After Anterior Temporal Lobectomy Research Articles

Relationship Between Pre-Operative Clinical Characteristics With Changes In Post-Operative Memory Scores On Temporal Lobe Epilepsy Patient

Background: Most temporal lobe epilepsy (TLE) will become seizure-free after anterior temporal lobectomy (ATL) surgery but often result in cognitive decline, specifically in verbal or visual memory. Objective: This study examined the relationship between several demographic characteristics and pre-operative clinical conditions with changes in pre-post surgical memory of TLE patients. Methods: This study used a retrospective cohort in which the subjects were TLE patients who had undergone ATL surgery at Kariadi Hospital or Telogorejo Hospital, Semarang. Demographic variables include the age of onset, duration of illness, level of education, and clinical variables include seizure frequency, EEG waveform, number of AED, lesion site, and IQ score. Results: Memory re-examination was conducted on TLE patients who had undergone surgery between 2018 and 2021, with 55 subjects who fulfilled the criteria. Characteristics of the subjects were male 31(56%) males, 38% Senior High School education, the mean age of onset was 13,87±6,899, age at surgery was 27,67±9,802, 21 (39%) normal pres-surgical EEG waveform, 31 (56%) lesion on the left and the most frequent seizures occurred in 36 subjects (65%). Statistical test results showed a significant relationship between age of onset and changes in verbal memory recognition scores (p 0.044), lesion side with changes in verbal memory task scores (p 0.018), recall (p 0.005), recognition (0.008), and IQ scores with changes in visual memory construction recall (p 0.041) Conclusion: Age of onset, lesion side, and IQ score characteristics were related to the changes in memory scores between pre- and post-operative anterior temporal lobectomy in TLE patients.

Causal Network Connectivity Patterns in Autism Spectrum Disorder Based on the Liang-Kleeman Information Flow Theory

To explore the structural and functional reorganization of contralateral hippocampus in patients with unilateral mesial temporal lobe epilepsy (mTLE) who achieved seizure-freedom after anterior temporal lobectomy (ATL).We obtained high-resolution structural MRI and resting-state functional MRI data in 28 unilateral mTLE patients and 29 healthy controls. Patients were scanned before and three and 24 months after surgery while controls were scanned only once. Hippocampal gray matter volume (GMV) and functional connectivity (FC) were assessed.No obvious GMV changes were observed in contralateral hippocampus before and after successful surgery. Before surgery, ipsilateral hippocampus showed increased FC with ipsilateral insula (INS) and temporoparietal junction (TPJ), but decreased FC with widespread bilateral regions, as well as contralateral hippocampus. After successful ATL, contralateral hippocampus showed: (1) decreased FC with ipsilateral INS at three months follow-up, without further changes; (2) decreased FC with ipsilateral TPJ, postcentral gyrus and rolandic operculum at three months, with an obvious increase at 24 months follow-up; (3) increased FC with bilateral medial prefrontal cortex (MPFC) and superior frontal gyrus (SFG) at three months follow-up, without further changes.Successful ATL may not lead to an obvious structural reorganization in contralateral hippocampus. Surgical manipulation may lead to a transient FC reduction of contralateral hippocampus. Increased FC between contralateral hippocampus and bilateral MPFC and SFG may be related to postoperative functional remodeling.

Prognostic value of histopathologic pattern for long-term surgical outcomes of 198 patients with confirmed mesial temporal lobe epilepsy

Hippocampal sclerosis (HS) is the most common neuropathologic findings in patients with intractable temporal lobe epilepsy (TLE). The international league against epilepsy has proposed a new classification of HS based on pyramidal cell loss on different subfields to facilitate the study of HS pathology in patients after anterior temporal lobectomy (ATL), and the influence of these HS patterns on the prognosis of patients with TLE is contradictory. This study aims to investigate the relationship between different HS subtypes and postoperative seizure outcomes for intractable patients with TLE. From January 2008 to December 2018, we retrospectively reviewed 198 TLE patients with ATL surgery, and all patients had a complete preoperative evaluation, a specimen of hippocampal tissue after surgery, cognitive test after surgery, and more than 2 years of postoperative follow-up. The main findings were as follows: 1) temporal neocortical gray matter heterotopia were more common in the no-HS group; 2) HS type 1 was associated with a longer duration of epilepsy; 3) history of meningitis was the independent predictor of HS type 1; 4) no-HS patients experienced worse postoperative seizure outcomes than those with HS type1 and type 2, whereas no difference in seizure outcomes was obtained between HS type 1 and type 2; 5) no-HS patients were at increased risk for verbal memory decline after left hippocampal resection. The HS subtypes were associated with the prognosis of patients with TLE, and other variables were the predictors of different HS types. `Further study was to identify the HS subtypes by noninvasive evaluation to approve better postoperative outcomes.

Anxiety and depressive symptoms long after mesial temporal epilepsy surgery: A prospective study

BackgroundAnxiety and depressive symptoms are prevalent in patients with refractory mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) before and after anterior temporal lobectomy (ATL). Aims(1) To follow the levels of anxiety and depressive symptoms long-term after ATL among patients with refractory MTLE-HS; (2) To identify pre- and postsurgical variables associated with the levels of anxiety and depressive symptoms after surgery. MethodsWe compared the levels of anxiety and depressive symptoms determined by the Hospital Anxiety and Depression Scale (HADS) before and long after ATL (mean 104 months, range 70–130) in 41 consecutive patients refractory MTLE-HS. The last follow-up was between September 2018 and March 2020. We also determined pre- and postsurgical variables independently associated with the HADS scores after surgery. ResultsThe scores of HADS and its subdomains related to anxiety and depression decreased significantly (p < 0.01) after ATL. After multiple linear regressions, the HADS-Anxiety scores before surgery (B = 0.47, CI 95% 0.20 to 0.75, p = 0.001) and at follow-up after surgery (B = 0.07, CI 0.00 to 0.14, p = 0.05) remain independently and positively associated with HADS-Anxiety scores after surgery. The HADS-Depression scores after surgery were independently positively associated with HADS-Depression scores before surgery (B = 0.39, CI 95% 0.10 to 0.76, p = 0.01) and worse seizure control after surgery (B = 1.55, CI 95% 0.23 to 2.87, p = 0.02). ConclusionAnxiety and depressive symptoms in patients with MTLE-HS significantly improved after ATL. Presurgical levels of anxiety and depressive symptoms, respectively, were positively associated with the postsurgical levels of those symptoms. Length of follow-up is associated with anxiety, and worse seizure control is associated with depressive symptoms after ATL. The results have implications for the surgical management of MTLE-HS patients.

Structural and functional reorganization of contralateral hippocampus after temporal lobe epilepsy surgery

ObjectiveTo explore the structural and functional reorganization of contralateral hippocampus in patients with unilateral mesial temporal lobe epilepsy (mTLE) who achieved seizure-freedom after anterior temporal lobectomy (ATL). MethodsWe obtained high-resolution structural MRI and resting-state functional MRI data in 28 unilateral mTLE patients and 29 healthy controls. Patients were scanned before and three and 24 months after surgery while controls were scanned only once. Hippocampal gray matter volume (GMV) and functional connectivity (FC) were assessed. ResultsNo obvious GMV changes were observed in contralateral hippocampus before and after successful surgery. Before surgery, ipsilateral hippocampus showed increased FC with ipsilateral insula (INS) and temporoparietal junction (TPJ), but decreased FC with widespread bilateral regions, as well as contralateral hippocampus. After successful ATL, contralateral hippocampus showed: (1) decreased FC with ipsilateral INS at three months follow-up, without further changes; (2) decreased FC with ipsilateral TPJ, postcentral gyrus and rolandic operculum at three months, with an obvious increase at 24 months follow-up; (3) increased FC with bilateral medial prefrontal cortex (MPFC) and superior frontal gyrus (SFG) at three months follow-up, without further changes. ConclusionsSuccessful ATL may not lead to an obvious structural reorganization in contralateral hippocampus. Surgical manipulation may lead to a transient FC reduction of contralateral hippocampus. Increased FC between contralateral hippocampus and bilateral MPFC and SFG may be related to postoperative functional remodeling.

Brain network alterations of mesial temporal lobe epilepsy with cognitive dysfunction following anterior temporal lobectomy

The aims of this study were to investigate the brain network connectivity alterations of intractable unilateral mesial temporal lobe epilepsy (MTLE) with cognitive dysfunction before and after anterior temporal lobectomy (ATL) using resting-state functional magnetic resonance imaging (rs-fMRI) study and to further observe the correlation between the brain network connectivity with cognitive performance. Fourteen patients with unilateral left MTLE before and after ATL were compared with thirty healthy controls (HCs) on functional connectivity (FC) between resting-state networks (RSNs). The correlation between the neuropsychological tests of patients and abnormal FC was further investigated. When compared with the HCs, patients before surgery showed significantly changed FC between special RSNs. No difference of FC was found between each RSN when patients were compared with the HCs after surgery. Compared with patients before surgery, patients after surgery showed significantly decreased FC between RSNs. Abnormal FC between RSNs significantly correlated with Montreal Cognitive Assessment (MoCA) scores. Our study suggested that dynamic alterations of RSN after ATL in unilateral MTLE may be closely related with seizure generating. However, unchanged FC between RSN before and after ATL may be closely related with cognitive performance. The present findings may help us understand the feature of brain network alterations in patients with left MTLE who became seizure-free following ATL.

Predictors of meaningful improvement in quality of life after temporal lobe epilepsy surgery: A prospective study.

To investigate prospectively the independent predictors of a minimum clinically important change (MCIC) in quality of life (QOL) after anterior temporal lobectomy (ATL) for drug-resistant mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) in Brazilian patients. Multiple binary logistic regression analysis was performed to identify the clinical, demographic, radiologic, and electrophysiologic variables independently associated with MCIC in the Quality of Life in Epilepsy-31 Inventory (QOLIE-31) overall score 1year after ATL in 77 consecutive patients with unilateral MTLE-HS. The overall QOLIE-31 score and all its subscale scores increased significantly (p<0.0001) 1year after ATL. In the final logistic regression model, absence of presurgical diagnosis of depression (adjusted odds ratio [OR] 4.4, 95% confidence interval [CI] 1.1-16.1, p=0.02) and a complete postoperative seizure control (adjusted OR 4.1, 95% CI 1.2-14.5, p=0.03) were independently associated with improvement equal to or greater than the MCIC in QOL after ATL. The overall model accuracy for MCIC improvement in the QOL was 85.6%, with a 95.2% of sensitivity and 46.7% of specificity. These results in Brazilian patients reinforce the external validation of previous findings in Canadian patients showing that presurgical depression and complete seizure control after surgery are independent predictors for meaningful improvement in QOL after ATL, and have implications for the surgical management of MTLE patients.

Gamma Knife radiosurgery for recurrent or residual seizures after anterior temporal lobectomy in mesial temporal lobe epilepsy patients with hippocampal sclerosis: long-term follow-up results of more than 4 years.

Gamma Knife radiosurgery (GKRS) has proven efficacy in the treatment of drug-resistant mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) and is comparable to conventional resective surgery. It may be effective as an alternative treatment to reoperation after failed temporal lobe surgery in patients with MTLE-HS. The purpose of this study was to investigate the efficacy of GKRS in patients with unilateral MTLE-HS who did not achieve seizure control or had recurrent seizures after anterior temporal lobectomy (ATL). Twelve patients (8 males; mean age 35.50 ± 9.90 years) with MTLE-HS who underwent GKRS after failed ATL (Engel Classes III-IV) were included. GKRS targets included the remnant tissue or adjacent regions of the previously performed ATL with a marginal dose of 24-25 Gy at the 50% isodose line in all patients. Final seizure outcome was assessed using Engel's modified criteria during the final 2 years preceding data analysis. A comparison between signal changes on follow-up MRI and clinical outcome was performed. All patients were followed up for at least 4 years with a mean duration of 6.18 ± 1.77 years (range 4-8.8 years) after GKRS. At the final assessment, 6 of 12 patients were classified as seizure free (Engel Class Ia, n = 3; Ic, n = 2; and Id, n = 1) and 6 patients were classified as not seizure free (Engel Class II, n = 1; III, n = 2; and IV, n = 3). Neither initial nor late MRI signal changes after GKRS statistically correlated with surgical outcome. Clinical seizure outcome did not differ significantly with initial or late MRI changes after GKRS. GKRS can be considered an alternative option when the patients with MTLE-HS who had recurrent or residual seizures after ATL refuse a second operation.

An evaluation of lateralizing signs in patients with temporal lobe epilepsy.

Resective epilepsy surgery has been accepted as an effective treatment for patients with medically intractable temporal lobe epilepsy (TLE) to control the seizures and to limit cognitive dysfunction. Complete resection of the epileptic zone, and therefore the success of the surgery, depends on the identification of the seizure focus. Reliable lateralizing semiologic signs, together with other presurgical assessments, are of great importance for an accurate identification of the seizure focus. In this respect, this study evaluated the frequency of semiologic signs in medically intractable temporal lobe epilepsy (TLE) together with the lateralizing values and variations according to the age and gender groups. Two hundred seventy-three seizures of 55 patients of the Adult Epilepsy Monitoring Unit of Gazi University Faculty of Medicine with the diagnosis of medically intractable TLE, whose epileptic foci were detected through noninvasive presurgical procedures and seizures were controlled successfully after anterior temporal lobectomy (ATL), were analyzed retrospectively. Seizure semiologies of the patients were evaluated in terms of lateralizing values, and it was inquired whether age/gender causes any variation. Versive head rotation, unilateral dystonic limb posturing, asymmetric tonic limb posturing, and the combination of unilateral hand automatisms and dystonic posturing were determined as the semiologic signs with the highest lateralizing values (90-100%). While hand automatisms were observed frequently in the group with early seizure-onset age (onset age ≤ 2), asymmetric tonic limb posturing was detected as more frequent in the group with later seizure-onset age (onset age > 2; p < .005). In addition to this, semiologic signs were noted to be different between male and female groups; psychic and autonomic auras and ictal emotional signs were associated with women (p < .005).

Diffusion tensor imaging tractography of Meyer's loop in planning resective surgery for drug-resistant temporal lobe epilepsy

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. 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 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. 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.

Recovery from Emotion Recognition Impairment after Temporal Lobectomy

Mesial temporal lobe epilepsy (MTLE) can be associated with emotion recognition impairment that can be particularly severe in patients with early onset seizures (1–3). Whereas, there is growing evidence that memory and language can improve in seizure-free patients after anterior temporal lobectomy (ATL) (4), the effects of surgery on emotional processing are still unknown. We used functional magnetic resonance imaging (fMRI) to investigate short-term reorganization of networks engaged in facial emotion recognition in MTLE patients. Behavioral and fMRI data were collected from six patients before and after ATL. During the fMRI scan, patients were asked to make a gender decision on fearful and neutral faces. Behavioral data demonstrated that two patients with early onset right MTLE were impaired in fear recognition while fMRI results showed they lacked specific activations for fearful faces. Post-ATL behavioral data showed improved emotion recognition ability, while fMRI demonstrated the recruitment of a functional network for fearful face processing. Our results suggest that ATL elicited brain plasticity mechanisms allowing behavioral and fMRI improvement in emotion recognition.

Memory Performance in Older Adults Before and After Temporal Lobectomy for Pharmacoresistant Epilepsy

Little is known about the effects of epilepsy surgery on memory in older adults. The purpose of this study was to determine if older adults exhibit greater memory decline than younger adults after anterior temporal lobectomy (ATL). Patients 55 years and older at time of surgery (23 left, 14 right ATL, range 55–66 years) were compared to patients age 25–35 years (44 left, 33 right ATL) to assess differences in preoperative to postoperative change in WMS-III index scores. Repeated-measures ANOVAs and ANCOVAs revealed that older patients did not demonstrate greater decline than younger patients across any of the memory indices. Rather, in the left ATL group, older patients showed less decline than younger patients on the Auditory Delayed Memory Index. Similarly, in the right ATL group, older patients showed less decline than younger patients on the Visual Delayed Memory Index. These patterns were also apparent in frequency of individual change. Results provide preliminary evidence that older adults who are good candidates for ATL are not at greater risk for memory decline when measured at 7 months postoperatively.

Editorial: Medial temporal epilepsy

In their article, Hu et al.3 have provided interesting data on the results of the 2 most commonly used approaches for treating medial temporal lobe epilepsy. They performed a meta-analysis comparing the seizure-free and memory (IQ) outcomes after anterior temporal lobectomy (ATL) versus selective amygdalohippocampectomy (SelAH). They found that ATL was more likely to result in seizure freedom than SelAH, although the percentages were similar (71% vs 66%). Fewer studies were available to compare memory outcomes, and there was no difference between the types of surgery in that important outcome measure. Hu and colleagues correctly describe the limitations of this evaluation, including the paucity of data from prospective studies, especially with respect to memory outcomes. Nevertheless, this analysis confirms in a meta-analysis what many epilepsy surgeons have understood: the most commonly performed selective resections of the medial temporal lobes are slightly less likely to result in seizure freedom and do not spare memory function. It should not be surprising that anterior lobectomy should result in somewhat improved seizure-free outcomes compared with the more selective resections. When electrocorticography is used to define the amount of tissue to be resected (so-called tailored approach), it is common to see combined medial and neocortical epileptiform activity.1 Anterior temporal neocortical resection may include some or all of these areas. What is not obvious is why selective resections do not confer an advantage with respect to verbal memory function. It is possible that the track taken through the brain to the medial temporal structures results in as much disruption of memory networks as tissue removal. Recent attempts to avoid damage to the neocortex have focused on the subtemporal approach.2,4 While early reports with small numbers of patients have been encouraging, subsequent evaluations have shown results similar to what is shown in this metaanalysis: that memory deficits may not be spared when direct comparisons are made with other techniques.7 Similarly, preliminary evidence from radiosurgical treatment of the medial temporal lobe indicates that there is a relative sparing of verbal memory.6 A larger series that randomizes patients between standard lobectomy and radiosurgery is underway. Given these results, it is difficult to understand why so many epilepsy surgeons seem to prefer the SelAH procedure. Perhaps it is the seeming elegance of the selective approach, using available technology (frameless stereotactic guidance and microsurgical technique) that is attractive. As the most important determinant of quality of life after epilepsy surgery is seizure freedom,5 the decision on the type of surgery to perform should be based on the best available evidence. As Hu et al. stated in their conclusions, further studies are needed to properly compare these techniques. However, until better data are available, appropriately directed, larger resections seem to have an advantage in the most important aspect of epilepsy surgery, seizure control. (http://thejns.org/doi/abs/10.3171/2013.5.JNS13704)

Atypical neuropsychological profiles and cognitive outcome in mesial temporal lobe epilepsy

Patients with left mesial temporal lobe epilepsy (MTLE) have deficits in verbal memory processes, while patients with right MTLE have visuospatial memory impairment. However, atypical cognitive phenotypes among patients with MTLE may occur. In this study, we analyzed preoperative memory deficits in a cohort of 426 right-handed patients with unilateral MTLE. We also evaluated the cognitive outcome after anterior temporal lobectomy (ATL) of patients with atypical profiles in comparison with those with typical memory profile. We found that 25% of our patients had a typical cognitive profile, with verbal memory deficits associated with left side hippocampal sclerosis (HS) and visuospatial memory deficits associated with right side HS. However, 75% of our patients had atypical memory profiles. Despite these atypical profiles, patients submitted to right ATL had no significant cognitive deficit after surgery. In patients submitted to left ATL, the higher the presurgical scores on verbal memory and naming tests, the higher the cognitive decline after surgery.

Sexual desire and satisfaction after resective surgery in patients with mesial temporal lobe epilepsy with hippocampal sclerosis

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.

Prognostic importance of serial postoperative EEGs after anterior temporal lobectomy

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). 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). 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. 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.

Visual field deficits following anterior temporal lobectomy: Long‐term follow‐up and prognostic implications

The aim of this study was to assess the incidence of mild (<or=90 degrees) versus severe (>90 degrees from vertical) visual field defects (VFDs) in patients after anterior temporal lobectomy (ATL), and their postoperative improvement over time. The angles of postoperative VFDs of 75 patients who underwent ATL were recorded at various time points (1, 2, 6, 12, 18, 24, and 36+ months). Of all 23 patients who came in for their <1 month postoperative appointment, 65% of patients had surgically induced VFDs <90 degrees , whereas 35% had VFDs >90 degrees postoperatively. Patients in the latter group were reported for suspension of their driver's license. However, 38% experienced improvement of their VFD to <90 degrees such that their driver's license could be reinstated. Of patients with any VFD, 18-30% improved on average by a magnitude of 38 degrees within the first year postoperatively. Although 35% of the VFDs that occur following temporal lobe surgery are severe, approximately 38% of these patients (especially those with starting postoperative VFDs closer to the 90 degrees angle) experience some improvement shortly after surgery. This may increase their chances of having their driver's license reinstated.

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.

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.

Wada memory asymmetry scores and postoperative memory outcome in left temporal epilepsy

Memory asymmetry scores are used in intracarotid amobarbital procedure (IAP) to predict memory outcome after anterior temporal lobectomy (ATL) in patients with temporal lobe epilepsy (TLE). Reversed asymmetry (RA) of memory scores occurs in a minority of patients, with better memory performance observed following contralateral injection. Left ATL patients with RA are reported to have poorer postoperative verbal memory outcome. Studies also suggest that dysphasia during language dominant left hemisphere injection may contribute to lower right-sided memory scores seen in RA. To examine the role of dysphasia in RA and investigate the relationship between RA scores and memory outcome after ATL. IAP asymmetry scores and duration of speech arrest following bilateral IAP injection were examined in 50 patients with unilateral left TLE. Postoperative memory outcome was examined in a subset of patients (n=31). Thirty-nine percent of patients had RA on IAP. The duration of speech arrest after left injection was significantly longer in the RA group compared to the expected asymmetry (EA) group. RA was not associated with negative postoperative memory outcome. In left TLE patients, RA of IAP memory scores does not preclude good postoperative memory outcome. Prolonged speech arrest after left injection may lower right side memory scores contributing to misleading RA. Memory asymmetry patterns are sensitive to IAP protocol effects; therefore, RA may not be a robust predictor of memory outcome following left ATL.