Refractory Medial Temporal Lobe Epilepsy Research Articles

Impaired Emotion Processing and Panic Disorder After Left Anterior Temporal Lobectomy: A Case Report of Successful Psychotherapeutic Intervention

BackgroundOver the last decades, brain surgery became a more frequently applied treatment for temporal lobe epilepsy (TLE). Despite its success, several studies found de-novo post-operative psychiatric symptoms in TLE surgery patients. Cognitive behavioural therapy is effective to treat brain healthy psychiatric patients but might not be translatable to patients with resections in emotion regulating networks as these areas seem to be essentially involved in successful psychotherapeutic treatment.MethodsHere we report the case of a female patient with medically refractory medial temporal lobe epilepsy resulting in left anterior temporal lobectomy at age 35. Post operation she did not show adequate fearful response but at the same time manifested symptoms of a severe panic disorder. We investigated if this patient, despite lesions in emotion-behaviour brain circuits, can benefit from cognitive behavioural therapy.ResultsThe intervention, customized to the specific resources and difficulties of the patient, was effective in stopping panic attacks and improving social functioning.ConclusionsThis case shows that MTL brain surgery patients may benefit from CBT and demonstrates the important and if yet still somewhat mysterious role of the amygdala in emotion regulation processes.

Auditory Temporal Ordering in Patients with Medial Temporal Lobe Epilepsy with and without Hippocampal Sclerosis.

Temporal lobe epilepsy can affect central auditory processing (CAP) skills. Auditory temporal ordering (ATO) is a CAP skill that can be evaluated using duration pattern test (DPT). The aim is to evaluate ATO in patients with medial temporal lobe epilepsy (MTLE) with hippocampal sclerosis (MTLE + HS) and without hippocampal sclerosis (MTLE-HS) and in their subgroups. It was a prospective cross-sectional behavioral observational study conducted in a tertiary neuropsychiatric hospital. The subjects were patients with refractory MTLE (N = 100), comprising 50 "MTLE + HS" patients and 50 "MTLE-HS". Age-range matched normal healthy subjects (n = 50) formed the control group. Both groups were administered duration pattern test (DPT). Analysis of variance (ANOVA) with post hoc analysis, Dunnett's two-sided and Bonferroni, paired sample t-test, Pearson's correlation, and independent t-test. The clinical groups performed significantly poorer than the control group, and however, did not differ significantly between them. The age at onset and the duration of the seizures did not have significant relation with the test measures. Patients with "MTLE + HS" as well as those with "MTLE-HS" and their respective subgroups revealed abnormal ATO indicating CAP dysfunction.

Hippocampal modulation of auditory processing in epilepsy

AbstractThe hippocampus is anatomically and functionally connected to other brain regions tightly. Especially in the field of memory research, it has become clear that the connections between the cerebral cortex, thalamus, and hippocampus are regulated via slow‐wave rhythms and high‐frequency oscillation. In addition, the hippocampus, as a limbic system, is more excitable to inputs than the cerebral cortex and has a reverberant circuit structure, which induces long‐lasting neural activity. Because of such characteristics of the hippocampus, it is treated as a key structure in epilepsy. Auditory processing has been shown to be affected by hippocampal activity, and impaired auditory processing function in patients with medial temporal lobe epilepsy has been elucidated using techniques such as cognitive behavior tests and electrophysiological recordings. We recorded the auditory‐induced magnetoencephalography of patients with refractory medial temporal lobe epilepsy and examined which hemisphere was more affected. In contrast to previous language studies, we only used simple tone stimulation, by which we could obtain the laterality information regarding epileptic activity and left‐right difference. In this article, we reviewed the effects of hippocampal activity on brain function, including the findings of our auditory stimulus‐induced magnetic field recordings of medial temporal lobe epilepsy.

Case Series: Unilateral Amygdala Ablation Ameliorates Post-Traumatic Stress Disorder Symptoms and Biomarkers

Background Post-traumatic stress disorder is a severe psychobiological disorder associated with hyperactivity of the amygdala, particularly on the right side. Highly selective laser ablation of the amygdalohippocampal complex is an effective neurosurgical treatment for medically refractory medial temporal lobe epilepsy that minimizes neurocognitive deficits relative to traditional open surgery. Objective To examine the impact of amygdalohippocampotomy upon symptoms and biomarkers of post-traumatic stress disorder. Methods Two patients with well-documented chronic post-traumatic stress disorder who subsequently developed late-onset epilepsy underwent unilateral laser amygdalohippocampotomy. Prospective clinical and neuropsychological measurements were collected in patient 1. Additional prospective measurements of symptoms and biomarkers were collected pre- and post-surgery in patient 2. Results After laser ablation targeting the nondominant (right) amygdala, both patients experienced not only reduced seizures, but also profoundly abated post-traumatic stress symptoms. Prospective evaluation of biomarkers in patient 2 showed robust improvements in hyperarousal symptoms, fear potentiation of the startle reflex, brain functional magnetic resonance imaging responses to fear-inducing stimuli, and emotional declarative memory. Conclusion These observations support the emerging hypothesis that the right amygdala particularly perpetuates the signs and symptoms of post-traumatic stress disorder and suggests that focal unilateral amydalohippocampotomy can provide therapeutic benefit.

Emotional asymmetries in refractory medial temporal and frontal lobe epilepsy: Their impact on predicting lateralization and localization of seizures

BackgroundEmotional disturbances have been reported in patients with epilepsy. Although conflicting results emanate from relevant studies, depressive symptoms are seen more often in temporal lobe epilepsy (TLE) whereas, hypomanic/manic symptoms usually accompany frontal lobe epilepsy (FLE); the above psychiatric symptoms are especially seen in refractory epilepsy. However, neocortical TLE and medial TLE are considered as distinct epileptic syndromes, and there is limited literature on comparison of affective traits in medial TLE (MTLE) and FLE. AimIn the present study, we sought to investigate affective traits among epilepsy surgery candidates suffering refractory left medial TLE (LMTLE), right medial TLE (RMTLE), left FLE (LFLE), and right FLE (RFLE). ResultsOur results revealed that patients with MTLE scored significantly higher than the ones with FLE in depression, anxiety, asthenia, and melancholia as measured by the Symptoms Rating Scale for Depression and Anxiety (SRSDA), while patients with FLE scored significantly higher in mania than those with MTLE. Moreover, patients with MTLE scored significantly higher than their FLE counterparts on the anxiety scale of the State Trait Personality Inventory (STPI)-trait version. When laterality of the seizure focus was taken into account, no differences were found among both patients with MTLE and patients with FLE, with exception for the Trail Making Test part B (TMT-B) in which patients with RMTLE performed significantly worse than patients with LMTLE. Seizure frequency was higher for FLE. ConclusionsWe provide evidence for an anterior-frontal versus a posterior-medial temporal cerebral functional asymmetry with regard to the manifestation of manic and depressive emotional traits in FLE and MTLE, respectively. Our results are mainly discussed within the frame of their contribution in localizing and to a lesser extent in lateralizing seizures foci in epilepsy surgery candidates. We suggest that this is of great importance in the context of preoperative monitoring of epilepsy surgery, especially when neuropsychologists are called upon to provide anatomical information in defining the functional deficit zone.

Adapting a memory fMRI research protocol in clinical routine: Feasibility and results

ObjectiveThe objective of this study was to test the reliability of functional magnetic resonance imaging (fMRI) evaluation of memory function in clinical practice to predict postoperative memory decline in patients with refractory medial temporal lobe epilepsy (MTLE) candidate to surgery. MethodsTwenty-six consecutive patients with MTLE who underwent a complete presurgical evaluation were included. All patients underwent fMRI memory study and complete neuropsychological assessment. Lesions consisted in hippocampal sclerosis in 18 patients (12 right and 6 left), dysembryoplastic neuroepithelial tumor (DNET) in 5 cases (4 right, 1 left), epidermoid cyst in one patient (right). Two patients had no lesion (2 left). ResultsNineteen patients (73%) underwent surgery. The other seven patients (27%) declined surgery, mainly because of the risk of memory deficit. The fMRI procedure correctly predicted both verbal and nonverbal memory postoperative outcome in 13 of the patients (72%), failed to predict a postoperative memory worsening in only two patients (12%), and predicted worsening in three patients (17%) that remained stable (versus 44%, 39%, and 17% with the sole neuropsychological testing). The reliability of the fMRI procedure was not influenced by the type of lesion, the side of the epileptic focus, or the type of preoperative memory profile (typical or atypical). SignificanceAppearing as a valuable clinical tool to predict postoperative memory outcome, fMRI may add information over and above other available tests.

Preoperative neuropsychological presentation of patients with refractory frontal lobe epilepsy.

This study investigated whether certain cognitive deficits are associated with frontal lobe epilepsy (FLE) aiming to contribute with localization data to the preoperative assessment of epilepsy surgery candidates. We evaluated 34 patients with refractory FLE, 37 patients with refractory medial temporal lobe epilepsy (MTLE), and 22 healthy individuals in attention, psychomotor speed, motor function, verbal memory span, verbal fluency, response inhibition/interference, concept formation and set shifting, anticipation and planning, global memory. Neuropsychological performances of FLE and MTLE were similar, with the only exception the WCST-number of categories index, measuring mental flexibility, in which MTLE patients performed significantly worse than FLE patients. Left-FLE patients presented more perseverative responding compared to both other patient groups and healthy controls (HCs), while left-MTLE patients showed worse sorting abilities than the other epilepsy groups. Our findings suggest a weak cognitive differentiation between FLE and MTLE, probably attributed to the intricate nature of fronto-temporal connectivity frequently resulting in overlapping deficits as well as the confounding effects of seizure-related variables. In clinical practice, a highly individualized (idiographic) neuropsychological approach along with the inclusion of concurrent EEG recordings (e.g., interictal coupling) may be of help for neuropsychologists in identifying FLE patients from those with medial temporal pathology presenting frontal dysfunction as a secondary cognitive symptom.

Electrical stimulation of hippocampus for the treatment of refractory temporal lobe epilepsy.

Temporal lobe epilepsy (TLE) is the most common epilepsy syndrome and is often associated with pharmacoresistance. Patients with pharmacoresistant TLE may be candidates for epilepsy surgery, and anterior temporal lobectomy if indicated is the most effective known treatment and has the best chance of a seizure-free outcome. For many patients with TLE, epilepsy surgery is not an option, for example when the seizure onset zone co-localizes with eloquent brain function and cannot be resected, or the seizure onset zone is not well localized, or when seizures independently originate from both temporal lobes. For many of these patients, electrical stimulation is a viable treatment option, such as electrical stimulation of the hippocampus, or temporal neocortex, or thalamus. Animal and clinical studies in humans have demonstrated electrical stimulation is an effective and safe treatment. Moreover, successful application of responsive neurostimulation system in the treatment of temporal lobe epilepsy has been reported recently. This review is intended to provide a comprehensive review of the modern history of electrical stimulation of the hippocampus for the treatment of refractory medial temporal lobe epilepsy and discuss the anatomical basis, validity, side effects, stimulation paradigm and mechanism of hippocampus stimulation and the responsive electrical stimulation trials.

Probabilistic ictal EEG sources and temporal lobe epilepsy surgical outcome.

For patients with medication refractory medial temporal lobe epilepsy (MTLE), surgery offers the hope of a cure. However, up to 30% of patients with MTLE continue to experience disabling seizures after surgery. The reasons why some patients do not achieve seizure freedom are poorly understood. A promising theory suggests that epileptogenic networks are broadly distributed in surgically refractory MTLE, involving regions beyond the medial temporal lobe. In this retrospective study, we aimed to investigate the distribution of epileptogenic networks in MTLE using Bayesian distributed EEG source analysis from preoperative ictal onset recordings. This analysis has the advantage of generating maps of source probability, which can be subjected to voxel-based statistical analyses. We compared 10 patients who achieved post-surgical seizure freedom with 10 patients who continued experiencing seizures after surgery. Voxel-based Wilcoxon tests were employed with correction for multiple comparisons. We observed that ictal EEG source intensities were significantly more likely to occur in lateral temporal and posterior medial temporal regions in patients with continued seizures post-surgery. Our findings support the theory of broader spatial distribution of epileptogenic networks at seizure onset in patients with surgically refractory MTLE.

Frequency dependence of behavioral modulation by hippocampal electrical stimulation

Electrical stimulation offers the potential to develop novel strategies for the treatment of refractory medial temporal lobe epilepsy. In particular, direct electrical stimulation of the hippocampus presents the opportunity to modulate pathological dynamics at the ictal focus, although the neuroanatomical substrate of this region renders it susceptible to altering cognition and affective processing as a side effect. We investigated the effects of three electrical stimulation paradigms on separate groups of freely moving rats (sham, 8-Hz and 40-Hz sine-wave stimulation of the ventral/intermediate hippocampus, where 8- and 40-Hz stimulation were chosen to mimic naturally occurring hippocampal oscillations). Animals exhibited attenuated locomotor and exploratory activity upon stimulation at 40 Hz, but not at sham or 8-Hz stimulation. Such behavioral modifications were characterized by a significant reduction in rearing frequency, together with increased freezing behavior. Logistic regression analysis linked the observed changes in animal locomotion to 40-Hz electrical stimulation independently of time-related variables occurring during testing. Spectral analysis, conducted to monitor the electrophysiological profile in the CA1 area of the dorsal hippocampus, showed a significant reduction in peak theta frequency, together with reduced theta power in the 40-Hz vs. the sham stimulation animal group, independent of locomotion speed (theta range: 4-12 Hz). These findings contribute to the development of novel and safe medical protocols by indicating a strategy to constrain or optimize parameters in direct hippocampal electrical stimulation.

Presurgical connectome and postsurgical seizure control in temporal lobe epilepsy

The objective of this study was to evaluate whether patients with surgically refractory medial temporal lobe epilepsy (MTLE) exhibit a distinct pattern of structural network organization involving the temporal lobes and extratemporal regions. We retrospectively studied 18 healthy controls and 20 patients with medication refractory unilateral MTLE who underwent anterior temporal lobectomy for treatment of seizures. Patients were classified as seizure-free or not seizure-free at least 1 year after surgery. The presurgical brain connectome was calculated through probabilistic connectivity from MRI-diffusion tensor imaging from 83 anatomically defined regions of interest encompassing the whole brain. The connectivity patterns were analyzed regarding group differences in regional connectivity and network graph properties. Compared with controls, patients exhibited a decrease in connectivity involving ipsilateral thalamocortical regions, with a pathologic increase in ipsilateral medial temporal lobe, insular, and frontal connectivity. Among patients, those not seizure-free exhibited a higher connectivity between structures in 1) the ipsilateral medial and lateral temporal lobe, 2) the ipsilateral medial temporal and parietal lobe, and 3) the contralateral temporal pole and parietal lobe. Patients not seizure-free also exhibited lower small-worldness in the subnetwork within the ipsilateral temporal lobe, with higher subnetwork integration at the expense of segregation. MTLE is associated with network rearrangement within, but not restricted to, the temporal lobe ipsilateral to the onset of seizures. Networks involving key components of the medial temporal lobe and structures traditionally not removed during surgery may be associated with seizure control after surgical treatment of MTLE.

Display of consistent ictal networks in refractory mesial temporal lobe epilepsy

ObjectiveExploration of emergent ictal networks was performed in homogeneous subjects with refractory medial temporal lobe epilepsy. MethodsMaximal Synchrony Index (SI) values were calculated for all electrode pairs for each second during 25 seizures and displayed as connectivity animations. Consistent temporal patterns of SI value and spatial connectivity were observed across seizures and subjects, and used to define a sequence of network stages. ResultsHighest SI values were found in electrodes within the area of surgical resection. Analysis of these electrodes by network stage demonstrated lateral temporal cortex dominance at seizure initiation, giving way to hippocampal synchrony during the major portion of the seizure, with lateral temporal regions re-emerging as the seizure terminated. SI values also corresponded to behavioral severity of seizures, and lower SI values were associated with post-surgical seizure freedom. ConclusionSI based methods of network characterization consistently display the intrinsic MTLE ictal network and may be sensitive to clinical features. SignificanceConsistency of EEG-derived network patterns is an important step as network features are applied towards improvement of clinical management. These data confirm consistency of network patterns within and across subjects and support the potential for these methods to distinguish relevant clinical variables.

Relationship of number of seizures recorded on video-EEG to surgical outcome in refractory medial temporal lobe epilepsy

Surgical planning for refractory medial temporal lobe epilepsy (rMTLE) relies on seizure localization by ictal electroencephalography (EEG). Multiple factors impact the number of seizures recorded. We evaluated whether seizure freedom correlated to the number of seizures recorded, and the related factors. We collected data for 32 patients with rMTLE who underwent anterior temporal lobectomy. Primary analysis evaluated number of seizures captured as a predictor of surgical outcome. Subsequent analyses explored factors that may seizure number. Number of seizures recorded did not predict seizure freedom. More seizures were recorded with more days of seizure occurrence (p<0.001), seizure clusters (p≤0.011) and poorly localized seizures (PLSz) (p=0.004). Regression modeling showed a trend for subjects with fewer recorded poorly localized seizures to have better surgical outcome (p=0.052). Total number of recorded seizures does not predict surgical outcome. Patients with more PLSz may have worse outcome.

A decade of experience with deep brain stimulation for patients with refractory medial temporal lobe epilepsy

A decade of experience with deep brain stimulation for patients with refractory medial temporal lobe epilepsy

Cognitive musical lateralization assessment during intracarotid propofol procedure

Event Abstract Back to Event Cognitive musical lateralization assessment during intracarotid propofol procedure Isabel Trujillo-Pozo1, 2*, Isabel M. Martin-Monzon1, Paloma Villalobos-Lopez2, Gonzalo Moreno-Castro2, Antonia Gomez1, Maria Oliver-Romero2, Juan J. Rodriguez-Uranga2, Jose M. Montero-Elena2, Alejandro Gonzalez-Garcia2, Francisco Villalobos-Chaves2, Dolores Jimenez-Hernandez2 and Fernando Rodriguez1 1 University of Seville, Laboratory of Psicobiology, Spain 2 Epilepsy Unit Virgen del Rocío Hospital, Spain The evidence from basic and clinical neuroscience suggests that listening and reading music involves many cognitive components with distinct brain substrates. Currently, results emanating from both lesion studies and neuroimaging techniques are used to dissociate between brain areas processing different aspects of musical stimuli. However, the intracarotid propofol procedure (Wada test) has not been used to analyze music processing. We used a neuropsychological assessment during the intracarotid propofol procedure in a musician, a 33 years old woman with refractory medial temporal lobe epilepsy (MTLE). Musical abilities, language, memory and other cognitive functions were tested after injection of propofol in both hemispheres by means of a novel and exhaustive neuropsychological procedure focussing on the processing of music. During the intracarotid propofol procedure, when the effects of the drug were still apparent, the different items of the musical protocol were presented. We used a selection of stimuli to analyze score reading, listening to a melody and rhythm-tempo discrimination. We also tested visual and auditory musical memory, learning non verbal auditory patterns, syntax and semantic musical processing. Neuropsychological testing revealed that the right hemisphere is involved in the processing of harmonic integration and possibly musical semantics, whereas score reading and rhythm-tempo processing activates both hemispheres. This research suggests that the neuropsychological assessment during intracarotid propofol procedure is an excellent preoperative method for identifying hemispheric lateralization of musical abilities in epileptic professional musicians who may be candidate for epilepsy surgery. Conference: 41st European Brain and Behaviour Society Meeting, Rhodes Island, Greece, 13 Sep - 18 Sep, 2009. Presentation Type: Poster Presentation Topic: Poster presentations Citation: Trujillo-Pozo I, Martin-Monzon IM, Villalobos-Lopez P, Moreno-Castro G, Gomez A, Oliver-Romero M, Rodriguez-Uranga JJ, Montero-Elena JM, Gonzalez-Garcia A, Villalobos-Chaves F, Jimenez-Hernandez D and Rodriguez F (2009). Cognitive musical lateralization assessment during intracarotid propofol procedure. Conference Abstract: 41st European Brain and Behaviour Society Meeting. doi: 10.3389/conf.neuro.08.2009.09.328 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 15 Jun 2009; Published Online: 15 Jun 2009. * Correspondence: Isabel Trujillo-Pozo, University of Seville, Laboratory of Psicobiology, Seville, Spain, itrujillo@us.es Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Isabel Trujillo-Pozo Isabel M Martin-Monzon Paloma Villalobos-Lopez Gonzalo Moreno-Castro Antonia Gomez Maria Oliver-Romero Juan J Rodriguez-Uranga Jose M Montero-Elena Alejandro Gonzalez-Garcia Francisco Villalobos-Chaves Dolores Jimenez-Hernandez Fernando Rodriguez Google Isabel Trujillo-Pozo Isabel M Martin-Monzon Paloma Villalobos-Lopez Gonzalo Moreno-Castro Antonia Gomez Maria Oliver-Romero Juan J Rodriguez-Uranga Jose M Montero-Elena Alejandro Gonzalez-Garcia Francisco Villalobos-Chaves Dolores Jimenez-Hernandez Fernando Rodriguez Google Scholar Isabel Trujillo-Pozo Isabel M Martin-Monzon Paloma Villalobos-Lopez Gonzalo Moreno-Castro Antonia Gomez Maria Oliver-Romero Juan J Rodriguez-Uranga Jose M Montero-Elena Alejandro Gonzalez-Garcia Francisco Villalobos-Chaves Dolores Jimenez-Hernandez Fernando Rodriguez PubMed Isabel Trujillo-Pozo Isabel M Martin-Monzon Paloma Villalobos-Lopez Gonzalo Moreno-Castro Antonia Gomez Maria Oliver-Romero Juan J Rodriguez-Uranga Jose M Montero-Elena Alejandro Gonzalez-Garcia Francisco Villalobos-Chaves Dolores Jimenez-Hernandez Fernando Rodriguez Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. 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Outcomes Remain Ambivalent for Deep Brain Stimulation and Epilepsy

Deep Brain Stimulation in Patients with Refractory Temporal Lobe Epilepsy. Boon P, Vonck K, De Herdt V, Van Dycke A, Goethals M, Goossens L, Van Zandijcke M, De Smedt T, Dewaele I, Achten R, Wadman W, Dewaele F, Caemaert J, Van Roost D. Epilepsia 2007;48(8):1551–1560. PURPOSE: This pilot study prospectively evaluated the efficacy of long-term deep brain stimulation (DBS) in medial temporal lobe (MTL) structures in patients with MTL epilepsy. METHODS: Twelve consecutive patients with refractory MTL epilepsy were included in this study. The protocol included invasive video-EEG monitoring for ictal-onset localization and evaluation for subsequent stimulation of the ictal-onset zone. Side effects and changes in seizure frequency were carefully monitored. RESULTS: Ten of 12 patients underwent long-term MTL DBS. Two of 12 patients underwent selective amygdalohippocampectomy. After mean follow-up of 31 months (range, 12–52 months), one of 10 stimulated patients are seizure-free (&gt;1 year), one of 10 patients had a &gt;90% reduction in seizure frequency; five of 10 patients had a seizure-frequency reduction of ≥50%; two of 10 patients had a seizure-frequency reduction of 30–49%; and one of 10 patients was a nonresponder. None of the patients reported side effects. In one patient, MRI showed asymptomatic intracranial hemorrhages along the trajectory of the DBS electrodes. None of the patients showed changes in clinical neurological testing. Patients who underwent selective amygdalohippocampectomy are seizure-free (&gt;1 year), AEDs are unchanged, and no side effects have occurred. CONCLUSIONS: This open pilot study demonstrates the potential efficacy of long-term DBS in MTL structures that should now be further confirmed by multicenter randomized controlled trials.

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

Little is known about the pathophysiology of transient global amnesia (TGA) and how it is related to epilepsy. We report here five typical episodes of TGA, each occurring several years...

11C]Flumazenil PET in Temporal Lobe Epilepsy: Do We Need an Arterial Input Function or Kinetic Modeling?

Reduced signal on [(11)C]]flumazenil (FMZ) positron emission tomography (PET) is associated with epileptogenic foci. Linear correlations within individuals between parametric and nonparametric images of FMZ binding have been shown, and various methods have been used, without comparison of diagnostic usefulness. Using hippocampal sclerosis (HS) as a test case, we formally compare the diagnostic yield of parametric images obtained either with a parent tracer arterial plasma input function and spectral analysis (yielding volume-of-distribution (VD) images), or with an image-based input function and the simplified reference tissue model (binding potential images, BP-SRTM) with the diagnostic yield of semiquantitative-integrated (ADD) images from 10 to 20 or 20 to 40 mins (ADD1020 and ADD2040). Dynamic 90-min [(11)C]FMZ PET datasets and arterial plasma input functions were available for 15 patients with medically refractory medial temporal lobe epilepsy (TLE) and histologically verified unilateral HS and for 13 control subjects. SPM2 was used for analysis. ADD1020 and ADD2040 images showed decreased FMZ uptake ipsilateral to the epileptogenic hippocampus in 13/15 cases; 6/13 had bilateral decreases in the ADD1020 analysis and 5/13 in the ADD2040 analysis. BP-SRTM images detected ipsilateral decreases in 12/15 cases, with bilateral decreases in three. In contrast, VD images showed ipsilateral hippocampal decreases in all 15 patients, with bilateral decreases in three patients. Bilateral decreases in the ADD images tended to be more symmetrical and in one case were more marked contralaterally. Full quantification with an image-independent input should ideally be used in the evaluation of FMZ PET; at least in TLE, intrasubject correlations do not predict equivalent clinical usefulness.

Deep Brain Stimulation in Patients with Refractory Temporal Lobe Epilepsy

This pilot study prospectively evaluated the efficacy of long-term deep brain stimulation (DBS) in medial temporal lobe (MTL) structures in patients with MTL epilepsy. Twelve consecutive patients with refractory MTL epilepsy were included in this study. The protocol included invasive video-EEG monitoring for ictal-onset localization and evaluation for subsequent stimulation of the ictal-onset zone. Side effects and changes in seizure frequency were carefully monitored. Ten of 12 patients underwent long-term MTL DBS. Two of 12 patients underwent selective amygdalohippocampectomy. After mean follow-up of 31 months (range, 12-52 months), one of 10 stimulated patients are seizure free (>1 year), one of 10 patients had a >90% reduction in seizure frequency; five of 10 patients had a seizure-frequency reduction of > or =50%; two of 10 patients had a seizure-frequency reduction of 30-49%; and one of 10 patients was a nonresponder. None of the patients reported side effects. In one patient, MRI showed asymptomatic intracranial hemorrhages along the trajectory of the DBS electrodes. None of the patients showed changes in clinical neurological testing. Patients who underwent selective amygdalohippocampectomy are seizure-free (>1 year), AEDs are unchanged, and no side effects have occurred. This open pilot study demonstrates the potential efficacy of long-term DBS in MTL structures that should now be further confirmed by multicenter randomized controlled trials.

Long‐term Prognosis and Psychosocial Outcomes after Surgery for MTLE

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