Correlation of health-related quality of life after surgery for mesial temporal lobe epilepsy with two seizure outcome scales

A Case of Treatment-Resistant Schizophrenia With Mesial Temporal Sclerosis: A Case Report

Mesial temporal sclerosis (MTS) is one of the most common causes of treatment-resistant epilepsy, especially temporal lobe epilepsy (TLE). Various psychiatric symptoms are common with temporal lobe epilepsy. However, the least established symptoms were psychotic symptoms. Furthermore, treatment-resistant schizophrenia is a significant proportion of schizophrenia patients who have failed treatment with at least two different antipsychotics, resulting in poor outcomes and a significant negative impact on the patient's life. In our case report, psychotic symptoms and abnormal behaviors were explained by schizophrenia for more than 17 years in a 32-year-old female, while the diagnosis of temporal lobe epilepsy with mesial temporal sclerosis was missed, resulting in incomplete treatment, which led to a deterioration of her quality of life for years. This case aims to shed light on TLE rare manifestations and to discuss the proper investigations and treatment that might increase the quality of life of these patients. Underlining the necessity for more research in treatment-resistant schizophrenia, this unusual case underscores the importance of exploring the underlying biological, psychological, and social risk factors. It also emphasizes the need to focus additional attention on formulating proper investigation strategies for the susceptible patient population.

Quality of life in elderly patients after surgery for drug-resistant epilepsy - The impact of seizure outcome, neurological deficits and anxiety

INTRODUCTION

Health related quality of life (HRQoL) has become a pivotal outcome parameter after surgery for drug-resistant epilepsy. The aim of the study was to investigate HRQoL and its relationship to seizure outcome, neurological deficits and anxiety after epilepsy surgery in a specific subpopulation of elderly patients.

METHODS

A total of 85 elderly patients (older than 50 years) answered a standardized HRQoL questionnaire one year after epilepsy surgery. The questionnaire addressed the present self-assessed HRQoL in four subdomains (physical function, cognitive function, mood, social interaction). The questionnaire was based on the "Epilepsy Surgery Inventory-55", adapted for use in German speaking patients and validated by the QOLIE -10 and Beck Depression Inventory.

RESULTS

A total of 51 patients (60%) were completely seizure free (ILAE1) at last available outcome (LAO). Permanent neurological deficits were observed in 8 patients (7%). Correlation analysis confirmed significant association between seizure outcome and overall HRQoL (r = -0.368, p < .001). New permanent neurological deficits showed impact on both HRQoL and the "cognitive function" subdomain. Anxiety and subjective assessment of postoperative status were strongly correlated with overall HRQoL (r = 0.692, p < .001 and r = 0.591, p < .001 respectively) and remained as independent prognostic factors in a multivariate regression analysis.

CONCLUSION

Surgery for drug-resistant epilepsy in elderly improves patients' HRQoL. Both seizure freedom and new neurological deficits influence overall HRQoL. Interestingly, anxiety and patients' subjective assessment of postoperative status showed the highest impact on HRQoL in this subpopulation of epilepsy patients.

Surgery for temporal lobe epilepsy in the elderly: Improving quality of life despite cognitive impairment

INTRODUCTION

Temporal lobe epilepsy (TLE) surgery is still underutilized, especially in the elderly population because of concerns related to postoperative complication rate and cognitive deterioration. The aim of the study was to evaluate surgical data, quality of life and neuropsychological outcome in elderly patients, who underwent resective surgery for drug resistant TLE.

METHODS AND MATERIALS

All patients underwent standardized presurgical assessment including clinical, neuroradiological, neuropsychological, and EEG examination. Elderly were considered all patients being 50 years or above (mean 56 yr., range 50-71 yr.). Neuropsychology was assessed before and after surgery, health-related quality of life (HRQOL) only after surgery.

RESULTS

A total of 94 consecutive elderly patients were analyzed. Temporo-mesial resections were performed in 85 patients (90 %). Seizure outcome was available in all patients with a mean follow-up of 5.2 years (1.2-19 ± 3.75 years). 57 patients (60.6 %) were completely seizure free (ILAE 1). The overall morbidity was 10 % including 5 surgical complications and 5 permanent neurological deficits. Neuropsychological assessments in 60 patients showed considerable preoperative impairment, losses in different domains in 25-45 % and gains in about 25 % of the patients. Postoperative HRQOL data was available in 75 patients, revealing significant increase of HRQOL in all domains. Complete seizure freedom was the strongest predictor for postoperative HRQOL (p < 0.001).

CONCLUSION

Surgery for drug resistant temporal lobe epilepsy is a feasible option for elderly patients as seizure control rates are comparable to the younger population. The acceptable rate of permanent neurological deficits and relevant improvements in quality of life, despite considerable postoperative cognitive impairment, justify surgical resection in properly selected elderly patients.

Insular Cortex Surgery for the Treatment of Refractory Epilepsy

Focal epilepsy originating from the insular cortex is rare. One reason is the small amount of cortical tissue compared with other lobes of the brain. However, the incidence of insular epilepsy might be underestimated because of diagnostic difficulties. The semiology and the surface EEG are often not meaningful or even misleading, and elaborated imaging might be necessary. The close connections of the insular cortex with other potentially epileptogenic areas, such as the temporal lobe or frontal/central cortex, is increasingly recognized as possible reason for failure of epilepsy surgery for temporal or extratemporal seizures. Therefore, some centers consider invasive EEG recording of the insular cortex not only in case of insular epilepsy but also in other focal epilepsies with nonconclusive results from the presurgical work-up. The surgical approach to and resection of insular cortex is challenging because of its deep location and proximity to highly eloquent brain structures. Over the last decades, technical adjuncts like navigation tools, electrophysiological monitoring and intraoperative imaging have improved the outcome after surgery. Nevertheless, there is still a considerable rate of postoperative transient or permanent deficits, in some cases as unavoidable and calculated deficits. In most of the recent series, seizure outcome was favorable and comparable with extratemporal epilepsy surgery or even better. Up to now, the data volume concerning long-term follow-up is limited. This review focusses on the surgical challenges of resections to treat insular epilepsy, on prognostic factors concerning seizure outcome, on postoperative deficits and complications. Moreover, less invasive surgical techniques to treat epilepsy in this highly eloquent area are summarized.

Salvage gamma knife radiosurgery in the management of dysembryoplastic neuroepithelial tumors: Long-term outcome in a single-institution case series

BACKGROUND

Dysembryoplastic neuroepithelial tumors (DNT/DNET) are rare epileptogenic tumors. Microsurgery remains the best treatment option, although case reports exist on the use of gamma knife radiosurgery (GKRS) in selected cases. We investigated the long-term outcome of GKRS-treated DNTs at our institution in the context of current diagnostic and treatment options.

CASE DESCRIPTIONS

We conducted a retrospective review of three consecutive adult patients (≥18 years) treated with salvage GKRS between 2002 and 2010 at Karolinska University Hospital, Stockholm, Sweden. The case series was supplemented by a review of current literature. A 20-year-old male underwent subtotal resection (STR) in 1997 and 2002 of DNT resulting in temporary control of intractable epilepsy despite antiepileptic drug treatment (AED). Long-term seizure control was obtained after GKRS of two separate residual DNT components along the surgical margin (2005 and 2010). A 27-year-old male undergoing gross total resection of the contrast-enhancing portion of a DNT (1999) resulted in temporary control of intractable epilepsy despite AEDs; lasting clinical control of seizures was achieved in 2002 after GKRS of a small, recurrent DNT component. A 28-year-old male underwent STR of DNT (1994 and 2004) resulting in temporary control of intractable epilepsy. Lasting seizure control was gained after GKRS of a residual tumor (2005).

CONCLUSION

GKRS as performed in our series was effective in terms of tumor and seizure control. No adverse radiation effects were recorded. Prospective studies are warranted to establish the role of GKRS in the treatment of DNTs.

Psychiatric symptoms after temporal epilepsy surgery. A one-year follow-up study

Psychiatric symptoms must be considered in patients with refractory temporal lobe epilepsy after epilepsy surgery. The main objectives of our study were to describe clinical and socio-demographical characteristics of a cohort of patients with pharmacoresistant temporal lobe epilepsy who underwent temporal lobe epilepsy surgery, and moreover, to evaluate possible risk factors for developing psychiatric symptoms. In order to achieve those goals, we conducted a prospective evaluation of psychopathology throughout the first year after surgery in a clinical sample of 72 patients, by means of three clinical rated measures; the Hamilton Anxiety Rating Scale (HARS), the Hamilton Depression Rating Scale (HDRS), and the Brief Psychiatric Rating Scale (BPRS). The psychopathological evaluations were performed by an experienced psychiatrist. A presurgical evaluation was done by a multidisciplinary team (that includes neurologist, psychiatrist, neurosurgeon, neurophysiologist, radiologists, and nuclear medicine specialist) in all patients. The decision to proceed to surgery was taken after a surgical meeting of all members of the Multidisciplinary Epilepsy Unit team. The psychiatrist conducted two postoperative assessments at 6months and 12months after surgery. The main finding was that past history of mental illness (patients who were receiving psychiatric treatment prior to the baseline evaluation) was a risk factor for anxiety, depression, and psychosis after temporal lobe epilepsy surgery.

Continuous Intraoperative Monitoring of Temporal Lobe Epilepsy Surgery

BACKGROUND/AIMS

The monitoring of interictal epileptiform discharge rates (IEDRs) all along anterior temporal lobe resections (ATLRs) has never been reported. Here the effect of ATLR on continuous IEDR monitoring is described.

METHODS

IEDRs computed automatically during entire interventions were recorded in 34 patients (38.2%, 13/34 depth; 61.8%, 21/34 scalp electrodes only). Monitorings were invalidated when burst suppression occurred or if initial IEDRs were <5.

RESULTS

Monitoring was successful for 69.2% (9/13) of the patients with depth recordings and for 4.8% (1/21) of the patients with scalp recordings. Burst suppressions precluded it in 30.8% (4/13) of the depth and in 57.1% (12/21) of the scalp recordings. Initial IEDRs were <5 for 38.1% (8/21) of the scalp recordings. Significant IEDR decreases were observed in 8/10 patients with successful monitoring. These decreases started with resection of the superior temporal gyrus. IEDRs decreased further with amygdalohippocampectomy in 3/5 patients. At the 12-month follow-up, all patients with IEDR decreases remained seizure free; both patients without did not.

CONCLUSION

IEDR monitoring was possible with depth, but not with scalp electrodes. IEDR decreases started with resection of the superior temporal gyrus. A larger patient cohort is necessary to confirm the high predictive values of IEDR monitoring that could become a tool for surgery customization.

Epilepsy and Adult Neurogenesis

Seizure activity in the hippocampal region strongly affects stem cell-associated plasticity in the adult dentate gyrus. Here, we describe how seizures in rodent models of mesial temporal lobe epilepsy (mTLE) affect multiple steps in the developmental course from the dividing neural stem cell to the migrating and integrating newborn neuron. Furthermore, we discuss recent evidence indicating either that seizure-induced aberrant neurogenesis may contribute to the epileptic disease process or that altered neurogenesis after seizures may represent an attempt of the injured brain to repair itself. Last, we describe how dysfunction of adult neurogenesis caused by chronic seizures may play an important role in the cognitive comorbidities associated with mTLE.

Health-related quality of life, mood, and patient satisfaction after epilepsy surgery in Sweden--a prospective controlled observational study

Objective

To evaluate health-related quality of life (HRQOL), mood, and patient satisfaction in epilepsy surgery candidates before and 2 years after epilepsy surgery or presurgical investigation.

Methods

In this prospective study of 141 patients, 96 underwent surgery and 45 did not. Questionnaires at baseline and at 2-year follow-up included the generic 36-item Short Form Health Survey (SF-36), the Hospital Anxiety and Depression scale (HAD), and operated patients answered patient satisfaction questions. SF-36 scores were compared with scores from a matched sample from the Swedish norm population. Numbers were calculated of patients achieving a minimum important change (MIC) in the SF-36 Physical Composite Summary (PCS) and Mental Composite Summary (MCS).

Results

At baseline, patients had significantly lower values than the norm on all SF-36 domains. At follow-up, operated patients were divided into seizure-free (International League Against Epilepsy [ILAE] class 1 and 2, n = 53) or with continued seizures (n = 43). No differences in baseline HAD or SF-36 values were found between these groups. Seizure-free patients reached the same levels as the norm in all SF-36 domains except Social Function. Operated patients with continued seizures and nonoperated patients had unchanged scores. Fifty-one percent of seizure-free patients had an improvement reaching MIC for PCS and 45% for MCS. Corresponding results for patients with continued seizures were 28% in PCS and 28% in MCS, for nonoperated 33% in PCS and 29% in MCS. HAD anxiety scores improved significantly in only the seizure-free patients. Of all operated patients, 80% were satisfied with having had surgery and 86% considered that they had benefited, whereas 20% thought that surgery caused some harm.

Significance

In patients who were seizure-free after epilepsy surgery HRQOL normalized and anxiety decreased. Operated patients overwhelmingly considered epilepsy surgery to be beneficial. Nonetheless, only about half of the seizure-free patients achieved important HRQOL improvements, suggesting that seizure freedom does not in and of itself guarantee improved patient well-being.

Trajectories of health-related quality of life in children with epilepsy: a cohort study

PURPOSE

Little is known about subgroups of children with epilepsy who may experience less favorable outcomes over time. The objectives of this study were to document trajectories of health-related quality of life (HRQL) and to identify predictors of the trajectory group in children with new-onset epilepsy.

METHODS

Data were obtained from the Health Related Quality of Life in Children with Epilepsy Study, a prospective multisite study of children 4-12 years old with new-onset epilepsy followed for 24 months. Health-related quality of life was measured using the Quality of Life in Childhood Epilepsy questionnaire. Trajectories of HRQL were investigated using latent class trajectory modeling. Multinomial logistic regression was used to identify child, parent, and family predictors of HRQL trajectories.

KEY FINDINGS

A total of 374 families responded at baseline and 283 (76%) completed the study. Five HRQL trajectories were observed: low-increasing (4%), moderate-decreasing (12%), moderate-increasing (22%), high-increasing (32%), and high-stable (30%). Many children in the low-increasing, moderate-increasing, high-increasing, and high-stable had clinically meaningful improvements in HRQL: 82%, 47%, 63%, and 44%, respectively. In contrast, the majority of children in the moderate-decreasing group (56%) experienced clinically meaningful declines in their HRQL. Factors predicting trajectories were number of antiepileptic drugs prescribed, presence of comorbid behavior or cognitive problems, parent depression, and family functioning and demands.

SIGNIFICANCE

Results suggested that children with epilepsy are not homogenous but rather consist of groups with different trajectories and unique predictors of HRQL. Problems associated with child behavior and cognition were the strongest predictors identified. Given that several risk factors are modifiable, it is important to examine these as potential targets within a family-centered framework to improve HRQL of children with new-onset epilepsy.

International consensus classification of hippocampal sclerosis in temporal lobe epilepsy: a Task Force report from the ILAE Commission on Diagnostic Methods

Hippocampal sclerosis (HS) is the most frequent histopathology encountered in patients with drug-resistant temporal lobe epilepsy (TLE). Over the past decades, various attempts have been made to classify specific patterns of hippocampal neuronal cell loss and correlate subtypes with postsurgical outcome. However, no international consensus about definitions and terminology has been achieved. A task force reviewed previous classification schemes and proposes a system based on semiquantitative hippocampal cell loss patterns that can be applied in any histopathology laboratory. Interobserver and intraobserver agreement studies reached consensus to classify three types in anatomically well-preserved hippocampal specimens: HS International League Against Epilepsy (ILAE) type 1 refers always to severe neuronal cell loss and gliosis predominantly in CA1 and CA4 regions, compared to CA1 predominant neuronal cell loss and gliosis (HS ILAE type 2), or CA4 predominant neuronal cell loss and gliosis (HS ILAE type 3). Surgical hippocampus specimens obtained from patients with TLE may also show normal content of neurons with reactive gliosis only (no-HS). HS ILAE type 1 is more often associated with a history of initial precipitating injuries before age 5 years, with early seizure onset, and favorable postsurgical seizure control. CA1 predominant HS ILAE type 2 and CA4 predominant HS ILAE type 3 have been studied less systematically so far, but some reports point to less favorable outcome, and to differences regarding epilepsy history, including age of seizure onset. The proposed international consensus classification will aid in the characterization of specific clinicopathologic syndromes, and explore variability in imaging and electrophysiology findings, and in postsurgical seizure control.

Efficacy of vagus nerve stimulation in posttraumatic versus nontraumatic epilepsy

OBJECT

In the US, approximately 500,000 individuals are hospitalized yearly for traumatic brain injury (TBI), and posttraumatic epilepsy (PTE) is a common sequela of TBI. Improved treatment strategies for PTE are critically needed, as patients with the disorder are often resistant to antiepileptic medications and are poor candidates for definitive resection. Vagus nerve stimulation (VNS) is an adjunctive treatment for medically refractory epilepsy that results in a ≥ 50% reduction in seizure frequency in approximately 50% of patients after 1 year of therapy. The role of VNS in PTE has been poorly studied. The aim of this study was to determine whether patients with PTE attain more favorable seizure outcomes than individuals with nontraumatic epilepsy etiologies.

METHODS

Using a case-control study design, the authors retrospectively compared seizure outcomes after VNS therapy in patients with PTE versus those with nontraumatic epilepsy (non-PTE) who were part of a large prospectively collected patient registry.

RESULTS

After VNS therapy, patients with PTE demonstrated a greater reduction in seizure frequency (50% fewer seizures at the 3-month follow-up; 73% fewer seizures at 24 months) than patients with non-PTE (46% fewer seizures at 3 months; 57% fewer seizures at 24 months). Overall, patients with PTE had a 78% rate of clinical response to VNS therapy at 24 months (that is, ≥ 50% reduction in seizure frequency) as compared with a 61% response rate among patients with non-PTE (OR 1.32, 95% CI 1.07-1.61), leading to improved outcomes according to the Engel classification (p < 0.0001, Cochran-Mantel-Haenszel statistic).

CONCLUSIONS

Vagus nerve stimulation should be considered in patients with medically refractory PTE who are not good candidates for resection. A controlled prospective trial is necessary to further examine seizure outcomes as well as neuropsychological outcomes after VNS therapy in patients with intractable PTE.

Seizure outcome, functional outcome, and quality of life after hemispherectomy in adults

BACKGROUND

Functional hemispherectomy is a well-established method in childhood epilepsy surgery with only a few reports on its application in adults.

METHODS

We report on 27 patients (median age 30 years, range 19-55) with a follow-up of more than 1 year (median 124 months, range 13-234). Etiology was developmental in two (one schizencephaly, one hemimegalencephaly), acquired in 21 (two hemiatrophy, 17 porencephaly, two postencephalitic), and progressive in four (Rasmussen's encephalitis).

RESULTS

At last available follow-up, 22 patients were seizure free (81 % ILAE class 1), one had auras (4 % ILAE class 2), one had no more than three seizures per year (4 % ILAE class 3). Thirty-seven percent were without antiepileptic drugs. Seventeen patients of 20 responding patients stated improved quality of life after surgery, one patient reported deterioration, and two patients reported no difference. Additionally, a self-rated postoperative functional status and changes compared to the pre-operative status was assessed. Six patients improved in gait, ten remained unchanged, and four deteriorated. Three patients improved in speech, none deteriorated. Hand function got worse five times, and in 15 cases remained unchanged. There was no mortality, one bone flap infection, and one subdural hematoma. Hydrocephalus was seen in three cases (12 %).

CONCLUSIONS

It is possible to achieve good seizure outcome results despite long-standing epilepsy across a variety of etiologies, comparable to epilepsy surgery in pediatric patients. Adult patients do not have to expect more problems with new deficits, appear to cope quite well, and mostly profit from surgery in several quality of life domains.

Very good inter-rater reliability of Engel and ILAE epilepsy surgery outcome classifications in a series of 76 patients

The inter-rater reliability, expressed as kappa score, k, of the Engel and International League Against Epilepsy (ILAE) classifications of epilepsy surgery seizure outcome has not previously been evaluated. In a consecutive series of 76 patients (40 male; 25 children), 75 undergoing resective and 1 disconnective surgery at a mean age of 27.5 years (13 months-62 years), one observer classified 88% (n=67) and a second observer classified 87% (n=66) of patients as either Engel I or II (free from or rare disabling seizures) after a median follow up of 36 months (range 12-92 months); comparably, both observers classified 84% (n=64) as ILAE 1-3. Correlation for Engel versus ILAE for observer 1 was 0.933 (p<.0005) and for observer 2 was 0.931 (p<.0005). Both ILAE (k 0.81, 95% confidence intervals 0.69, 0.91) and Engel (k 0.77, 95% CI 0.65, 0.87) classifications have very acceptable inter-rater reliability as well as significant correlation.

Determinants of quality of life after epilepsy surgery: systematic review and evidence summary

We systematically reviewed evidence-based determinants of health-related quality of life (QOL) in adults undergoing epilepsy surgery and assessed the effect of study methods. Medline, Embase, and the Cochrane library (1950-2008) were searched systematically. Two authors independently performed every step of the review. We obtained the proportion of studies reporting statistically significant positive or negative impact on QOL. Of 39 eligible studies, 32 assessed the impact of surgery on QOL and 29 (90.6%) found a significant positive effect. The most prevalent preoperative determinant was psychological function. Seizure freedom was the most prevalent postoperative determinant (80% of studies), followed by antiepileptic drug adverse events, employment status, and psychological function. Psychosocial (95%), physical (91%), and overall QOL (90%) domains improved most frequently, whereas role limitation (63%) and cognition (78%) improved least frequently. Methods, choice of instrument, and time of measurement influenced QOL outcomes and should be carefully chosen in future studies.

Epilepsy and insular Grade II gliomas: an interdisciplinary point of view from a retrospective monocentric series of 46 cases

OBJECT

There are few data in the literature concerning a multimodal approach to insular WHO Grade II gliomas (GIIGs) and the control of epilepsy after treatment. In this paper, the authors describe a monocentric series of 46 cases in which patients underwent various sequential treatments for insular GIIGs. On the basis of global results with regard to epilepsy, the respective interests in the various treatments are discussed.

METHODS

Available data on 46 patients harboring insular GIIGs were extracted from a local database of 288 GIIGs. The various therapeutic sequences were analyzed in parallel with the course of seizure frequency.

RESULTS

Despite the usual difficulties with seizure quantification in retrospective studies, the authors showed that 1) the negative course of seizure frequency was mostly connected to tumor progression, 2) surgery almost always had a favorable effect on epilepsy, and 3) chemotherapy had a mostly favorable effect with acceptable tolerance. The authors were unable to draw conclusions about the role of radiotherapy given the too few cases.

CONCLUSIONS

This extensive experience with insular GIIGs tends to confirm interest in their surgical removal and supports interest in chemotherapy from an epileptological point of view.

Towards a clinico-pathological classification of granule cell dispersion in human mesial temporal lobe epilepsies

The dentate gyrus (DG) plays a pivotal role in the functional and anatomical organization of the hippocampus and is involved in learning and memory formation. However, the impact of structural DG abnormalities, i.e., granule cell dispersion (GCD), for hippocampal seizure susceptibility and its association with distinct lesion patterns in epileptic disorders, such as mesial temporal sclerosis (MTS) remains enigmatic and a large spectrum of pathological changes has been recognized. Here, we propose a clinico-pathological classification of DG pathology based on the examination of 96 surgically resected hippocampal specimens obtained from patients with chronic temporal lobe epilepsy (TLE). We observed three different histological patterns. (1) A normal granule cell layer was identified in 11 patients (no-GCP; 18.7%). (2) Substantial granule cell loss was evident in 36 patients (referred to as granule cell pathology (GCP) Type 1; 37.5%). (3) Architectural abnormalities were observed in 49 specimens, including one or more of the following features: granule cell dispersion, ectopic neurons or clusters of neurons in the molecular layer, or bi-lamination (GCP Type 2; 51%). Cell loss was always encountered in this latter cohort. Seventy-eight patients of our present series suffered from MTS (81.3%). Intriguingly, all MTS patients displayed a compromised DG, 31 (40%) with significant cell loss (Type 1) and 47 (60%) with GCD (Type 2). In 18 patients without MTS (18.7%), seven displayed focally restricted DG abnormalities, either cell loss (n = 5) or GCD (n = 2). Clinical histories revealed a significant association between DG pathology patterns and higher age at epilepsy surgery (p = 0.008), longer epilepsy duration (p = 0.004), but also with learning dysfunction (p < 0.05). There was no correlation with the extent of pyramidal cell loss in adjacent hippocampal segments nor with postsurgical seizure relief. The association with long-term seizure histories and cognitive dysfunction is remarkable and may point to a compromised regenerative capacity of the DG in this cohort of TLE patients.

Modeling epilepsy with pluripotent human cells

Pluripotency is generally defined by the ability to differentiate into cell types representing all three germ layers: ectoderm, mesoderm, and endoderm. Human pluripotent stem cells hold great promise in regenerative medicine and in cell replacement therapies because of their ability to self-renew and their developmental potential to become all cell types in the body. Moreover, pluripotent cells represent a unique system in which to study the normal development of the human nervous system and the several instances where the process may fail. Here, I propose several strategies for how pluripotent stem cells, both human embryonic stem cells and induced pluripotent stem cells, can potentially be used to gain insights into the biology of temporal lobe epilepsy.

The surgery of epilepsy

The idea of surgical treatment for epilepsy is not new. However, widespread use and general acceptance of this treatment has only been achieved during the past three decades. A crucial step in this direction was the development of video electroencephalographic monitoring. Improvements in imaging resulted in an increased ability for preoperative identification of intracerebral and potentially epileptogenic lesions. High resolution magnetic resonance imaging plays a major role in structural and functional imaging; other functional imaging techniques (e.g., positron emission tomography and single-photon emission computed tomography) provide complementary data and, together with corresponding electroencephalographic findings, result in a hypothesis of the epileptogenic lesion, epileptogenic zone, and the functional deficit zone. The development of microneurosurgical techniques was a prerequisite for the general acceptance of elective intracranial surgery. New less invasive and safer resection techniques have been developed, and new palliative and augmentative techniques have been introduced. Today, epilepsy surgery is more effective and conveys a better seizure control rate. It has become safer and less invasive, with lower morbidity and mortality rates. This article summarizes the various developments of the past three decades and describes the present tools for presurgical evaluation and surgical strategy, as well as ideas and future perspectives for epilepsy surgery.

Quality-of-life trajectories in epilepsy: a review of the literature

The potential psychosocial sequelae of epilepsy are well-documented, but it cannot be assumed that trajectories for quality of life (QOL) of people with epilepsy will inevitably follow its clinical course. In this article, we draw on available literature to suggest likely QOL trajectories associated with epilepsy and the broad range of disease-, patient-, and other-focused factors that appear important in determining them. We conclude that both the likely shape and time frame for QOL trajectories associated with particular clinical scenarios can be delineated, but that their shape can be altered by a much wider range of factors than those represented as epilepsy disease progression. We identify contributory factors currently relatively unexplored and highlight implications for treatment and areas for future research.

Seizure-associated, aberrant neurogenesis in adult rats characterized with retrovirus-mediated cell labeling

Seizure activity within the hippocampal circuitry not only affects pre-existing structures, but also dramatically increases the number of newborn granule cells. A retroviral strategy was used to label dividing cells and their progeny in the adult dentate gyrus and to analyze the impact of epileptic activity on adult-generated cells labeled before or after seizures. We show that epileptic activity led to dramatic changes in the neuronal polarity, migration, and integration pattern of newborn granule cells, depending on the time of birth in relation to the epileptic insult. Aberrant neurons were stably integrated into the dentate circuitry, and the consequences on hippocampal neurogenesis were long lasting. The data presented characterized the consequences of seizure-associated plasticity on adult neurogenesis leading to long-term structural changes in the hippocampal circuitry that might represent a pivotal component of the epileptic disease process.

A new clinico-pathological classification system for mesial temporal sclerosis

We propose a histopathological classification system for hippocampal cell loss in patients suffering from mesial temporal lobe epilepsies (MTLE). One hundred and seventy-eight surgically resected specimens were microscopically examined with respect to neuronal cell loss in hippocampal subfields CA1–CA4 and dentate gyrus. Five distinct patterns were recognized within a consecutive cohort of anatomically well-preserved surgical specimens. The first group comprised hippocampi with neuronal cell densities not significantly different from age matched autopsy controls [no mesial temporal sclerosis (no MTS); n = 34, 19%]. A classical pattern with severe cell loss in CA1 and moderate neuronal loss in all other subfields excluding CA2 was observed in 33 cases (19%), whereas the vast majority of cases showed extensive neuronal cell loss in all hippocampal subfields (n = 94, 53%). Due to considerable similarities of neuronal cell loss patterns and clinical histories, we designated these two groups as MTS type 1a and 1b, respectively. We further distinguished two atypical variants characterized either by severe neuronal loss restricted to sector CA1 (MTS type 2; n = 10, 6%) or to the hilar region (MTS type 3, n = 7, 4%). Correlation with clinical data pointed to an early age of initial precipitating injury (IPI < 3 years) as important predictor of hippocampal pathology, i.e. MTS type 1a and 1b. In MTS type 2, IPIs were documented at a later age (mean 6 years), whereas in MTS type 3 and normal appearing hippocampus (no MTS) the first event appeared beyond the age of 13 and 16 years, respectively. In addition, postsurgical outcome was significantly worse in atypical MTS, especially MTS type 3 with only 28% of patients having seizure relief after 1-year follow-up period, compared to successful seizure control in MTS types 1a and 1b (72 and 73%). Our classification system appears suitable for stratifying the clinically heterogeneous group of MTLE patients also with respect to postsurgical outcome studies.