Safety of video-EEG monitoring and surgical outcome in patients with mesial temporal sclerosis and psychosis of epilepsy

PurposeCortico-amygdalohippocampectomy (CAH) has become an important treatment option for patients with refractory temporal lobe epilepsy and mesial temporal sclerosis (TLE-MTS); it has resulted in a 60–70% seizure remission rate and significant quality of life (QOL) improvements. Video-electroencephalography (VEEG) monitoring has been widely used in epilepsy centers for pre-surgical evaluation. A major concern in epilepsy surgery is whether to consider CAH treatment in patients with psychosis of epilepsy (POE). This study analyzed the safety and adverse events (AEs) of VEEG monitoring and the post-surgical outcomes of patients with refractory TLE-MTS and POE who underwent CAH.MethodClinical, sociodemographic and VEEG data from 18 patients with TLE-MTS and POE were analyzed. Psychiatric evaluations were performed using DSM-IV and ILAE criteria. The seizure outcome was evaluated using Engel's criteria.ResultsTwo patients (11.2%) presented AEs that did not result in increased lengths of hospitalization. Of the 10 patients (55.5%) who underwent CAH, 6 (60%) became free of disabling seizures (Engel I). The psychiatric and QOL evaluations revealed improvements of psychotic symptoms (p = 0.01) and in Physical Health (p = 0.01) following surgery.ConclusionThese data reinforce that VEEG monitoring is a safe method to evaluate patients with refractory TLE-MTS and POE in epilepsy centers.     

Type of preoperative aura may predict postsurgical outcome in patients with temporal lobe epilepsy and mesial temporal sclerosis

PurposeAs the initial symptoms of epileptic seizures, many types of auras have significant localizing or lateralizing value. In this study, we hypothesized that the type of aura may predict postsurgical outcome in patients with medically refractory temporal lobe epilepsy (TLE) and mesial temporal sclerosis (MTS).MethodsIn this retrospective study, all patients with a clinical diagnosis of medically refractory TLE due to unilateral mesial temporal sclerosis who underwent epilepsy surgery at the Jefferson Comprehensive Epilepsy Center were recruited. Patients were prospectively registered in a database from 1986 through 2014. Postsurgical outcome was classified into two groups: seizure freedom or relapse. Outcome was compared between seven groups of patients according to their preoperative auras.ResultsTwo hundred thirty-seven patients were studied. The chance of becoming free of seizures after surgery in patients with abdominal aura was 65.1%, while in other patients, this was 43.3% (P = 0.01). In two-by-two comparisons, no other significant differences were observed.ConclusionPatients with medically refractory TLE–MTS who reported abdominal auras preceding their seizures fared better postoperatively with regard to seizure control compared with those who did not report auras, which may indicate bitemporal dysfunction, and to patients with other auras, which may indicate a widespread epileptogenic zone in the latter group of patients.     

Outcome after cortico-amygdalo-hippocampectomy in patients with temporal lobe epilepsy and normal MRI

RationaleWe describe seizure and neuropsychological outcome obtained after CAH in patients with TLE and normal MRI evaluated in the modern imaging era.MethodsForty-five adult consecutive patients with TLE and normal MRI were studied. All patients had neuropsychological testing, interictal and ictal EEG recordings and MRI. They were divided into two groups: Group 1 (n = 18), included patients in whom non-invasive neurophysiological evaluation was lateralizing and Group 2 (n = 27) included patients with non-lateralizing neurophysiological data who were submitted to invasive recordings.ResultsSeventy-seven percent of the Group 1 patients were rated as Engel I; 11% were rated as Engel II and 11% as Engel III. In Group 2, there were 57% of patients seizure-free, 26% in Engel II and 14% in Engel III. Pre-operatively, mean general IQ was 82 and 78 in Groups1 and 2, respectively; post-operatively, mean general IQ was respectively 86 and 71. Some degree of verbal memory decline was noted in all patients submitted to dominant temporal lobe resection in both Groups 1 and 2. At last follow-up visit, 22% of Group 1 and 11% of Group 2 patients were receiving no antiepileptic drugs (AED).ConclusionsOur data showed that patients with TLE and normal MRI could get good surgical results after CAH although 60% of them would need invasive recordings and their results regarding seizure control and cognition were worse than those obtained in patients with MRI defined temporal lobe lesions. Caution should be taken in offering dominant temporal lobe resection to this subset of patients.     

Intracranial EEG seizure onset patterns in unilateral temporal lobe epilepsy and their relationship to other variables

ObjectiveWe performed a retrospective study to determine the different types of seizure onset patterns (SOP) in invasive EEG (IEEG) in patients with temporal lobe epilepsy (TLE).MethodsWe analyzed a group of 51 patients (158 seizures) with TLE who underwent IEEG. We analyzed the dominant frequency during the first 3 s after the onset of ictal activity. The cut-off value for distinguishing between fast and slow frequencies was 8 Hz. We defined three types of SOPs: (1) fast ictal activity (FIA) – frequency ?8 Hz; (2) slow ictal activity (SIA) – frequency <8 Hz; and (3) attenuation of background activity (AT) – no clear-cut rhythmic activity during the first 3 s associated with changes of IEEG signal (increase of frequency, decrease of amplitude). We tried to find the relationship between different SOP types and surgery outcome, histopathological findings, and SOZ localization.ResultsThe most frequent SOP was FIA, which was present in 67% of patients. More patients with FIA were classified postoperatively as Engel I than those with SIA and AT (85% vs. 31% vs. 0) (P < 0.001). There were no statistically significant differences in the type of SOP, in the histopathological findings, or in the SOZ localization.ConclusionIn patients with refractory TLE, seizure onset frequencies ?8 Hz during the first 3 s of ictal activity are associated with a better surgical outcome than frequencies <8 Hz.SignificanceOur study suggests that very early seizure onset frequencies in IEEG in patients with TLE could be the independent predictive factor for their outcome, regardless of the localization and etiology.     

Psychogenic nonepileptic seizures in patients with surgically treated temporal lobe epilepsy: Presurgical and de novo postsurgical occurrence

Whether occurring before or after an epilepsy surgery, psychogenic nonepileptic seizures (PNES) impact treatment options and quality of life of patients with epilepsy. We investigated the frequency of pre- and postsurgical PNES, and the postsurgical Engel and psychiatric outcomes in patients with drug-resistant temporal lobe epilepsy (TLE). We reviewed 278 patients with mean age at surgery of 37.1 ± 12.4 years. Postsurgical follow-up information was available in 220 patients, with average follow-up of 4 years.Nine patients (9/278 or 3.2%) had presurgical documented PNES. Eight patients (8/220 or 3.6%) developed de novo PNES after surgery. Pre- and postsurgery psychiatric comorbidities were similar to the patients without PNES. After surgery, in the group with presurgical PNES, five patients were seizure-free, and three presented persistent PNES. In the group with de novo postsurgery PNES, 62.5% had Engel II–IV, and 37.5% had Engel I. All presented PNES at last follow-up.Presurgical video-EEG monitoring is crucial in the diagnosis of coexisting PNES. Patients presenting presurgical PNES and drug-resistant TLE should not be denied surgery based on this comorbidity, as they can have good postsurgical epilepsy and psychiatric outcomes. Psychogenic nonepileptic seizures may appear after TLE surgery in a low but noteworthy proportion of patients regardless of the Engel outcome.     

Long term outcome of functional hemispherectomy for refractory epilepsy: Experience from a single center

BackgroundHemispherectomy has an established role as a treatment of last resort in patients with unilateral hemispheric lesions suffering from refractory epilepsy.MethodsSeven patients were evaluated at our Epilepsy Unit. We compared the seizure outcome at 6 months, 1, 2, 5 years post-surgery, as well as at end follow-up (mean 7.1 years) using Engel classification. Reduction of antiepileptic drugs (AEDs) was also assessed utilizing equal time frames.ResultsThe mean age of seizure onset was 5.4 years. Engel I was achieved in 5 patients at 6 months (71.4%). Engel at 1 year was predicted by the Engel at 6 months (p = 0.013) with a similar number of patients being classified as Engel I outcome. Engel at 2 years was also predicted by Engel at 6 months and at 1 year (p = 0.030). At end follow-up only 3 patients (42.9%) remained categorized as Engel I outcome. There was a trend toward a stability in Engel classification. All patients with developmental causes for their epilepsy experienced some deterioration of the surgical outcomes. Conversely, all patients with acquired causes were stable throughout follow-up. Seizure outcome at 6 months was worse in the patients who had post-op complications (p = 0.044). Adult and pediatric populations did not differ significantly in any tested variable.ConclusionsHemispherectomy is a valuable resource for seizure control in properly selected patients. Engel patient's evolution could be predicted at 6 months interval. Hemispherectomy could be considered a useful attitude in difficult cases.     

Preoperative depressive symptoms predict postoperative seizure outcome in temporal and frontal lobe epilepsy

ObjectiveRecent research has pointed to the possibility of a bidirectional relationship between seizure frequency in epilepsy and depressive symptoms. The study described here investigated the relationship between preoperative depressive symptomatology and postoperative seizure outcome in a sample of patients with temporal (TLE) and frontal (FLE) lobe epilepsy.MethodsA retrospective analysis was conducted on the data from 115 eligible patients with TLE (N = 97) and FLE (N = 18) and resections limited to one cortical lobe who were evaluated preoperatively and 1 year after epilepsy surgery with respect to depressive symptoms (Beck Depression Inventory, BDI) and seizure outcome. The latter was assessed in terms of actual total seizure frequency as well as a dichotomous variable (seizure free vs. not seizure free) for the 1-year outcome. Repeated-measures analyses of variance and regression analyses were applied.ResultsSeizure-free patients had significantly lower BDI scores preoperatively as well as postoperatively than patients who were not seizure free. In the regression analyses, the preoperative BDI score was a significant predictor of postoperative seizure frequency as well as seizure freedom. When only patients with TLE were analyzed, the results for the association between preoperative BDI and postoperative seizure frequency and seizure freedom remained consistent.ConclusionThe present results provide evidence for a statistical bidirectionality of the relationship between depressive symptoms and postoperative seizure status in a mixed sample of patients with TLE and FLE. Possible reasons for this bidirectional association include an underlying common pathology in both depression and epilepsy, for example, structural changes or functional alterations in neurotransmitter systems.     

Psychosocial factors associated with in postsurgical prognosis of temporal lobe epilepsy related to hippocampal sclerosis

We examined the long-term psychosocial trajectory in a consecutive and homogeneous series of 120 patients followed up for five years after corticoamygdalohippocampectomy (CAH). Evaluation of psychosocial variables at baseline and at five-year follow-up were compared. After five years of CAH, a significant improvement in educational level (p = 0.004) and employment status (p < 0.001) was observed, although retirement (p < 0.001) and divorce (p = 0.021) rates increased. In a long-term follow-up, a tendency to have similar QOL profile was observed between Engel classes IA and IB (p > 0.05). A more favorable surgical outcome (Engel IA) was related to better psychiatric status (p = 0.012). Poor psychosocial adjustment before surgery was the most important predictor of QOL outcome (p < 0.05). Patients' trajectory after surgical treatment showed positive effects mainly in those with better seizure outcome. Our results emphasized the influence regarding baseline psychosocial functioning on postoperative psychosocial adjustment. Furthermore, many psychosocial gains and difficulties after surgery may be similar in developing and developed countries.     

Temporal lobe surgery in medically refractory epilepsy: A comparison between populations based on MRI findings

IntroductionHigh resolution MRI findings suggestive of mesial temporal sclerosis (MRI-MTS) correlate with good outcome after surgery. However, a large group of patients present with normal brain MRI (N-MRI) and temporal lobe epilepsy (TLE). We aim to compare pre-operative ictal EEG patterns in predicting surgical outcomes in the population with MRI-MTS vs. N-MRI after selective anterior-mesial temporal lobe (AMTL) resection.Methods241 patients with unilateral anterior ictal EEG findings underwent selective AMTL resection. 143 MRI-MTS and 98 N-MRI patients were identified. Outcome was based on the modified Engel classification, ictal EEG pattern at seizure onset, demographics and MRI findings.ResultsSeizure-free outcome was seen in the MRI-MTS in 79% of patients, compared to 59.1% (p < .005) of the N-MRI group. No significant difference was identified in ictal EEG patterns at presentation between groups. Class I outcome was achieved in 78.9% of patients that had theta rhythm and MRI-MTS compared to 57.9% of patients that had theta rhythm and N-MRI (p < 0.05).Discussion and conclusionSurgical treatment for mesial TLE is effective. Positive MRI suggestive of mesial temporal sclerosis (MTS) predicts better seizure control after surgery. Theta rhythm is the most common ictal pattern and seems to carry the best prognosis for TLE. However, a well-selected group of patients with N-MRI will benefit from surgical intervention, and similar outcome to MRI-MTS patients can be achieved if delta ictal EEG pattern is presented at initial onset. Early referral to an epilepsy center cannot be emphasized enough, even in situations when high-resolution brain MRI is normal.     

Patient satisfaction with temporal lobectomy/selective amygdalohippocampectomy for temporal lobe epilepsy and its relationship with Engel classification and the side of lobectomy

PurposeThe aim of this study was to investigate not only the effectiveness of epilepsy surgery in improving seizure control but also patient satisfaction with the result of the procedure in a sample of patients operated on at a specialized epilepsy unit.MethodsPatients with temporal lobe epilepsy who had undergone epilepsy surgery (temporal lobectomy/amygdalohippocampectomy) were interviewed in a standardized telephone survey about their satisfaction with the results of the surgery. The morbidity of the surgery was also analyzed retrospectively. The initial study population consisted of 6 amygdalohippocampectomy and 102 temporal lobectomy patients and was reduced to a final sample consisting of 4 amygdalohippocampectomy and 67 lobectomy patients, as the other patients were not available for interview. Surgical results were based on the Engel classification, and satisfaction with the surgery was assessed by asking patients to rate their result and state whether they would make the same decision (to be operated on) again.ResultsA significant number of patients classified as Engel I or II, who considered the surgical outcome good or excellent, said they would have the surgery again (p < 0.001). Left temporal lobectomy patients whose results fell in the Engel III/IV bracket were less satisfied (p = 0.001) than right temporal lobectomy patients with the same Engel classifications (0.048). Left temporal lobectomy patients who were classified as Engel class III and IV were less likely to have the surgery again if they had the choice (p = 0.016).DiscussionPatient satisfaction with the results of epilepsy surgery may depend not only on achieving seizure control but also on the temporal lobe resected. Since worse results were associated with lower satisfaction rates only for left temporal resection patients, it is possible that the cognitive consequences of this procedure compound the worse surgical result, leading to decreased satisfaction.     

Psychiatric outcome of epilepsy surgery in patients with psychosis and temporal lobe drug-resistant epilepsy: A prospective case series

ObjectivesTemporal lobe resistant epilepsy has been associated with a high incidence of psychotic disorders; however, there are many controversies; while some patients get better after surgery from their psychiatric condition, others develop psychosis or de novo depression. The aim of this study was to determine the psychiatric and seizure outcome after epilepsy surgery in patients with a previous history of psychoses.MethodsSurgical candidates with temporal lobe drug-resistant epilepsy and a positive history of psychosis diagnosed during the presurgical psychiatric assessment were included. A two-year prospective follow-up was determined after surgery. The DSM-IV Structural Interview, GAF (global assessment of functionality, DSM-IV), Ictal Classification for psychoses, and Engel's classification were used. The Student t test and chi-square–Fisher tests were used.ResultsDuring 2000–2010, 89 patients were admitted to the epilepsy surgery program, 14 patients (15.7%) presented psychoses and were included in this series. After surgery, six patients (43%) did not develop any psychiatric complications, three patients (21%) with chronic interictal psychosis continued with no exacerbation, three patients (21%) developed acute and transient psychotic symptoms, and two patients (14%) developed de novo depression. Seizure outcome was Engel class I-II in 10 patients (71%). Total GAF scores were higher after surgery in patients found to be in Engel class I–II (p < 0.05).ConclusionsPatients with comorbid psychosis and temporal lobe drug-resistant epilepsy may benefit from epilepsy surgery under close psychiatric supervision.     

Differences between mesial and neocortical magnetic-resonance-imaging-negative temporal lobe epilepsy

ObjectiveThe aim of this study was to assess clinical and electrophysiological differences within a group of patients with magnetic-resonance-imaging-negative temporal lobe epilepsy (MRI-negative TLE) according to seizure onset zone (SOZ) localization in invasive EEG (IEEG).MethodsAccording to SOZ localization in IEEG, 20 patients with MRI-negative TLE were divided into either having mesial SOZ–mesial MRI-negative TLE or neocortical SOZ–neocortical MRI-negative TLE. We evaluated for differences between these groups in demographic data, localization of interictal epileptiform discharges (IEDs), and the ictal onset pattern in semiinvasive EEG and in ictal semiology.ResultsThirteen of the 20 patients (65%) had mesial MRI-negative TLE and 7 of the 20 patients (35%) had neocortical MRI-negative TLE. The differences between mesial MRI-negative TLE and neocortical MRI-negative TLE were identified in the distribution of IEDs and in the ictal onset pattern in semiinvasive EEG. The patients with neocortical MRI-negative TLE tended to have more IEDs localized outside the anterotemporal region (p = 0.031) and more seizures without clear lateralization of ictal activity (p = 0.044). No other differences regarding demographic data, seizure semiology, surgical outcome, or histopathological findings were found.ConclusionsAccording to the localization of the SOZ, MRI-negative TLE had two subgroups: mesial MRI-negative TLE and neocortical MRI-negative TLE. The groups could be partially distinguished by an analysis of their noninvasive data (distribution of IEDs and lateralization of ictal activity). This differentiation might have an impact on the surgical approach.     

Factors predicting 10-year seizure freedom after temporal lobe resection

Background

Resective surgery is an established and evidence-based treatment approach in pharmacoresistant temporal lobe epilepsy (TLE). Extra-long-term follow-up data are important to allow for good patient counseling. So far, only few trials provide prospective or retrospective data exceeding 5 years.

Objective

This study aimed to present data of continuous seizure outcome over an extended time period, with a particular focus on patients who remained seizure free for 10 years.

Methods

We analyzed seizure outcome after epilepsy surgery for TLE in 46 consecutive patients, who were seen on an annual basis for 10 years in a single center (Epilepsy Center Berlin Brandenburg). Factors for remaining seizure free for 10 years were determined by univariate analysis.

Results

The class I outcome changed each year by 74–78%. Of the patients, 63% remained continuously in Engel class I (48% Engel Class IA for 10 years) for 10 years. Six patients were never seizure free (12.5%). After 10 years, 35% of the patients were cured (i.e., seizure-free without medication). A higher number of antiepileptic drugs and seizures before surgery as well as the indication for invasive presurgical monitoring were associated with “unsuccessful surgery.”

Conclusion

With almost half of the patients completely seizure free and more than a third “cured,” epilepsy surgery remains the mainstay of therapy for TLE patients. Analysis in larger cohorts with extra-long-term follow-up is needed to assess good prognostic factors and other postsurgical outcome issues such as neuropsychological, psychiatric, and psychosocial outcomes.

     

Treatment of depression in patients with temporal lobe epilepsy: A pilot study of cognitive behavioral therapy vs. selective serotonin reuptake inhibitors

There is a high prevalence of depression in patients with epilepsy, which negatively impacts their quality of life (QOL) and seizure control. Currently, the first-line of treatment for depression in patients with epilepsy is based on selective serotonin reuptake inhibitors (SSRIs). The main objective of this pilot study was to compare cognitive behavioral therapy (CBT) versus SSRIs for the treatment of major depressive disorder (MDD) in patients with temporal lobe epilepsy (TLE). Seven patients who received group CBT were compared with eight patients treated with SSRIs. All were diagnosed with MDD and TLE. Patients were assessed at baseline before treatment and at six and 12 weeks during treatment with the Quality of Life in Epilepsy Scale of 31 items (QOLIE 31), the Beck Depression Inventory (BDI), and the Hospital Anxiety and Depression Scale (HADS). Seizure records were also taken on a monthly basis. After 12 weeks of treatment, both groups showed improved QOL and reduced severity of depression symptoms. There were no statistically significant group differences in the final scores for the BDI (p = 0.40) and QOLIE 31 (p = 0.72), although the effect size on QOL was higher for the group receiving CBT. In conclusion, the present study suggests that both CBT and SSRIs may improve MDD and QOL in patients with TLE. We found no significant outcome differences between both treatment modalities. These findings support further study using a double-blind controlled design to demonstrate the efficacy of CBT and SSRIs in the treatment of MDD and QOL in patients with TLE.     

A retrospective study comparing preoperative evaluations and postoperative outcomes in paediatric and adult patients undergoing surgical resection for refractory epilepsy

PurposeTo review and compare the preoperative characteristics and postsurgical outcomes in paediatric and adult patients who underwent surgical resections from 2001 to 2009.MethodsCombined data from noninvasive measures such as ictal semiology, interictal/ictal scalp EEGs, MRI and SPECT were utilised to identify the epileptogenic zones (EZ). When noninvasive investigations produced inconclusive or inconsistent findings, patients underwent intracranial EEG monitoring. Resective micro-surgical procedures were conducted according to the results of the anatomo-electro-clinical investigations and were carried out to remove the EZ. We then followed up 222 paediatric (≤18 years old) and 100 adult patients (≥19 years old) for 1–9 years postoperatively.ResultsThe mean age of seizure onset in paediatric group was significantly lower than that in adult group. 95 (43%) of the paediatric and 42 (42%) of the adult patients required long-term intracranial EEG recording. 54 (24.3%) of the paediatric and 62 (62%) of the adult patients were found to have temporal lobe epilepsy (TLE), while 149 (67.1%) of the paediatric and 37 (37.0%) of the adult patients had extra-temporal lobe epilepsy (ETLE) (p = 0.000). 19 (8.6%) of the paediatric patients and 1 (1%) adult patient had hemispheric lesions (p = 0.009). 148 (66.7%) of the paediatric and 61 (61.0%) of the adult patients were seizure-free during the follow-up period. 17 of 19 (89.5%) children who underwent hemispherectomy were seizure-free. In both paediatric and adult groups, the surgical outcome for patients with TLE was significantly better than that of patients with ETLE (p = 0.018 in children, p = 0.029 in adults). Both the location of EZs and seizure-free ratio were significantly different (p < 0.001) between the preadolescent (≤12 years old) and adolescent (13–18 years old) group. Hippocampal sclerosis was the most common pathologic finding in patients with TLE in both groups, and was followed by focal cortical dysplasia. In patients with TLE, the proportion of tumour was significantly higher in the paediatric than the adult group (25.9% vs. 10%, p = 0.021).ConclusionPaediatric patients with refractory seizures had more extratemporal or hemispheric resectable epileptogenic foci and fewer temporal foci than adults. Our study demonstrates that resective surgery is an effective and safe early intervention in strictly selected paediatric patients with refractory epilepsy.     

Sleep before and after temporal lobe epilepsy surgery

PurposePatients with epilepsy often complain of non-restorative sleep. This is the consequence of the acute effect of seizures and the chronic effect of epilepsy responsible for disrupting sleep architecture. Other factors such as antiepileptic drugs (AEDs), also play a role in the alteration of sleep organization. The aim of this study was to evaluate the specific effect of seizures and interictal epileptiform abnormalities (IEAs) on sleep, in particular to see whether reducing seizure frequency by epilepsy surgery might improve sleep organization in these patients.MethodsEleven patients with refractory mesial temporal lobe epilepsy, who underwent surgical treatment and who were seizure free at the follow-up, were included in the study. Treatment with AEDs was not significantly modified before the second year of follow-up. Patients were evaluated before surgery, at 1-year and 2-year follow-up visits with a videoEEG monitoring (24 h/24). At each follow-up visit, interictal epileptiform abnormalities and sleep macrostructure parameters were assessed.ResultsAll patients showed a reduction of their IEAs. At 1-year follow-up, total sleep time and REM sleep increased significantly (p = 0.032 and p = 0.006, respectively). At 2-year follow-up, an important increase of REM sleep was observed (p = 0.028). Most significant variations were noted 1 year after surgery. No significant variations were observed between the first and the second year after surgery.ConclusionsSurgical treatment of temporal lobe epilepsy may improve sleep macrostructure by reducing the number of seizures and of IEAs. These results indirectly confirm the role of epilepsy in disrupting sleep organization chronically.     

Long-term accelerated forgetting of verbal and non-verbal information in temporal lobe epilepsy

IntroductionWe investigated whether pre-surgical patients with temporal lobe epilepsy (TLE) forget verbal and non-verbal material faster than healthy controls over retention intervals of an hour and 6 weeks, and whether any observed memory loss was associated with structural changes to the hippocampus and/or seizure frequency.MethodsA mixed factorial design compared the performance of 27 patients with TLE and 22 healthy control participants, matched for IQ, age and gender, on tests of story recall and complex figure recall at three delays: immediate, 1 h and 6 weeks. Performance of the patient and control groups was matched at the immediate delay, which enabled comparisons of forgetting rate over the longer delays.ResultsWe found that TLE can affect the acquisition and retention of new memories over a relatively short delay of 1 h. This deficit was associated with structural hippocampal abnormality, with a material-specific effect that was particularly evident for the verbal task. We also found evidence of accelerated long-term forgetting in both patient groups, for the verbal and non-verbal tasks. It was demonstrated most strongly on the verbal task by the patients with right lateralized hippocampal sclerosis whose verbal recall was normal at the 1-h delay. Accelerated long-term forgetting was not associated with hippocampal pathology, but was associated with the frequency of epileptic seizures.DiscussionThe findings from the verbal task in particular provide evidence consistent with an extended period of memory consolidation that can be disrupted by both left and right TLE. The material-specific effects at the 1-h delay only, suggest that the initial consolidation of verbal and non-verbal, information depends on the integrity of the left and right hippocampus, respectively.     

Is ‘burned-out hippocampus’ syndrome a distinct electro‐clinical variant of MTLE-HS syndrome?

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

Long-term outcome and predictors of resective surgery prognosis in patients with refractory extratemporal epilepsy

PurposeWe analyzed the long-term postoperative outcome and possible predictive factors of the outcome in surgically treated patients with refractory extratemporal epilepsy.MethodsWe retrospectively analyzed 73 patients who had undergone resective surgery at the Epilepsy Center Brno between 1995 and 2010 and who had reached at least 1 year outcome after the surgery. The average age at surgery was 28.3 ± 11.4 years. Magnetic resonance imaging (MRI) did not reveal any lesion in 24 patients (32.9%). Surgical outcome was assessed annually using Engel's modified classification until 5 years after surgery and at the latest follow-up visit.ResultsFollowing the surgery, Engel Class I outcome was found in 52.1% of patients after 1 year, in 55.0% after 5 years, and in 50.7% at the last follow-up visit (average 6.15 ± 3.84 years). Of the patients who reached the 5-year follow-up visit (average of the last follow-up 9.23 years), 37.5% were classified as Engel IA at each follow-up visit. Tumorous etiology and lesions seen in preoperative MRI were associated with significantly better outcome (p = 0.035; p < 0.01). Postoperatively, 9.6% patients had permanent neurological deficits.ConclusionSurgical treatment of refractory extratemporal epilepsy is an effective procedure. The presence of a visible MRI-detected lesion and tumorous etiology is associated with significantly better outcome than the absence of MRI-detected lesion or other etiology.     

The duration of temporal lobe epilepsy and seizure outcome after epilepsy surgery

To assess the effect of the duration of epilepsy on the outcome of epilepsy surgery in non-lesional medically refractory temporal lobe epilepsy we reviewed the outcome of 76 patients.MethodsAll patients had anterior temporal resections for “non-lesional” temporal epilepsy (excluding any patient with tumours or vascular malformations but including patients with hippocampal sclerosis). Outcome at one year was assessed using Engel's scale.Results67% had a good outcome (Engel I or II). The mean duration of epilepsy was 23.0 years (range 2.9–46.9 years). Overall, there was no significant difference between patients with good outcome (mean duration 22.4 years) and poor outcome (mean duration 24.2 years) (p = 0.49). The proportion of patients with good outcome was slightly higher in the shorter duration groups. (Duration less than 10 years 75%, 10–19 years 71%, 20–29 years 65%, 30–39 years 62%, and 40–49 years 60% good outcome, p = 0.95).ConclusionWe found no significant associations between outcome and duration of epilepsy.