RESUMEN

OBJECTIVE: Focal cortical dysplasias (FCD) are characterized by distinct interictal spike patterns and high frequency oscillations (HFOs; ripples: 80-250 Hz; fast ripples: 250-500 Hz) in the intra-operative electrocorticogram (ioECoG). We studied the temporal relation between intra-operative spikes and HFOs and their relation to resected tissue in people with FCD with a favorable outcome. METHODS: We included patients who underwent ioECoG-tailored epilepsy surgery with pathology confirmed FCD and long-term Engel 1A outcome. Spikes and HFOs were automatically detected and visually checked in 1-minute pre-resection-ioECoG. Channels covering resected and non-resected tissue were compared using a logistic mixed model, assessing event numbers, co-occurrence ratios, and time-based properties. RESULTS: We found pre-resection spikes, ripples in respectively 21 and 20 out of 22 patients. Channels covering resected tissue showed high numbers of spikes and HFOs, and high ratios of co-occurring events. Spikes, especially with ripples, have a relatively sharp rising flank with a long descending flank and early ripple onset over resected tissue. CONCLUSIONS: A combined analysis of event numbers, ratios, and temporal relationships between spikes and HFOs may aid identifying epileptic tissue in epilepsy surgery. SIGNIFICANCE: This study shows a promising method for clinically relevant properties of events, closely associated with FCD.

Asunto(s)

RESUMEN

Ictal asystole (IA) is a rare but potentially life-threatening complication of focal epilepsy. The sudden onset of loss of consciousness and drop attacks in a patient with chronic epilepsy should suggest the possibility of this complication. Once the diagnosis is established, rapid management should be considered, especially in high-risk cases. The approach does not differ between temporal and extratemporal lobe epilepsies. Strategies can be aimed at preventing the emergence of cortical epileptic activity from the beginning (surgery, antiseizure therapy), neutralizing negative chronotropic effects on the heart (cardiac neuromodulation), or restarting the heart rhythm with a pacemaker. Pacemaker implantation is not a completely complication-free treatment, and living with a device that requires care and follow-up throughout life makes alternative treatment methods more valid for young patients with many years to live or cases that could benefit from surgery. In this article, we present a patient with a left occipital glioneuronal tumor and drug-resistant occipital lobe epilepsy. IA was documented by long-term video EEG monitoring (VEM). During about 2 years of follow-up after a cardiac neuromodulation procedure, there were no drop attacks or asystole with seizures, confirmed by long-term VEM.

Asunto(s)

RESUMEN

Epilepsy is one of the most frequent neurological conditions with an estimated prevalence of more than 50 million people worldwide and an annual incidence of two million. Although pharmacotherapy with anti-seizure medication (ASM) is the treatment of choice, ~30% of patients with epilepsy do not respond to ASM and become drug resistant. Focal epilepsy is the most frequent form of epilepsy. In patients with drug-resistant focal epilepsy, epilepsy surgery is a treatment option depending on the localisation of the seizure focus for seizure relief or seizure freedom with consecutive improvement in quality of life. Beside examinations such as scalp video/electroencephalography (EEG) telemetry, structural, and functional magnetic resonance imaging (MRI), which are primary standard tools for the diagnostic work-up and therapy management of epilepsy patients, molecular neuroimaging using different radiopharmaceuticals with single-photon emission computed tomography (SPECT) and positron emission tomography (PET) influences and impacts on therapy decisions. To date, there are no literature-based praxis recommendations for the use of Nuclear Medicine (NM) imaging procedures in epilepsy. The aims of these guidelines are to assist in understanding the role and challenges of radiotracer imaging for epilepsy; to provide practical information for performing different molecular imaging procedures for epilepsy; and to provide an algorithm for selecting the most appropriate imaging procedures in specific clinical situations based on current literature. These guidelines are written and authorized by the European Association of Nuclear Medicine (EANM) to promote optimal epilepsy imaging, especially in the presurgical setting in children, adolescents, and adults with focal epilepsy. They will assist NM healthcare professionals and also specialists such as Neurologists, Neurophysiologists, Neurosurgeons, Psychiatrists, Psychologists, and others involved in epilepsy management in the detection and interpretation of epileptic seizure onset zone (SOZ) for further treatment decision. The information provided should be applied according to local laws and regulations as well as the availability of various radiopharmaceuticals and imaging modalities.

Asunto(s)

RESUMEN

Drug-resistant epilepsy (DRE) is associated with high extracellular levels of glutamate. Studies support the idea that cannabidiol (CBD) decreases glutamate over-release. This study focused on investigating whether CBD reduces the evoked glutamate release in cortical synaptic terminals obtained from patients with DRE as well as in a preclinical model of epilepsy. Synaptic terminals (synaptosomes) were obtained from the epileptic neocortex of patients with drug-resistant temporal lobe epilepsy (DR-TLE, n = 10) or drug-resistant extratemporal lobe epilepsy (DR-ETLE, n = 10) submitted to epilepsy surgery. Synaptosomes highly purified by Percoll-sucrose density gradient were characterized by confocal microscopy and Western blot. Synaptosomes were used to estimate the high KCl (33 mM)-evoked glutamate release in the presence of CBD at different concentrations. Our results revealed responsive tissue obtained from seven patients with DR-TLE and seven patients with DR-ETLE. Responsive tissue showed lower glutamate release (p < 0.05) when incubated with CBD at low concentrations (less than 100 µM) but not at higher concentrations. Tissue that was non-responsive to CBD (DR-TLE, n = 3 and DR-ELTE, n = 3) showed high glutamate release despite CBD exposure at different concentrations. Simultaneously, a block of the human epileptic neocortex was used to determine its viability through whole-cell and extracellular electrophysiological recordings. The electrophysiological evaluations supported that the responsive and non-responsive human epileptic neocortices used in the present study exhibited proper neuronal viability and stability to acquire electrophysiological responses. We also investigated whether the subchronic administration of CBD could reduce glutamate over-release in a preclinical model of temporal lobe epilepsy. Administration of CBD (200 mg/kg, p.o. every 24 h for 7 days) to rats with lithium-pilocarpine-evoked spontaneous recurrent seizures reduced glutamate over-release in the hippocampus. The present study revealed that acute exposure to low concentrations of CBD can reduce the glutamate over-release in synaptic terminals obtained from some patients with DRE. This effect is also evident when applied subchronically in rats with spontaneous recurrent seizures. An important finding was the identification of a group of patients that were non-responsive to CBD effects. Future studies are essential to identify biomarkers of responsiveness to CBD to control DRE.

RESUMEN

Extratemporal facial nerve schwannomas are rare entity. Pre-operative assessment is mostly inconclusive with differential diagnosis of parotid tumors. We hereby report a case of 28 years female who presented with painless swelling in right parotid region with normal facial nerve function. Ultrasonography was suggestive well circumscribed and homogenous mass arising from the deep lobe of parotid gland. The Fine-needle aspiration cytology came out to be inconclusive. For further characterization of the tumor contrast enhanced MR imaging was performed. The MR imaging revealed well-defined cystic, heterogeneous, pear-shaped mass lesion situated near the stylomastoid foramen. Post operatively the mass came out to be schwannoma on histopathological examination.

RESUMEN

BACKGROUND: Subclinical seizures(SCSs) are overlooked in clinical practice. This study aims to investigate clinical, electrophysiological features of SCSs detected during video-electroencephalography(EEG) monitorization(VEM), concordance of the epilepsy type and SCSs, and predictors of the concordance. METHODS: The data of drug-resistant epilepsy patients who had undergone video-EEG between 2010 and 2020 were investigated. Ictal activities showing temporospatial evolution lasted ≥ 10 s, without any behavioural changes were considered SCSs. Findings were re-evaluated for ictal localization, lateralization, ictal discharge type, vigilance status, and duration of SCSs to the accompaniment of clinical findings. Additionally, the concordance of epilepsy type and SCSs were analyzed. RESULTS: Fifty-five SCSs were obtained in 24 of 804 patients (2,9 %) who were followed in the VEM unit; the epilepsy type of the patients was temporal in 26 and extratemporal lobe epilepsy in 29 SCSs. Among 55 SCSs recordings, 30 originated from the temporal lobe and 24 from the extratemporal lobe, and seizure localization could not be determined in one. The patients were younger, age at seizure onset was earlier, habitual seizures were more frequent, multiple anti-seizure drug use was higher, seizures more frequently occurred during sleep, cranial MR tended to be abnormal, patients were more likely to have a history of perinatal injury/head trauma, and the concordance of discharge patterns was lower in extratemporal SCSs.The concordance of epilepsy type with localization and lateralization of SCSs was not statistically significant. CONCLUSIONS: SCSs originating from the temporal and extratemporal lobes might show similar characteristics with the epilepsy type, and SCSs might have clinical importance apart from epilepsy surgery.

Asunto(s)

RESUMEN

OBJECTIVE: To evaluate the ability of semiology alone in localising the epileptogenic zone (EZ) in people with frontal lobe epilepsy (FLE) who underwent resective surgery. METHODS: We examined data on all individuals who had FLE surgery at our centre between January 01, 2011 and December 31, 2020. Descriptions of ictal semiology were obtained from video-EEG telemetry reports and presurgical multidisciplinary meeting summaries. The putative EZ was represented by the final site of resection. We assessed how well initial and combined set-of-semiologies correlated anatomically with the EZ, using a semiology visualisation tool to generate probabilistic cortical heatmaps of involvement in seizures. RESULTS: Sixty-one individuals had FLE surgery over the study period. Twelve months following surgery, 28/61 (46%) were completely seizure-free, with a further eight experiencing only auras. Comparing the semiology database with the putative EZ, combined set-of-semiology correctly lateralised in 77% (95% CI: 69-85%), localised to the frontal lobe in 57% (95% CI: 48-67%), frontal lobe subregions in 52% (95% CI: 43-62%), and frontal gyri in 25% (95% CI: 16-33%). No difference in degree of correlation was seen comparing those with ongoing seizures 12 months after surgery to those seizure free. SIGNIFICANCE: Semiology alone was able to correctly lateralize the putative EZ in 77%, and localise to a sublobar level in approximately half of individuals who had FLE surgery. Semiology is not adequate alone and must be combined with imaging and EEG data to identify the epileptogenic zone.

Asunto(s)

RESUMEN

OBJECTIVE: Resective surgery for selected individuals with frontal lobe epilepsy can be effective, although multimodal outcomes are less established than in temporal lobe epilepsy. We describe long-term seizure remission and relapse patterns, psychiatric comorbidity, and socioeconomic outcomes following frontal lobe epilepsy surgery. METHODS: We reviewed individual data on frontal lobe epilepsy procedures at our center between 1990 and 2020. This included the presurgical evaluation, operative details and annual postoperative seizure and psychiatric outcomes, prospectively recorded in an epilepsy surgery database. Outcome predictors were subjected to multivariable analysis, and rates of seizure freedom were analyzed using Kaplan-Meier methods. We used longitudinal assessment of the Index of Multiple Deprivation to assess change in socioeconomic status over time. RESULTS: A total of 122 individuals with a median follow-up of seven years were included. Of these, 33 (27 %) had complete seizure freedom following surgery, with a further 13 (11 %) having only auras. Focal MRI abnormality, histopathology (focal cortical dysplasia, cavernoma or dysembryoplastic neuronal epithelial tumor) and fewer anti-seizure medications at the time of surgery were predictive of a favorable outcome; 67 % of those seizure-free for the first 12 months after surgery never experienced a seizure relapse. Thirty-one of 50 who had preoperative psychiatric pathology noticed improved psychiatric symptomatology by two years postoperatively. New psychiatric comorbidity was diagnosed in 15 (13 %). Persistent motor complications occurred in 5 % and dysphasia in 2 %. No significant change in socioeconomic deciles of deprivation was observed after surgery. SIGNIFICANCE: Favorable long-term seizure, psychiatric and socioeconomic outcomes can be seen following frontal lobe epilepsy surgery. This is a safe and effective treatment that should be offered to suitable individuals early.

Asunto(s)

RESUMEN

Objective: We explored changes in heart rate during the peri-ictal period in patients with focal epilepsy, and differences in heart rate changes according to epileptic site and side were assessed. Methods: A total of 198 epileptic seizures in 102 patients with focal epilepsy, who had a definite epileptogenic focus and had undergone surgical treatment, were assessed from 2014 to 2019. Heart rate was measured manually during the peri-ictal period. Change in heart rate and the time it occurred were assessed and compared between different epileptic sites and sides. Results: Heart rate increased in 177 (89.4%) of 198 seizures. In 82 (44.8%) of 183 seizures, the change in heart rate occurred before seizure onset. The median period of heart rate change was seven seconds (interquartile range: 3­11 seconds) in seizures with heart rate change before seizure onset. The number of seizures with heart rate increase before seizure onset was significantly greater for medial temporal lobe epilepsy compared to lateral temporal lobe epilepsy (p=0.019) and extratemporal lobe epilepsy (p=0.002). Significance: A change in heart rate prior to seizure onset is more likely to occur in patients with medial temporal lobe epilepsy, compared to those with lateral temporal lobe epilepsy and extratemporal lobe epilepsy. Patients with medial temporal lobe epilepsy may likely benefit from seizure warning and detection devices.

Asunto(s)

RESUMEN

OBJECTIVE: Epilepsy surgery has shown efficacy in children. We aimed to assess long-term seizure outcome in children who underwent epilepsy surgery and determine predictive factors for seizure freedom. METHODS: This is a retrospective study of 196 children who underwent epilepsy surgery between 1994 and 2015 and had a minimum postoperative follow-up of 5 years. RESULTS: The median age at the time of surgery was 9.5 (0.08-19.8) years; 110 (56.1%) had temporal, 62 (31.6%) had extratemporal resections, and 24 (12.2%) had hemispheric surgery. The duration of postsurgical follow-up was between 5 and 20 years (mean±SD: 7 ± 3.2). Overall, 129 of 196 (65.8%) patients had Engel class I outcome at final visit. Among patients who underwent temporal, extratemporal and hemispheric surgery; 84 of 110 (76.4%), 34 of 62 (54.8%), and 11 of 24 (45.8%) patients had complete seizure freedom, respectively (p: 0.016). Patients with tumors had the best outcome, with 83.1% seizure freedom. The number of preoperative antiseizure medications (OR 3.19, 95% CI 1.07-9.48), the absence of postoperative focal epileptiform discharges (OR 8.98, 95% CI 4.07-19.79) were independent predictors of seizure freedom. Across two decades, the age at surgery was decreased (p: 0.003), overall seizure freedom (61.8% vs 68%) did not differ. In the past decade, a higher proportion of malformations of cortical development was operated (14.7% vs 35.9%, p: 0.007). SIGNIFICANCE: Our findings showed favorable long-term seizure outcome in children who underwent epilepsy surgery. The results are encouraging for developing centers with limited resources to establish pediatric epilepsy programs.

Asunto(s)

RESUMEN

Different sleep stages exert differential effects on interictal discharges, neural synchrony and seizure threshold. We sought to assess the relationship between localization of the epileptogenic focus and seizure distribution in sleep versus wakefulness among patients with refractory epilepsy. We conducted a retrospective chart review-based study. Video-electroencephalography of patients with refractory epilepsy, planned for resective surgery, were reviewed for seizure localisation and occurrence relative to stage of sleep/wakefulness. Demographic/clinical data, including details of surgery, were also recorded. Bivariate analysis was conducted using the chi-square test for proportions and unpaired t-test/ANOVA to compare the means within groups. We enrolled 175 patients (107 males) with a mean age of 26.1 + 9.8 years (range: 4-53 years). We analysed 1,282 seizures, of which 916 (71.5%) were temporal, 95 (7.4%) frontal, 144 (11.2 %) central/ parietal and 19 (1.5%) arose from the occipital lobe. Temporal lobe onset seizures were more frequent during wakefulness (77.7%) compared to extra-temporal localization (65%) (p<0.0001). Amongst temporal lobe onset seizures, those during wakefulness arose more frequently from the lateral temporal (88.6%) compared to the mesial temporal lobe (75.5%) (p=0.0003). A higher proportion of seizures evolved into secondary generalisation during sleep (23.5%) versus 8.7% during wakefulness (p<0.0001). Our study demonstrates that lobar location of epileptogenic foci is associated with a predilection of seizures to occur, as well as secondarily generalise, during sleep/wakefulness. Seizures with lateral temporal lobe as well as extratemporal lobe onset were more likely to occur during wakefulness. Overall, sleep related seizures were more likely to be of extratemporal lobe onset, though.

Asunto(s)

RESUMEN

OBJECTIVES: Recent literature documents a trend of gradual decline in temporal lobe (resective) epilepsy surgery over the past decade. Amongst these, a large scale, comprehensive survey done in selected European, Australian and American centres documents trends of resective temporal epilepsy surgery across two decades. Montreal Neurological Institute has been the leading epilepsy surgery centre for more than 50 years now. It has been at the forefront of investigating and managing epilepsy in Canada. We have looked into the trends of epilepsy surgery in our institute in the past 44 years. METHODS: The records of all adult epilepsy surgery procedures (excluding reoperations) performed by the senior authors were analysed from 1971 to 2015. Data retrieved for analysis included type of surgery (intracranial recording, resective, and neuromodulatory) and the specific surgical target for resection. Procedures were grouped into temporal resective, extratemporal (ET) resective and placement of intracranial electrodes (stereotactic electroencephalogram (SEEG)). RESULTS: A total of 2,078 new procedures were performed from 1971 to 2015 at the Montreal Neurological Institute. Temporal procedures constituted the bulk of the proportion of all procedures each year and the entire study period. SEEG group shows linear increase in the number of cases over the years catching up with the total number of temporal procedures. CONCLUSIONS: Our study involving a homogenous dataset spanning nearly 50 years shows a decline in temporal lobe surgeries and an increase in intracranial investigations despite the class I evidence of its effectiveness. This corroborates the trends in epilepsy surgery practice profiles in tertiary centres of developed countries.

Asunto(s)

RESUMEN

OBJECTIVE: To validate relative source power (RSP) imaging of extratemporal interictal epileptiform discharges (IEDs). METHODS: The accuracy of RSP was validated in a cohort of patients with extratemporal focal epilepsy and a confined epileptogenic lesion (<19 cm3) using distance to the lesion, concordance with resected area and postoperative outcome. Performance was compared with three conventional methods: voltage maps, equivalent current dipole and a distributed source model. RESULTS: Thirty-three of 41 consecutive patients (80%) had IED averages suitable for analysis. While the peak negativity in voltage maps localized above the epileptogenic lesion only in 18 cases, RSP-maps matched in 29 cases (88%, p < 0.0026). Source localization showed a median distance of 9.8 mm from the lesion. Source-regions with 20 mm radius included 98% of all source-to-lesion distances. In the 21 surgical cases, outcome showed a sensitivity of 82.35% and specificity of 50% without significant differences between the three source imaging methods. CONCLUSIONS: RSP-maps provide a rapid, intuitive and more accurate source estimation than voltage maps. At sublobar level, RSP localizes with an accuracy similar to conventional methods and results of previous studies. SIGNIFICANCE: The definition of a source region with 20 mm radius helps in guiding further exploration in extratemporal focal epilepsy.

Asunto(s)

RESUMEN

PURPOSE: Exploration of the effect of chronic recurrent seizures in focal epilepsy on brain volumes has produced many conflicting reports. To determine differences in brain structure in temporal lobe epilepsy (TLE) and extratemporal epilepsy (using frontal lobe epilepsy (FLE) a surrogate) further, we performed a retrospective analysis of a large cohort of patients with seizure-onset zone proven by intracranial monitoring. METHODS: A total of 120 TLE patients, 86 FLE patients, and 54 healthy controls were enrolled in this study. An analysis of variance of voxel-based morphometry (VBM) was used to seek morphometric brain differences among TLE patients, FLE patients, and healthy controls. Additionally, a vertex-based surface analysis was utilized to analyze the hippocampus and thalamus. Significant side-specific differences in hippocampal gray matter volume were present between the left TLE (LTLE), right TLE RTLE (RTLE), and control groups (p<0.05, family-wise error (FWE) corrected). RESULTS: Vertex analyses revealed significant volume reduction in inferior parts of the left hippocampus in the LTLE group and lateral parts of the right hippocampus in the RTLE group compared to controls (p<0.05, FWE corrected). Significant differences were also detected between the LTLE and control group in the bilateral medial and inferior thalamus (p<0.05, FWE corrected). FLE patients did not exhibit focal atrophy of gray matter across the brain. CONCLUSION: Our results highlight the variation in morphometric lateralized changes in the brain between different epilepsy onset zones, providing critical insight into the natural history of people with drug-resistant focal epilepsies.

Asunto(s)

RESUMEN

BACKGROUND: Focal epilepsy accounts for most epilepsy cases, and frontal lobe epilepsy (FLE) accounts for the largest proportion of cases of extratemporal epilepsy syndrome. The epileptogenic zone is usually not easy to locate, contributing to a lack of imaging studies. The objective of this study was to evaluate functional connectivity patterns to explore the underlying pathological mechanisms of this disorder. METHODS: Forty-three patients with focal extratemporal epilepsy [mean age ± standard deviation (SD): 29.51±8.04 years, 19 males] and the same number of healthy controls (mean age ± SD: 29.56±8.02 years, 19 males) were recruited to undergo functional magnetic resonance imaging. Mean regional homogeneity (ReHo) was measured, and regions showing significant alterations in ReHo in patients were identified to examine functional connectivity (FC). In particular, FC within the default mode network (DMN) in patients was analyzed. RESULTS: Patients with extratemporal lobe epilepsy showed significantly higher ReHo in the bilateral precentral gyrus, and lower ReHo in frontal-cerebellum regions than healthy controls [P<0.05, Gaussian random field (GRF)-corrected]. FC analysis based on regions of interest showed significantly higher connectivity in the frontoparietal-insula region and lowered FC in the frontal-cerebellum regions (P<0.05, GRF-corrected). Altered FC within DMN was also demonstrated (P<0.05, GRF-corrected). CONCLUSIONS: Analyses of ReHo and FC based on regions of interest suggest epilepsy-related neural networks are located mainly in frontal regions in extratemporal lobe epilepsy. These findings reveal disruptions of interactions and connectivity of large-scale neural networks and frontotemporal-cerebellar regions, suggesting connectivity-based pathophysiology.

RESUMEN

Neuropathology of drug resistant epilepsy (DRE) has direct bearing on the clinical outcome. Classification of the most common pathologies, hippocampal sclerosis (HS) and focal cortical dysplasia (FCD) have undergone several revisions and studies on the surgical pathology of DRE employing the updated ILAE classification are scarce. Here, we report the neuropathological spectrum of 482 surgically treated cases of DRE from a single institute using the latest ILAE classifications along with clinicoradiologic correlation. Majority of the cases (324, 67.2%) had temporal lobe epilepsy (TLE), with 158 (32.8%) having extratemporal seizure focus. Among TLE, HS was most common (n = 208, 64.2%), followed by neoplasms (42, 13%), FCD (26, 8%) and dual pathology (23, 7%). Less frequent were vascular malformations (cavernoma-3, arteriovenous malformation-1), mild malformation of cortical development (mMCD, 3), gliotic lesions (5), cysticercosis (2), double pathology (2) and polymicrogyria (1). Among extratemporal epilepsies, FCD was most common (46, 29.1%), followed by neoplasms (29, 18.3%), gliotic lesions (27, 17.1%), Rasmussen encephalitis (18, 11.4%), hypothalamic hamartoma (12, 7.6%), malformations of cortical development (10, 6.3%) and vascular malformations (6, 3.8%). Less frequent were double pathology (2, cysticercosis + FCD type IIb, DNET + FCD type IIb), mMCD (2), cysticercosis (1) and dual pathology (1). No underlying pathology was detected in 12 cases (2.5%). Radiopathological concordance was noted in 83%. In 36 cases (7.5%), histopathology detected an unsuspected second pathology that included FCD type III (n = 16) dual pathology (n = 18) and double pathology (n = 2). Further, in four MRI negative cases, histopathology was required for a conclusive diagnosis.

Asunto(s)

RESUMEN

OBJECTIVE: This longitudinal study aimed to measure the time course of intellectual changes after pediatric focal resective epilepsy surgery and to identify their predictors. METHODS: We analyzed a cohort of 81 school-aged children with focal epilepsy and intractable seizures who underwent neurosurgery (focal resection) from 2000 to 2018 in La Timone Hospital (Marseille). Neuropsychological assessments were carried out before and then 1, 2, 3, and 5 years after epilepsy surgery. RESULTS: Eighty-one patients with a median age at surgery of 13.74 years [4.25] were enrolled. Overall, 45 of the 81 (55%) recruited patients were improved after the surgery on at least one of the five domains of the Wechsler Intelligence Scale. Temporal lobe localization and postoperative seizure freedom were the main prognostic factors impacting intellectual outcome (improvement and decline) after epilepsy surgery. Younger patients at surgery were less likely to have a postoperative IQ decline. Intellectual improvement after epilepsy surgery could be delayed for up to 5 years after surgery and concerned all intellectual domains except the Verbal Comprehension Index (VCI). Intellectual decline after epilepsy surgery occurred mainly during the first two years after the surgery and was reflected in full-scale intelligence quotient (FSIQ) and Working Memory Index (WMI). CONCLUSIONS: Our study points out that children and adolescents with TLE who achieved freedom from seizure after epilepsy surgery are the leading candidates for achieving postoperative intellectual improvement. This enhancement in intellectual function shows a long time course, whereas intellectual decline is evidenced earlier.

Asunto(s)

RESUMEN

OBJECTIVE: to present the postsurgical outcome of extratemporal epilepsy (ExTLE) patients submitted to preoperative multimodal evaluation and intraoperative sequential electrocorticography (ECoG). SUBJECTS AND METHODS: thirty-four pharmaco-resistant patients with lesional and non-lesional ExTLE underwent comprehensive pre-surgical evaluation including multimodal neuroimaging such as ictal and interictal perfusion single photon emission computed tomography (SPECT) scans, subtraction of ictal and interictal SPECT co-registered with magnetic resonance imaging (SISCOM) and electroencephalography (EEG) source imaging (ESI) of ictal epileptic activity. Surgical procedures were tailored by sequential intraoperative ECoG, and absolute spike frequency (ASF) was calculated in the pre- and post-resection ECoG. Postoperative clinical outcome assessment for each patient was carried out one year after surgery using Engel scores. RESULTS: frontal and occipital resection were the most common surgical techniques applied. In addition, surgical resection encroaching upon eloquent cortex was accomplished in 41% of the ExTLE patients. Pre-surgical magnetic resonance imaging (MRI) did not indicate a distinct lesion in 47% of the cases. In the latter number of subjects, SISCOM and ESI of ictal epileptic activity made it possible to estimate the epileptogenic zone. After one- year follow up, 55.8% of the patients was categorized as Engel class I-II. In this study, there was no difference in the clinical outcome between lesional and non lesional ExTLE patients. About 43.7% of patients without lesion were also seizure- free, p = 0.15 (Fischer exact test). Patients with satisfactory seizure outcome showed lower absolute spike frequency in the pre-resection intraoperative ECoG than those with unsatisfactory seizure outcome, (Mann- Whitney U test, p = 0.005). CONCLUSIONS: this study has shown that multimodal pre-surgical evaluation based, particularly, on data from SISCOM and ESI alongside sequential intraoperative ECoG, allow seizure control to be achieved in patients with pharmacoresistant ExTLE epilepsy.

RESUMEN

OBJECTIVE: To analyze the surgical outcome in non-lesional intractable focal epilepsies in our center and to find possible predictors for better outcome. METHODS: This is a retrospective study for 40 adult patients with intractable focal epilepsy following at KFSHRC-Riyadh, who underwent presurgical evaluation followed by resective surgery and continued follow up for a minimum of 2 years. The surgery outcome was evaluated based on the type of surgical procedure and histopathology results. RESULTS: Out of all 40 patients studied, seizure freedom was achieved in 19 (47.5 %) and 17 (42.5 %) patients at the first and second year respectively in all non-lesional cases. Seizure freedom in non-lesional temporal lobe surgery was achieved in 10 (45 %) of patients at 2 years, 5 (38 %) in non-lesional frontal lobe patients at 2 years and 8 (44 %), 7 (38 %) for all extratemporal at 1 and 2 years respectively. Good prognosis was seen in patients with localized positron emission tomography (PET), had no aura and had a clear ictal onset either on scalp electroencephalogram (EEG) or subdural invasive electroencephalogram. SIGNIFICANCE: The best surgical outcome is achievable in patients with non-lesional focal epilepsy. This study highlights the prognostic value of the PET scan and ictal scalp/subdural invasive EEG.

Asunto(s)

RESUMEN

Video-EEG monitoring is an established gold-standard procedure for diagnosis and differentiation of epileptic and non-epileptic seizures. Epilepsy misdiagnosis, to which factors such as EEG artifact misinterpretation contribute to, is common, and can have long-lasting iatrogenic repercussions to the clinical management of affected patients. Among the many types of responses to photic stimulation, artifacts and physiologic and epileptic responses are possible. All of these can interfere with EEG interpretation when provoked by a source of illumination. Photic-induced responses are of increasing relevance given the ubiquity of screens and other light-emitting electronics in our modern world. One of these, the photoparoxysmal response, is a frequent finding in photosensitive patients with genetic generalized epilepsies. Various responses beyond abnormal occurrence of cortical spikes or spike-and-wave discharges are known to occur on EEG in response to intermittent photic stimulation (IPS), with different clinical implications. To our knowledge, we report a unique electronegative photoparoxysmal response during video-EEG monitoring induced by fluctuating illumination caused by a distant television screen. This response mimicked an extratemporal seizure in a young woman with frontal lobe epilepsy, admitted for presurgical evaluation. Novel electronegative responses to electronic devices during video-EEG monitoring merit consideration by EEG interpreters to help avoid misdiagnosis.

Asunto(s)