could undergo surgery. They were denied surgical candidacy with SPh (p<0.001)., Significance: One-third of patients after SPh placement were selected for resective surgery obviating the need for invasive monitoring. The maximum yield was noted in unilateral MTS (associated with additional neocortical features or non-lateralized bilateral temporal interictal IEDs or diffuse ictal onset in scalp EEG) and in bilateral MTS. Those with normal MRI/temporal plus epilepsy could be excluded from direct resective surgery., (Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Introduction: Failure to identify the association antiepileptic drug (AED)-resistant temporal lobe epilepsy (TLE) with idiopathic generalized epilepsy (IGE) can interfere with decision for anterior temporal lobectomy (ATL) and prediction of post-ATL seizure outcome., Methods: Out of the 664 consecutive patients who underwent ATL between March 1995 and December 2007, 12 (1.8%) had coexisting IGE. The decision for ATL was made after a thorough discussion in the multidisciplinary patient management conference based upon the concordance between the clinical, electroencephalographic and magnetic resonance imaging data. All of them underwent epilepsy surgery for AED-resistant TLE., Results: In seven of the 12 patients, IGE was not identified until post-ATL. During a median follow-up period of 8.5 years, 8 of our 12 patients were seizure-free; the remaining 4 patients only had infrequent myoclonus. In two them, AEDs were discontinued; others were on montherapy for IGE., Conclusions: Our study highlights the rare association of IGE with TLE, the most common AED-resistant focal epilepsy syndrome. As the seizure outcome following ATL is similar in AED-resistant TLE patients with and without IGE, their co-existence is not a contraindication for ATL. Future studies should explore the molecular genetic basis of the rare association between these two epilepsy syndromes., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Objective: To assess the value of postoperative EEG in predicting seizure outcome and seizure recurrence following antiepileptic drug (AED) withdrawal in patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS)., Methods: We studied 262 consecutive patients with MTLE-HS with serial EEGs at 3 months, and at 1, 2, and 3 years after anterior temporal lobectomy (ATL), and considered the presence of interictal epileptiform discharges (IED) as abnormal. We attempted AED withdrawal in all seizure-free patients. We defined favorable outcome as freedom from seizures/auras during the entire follow-up period (outcome 1) and during terminal 1-year follow-up (outcome 2)., Results: During mean follow-up period of 7.6 (range 5-12) years, 129 (49.2%) patients had favorable outcome 1 and 218 (83.2%) had favorable outcome 2. Of 225 (85.9%) patients in whom AED withdrawal was attempted, 61 (27.1%) had seizure recurrence. Compared to patients with normal EEG, those with IED on 1-year post-ATL EEG had a 3-fold increased risk for unfavorable outcome 1 and 7-fold increased risk for unfavorable outcome 2. The patients in whom all the 4 EEGs were abnormal had 9-fold odds for unfavorable outcome 1 and 26-fold odds for unfavorable outcome 2. An abnormal EEG at 1 year increased the risk of seizure recurrence following AED withdrawal by 2.6-fold., Conclusions: Post-ATL EEG predicts seizure outcome and seizure recurrence following AED withdrawal. Serial EEGs predict outcome better than single EEG. This information will be helpful in counseling of patients after ATL, and in making rational decisions on AED withdrawal.

Purpose: The existing data on the implications of the characteristics of seizures that recur during the first year following epilepsy surgery on subsequent seizure outcome are conflicting. We investigated the impact of recurrent seizures in the first postoperative year and their attributes on long-term seizure outcome., Methods: We studied the postoperative courses of 492 patients who had completed two or more years of follow-up after temporal lobe resective epilepsy surgery. We used Kaplan-Meier survival curves to define long-term seizure outcome and assessed the predictive value of recurrent seizure characteristics on the outcome by univariate and multivariate proportional hazards regression models., Key Findings: In our patients, seizure recurrences during the first postoperative year, irrespective of the attributes of recurrent seizures (such as provoked vs. unprovoked, and timing and number of recurrences), imparted fourfold to sevenfold increased hazards for continued seizures beyond the first postoperative year. Although patients with complex partial seizures with or without secondary generalized tonic-clonic seizures (CPS/GTCS) had a sixfold increased risk, those with auras alone had only a borderline risk for seizures beyond the first postoperative year. In the multivariate model, CPS/GTCS as the predominant seizure type and three or more seizure recurrences during the first postoperative year independently predicted unfavorable long-term seizure outcome., Significance: Our study provides valuable information that is helpful in prognosticating and counseling patients, and in making rational decisions on the withdrawal of antiepileptic drugs following surgery. Our findings enhance the general understanding of the etiopathogenesis of surgical failure., (Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.)

Purpose: To investigate the feasibility of antiepileptic drug (AED) withdrawal following anterior temporal lobectomy (ATL) and to identify the predictors of post withdrawal seizure recurrence., Methods: We prospectively studied the seizure outcome of 310 consecutive patients, who were followed for a minimum of 5 years following ATL for medically refractory mesial temporal lobe epilepsy. In seizure-free patients, we started AED tapering at 3 months in patients on duotherapy/polytherapy and at 1 year after ATL for those on monotherapy. We used Kaplan-Meier survival curves to estimate the probability of seizure recurrence and complete AED discontinuation, and compared the attributes of recurred and nonrecurred groups of patients by univariate and multivariate logistic regression analyses., Key Findings: Immediately after ATL, 197 patients were on duotherapy and 101 were on monotherapy. We attempted AED withdrawal in 258 patients (83.2%). Sixty-four patients (24.8%) had seizure recurrence while reducing AEDs. Of 26 patients who had seizure recurrence after complete AED withdrawal, 24 (92.3%) again became seizure-free after restarting the AEDs. Absence of hippocampal sclerosis on pathologic examination and abnormal postoperative electroencephalogram (EEG) predicted seizure recurrence on multivariate analysis. At the end of follow-up duration of 8.0 ± 2.0 years, 163 patients (52.6%) were AED free. The cumulative probability of achieving AED-free status among patients in whom AED withdrawal was attempted, was 44% at fourth year, 65% at sixth year, 71% at eighth year, and 77% at 10th year after ATL., Significance: AED withdrawal can be safely attempted following successful ATL. Seizure recurrences are few and can be managed easily., (Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.)

Purpose: To assess the prevalence and attributes of atypical language lateralization (ALL) in patients with left mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS)., Methods: We recruited consecutive patients with left MTLE-HS, who had undergone resective surgery and had pathologically proven HS. Based on the Wada test, language lateralization was classified into typical (left hemispheric) or atypical (right hemispheric or codominant). We assessed the attributes of patients with ALL using univariate and multivariate analyses., Results: Of 124 patients with left MTLE-HS, 23 (18.5%) had ALL. ALL occurred more frequently in patients with severe initial precipitating injury (IPI), early onset of epilepsy, and a short latent period between IPI and onset of habitual seizures. ALL was more common in patients with bitemporal and extratemporal interictal epileptiform discharges (IEDs) on electroencephalogram (EEG) and extratemporal changes on magnetic resonance imaging (MRI). On multivariate analyses, the age at onset of habitual seizures <6 years, atypical IPI, nonunilateral temporal IEDs, and extratemporal MRI abnormalities independently predicted ALL. The likelihood of ALL was very low ( approximately 1%) when all of these four risk factors were absent, whereas it was very high (>95%), if any three or all four of them were present., Conclusions: ALL occurs in one-fifth of patients with left MTLE-HS. ALL is more frequent in those with structural or functional extrahippocampal involvement and early onset of epilepsy interrupting the development of normal language networks. Because ALL is uncommon in those with damage/dysfunction restricted to the hippocampus, the hippocampus itself may have only a limited role in determining language lateralization.

To define the determinants of impaired facial emotion recognition (FER) in patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS), we examined 76 patients with unilateral MTLE-HS, 36 prior to antero-mesial temporal lobectomy (AMTL) and 40 after AMTL, and 28 healthy control subjects with a FER test consisting of 60 items (20 each for anger, fear, and happiness). Mean percentages of the accurate responses were calculated for different subgroups: right vs. left MTLE-HS, early (age at onset <6 years) vs. late-onset, and before vs. after AMTL. After controlling for years of education, duration of epilepsy and number of antiepileptic drugs (AEDs) taken, on multivariate analysis, fear recognition was profoundly impaired in early-onset right MTLE-HS patients compared to other MTLE patients and control subjects. Happiness recognition was significantly better in post-AMTL MTLE-HS patients compared to pre-AMTL patients while anger and fear recognition did not differ. We conclude that patients with right MTLE-HS with age at seizure onset <6 years are maximally predisposed to impaired fear recognition. In them, right AMTL does not further worsen FER abilities. Longitudinal studies comparing FER in the same patients before and after AMTL will be required to refine and confirm our cross-sectional observations.

Purpose: To investigate the electro-clinical significance of premature accumulation of corpora amylacea (CoA) in the resected hippocampus of patients with medically refractory mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS)., Methods: We compared the clinical and EEG characteristics, and post-operative seizure outcome of 373 (mean age 29.4 years, range 7-55 years) surgically treated MTLE-HS patients with (MTLE-HS-CoA(+), n=129 [34.5%]) and without (MTLE-HS-CoA(-), n=244 [65.5%]) CoA., Results: Age at surgery was significantly higher and duration of epilepsy before surgery was significantly longer for MTLE-HS-CoA(+) patients compared to MTLE-HS-CoA(-) patients. Although the distribution of interictal epileptiform EEG abnormalities did not differ, type 1 ictal EEG pattern was more frequent in MTLE-HS-CoA(+) patients. Among the 21 patients with major interictal psychosis detected prior to epilepsy surgery, 19 (90.5%) belonged to MTLE-HS-CoA(+) group. Schizophrenia-like psychosis was most prevalent. The post-operative seizure-free outcome was comparable, but significantly more MTLE-HS-CoA(-) patients were free of antiepileptic drugs., Conclusions: Overall, our observations support the hypothesis that the pathological process in MTLE-HS is progressive. MTLE-HS-CoA(+) patients are predisposed to increased psychiatric morbidity. In vivo detection of hippocampal CoA accumulation in the future will help us to understand the neurobiological significance of this phenomenon.

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.

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.

Purpose: Very little reliable information is available regarding the role of anterior temporal lobectomy (ATL), optimal presurgical evaluation strategy, post-ATL seizure outcome, and the factors that predict the outcome in patients with medically refractory temporal lobe epilepsy (TLE) and normal high-resolution magnetic resonance imaging (MRI). To be cost-effective, epilepsy surgery centers in developing countries will have to select candidates for epilepsy surgery by using the locally available technology and expertise., Methods: We reviewed the electroclinical and pathological characteristics and seizure outcome of 17 patients who underwent ATL for medically refractory TLE after being selected for ATL based on a noninvasive selection protocol without the aid of positron emission tomography (PET) or single-photon emission computed tomography (SPECT), despite a normal preoperative high-resolution MRI., Results: Seven (41%) patients achieved an excellent seizure outcome; five of them were totally seizure free. An additional five (29%) patients had >75% reduction in seizure frequency. The following pre-ATL factors predicted an excellent outcome: antecedent history of febrile seizures, strictly unilateral anterior temporal interictal epileptiform discharges (IEDs), and concordant type 1 ictal EEG pattern. All the five patients with pathologically verified hippocampal formation neuronal loss were seizure free. The presence of posterior temporal, bilateral temporal, and generalized IEDs portended unfavorable post-ATL seizure outcome., Conclusions: A subgroup of patients destined to have an excellent post-ATL outcome can be selected from MRI-negative TLE patients by using history and scalp-recorded interictal and ictal EEG data. The attributes of these patients are antecedent history of febrile seizures, strictly unilateral anterior IEDs, and concordant type 1 ictal EEG pattern., (Copyright 2004 International League Against Epilepsy)

Temporal lobe epilepsy (TLE) associated with mesial temporal sclerosis (MTS), mesial TLE (MTLE), is the commonest medically refractory adult epilepsy syndrome. Corpora amylacea (CoA) have been shown to be a marker of MTS. We compared 9 patients with MTS who had dense deposition of CoA in their hippocampi with 25 patients with MTS who did not have CoA. The patients with CoA were significantly older and they showed a trend towards having a significantly longer duration of epilepsy. The postoperative seizure outcome at 2 years was not different in the 2 groups. Our results could indicate the progressive nature of the pathology of MTS, probably indicating excitotoxic damage due to recurrent seizures, but they need to be verified by clinicopathological correlation among a larger number of patients with MTLE.

The selection of patients with medically refractory temporal lobe epilepsy (TLE) for surgery depends on the concordance of data from clinical, imaging and electroencephalographic evaluation. Though clinical examination is often normal, emotional facial paresis has been described in patients with TLE. Utilizing a well-characterized group of mesial TLE (MTLE) patients, who have achieved excellent seizure outcome following anterior temporal lobectomy with amygdalohippocampectomy (ATL), we investigated the prevalence, predictive value and associations of emotional facial paresis. When compared to 8 out of 50 control subjects (16%), 36 out of 50 MTLE patients (72%) exhibited unilateral emotional facial paresis; the difference was highly significant (P<0.0001). The presence of contralateral emotional facial paresis correctly predicted the side of ATL in 86.1% patients. The occurrence of emotional facial paresis was significantly associated with longer duration of epilepsy prior to ATL and left ATL. Our observations confirm that emotional facial parersis contralateral to the side of mesial temporal sclerosis (MTS) is a valuable localizing sign in correctly predicting the epileptogenic temporal lobe. We hypothesize that the presence of an intact right hemisphere and pathological changes more extensive than MTS may be required for emotional facial paresis to readily manifest.

This study illustrates the outcome and cost-effectiveness of anterior temporal lobectomy (ATL) among patients with medically refractory temporal lobe epilepsy (TLE) treated in an epilepsy center in Kerala, South India. Patients for ATL were selected on the basis of a noninvasive protocol comprising clinical, interictal scalp electroencephalogram (EEG), magnetic resonance imaging, and ictal video-EEG data. The authors compared the outcome and direct cost of 119 patients (mean age, 25.6 years; mean duration of epilepsy before ATL, 16.1 years) who have completed at least 1 year follow-up after ATL with 71 refractory TLE patients (mean age, 27.1 years; mean duration of epilepsy, 15.4 years) who did not undergo ATL. Patients in the study who underwent ATL had a 70% likelihood of becoming seizure-free after ATL and a 30% chance of being completely off of antiepileptic drug treatment within 3 years after ATL. The out-of-pocket one-time payment for ATL (including presurgical evaluation) in this setup is Indian Rupees (INR) 47,000 (US$ 1,200). The total direct medical cost of caring for TLE patients aged 26 to 60 years would be INR 200,000 (US$ 5,000). Patients freed from seizures often can be better employed and achieve an improved quality of life. It is concluded that ATL for refractory TLE is a more cost-effective option than continued medical treatment. Epilepsy surgery is not only possible in a developing country but can also be undertaken in a cost-effective way.