Left Mesial Temporal Sclerosis Research Articles

A Cross-sectional Study on Neuroimaging in Epilepsy: Diagnostic Value of T2 Relaxometry in Mesial Temporal Lobe Epilepsy

Introduction: The use of Magnetic Resonance Imaging (MRI) T2 relaxometry and spectroscopy has added new dimensions to the imaging of Temporal Lobe Epilepsy (TLE). Advanced techniques like MRI diffusion and MRI perfusion are new additions to the MRI protocol for epilepsy. Aim: To study the diagnostic value of T2 relaxation time in Electroencephalogram (EEG) confirmed seizure cases. Materials and Methods: A single-centre, cross-sectional study was conducted at Department of Radiodiagnosis, Saveetha Medical College, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, India, from December 2020 to November 2022 at a tertiary care hospital. All patients were subjected to MRI with a special epilepsy protocol and T2 relaxometry. Hippocampal T2 relaxation values for each slice were measured by placing a Region of Interest (ROI) on the representative image obtained from the T2 relaxometry sequence, focusing on the hippocampus in both the control and study groups. The control group (n=30) consisted of healthy volunteers, whereas the case group (n=36) comprised patients presenting with a history of seizures with positive MRI and EEG findings. Mean T2 relaxation time was calculated in each ROI, and an average was derived. Mean and Standard Deviation (SD) were calculated for the continuous variables, while ratios and proportions were calculated for the categorical variables. To determine the association of T2 relaxometry values in the study and control groups, an unpaired t-test was used. Results: The mean age of participants was 25.14±9.35 years (ranging from 9 to 51 years). The male-to-female ratio was 1.25:1. Hippocampal atrophy (32 out of 36 cases) and T2 signal alteration (30 out of 36 cases) were the most commonly identified features in Mesial Temporal Sclerosis (MTS). MRI without T2 relaxometry had a sensitivity of 94%. In two cases, where only mild hippocampal atrophy was identified in the conventional MRI sequence, making the diagnosis dubious, T2 relaxometry revealed increased T2 relaxation time in the head of the hippocampus and guided a proper diagnosis. EEG was able to lateralise seizures in 8 out of 13 right MTS cases (61.5%), 10 out of 17 left MTS cases (58.9%), and 5 out of 6 cases of bilateral MTS (83%). Conclusion: T2 relaxometry allows quantification of hippocampal signal intensity, allowing the detection of even subtle changes in signal intensity that are difficult to perceive by visual assessment.

Touch-screen automatisms in the digital age

ObjectiveTo describe a novel set of gestural automatisms related to the use of digital screens on smartphones and tablets in patients with epilepsy. MethodsRepresentative patients were selected from among those admitted to the Epilepsy Monitoring Unit at the Toronto Western Hospital between April 2016 and January 2020, and included if they exhibited automatisms clearly related to or mimicking digital device use. ResultsIn total 5 patients were included, 4 female. All had temporal lobe epilepsy: 2 had left mesial temporal sclerosis and 3 had normal imaging. Nearly equal numbers of seizures began with right (5/9) and left (4/9) temporal onsets, with most automatisms occurring after seizure propagation to bilateral temporal involvement (6/9). Left-handed automatisms were most common (8/9). The majority of the automatisms (7/9) were perseverative on device usage prior to the seizure. ConclusionGestural automatisms appear related to the contemporary lived experience, culture, and habitual behaviour of patients with epilepsy. In the modern era, the use of smartphones and tablets are both common and habitual for many, and this case series shows that touch-screen automatisms may be added to the semiological panoply of temporal lobe seizures.

Technical challenges to anterior temporal lobectomy after laser interstitial thermal therapy for mesial temporal lobe epilepsy: technical note.

Mesial temporal sclerosis (MTS) is a frequent cause of medically refractory epilepsy, for which laser interstitial thermal therapy (LITT) is an effective treatment. However, experience with the technical considerations posed by additional surgery after an initial LITT procedure is lacking. The authors present the case of a 12-year-old female with medically refractory temporal lobe epilepsy and left MTS who underwent LITT at a separate institution prior to referral. This patient had no change in early postoperative seizure control (Engel class IVB) and then her seizures worsened despite ongoing medical treatment (Engel class IVC). Post-LITT MRI revealed sparing of the mesial hippocampus head, a poor prognostic factor. The authors describe the technical details illustrated by this case of secondary, stereotactic electroencephalography-guided mesial temporal resection following LITT. The case was managed with anterior temporal lobectomy including the resection of residual hippocampus and amygdala.

Stealth Autoguide for robotic-assisted laser ablation for lesional epilepsy: illustrative case

BACKGROUNDLaser interstitial thermal therapy has been used in tumor and epilepsy surgery to maximize clinical treatment impact while minimizing morbidity. This intervention places a premium on accuracy. With the advent of robotics, neurosurgery is entering a new age of improved accuracy. Here, the authors described the use of robotic-assisted laser placement for the treatment of epileptiform lesions.OBSERVATIONSThe authors presented a case of a 21-year-old woman with medically intractable epilepsy, localized to left mesial temporal sclerosis and left temporal encephalocele by way of stereotactic electroencephalography, who presented for consideration of surgical intervention. When presented with resection versus laser ablation, the patient opted for laser ablation. The patient received robotic-assisted stereotactic laser ablation (RASLA) using a Stealth Autoguide. The patient was seizure free (10 weeks) after surgical ablation.LESSONSRASLA is an effective way to treat epilepsy. Here, the authors reported the first RASLA procedure with a Stealth Autoguide to treat epilepsy. The procedure can be performed effectively and efficiently for multiple epileptic foci without the need for bulkier robotic options or head frames that may interfere with the use of magnetic resonance imaging for heat mapping.

A meta-analysis of case-reports and case-series of dacrystic epilepsy in children and adolescence

This meta-analysis aimed to advance our knowledge about dacrystic epilepsy in children in the present time. PubMed searches for peer-reviewed case reports and case series were conducted using the keywords “dacrystic epilepsy”, “dacrystic seizures”, “crying epilepsy”, “ictal crying”, “crying seizures”. The databases were developed in accordance with preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. The author collected relevant information to characterise the study population including clinical outcome. Eleven studies out of 353 citations between 1998 and 26 May 2021 met the inclusion criteria, including both single cases and series pertaining to dacrystic epilepsy. Eight case reports and three case series were eligible for this meta-analysis and included twenty one cases. The seizure patterns were dacrystic seizures alone in seven cases (33%), and a combination of dacrystic seizures and gelastic seizures in fourteen cases (67%). Neuroimaging revealed structural abnormality in 95% cases. Hypothalamic hamartoma was found in most of the cases (79%) with combined dacrystic seizures and gelastic seizures, whereas it was found in one case (16%) with dacrystic seizures alone. The other underlying lesions in children with dacrystic seizures alone were subependymal nodules and cortical hamartomas (17%), left mesial temporal sclerosis (33%), and cortical dysplasia (17%). Regarding outcome, antiepileptic drugs alone achieved seizure freedom in four cases (22%) only and others (78%) were difficult to treat cases excluding three cases where treatments were not mentioned. Six cases underwent surgical intervention and two cases received ablative radiotherapy. Lesional dacrystic epilepsy is predominant and pharmaco-resistant in children. However, antiepileptic drugs lead to achieving seizure remission in few cases.

Nonverbal fluency assessed by the five-point test in epilepsy patients with unilateral mesial temporal sclerosis—a Brazilian study

Objective To investigate the performance of epilepsy patients diagnosed with unilateral mesial temporal sclerosis (MTS) on a nonverbal fluency measure using the five-point test (FPT). Our secondary aim was to investigate any differences in FPT and verbal fluency test (VFT) scores between left and right MTS. We hypothesized that scores on the FPT, commonly utilized in the assessment of individuals with presumed frontal lobe damage, would be lower in patients with temporal lobe dysfunction. Method One hundred eighty patients diagnosed with temporal lobe epilepsy (TLE) and 150 healthy controls (HCs) were included in this retrospective study. We analyzed correlations between scores obtained from FPT and phonemic and semantic VFT, and scores according to the lateralization of epileptogenic focus in the TLE group. Results Overall, the TLE patients had lower performance than the HCs on the FPT, but no differences were observed on perseverance rates (p = 0.992). Statistically significant difference was found in both sections of the VFT in association with the lateralization of the epileptogenic zone (p < 0.001). As for the FPT, differences did not reach statistical significance (p = 0.0857). Conclusions Our results support the hypothesis of involvement of the temporal areas on tasks such as the FPT, despite the lack of a lateralizing effect. Our findings also contribute to better understanding of the role of the FPT in assessment of executive function in patients with unilateral MTS, and provide further psychometric data on a native Brazilian population.

Seizure Frequency Is Associated with Effective Connectivity of the Hippocampal-Diencephalic-Cingulate in Epilepsy with Unilateral Mesial Temporal Sclerosis.

Background: Temporal lobe epilepsy (TLE) with mesial temporal sclerosis (MTS) is a common intractable epilepsy. To seek neural correlates of seizure recurrence, this study investigated aberrant intrinsic effective connectivity (iEC) in TLE with unilateral MTS and their associations with seizure frequency. Methods: Thirty patients with unilateral MTS (left/right MTS = 14/16) and 37 age-matched healthy controls underwent resting-state functional magnetic resonance imaging (rsfMRI) on a 3-Tesla magnetic resonance imaging (MRI) system. The structural equation modeling was employed to estimate the iEC of the three candidate epilepsy models, including the Papez circuit, hippocampal-diencephalic-cingulate (HDC) model, and simplified HDC model. After comparing the performance of model fitting, the best model was selected to compare iEC among the study groups. The linear regression analysis was performed to associate abnormal iEC with seizure frequency. Results: The simplified HDC model was the best model to estimate iEC across the three study groups (p < 0.05), and it composed of the 26 interconnected pathway between the mesial temporal lobe, thalamus, and cingulate cortices. The linear regression analysis revealed a significant relationship between the shared iEC alterations in both patient groups and seizure frequency (adjusted-R2 = 0.350; p = 0.037), including the three paths of mammillary body (MB) → bilateral anterior thalamic nuclei (left: standardized β-value = 0.580, p = 0.013; right: standardized β-value = -0.711, p = 0.006) and right hippocampus → MB (standardized β-value = 0.541, p = 0.045). Conclusions: Our findings provide new insights into neurophysiological significance relevant to seizure recurrence. Aberrant iEC on the neural paths connected to the MB can be a potential imaging marker, aiding the therapeutic management in TLE with unilateral MTS. Impact statement Within the simplified hippocampal-diencephalic-cingulate model, we identified that altered intrinsic effective connectivity (iEC) on the three paths connecting to the mammillary body was common in temporal lobe epilepsy (TLE) with left and right mesial temporal sclerosis (MTS) and was associated with seizure frequency. Therefore, these common iEC alterations could be a potential imaging marker, aiding the therapeutic management in patients with TLE with unilateral MTS.

Baseline neuropsychological characteristics in patients with epilepsy with left temporal lobe encephaloceles compared with left mesial temporal sclerosis

BackgroundTemporal lobe encephaloceles (TE) are increasingly recognized as a cause of drug-resistant temporal lobe epilepsy. Improved recognition of these lesions offers an opportunity to treat them with a limited resection sparing the hippocampus. However, as they can be difficult to identify on imaging, additional clues pointing to the diagnosis can be helpful. We sought to understand the baseline cognitive/neuropsychological profile in patients with left temporal lobe epilepsy caused by encephaloceles compared with that caused by mesial temporal sclerosis (MTS), a common entity in the differential diagnosis. MethodsNeuropsychological testing, including language (semantic and phonemic fluency and naming), verbal memory, intelligence quotient (IQ), and executive function measures were compared across two groups (five patients with left TE and five age- and gender-matched patients with left MTS). Other clinical variables related to cognition, including patient age, electroencephalographic characteristics, epilepsy duration, and factors related to antiseizure medication dosing, were also compared between groups. ResultsMore patients with left MTS had atypical language lateralization (3/5 with right-sided language in the group with MTS compared with 0/5 in the group with TE). Patients with MTS had significantly worse scores on the Verbal Comprehension Index (VCI) subscore of the Wechsler Adult Intelligence Scale (WAIS; p = 0.026). General IQ was also worse in patients with MTS (p = 0.028). There was a trend towards worse executive function in patients with MTS as measured on Trails B (p = 0.096). Other measures related to language and verbal memory did not differ significantly between the groups nor did other relevant clinical variables, except epilepsy duration, which was significantly longer in patients with MTS (p = 0.0001). ConclusionsThis pilot study demonstrates few significant differences between the groups with left MTS and TE surveyed. A higher rate of atypical language lateralization was noted in patients with left MTS. The higher baseline global IQ and VCI scores in patients with left TE compared with patients with MTS may be attributable to longer duration of epilepsy in patients with left MTS. Future work with a larger sample size will focus on establishing a unique neuropsychological profile related to epilepsy due to TE.

Responsive Neurostimulation for Intractable Epilepsy in Phelan–McDermid Syndrome

AbstractResponsive neurostimulation (RNS) is an approved treatment for intractable epilepsy in the adult population but has not yet been approved for pediatric patients. We present here the first reported case of a 14-year-old adolescent with 22q13.3 syndrome (more commonly known as Phelan–McDermid syndrome) with intractable epilepsy who showed clinical improvement after implantation of an RNS device. The patient had trialed 10 antiepileptic drugs without improvement and despite magnetic resonance imaging (MRI) demonstrating left mesial temporal sclerosis (MTS), the patient was not considered as a candidate for temporal lobe resection due to multifocal seizure activity on electroencephalogram (EEG). At 23 months postoperatively, she has experienced 86.7% reduction in seizure frequency; a clinical improvement which emphasizes the importance of considering RNS treatment for those with intractable epilepsy in the pediatric population, even in the setting of known genetic syndromes.

Epilepsy surgery in Indonesia: Achieving better result with limited resources

Background: Even with modern medication, 30 to 40% of epilepsy patients will be intractable and this condition leads to cognitive and psychosocial decline, resulting in worse quality of life and higher mortality. With 0.5–0.6% prevalence, there will be about 1.5 million epileptic in Indonesia, about 440.000 will be intractable, and 220.000 of them are potential candidates for epilepsy surgery (ES). A decade has passed since the first ES performed on July 1999, and the number increases every year reaching 35–47 ES per year in 2007–2009. Despite the excellent result shown, all of these ES were still performed in Semarang (Diponegoro University) while the patients were from all part of Indonesia. The major reason behind the unavailability of ES in most part of the country should be discussed for the sake of future development of ES in Indonesia.&#x0D; Material: Epilepsy surgery was started in July 1999 with anterior temporal lobectomy for a 34 Y-old female with left mesial temporal sclerosis (MTS) causing a long standing intractable seizures. The number of cases increases every year. Until the end of 2009, there were 238 cases of epilepsy surgery, including 212 anterior temporal lobectomies. Among these, 106 cases had been follow up more than 36 months, and evaluated for surgical results.&#x0D; Methods: To evaluate the patient's selection and the presurgical evaluation, we divide the ES cases into the first 5 years (56 cases) and the recent 5 years (182 cases). But for the purpose of evaluating surgical results, only those with at least 36 months postoperative follow-up were included (106 cases) and grouped into those operated before or after the age of 25 Y-old (group A and group B), and into those operated before or after the length of epilepsy of 10 years (group I and group II).&#x0D; Results: For the first five years-period, decision to operate were based on MRI and routine interictal EEG in 54 out of 56 TLE cases. One patient had long-term ictal EEG and another had subdural grid EEG implanted, since MRI in both patients showed visually normal MRI. For the last five years, decision to operate were based on MRI and routine EEG in 91 out of 156 TLE cases. Long term ictal EEG were performed in 46 patients, subdural grid EEG in 10 patients, PET study in 7 patients, and EcoG in 2 patients. The overall seizure free (SF) rate were 70.75%, but if grouped according to patient's age at surgery (less than or over 25 Y-old), the SF rates were 75.4% vs 66.04% respectively. So did if grouped according to length of disease (less than or more than 10 years), the SF rates were 78.72% vs 64.40% respectively.&#x0D; Conclusion: MRI plays very important role to decide the side of the epileptic temporal side, but this role is decreasing as it was 96.4% during the beginning five years to become 58.34% for the last five years. This means that we are working on more difficult epilepsy cases recently. SF rate was significantly higher for those who was operated at younger age and for those with shorter duration of epilepsy. This means that surgery should be offered earlier for those intractable TLE patients with obvious focus on MRI.

New MRI Finding in Migraineurs: Mesial Temporal Sclerosis.

Background: Based on our experience, a noticeable number of migraineurs without history of epilepsy disclose mesial temporal sclerosis (MTS) on their brain MRI.Objective: This prospective study was conducted to assess the frequency of MTS in migraineurs and also determine the ratio of unilateral and bilateral cases.Material and Methods: In this cross sectional study, the frequency of MTS in MRI of 84 migraine patients, who had symptoms for at least 2 years, assessed. Brain MRI was done with T1 and T2 weighted protocols. Two radiologists separately interpreted findings, defining MTS as presence of any of hippocampal atrophy, increased T2 signal of hippocampus, decreased T1 signal of hippocampus or loss of internal architecture. Patients who radiologists had not agreement on their diagnoses excluded. Stat analysis done using ‘N - 1’ chi squared test.Results: Eleven patients were excluded due to non-accordant interpretation of MRI findings by the two examining radiologists. MTS was detected in 14 out of 73 patients (19%). Bilateral involvement of mesial temporal lobe was seen in 6 (8%) patients (M 67%, F 33%). Five cases (7%) had unilateral left MTS (M 67%, F 33%) while 3 (4%) were affected with right-sided MTS (M 33%, F 67%). These findings highly suggest association of MTS and Migraine (P-value <0.0001). Conclusion: While MTS is a prevalent finding in migraineurs, incidental finding of MTS in MRI should suspect physicians of migraine as well as temporal lobe epilepsy. MTS can be proposed as an etiology of migraine but most likely, consequence of it.

FMRI and electroencephalographic evaluation of sleep deprivation in epilepsy patients: An observational study

BackgroundSleep deprivation (SD) is considered an important activation test to facilitate the visualization of electroencephalogram (EEG) epileptic abnormalities, in order to perform a correct diagnosis. ObjectiveThe aim of this study was to evaluate the local functional activity in healthy controls (HC) subjects and left mesial temporal lobe epilepsy-hippocampal sclerosis patients, after a SD, by using functional Magnetic Resonance Imaging (fMRI) and EEG. Materials and methodsWe enrolled 22 healthy controls and 34 patients with a diagnosis of left mesial temporal lobe epilepsy-hippocampal sclerosis. Each participant underwent two examinations separately: an fMRI study using 3 T MRI to detect spontaneous activity during the RS-fMRI and an EEG. ResultsThe SD-EEG results showed the presence of epileptiform discharges predominantly in left fronto-centro-temporal areas. fMRI findings if compared to HC showed an increase of functional activity in some areas. DiscussionWe showed that SD-EEG study confirmed a high specificity to assess a specific diagnosis. Therefore, the decrease of activity observed in DMN could be explain by a different amount of sleep/awake time during fMRI recording in the two groups or the interictal activity during fMRI acquisition. Our study highlighted alterated functional activity in SD cortical areas of epileptic patients if compared to HC.

A-37 Effects of Atypical Language Representation in Populations Suffering From Intractable Epilepsy

Abstract Objective Atypical language laterality, secondary to refractory epilepsy, presents complications to surgical planning/cognitive outcomes. Extant research shows the non-dominant hemisphere reallocates neural resources for language compensation in response to left-sided lesions (resulting in decreased visuoperceptual/visual memory). The present study examined relationships between 1) lesion location and atypical language organization and 2) lesion location/language laterality on performance on memory (California Verbal Memory Test 2nd-edition (CVLT; Delayed Recall), and visuoperceptual (Rey-Osterrieth Complex Figure Test, ROCFT; Copy) tests in relation to lesion location in a sample of patients with intractable epilepsy. Method Retrospective data was compiled on patients with refractory epilepsy undergoing interdisciplinary pre-surgical workup (N = 101), mean age of 37.2 (SD = 11.9) and mean education of 12.3 (SD = 3.7). The sample was then stratified by non-lesional (n = 48), left (n = 26), right (n = 21) or bilateral (n = 6) mesial temporal sclerosis (MTL); and, language laterality was confirmed by neuroradiologists via functional Magnetic Resonance Imaging (fMRI) scans. Results Analyses showed patients with left MTS were more likely to have atypical language organization, X2 (1, N = 47) = 6.6, p = .01. Moreover, significant differences on T-scores for CVLT, F (3,15) = 3.81, p = .04, 95% Cl [-1.73, -.08] and ROCFT, F(4,28) = 2.85, p = .046 95% Cl [31.62, 46.17] were found between groups stratified by lesion location/language laterality, respectively. Conclusions Organization of language in epileptic populations presents atypically in conjunction with left-sided lesions. Additionally, cognitive processes such as verbal memory and visuoperceptual abilities suffer based on lesion presence/location and language laterality in this fMRI confirmed sample.

Hemispheric Regional Based Analysis of Diffusion Tensor Imaging and Diffusion Tensor Tractography in Patients with Temporal Lobe Epilepsy and Correlation with Patient outcomes

Imaging in the field of epilepsy surgery remains an essential tool in terms of its ability to identify regions where the seizure focus might present as a resectable area. However, in many instances, an obvious structural abnormality is not visualized. This has created the opportunity for new approaches and imaging innovation in the field of epilepsy, such as with Diffusion Tensor Imaging (DTI) and Diffusion Tensor Tractography (DTT). In this study, we aim to evaluate the use of DTI and DTT as a predictive model in the field of epilepsy, specifically Temporal Lobe Epilepsy (TLE), and correlate their clinical significance with respect to postsurgical outcomes. A hemispheric based analysis was used to compare the tract density, as well as DTI indices of the specific regions of interest from the pathologic hemisphere to the healthy hemisphere in TLE patients. A total of 22 patients with TLE (12 males, 10 females, 22–57 age range) underwent either a craniotomy, Anterior Temporal Lobectomy (ATL), or a less invasive method of Selective Laser Amygdalohippocampectomy (SLAH) and were imaged using 3.0 T Philips Achieva MR scanner. Of the participants, 12 underwent SLAH while 10 underwent ATL. The study was approved by the institutional review board of Thomas Jefferson University Hospital. Informed consent was obtained from all patients. All patients had a diagnosis of TLE according to standard clinical criteria. DTI images were acquired axially in the same anatomical location prescribed for the T1-weighted images. The raw data set consisting of diffusion volumes were first corrected for eddy current distortions and motion artifacts. Various DTI indices such as Fractional Anisotropy (FA), Mean Diffusivity (MD), Radial Diffusivity (RD) and Axial Diffusivity (AD) were estimated and co-registered to the brain parcellation map obtained by freesurfer. 16 consolidated cortical and subcortical regions were selected as regions of interest (ROIs) by a functional neurosurgeon and DTI values for each ROI were calculated and compared with the corresponding ROI in the opposite hemisphere. Also, track density imaging (TDI) of 68 white matter parcels were generated using fiber orientation distribution (FOD) based deterministic fiber tracking and compared with contralateral side of the brain in each epileptic group: left mesial temporal sclerosis (LMTS) and right MTS (RMTS)). In patients with LMTS, MD and RD values of the left hippocampus decreased significantly using two-tailed t-test (p = 0.03 and p = 0.01 respectively) compared to the right hippocampus. Also, RD showed a marginally significant decrease in left amygdala (p = 0.05). DTT analysis in LMTS shows a marginally significant decrease in the left white matter supramarginal parcel (p = 0.05). In patients with RMTS, FA showed a significant decrease in the ipsilateral mesial temporal lobe (p = 0.02), parahippocampal area (p = 0.03) and thalamus (p = 0.006). RD showed a marginally significant increase in the ipsilateral hippocampus (p = 0.05) and a significant increase in the ipsilateral parahippocampal area (p = 0.03). Also, tract density of the ipsilateral white matter inferior parietal parcel showed a marginally significant increase compared to the contralateral side (p = 0.05). With respect to postsurgical outcomes, we found an association between residual seizures and tract density in five white matter segments including ipsilateral lingual (p = 0.04), ipsilateral temporal pole (p = 0.007), ipsilateral pars opercularis (p = 0.03), ipsilateral inferior parietal (p = 0.04) and contralateral frontal pole (p = 0.04). These results may have the potential to be developed into imaging prognostic markers of postoperative outcomes and provide new insights for why some patients with TLE continue to experience postoperative seizures if pathological/clinical correlates are further confirmed.

Computer-aided detection of mesial temporal sclerosis based on hippocampus and cerebrospinal fluid features in MR images

Mesial temporal sclerosis (MTS) is the commonest brain abnormalities in patients with intractable epilepsy. Its diagnosis is usually performed by neuroradiologists based on visual inspection of magnetic resonance imaging (MRI) scans, which is a subjective and time-consuming process with inter-observer variability. In order to expedite the identification of MTS, an automated computer-aided method based on brain MRI characteristics is proposed in this paper. It includes brain segmentation and hippocampus extraction followed by calculating features of both hippocampus and its surrounding cerebrospinal fluid. After that, support vector machines are applied to the generated features to identify patients with MTS from those without MTS. The proposed technique is developed and evaluated on a data set comprising 15 normal controls, 18 left and 18 right MTS patients. Experimental results show that subjects are correctly classified using the proposed classifiers with an accuracy of 0.94 for both left and right MTS detection. Overall, the proposed method could identify MTS in brain MR images and show a promising performance, thus showing its potential clinical utility.

Diagnosis of mesial temporal sclerosis: sensitivity, specificity and predictive values of the quantitative analysis of magnetic resonance imaging.

In the diagnosis of mesial temporal sclerosis (MTS), sensitivity, specificity and predictive values of qualitative assessment using conventional magnetic resonance imaging are low, mainly in mild or bilateral atrophy. Quantitative analysis may improve this performance. We evaluated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of quantitative analysis using the hippocampal volumetric index (HVI) and hippocampal asymmetry index (HAI) compared with qualitative assessment in the MTS diagnosis. Twenty-five patients diagnosed with MTS, and 25 healthy subjects underwent conventional magnetic resonance imaging. Hippocampal volumes were obtained using an automated software (FreeSurfer); HVI and HAI were calculated. Receiver operating characteristic curve analysis was performed to obtain the optimal threshold values. Sensitivity, specificity and predictive values were calculated. Sensitivity, specificity, PPV and NPV for qualitative analysis were 44.00%, 96.00%, 91.67% and 63.16%, respectively. In the quantitative analysis, a threshold value of K = 0.22 for HVI provided a sensitivity value of 76.00%, specificity value of 96.00%, PPV of 95.00% and NPV of 80.00%. A threshold value of K = 0.06 for HAI provided the minimum C1 and C2 errors, with a sensitivity value of 88.00%, specificity value of 100%, PPV of 100% and NPV of 89.30%. A statistically significant difference was observed for HAI ( P < 0.0001), and ipsilateral HVI (left MTS, P = 0.0152; right MTS, P < 0.0001), between MTS and healthy groups. The HVI and HAI, both individually and in conjunction, improved the sensitivity, specificity and predictive values of magnetic resonance imaging in the diagnosis of MTS compared to the qualitative analysis and other quantitative techniques. The HAI is highly accurate in the diagnosis of unilateral MTS, whereas the HVI may be better for bilateral MTS cases.

Correlation of Electroencephalography and Magnetic Resonance Imaging in Patients with Mesial Temporal Sclerosis.

To determine the lateralization of lesion by non-invasive methods through correlation of cranial magnetic resonance imaging (MRI) and electroencephalography (EEG) findings in patients with mesial temporal sclerosis (MTS). This study included 40 patients (Age range, 19 to 55 years) among 1850 patients who were attending outpatient epilepsy clinic of Haydarpaşa Numune Hospital between the years 2000 and 2013. Exclusion criteria were surgery due to MTS, metabolic and systemic disorders, indefinite diagnosis, and inadequate MRI and EEG evaluations. EEG findings were within normal limits in 10 (25%) patients who had MTS on MRI. Of these, 5 patients had right MTS, 4 had left MTS, and one patient had bilateral MTS. In this study, we used electrophysiological diagnostic methods together with MR imaging to determine epileptogenic localization in patients with MTS. We suggest that, when correlated with MRI, EEG is a non-invasive and easy method to identify lateralization findings.

P257 Smell triggered seizure in a patient with temporal lobe epilepsy

Introduction Among the reflex seizures, those triggered by smell are very rarely reported. We aimed to present a patient with temporal lobe epilepsy (TLE), who experienced a video-EEG recorded seizure while smelling ylang-ylang extract during a study protocol. Patient and methods The patient is a 34-year-old woman with drug-resistant TLE, which had started when she was 9 years old. Her MRI revealed left mesial temporal lobe sclerosis. She had 1–5 focal seizures impairing awareness per month. Stress and sadness were the only reported seizure triggers. During her routine pre-surgical evaluation, a standardized video-EEG study protocol was also applied after taking her consent. Baseline, hyperventilation, intermittent photic stimulation and olfactory stimulations (OS) were performed with a published standard protocol. One ml of odorant solution of ylan-ylang extract was dropped on a cotton ball, and was applied to the middle of both nostrils during 3 min. This activation was repeated twice and followed by 15 min of resting records (post-OS1 and post-OS2). We investigated modulation of epileptiform discharges by OS by counting the interictal spikes. However, a focal seizure has occurred in the first minute of smelling. After 5 months, video-EEG with the same protocol was repeated and increase in spike counts during post-OS periods was documented. Moreover, she was found to have hypo-osmia with Sniffin Sticks test, despite she had no complaints. Conclusion Our results suggested that olfactory stimulation may trigger reflex seizures and increase interictal spikes in some patients with TLE.

Seizure outcome after hippocampal deep brain stimulation in patients with refractory temporal lobe epilepsy: A prospective, controlled, randomized, double-blind study.

We designed a prospective, randomized, controlled, double-blind study to evaluate the efficacy of hippocampal deep brain stimulation (Hip-DBS) in patients with refractory temporary lobe epilepsy (TLE). Sixteen adult patients with refractory TLE were studied. Patient's workup included medical history, interictal and ictal electroencephalography (EEG), and high-resolution 1.5T magnetic resonance imaging (MRI). Patients were randomized on a 1:1 proportion to an active (stimulation on) or to a control (no stimulation) arm. After implantation, patients were allowed to recover for 1 month, which was followed by a 1-month titration (or sham) period. The 6-month blinded phase started immediately afterward. A postoperative MRI confirmed the electrode's position in all patients. All patients received bipolar continuous stimulation. Stimulus duration was 300 μs and frequency was 130 Hz; final intensity was 2 V. Patients were considered responders when they had at least 50% seizure frequency reduction. All patients had focal impaired awareness seizures (FIAS, complex partial seizures), and 87% had focal aware seizures (FAS, simple partial seizures). Mean preoperative seizure frequency was 12.5 ± 9.4 (mean ± standard deviation) per month. MRI findings were normal in two patients, disclosed bilateral mesial temporal sclerosis (MTS) in three, left MTS in five, and right MTS in six patients. An insertional effect could be noted in both control and active patients. In the active group (n = 8), four patients became seizure-free; seven of eight were considered responders and one was a nonresponder. There was a significant difference regarding FIAS frequency between the two groups from the first month of full stimulation (p < 0.001) until the end of the blinded phase (p < 0.001). This was also true for FAS, except for the third month of the blinded phase. Hip-DBS was effective in significantly reducing seizure frequency in patients with refractory TLE in the active group, as compared to the control group. Fifty-percent of the patients in the active group became seizure-free. The present study is the larger prospective, controlled, double-blind study to evaluate the effects of Hip-DBS published to date.

Contralateral ictal electrographic involvement is associated with decreased memory performance in unilateral mesial temporal sclerosis

PurposeTo evaluate the effect of contralateral electrographic involvement on memory performance (measured by neuropsychological and Wada memory testing) in patients with epilepsy associated with unilateral mesial temporal sclerosis (MTS). MethodsWe studied 51 patients with medically-refractory epilepsy associated with unilateral MTS (27 women, 30/51, left MTS) submitted to prolonged non-invasive video-EEG monitoring and bilateral Wada testing. According to ictal electrographic involvement, patients were classified as: Contralateral ictal involvement, when one or more seizures evolved with rhythmic activity in the temporal region contralateral to the MTS or exclusive ipsilateral ictal involvement if all seizures showed ictal EEG activity exclusively on the MTS side. Wada testing involved a twelve-item memory paradigm. Wada memory asymmetry score was calculated for each patient subtracting the number of recalled items after injection on the lesion side from the number of recalled items after contralateral injection. Expected asymmetry (EA) was considered if Wada memory asymmetry>0, and Symmetrical or Reversed memory asymmetry (S-RA) when ≤0. Neuropsychological testing was applied in the 51 patients and in 40 healthy controls. Verbal Memory was evaluated with the Rey Auditory Verbal Learning Test (RAVLT), considering the number of recalled items on immediate recall after the initial five consecutive encoding trials (RAVLT 6), a post-interference delayed (30min) recall (RAVLT 7), and recall after 7days. Nonverbal memory was tested with Wechsler Memory Scale-III (WMS-III) Faces subtests 1 e 2. ResultsGroups did not differ in demographic, clinical and video-EEG monitoring variables. S-RA was observed more frequently in the group with contralateral ictal involvement (57.2% vs. 27.0%; p: 0.03). Logistic regression analysis considering demographic, clinical, hippocampal volume and video-EEG monitoring variables showed contralateral ictal involvement as the only independent variable associated with S-RA (coefficient=1.32, p=0.029, odds ratio 3.77; 95% CI 1.1–12.47). Additionally, the patient group with contralateral ictal EEG involvement displayed worse verbal and nonverbal memory scores compared to healthy controls. ConclusionIn this cohort of unilateral MTS patients, contralateral ictal involvement was associated with decreased memory performance on Wada and on neuropsychological testing.