Seizure and memory outcome following temporal lobe surgery: selective compared with nonselective approaches for hippocampal sclerosis (original) (raw)
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Seizure, 2005
Objectives: To investigate the effects of the resection of hippocampus and temporal neocortex on postsurgical seizure and memory outcomes in mesial temporal lobe epilepsy (mTLE) patients. Methods: Sixty-eight mTLE patients underwent pre-and postsurgical brain magnetic resonance imaging (MRI). The patients were divided into seizure-free group (SF, N = 54) and non-seizure-free group (NSF, N = 14). The resection length of hippocampus was determined by the difference between presurgical and postsurgical hippocampus lengths in MRIs. The lengths of resected temporal gyri were measured on threedimensional MRI reconstruction. Among SF group, 37 patients performed pre-and postsurgical neuropsychological tests. The postsurgical memory decline (PMD) was calculated by subtracting postsurgical memory score from presurgical one in verbal and visual memory tests. Results: The resection length of hippocampus in SF was significantly longer than in NSF (32.7 AE 7.7 mm versus 25.1 AE 7.3 mm, t-test, p = 0.002), regardless of * Corresponding author. Tel.: +82 2 3410 3592; fax: +82 2 3410 0052.
Epilepsy Research, 2013
Several studies have demonstrated the positive effect of resective epilepsy surgery in drug-resistant temporal lobe epilepsy (TLE). However, it is still a matter of debate whether selective amygdalohippocampectomy (SAH) or standard temporal lobectomy (STL) are the most effective approaches concerning seizure outcome, quality of life and memory. In each of the two centers participating in this study either SAH or STL was the neurosurgical standard procedure irrespective of contextual aspects. Thus, with this postoperative assessment of resected patients we sought to avoid any selection bias that usually impaired comparative trials of both surgical approaches. We finally identified and studied 95 adult patients who had undergone either SAH (n=46) or STL (n=49) between 1999 and 2009 and fulfilled the inclusion criteria, namely drug-resistant unilateral mesial TLE with hippocampal sclerosis without any further structural lesions. We assessed the postoperative seizure outcome according to the ILAE criteria and postoperative quality of life by means of standardized questionnaires. Finally, we compared postoperative neuropsychological performance in 60 completely seizure-free patients (n=27 after SAH, n=33 after STL) prior to, one year after surgery and at a long-term follow-up with a mean of seven years. 78.2% of SAH and 85.7% of STL were seizure-free at the last observation. Quality of life had improved in 95.6% of the SAH patients and 89.8% of the STL patients. These differences were not statistically significant. Left-sided TLE patients had a significantly worse verbal memory outcome irrespective of the surgical method. However, SAH patients had a significantly better outcome concerning visual encoding, verbal and visual short-term memory and visual working memory. In this study, seizure outcome and quality of life did not differ depending on the surgical approach. However, a more selective resection led to better neuropsychological performances.
Journal of Epilepsy and Clinical Neurophysiology, 2005
One of the objectives of pre-surgical evaluation in mesial temporal epilepsy associated to hippoocampal sclerosis is the identification of patients with bad surgical prognosis for seizure control. At least theoretically, neuropsychological tests could be used in this venue. Objective: To evaluate whether verbal and visual memory tests can be used as isolate predictors of the post-surgical seizure outcome in patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis refractory to pharmacological treatment. Methods: In a retrospective cohort study using the control of epileptic seizures as end-point, we evaluated 187 patients and calculated the correlation of clinical variables, cognitive evaluation, neuroimaging data, demographic data and electrophysiological findings with the result of seizure control after lobectomy in these patients. Results: An unfavorable prognosis during the postoperative period was observed only in association with low visual reproduction scores (visual memory). However, after Bonferroni correction, which was necessary to reduce the chance of type I error, this result was found to be spurious. Conclusion: We conclude that neuropsychological tests of verbal and visual memory such as those used in the routine presurgical evaluation of our patients with temporal lobe epilepsy are not good isolated predictors of surgical outcome.
Surgical outcome of patients with mesial temporal lobe epilepsy related to hippocampal sclerosis
Epilepsia, 2008
Seizure outcome in mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) that was evaluated according to a noninvasive protocol was assessed in 165 patients and reported using both Engel's and ILAE classifications. The mean postoperative follow-up was 5.0 ± 2.7 years. At the end of first year, 77.1% of patients were in Engel-I, and 52.7% were in ILAE-I. Antiepileptic drugs (AEDs) were discontinued in 41 patients (42.7%), all remained seizure-free for >2 years that could be accepted as "cure." Thirty-six patients had recur-rences, 19 had running-down phenomena. Anterior temporal lobectomy (ATL) was performed in 27 patients with a better outcome when compared to patients operated by selective anterior hippocampectomy. Clinical risk factors for better and worse outcome, which show some similarity in different reports, seem to veil the main reason, which is the accurate delineation of epileptogenic zone considering the presence of different subgroups and underlying developmental pathologies.
Epilepsia, 2017
The reasons for failure of surgical treatment for mesial temporal lobe epilepsy (MTLE) associated with hippocampal sclerosis (HS) remain unclear. This retrospective study analyzed seizure, cognitive, and psychiatric outcomes, searching for factors associated with seizure relapse or cognitive and psychiatric deterioration after MTLE-HS surgery. Seizure, cognitive, and psychiatric outcomes were reviewed after 389 surgeries performed between 1990 and 2015 on patients aged 15-67 years at a tertiary center. Three surgical approaches were used: anterior temporal lobectomy (ATL; n = 209), transcortical selective amygdalohippocampectomy (SAH; n = 144), and transsylvian SAH (n = 36). With an average follow-up of 8.7 years (range = 1.0-25.2), seizure outcome was classified as Engel I in 83.7% and Engel Ia in 57.1% of patients. The histological classification of HS was type 1 for 75.3% of patients, type 2 for 18.7%, and type 3 for 1.2%. Two factors were significantly associated with seizure re...
Cognitive Outcome after Surgery in Patients with Mesial Temporal Lobe Epilepsy
Noro Psikiyatri Arsivi, 2016
The aim of the present study was to evaluate the neuropsychological outcomes of patients with medically intractable unilateral mesial temporal lobe epilepsy (MTLE) due to hippocampal sclerosis (HS) treated either by anterior temporal lobectomy (ATL) or selective amygdalohippocampectomy (SAH). Methods: This was a retrospective study where 67 patients who had undergone surgery for MTLE were evaluated. Thirty-two patients underwent ATL and 35 underwent SAH. All patients underwent a detailed neuropsychological evaluation before and 1 year after surgery. Results: The verbal memory outcome was unchanged after left-sided surgery, whereas learning capacity increased after right-sided surgery (p=0.038). The visual memory outcome improved after right-sided surgery. Improvement of executive functions, particularly in the resistance of interference pattern in the Stroop Test, shortened 5th card time (p=0.000), and decreased corrections (p=0.003), after right-sided surgery and increased attention (p=0.027) after left-sided surgery were observed. After both surgery types, although statistically insignificant, there was a marked decrease in incorrect answers in the Stroop Test, which also showed an improvement in the resistance of interference pattern. Moreover, there was a significant decrease in switching errors with word pairs in the Verbal Fluency Test (p=0.008) after right-sided surgery. When the two sides were compared, we observed that the recall phase of the verbal memory worsened (p=0.018); however, the recognition phase improved (p=0.015) after left-sided surgery. Additionally, the short-term visual memory was better for both sides (p=0.035). Conclusion: Our results showed that patients with left MTLE were not worsened in verbal memory, but despite improved recognition, they have some problems in recalling information and only a minor improvement in attention. Patients with right MTLE improved in their verbal learning capacity, visual memory, and resistance of interference pattern 1 year after surgery. It was thus shown that while epilepsy surgery is associated with some negative cognitive changes, it may also improve some cognitive functions.
Optimal Surgical Extent for Memory and Seizure Outcome in Temporal Lobe Epilepsy
Annals of Neurology, 2021
ObjectivePostoperative memory decline is an important consequence of anterior temporal lobe resection (ATLR) for temporal lobe epilepsy (TLE), and the extent of resection may be a modifiable factor. This study aimed to define optimal resection margins for cognitive outcome while maintaining a high rate of postoperative seizure freedom.MethodsThis cohort study evaluated the resection extent on postoperative structural MRI using automated voxel‐based methods and manual measurements in 142 consecutive patients with unilateral drug refractory TLE (74 left, 68 right TLE) who underwent standard ATLR.ResultsVoxel‐wise analyses revealed that postsurgical verbal memory decline correlated with resections of the posterior hippocampus and inferior temporal gyrus, whereas larger resections of the fusiform gyrus were associated with worsening of visual memory in left TLE. Limiting the posterior extent of left hippocampal resection to 55% reduced the odds of significant postoperative verbal memory...
Journal of Neurology, Neurosurgery, and Psychiatry, 2013
Objectives To evaluate the very long-term clinical outcome of surgery for mesial temporal lobe epilepsy and unilateral hippocampal sclerosis (MTLE/HS) without atypical features. The impact of surgical technique and postoperative reduction of medication on this outcome was investigated. Design Prospective longitudinal cohort follow-up study for up to18 years. Setting Epilepsy surgery centre in a university hospital. Patients 108 patients who underwent unilateral MTLE/HS. Intervention Surgery for MTLE/HS. Main outcome measure Engel classification (I). Clinical evaluations were based on systematic interviews in person or by phone. Kaplan-Maier survival curves estimated the probability of remaining seizure free. The impact of medication management in the postoperative outcome was analysed using Cox regression. Results The probability of remaining completely seizure-free at 12 and 18 years after MTLE/HS surgery was 65% and 62%, respectively. The risk of having any recurrence was 22% during the first 24 months and increased 1.4% per year afterwards. Type of surgical technique (selective amygdalohippocampectomy vs anterior temporal lobectomy) did not impact on outcome. Remaining on antiepileptic drugs and history of generalised clonic seizure diminished the probability of remaining seizure free. Conclusions MTLE/HS surgery is able to keep patients seizure free for almost up to two decades. Removal of the neocortex besides the mesial portion of the temporal lobe does not lead to better chances of seizure control. These findings are applicable to the typical unilateral MTLE/HS syndrome and cannot be generalised for all types of TLE. Future longitudinal randomised controlled studies are needed to replicate these findings.
Journal of Postgraduate Medicine, Education and Research
Introduction: Anterior temporal lobectomy with amygdalohippocampectomy is the most common surgical procedure for refractory epilepsy secondary to mesial temporal sclerosis. There is no consensus on whether the degree of hippocampal or amygdala resection has any influence on determining outcomes after epilepsy surgery. In this study, we assessed the seizure control and neuropsychological outcome and correlated these with the degree of surgical resection as determined on postoperative magnetic resonance imaging (MRI) in patients who had undergone surgery for refractory temporal lobe epilepsy. Materials and methods: A total of 20 patients of refractory medial temporal lobe epilepsy were taken who underwent anterior temporal lobectomy with hippocampal and amygdala resection. Pre and Post-op clinical and neuropsychological assessment was done. Pre-and post-operative MR scans were compared for degree of hippocampal and amygdala resection. Seizure control was assessed based upon the degree of resection. Results: Out of 18 patients with complete resection of the hippocampal body, 17 (94.4%) patients had Engels class I outcome and one (5.6%) patient had Engels class II outcome. But in patients with partial body resection, both the patients (100%) had Engel's class II outcome. On complete resection of the tail, 12 patients had class I and one patient had class II outcome. When the tail of hippocampus was partially resected, or unresected resection five patients had class I but two patients had class II outcome. Conclusion: It is required to achieve complete removal of pes hippocampus and hippocampal body for better seizure control and improvement in neuropsychological performance. The degree of the hippocampal tail or amygdala resection does not affect the outcome.
Neuropsychiatric Disease and Treatment, 2015
Background and purpose: Mesial temporal structures play an important role in human memory. In mesial temporal lobe epilepsy (MTLE), seizure activity is generated from the same structures. Surgery is the definitive treatment for medically intractable MTLE. In addition to standard temporal lobe microsurgical resection, stereotactic radiofrequency amygdalohippocampectomy (SAHE) is used as an alternative MTLE treatment. While memory impairments after standard epilepsy surgery are well known, it has been shown that memory decline is not a feature of SAHE. The aim of the present study was to correlate the volume of the remnant hippocampus and amygdala in patients treated by SAHE with changes in memory parameters. Materials and methods: Thirty-seven MTLE patients treated by SAHE (ten right, 27 left) were included. Patients underwent magnetic resonance imaging examinations including hippocampal and amygdalar volumetry and neuropsychological evaluation preoperatively and 1 year after surgery. Results: Using Spearman correlation analyses, larger left-sided hippocampal reductions were associated with lower verbal memory performance (ρ=-0.46; P=0.02). On the contrary, improvement of global memory quotient (MQ) was positively correlated with larger right-sided hippocampal reduction (ρ=0.66; P=0.04). Similarly, positive correlations between the extent of right amygdalar reduction and verbal MQ (ρ=0.74; P=0.02) and global MQ change (ρ=0.69; P=0.03) were found. Thus, larger right hippocampal and amygdalar reduction was associated with higher global and verbal MQ change after SAHE. Conclusion: Larger left-sided hippocampal reductions were associated with lower verbal memory performance. This finding is in accordance with the material-specific model of human memory, which states that the dominant hemisphere is specialized for the learning and recall of verbal information. We hypothesize that larger right-sided ablations enable the left temporal lobe to support memory more effectively, perhaps as a consequence of epileptiform discharges spreading from remnants of right mesiotemporal structures to the left.