Diagnosis Of Mesial Temporal Sclerosis Research Articles

Usefulness of magnetic resonance spectroscopy in mesial temporal sclerosis: a systematic review.

Magnetic resonance spectroscopy (MRS) provides non-invasive information about metabolic features in different regions of the brain affected by mesial temporal sclerosis (MTS). To review articles analyzing the most common alterations in biochemical parameters in MTS and the applications of MRS in presurgical assessment. We undertook a systematic literature search for MRS in MTS in PubMed, SCOPUS, and Cochrane based on the MESH terms ""Magnetic Resonance Spectroscopy", "Proton Magnetic Resonance Spectroscopy", "Carbon-13 Magnetic Resonance Spectroscopy", "1H-MRS", "31P-MRS", "mesial temporal sclerosis", "hippocampal sclerosis", "mesial temporal seizure", and "mesial temporal epilepsy". Of the initial 134 articles found, 30 were selected after the exclusion process. Of these, 13 detected a decrease in N-acetylaspartate (NAA), 9 showed a decreased in the ratio NAA/Cho+Cr, and 8 demonstrated a decreased in the ratio NAA/Cr, all of them in the ipsilateral hippocampus. Nine studies also found reduced NAA levels in extrahippocampal regions. The main findings were a decrease in NAA in the ipsilateral hippocampus. In addition, NAA levels were low outside the hippocampus so MTS could be a more extensive disease. Patients without MTS also presented a decrease in NAA in the ipsilateral hippocampus although NAA was even lower in the MTS patients. Thus, MRS could be useful in the presurgical evaluation to locate the epileptogenic focus, but not specific for the diagnosis of MTS.

An image processing algorithm to aid diagnosis of mesial temporal sclerosis in children: a case-control study.

Mesial temporal sclerosis (MTS) is an important cause of intractable epilepsy. Early and accurate diagnosis of MTS is essential to providing curative and life-changing therapy but can be challenging in children in whom the impact of diagnosis is particularly high. Magnetic resonance imaging (MRI) plays an important role in the diagnosis of MTS, and image processing of MRI is a recently studied strategy to improve its accuracy. In a retrospective case-control study, we assessed the performance of an image processing algorithm (Correlative Image Enhancement [CIE]) for detecting MTS-related hippocampal signal abnormality in children. Twenty-seven pediatric MTS cases (9 males, 18 females; mean age: 16±standard deviation [SD] 6.7years) were identified from a pathology database of amygdylo-hippocampectomies performed in children with epilepsy. Twenty-seven children with no seizure history (9 males, 18 females; mean age: 13.8±SD 2.8years), and with normal brain MRI, were identified for the control group. Blinded investigators processed the MRI coronal FLAIR (fluid-attenuated inversion recovery) images with CIE, saved the processed images as a separate series, and made equivalent region of interest measurements on the processed and unprocessed series to calculate contrast-to-noise ratio. Six blinded reviewers then rated the randomized series for hippocampal signal abnormality and MTS disease status. CIE increased signal intensity and contrast-to-noise ratio in 26/27 hippocampi with pathologically confirmed MTS (96.3%) with the mean (SD) contrast-to-noise ratio of cases increasing from 14.9 (11.1) to 77.7 (58.7) after processing (P<0.001). Contrast-to-noise ratio increased in 1/54 normal control hippocampi (1.9%), with no significant change in the mean contrast-to-noise ratio of the control group after processing (P=0.57). Mean (SD) reader sensitivity for detecting abnormal signal intensity increased from 83.3% (14.2) to 94.8% (3.3) after processing. Mean specificity for abnormal signal intensity increased from 94.4% (7.3) to 96.3% (0). While sensitivity improved after processing for detection of MTS disease status in 4/6 readers, the mean reader sensitivity and specificity for MTS detection increased only minimally after processing, from 79.6% to 80.7% and from 95.7% to 96.3%, respectively. The CIE image processing algorithm selectively increased the contrast-to-noise ratio of hippocampi affected by MTS, improved reader performance in detecting MTS-related hippocampal signal abnormality and could have high impact on pediatric patients undergoing work-up for seizures.

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.

Automated volumetry of hippocampus is useful to confirm unilateral mesial temporal sclerosis in patients with radiologically positive findings.

Background and purpose We evaluated two methods to identify mesial temporal sclerosis (MTS): visual inspection by experienced epilepsy neuroradiologists based on structural magnetic resonance imaging sequences and automated hippocampal volumetry provided by a processing pipeline based on the FMRIB Software Library. Methods This retrospective study included patients from the epilepsy monitoring unit database of our institution. All patients underwent brain magnetic resonance imaging in 1.5T and 3T scanners with protocols that included thin coronal T2, T1 and fluid-attenuated inversion recovery and isometric T1 acquisitions. Two neuroradiologists with experience in epilepsy and blinded to clinical data evaluated magnetic resonance images for the diagnosis of MTS. The diagnosis of MTS based on an automated method included the calculation of a volumetric asymmetry index between the two hippocampi of each patient and a threshold value to define the presence of MTS obtained through statistical tests (receiver operating characteristics curve). Hippocampi were segmented for volumetric quantification using the FIRST tool and fslstats from the FMRIB Software Library. Results The final cohort included 19 patients with unilateral MTS (14 left side): 14 women and a mean age of 43.4 ± 10.4 years. Neuroradiologists had a sensitivity of 100% and specificity of 73.3% to detect MTS (gold standard, k = 0.755). Automated hippocampal volumetry had a sensitivity of 84.2% and specificity of 86.7% (k = 0.704). Combined, these methods had a sensitivity of 84.2% and a specificity of 100% (k = 0.825). Conclusions Automated volumetry of the hippocampus could play an important role in temporal lobe epilepsy evaluation, namely on confirmation of unilateral MTS diagnosis in patients with radiological suggestive findings.

The use of hippocampal volumetric measurements to improve diagnostic accuracy in pediatric patients with mesial temporal sclerosis.

OBJECTIVE Many patients with medically intractable epilepsy have mesial temporal sclerosis (MTS), which significantly affects their quality of life. The surgical excision of MTS lesions can result in marked improvement or even complete resolution of the epileptic episodes. Reliable radiological diagnosis of MTS is a clinical challenge. The purpose of this study was to evaluate the utility of volumetric mapping of the hippocampi for the identification of MTS in a case-controlled series of pediatric patients who underwent resection for medically refractory epilepsy, using pathology as a gold standard. METHODS A cohort of 57 pediatric patients who underwent resection for medically intractable epilepsy between 2005 and 2015 was evaluated. On pathological investigation, this group included 24 patients with MTS and 33 patients with non-MTS findings. Retrospective quantitative volumetric measurements of the hippocampi were acquired for 37 of these 57 patients. Two neuroradiologists with more than 10 years of experience who were blinded to the patients' MTS status performed the retrospective review of MR images. To produce the volumetric data, MR scans were parcellated and segmented using the FreeSurfer software suite. Hippocampal regions of interest were compared against an age-weighted local regression curve generated with data from the pediatric normal cohort. Standard deviations and percentiles of specific subjects were calculated. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined for the original clinical read and the expert readers. Receiver operating characteristic curves were generated for the methods of classification to compare results from the readers with the authors' results, and an optimal threshold was determined. From that threshold the sensitivity, specificity, PPV, and NPV were calculated for the volumetric analysis. RESULTS With the use of quantitative volumetry, a sensitivity of 72%, a specificity of 95%, a PPV of 93%, an NPV of 78%, and an area under the curve of 0.84 were obtained using a percentage difference of normalized hippocampal volume. The resulting specificity (95%) and PPV (93%) are superior to the original clinical read and to Reader A and Reader B's findings (range for specificity 74%-86% and for PPV 64%-71%). The sensitivity (72%) and NPV (78%) are comparable to Reader A's findings (73% and 81%, respectively) and are better than those of the original clinical read and of Reader B (sensitivity 45% and 63% and NPV 71% and 70%, respectively). CONCLUSIONS Volumetric measurement of the hippocampi outperforms expert readers in specificity and PPV, and it demonstrates comparable to superior sensitivity and NPV. Volumetric measurements can complement anatomical imaging for the identification of MTS, much like a computer-aided detection tool would. The implementation of this approach in the daily clinical workflow could significantly improve diagnostic accuracy.

Anterior temporal lobectomy for older adults with mesial temporal sclerosis

ObjectiveTo compare postoperative seizure-free survival between older and younger adults. MethodsA retrospective cohort of 107 temporal lobe epilepsy patients with a diagnosis of mesial temporal sclerosis (MTS) received anterior temporal lobectomy (ATL) between 1993 and 2014. We divided the lower three quartiles (younger) and top quartile (older, all 47+ years) of patients, then reviewed patient registry and electronic medical records to determine time to first self-reported seizure after ATL, the primary outcome (mean=3.5years of follow-up, SD=3.6). We also assessed Engel classifications, intraoperative and postoperative treatment complications, and social disability. We used Cox proportional hazard models to assess the association between individual traits and time of seizure recurrence. ResultsDuring follow-up, 35/107 (32.7%) patients had post-operative seizure(s). After adjustment for potential confounders there were no significant differences in the probability of post-operative seizures between the older and younger groups, though we had limited precision (hazard ratio of 0.67 [0.28–1.59]), (p=0.36). There were more treatment complications and disability in older patients (18% vs. 1.3% for any complications, 84.62% vs. 58.23% for driving disability, and 84.6% vs. 60.7% for work disability, p<0.05). ConclusionOlder patients appear to have more complications after ATL, compared with younger patients. Age, however, does not appear to have a large independent association with seizure recurrence.

Seasonality of birth in patients with temporal lobe epilepsy.

We investigated the seasonal pattern in births of patients with temporal lobe epilepsy and mesial temporal sclerosis. We hypothesized that the seasonal pattern in births of these patients is different from that in the general population. In this retrospective study, all patients who were evaluated for epilepsy surgery at Jefferson Comprehensive Epilepsy Center, Thomas Jefferson, Philadelphia, USA, between 1986 and 2014 and had a diagnosis of mesial temporal sclerosis (made by definite imaging findings of atrophy and/or sclerosis) were included. The seasonality in births of patients was compared with the seasonal pattern in the live births of the general population from Pennsylvania State. Two hundred and eighty-two patients (146 females and 136 males) were studied. The seasonality pattern in birth of patients was not statistically different from that in the general population. The observed contradictory findings among various studies indicate the need for further studies to elucidate whether season of birth brings the possibility of acquiring various epilepsy syndromes in the future. To investigate any possible association between season of birth and epilepsy, we suggest avoid pooling all patients with epilepsy together.

Volumetric brain analysis in neurosurgery: Part 3. Volumetric CT analysis as a predictor of seizure outcome following temporal lobectomy.

The incidence of temporal lobe epilepsy (TLE) due to mesial temporal sclerosis (MTS) can be high in developing countries. Current diagnosis of MTS relies on structural MRI, which is generally unavailable in developing world settings. Given widespread effects on temporal lobe structure beyond hippocampal atrophy in TLE, the authors propose that CT volumetric analysis can be used in patient selection to help predict outcomes following resection. Ten pediatric patients received preoperative CT scans and temporal resections at the CURE Children's Hospital of Uganda. Engel classification of seizure control was determined 12 months postoperatively. Temporal lobe volumes were measured from CT and from normative MR images using the Cavalieri method. Whole brain and fluid volumes were measured using particle filter segmentation. Linear discrimination analysis (LDA) was used to classify seizure outcome by temporal lobe volumes and normalized brain volume. Epilepsy patients showed normal to small brain volumes and small temporal lobes bilaterally. A multivariate measure of the volume of each temporal lobe separated patients who were seizure free (Engel Class IA) from those with incomplete seizure control (Engel Class IB/IIB) with LDA (p<0.01). Temporal lobe volumes also separate normal subjects, patients with Engel Class IA outcomes, and patients with Class IB/IIB outcomes (p<0.01). Additionally, the authors demonstrated that age-normalized whole brain volume, in combination with temporal lobe volumes, may further improve outcome prediction (p<0.01). This study shows strong evidence that temporal lobe and brain volume can be predictive of seizure outcome following temporal lobe resection, and that volumetric CT analysis of the temporal lobe may be feasible in lieu of structural MRI when the latter is unavailable. Furthermore, since the authors' methods are modality independent, these findings suggest that temporal lobe and normative brain volumes may further be useful in the selection of patients for temporal lobe resection when structural MRI is available.

Hippocampal volumetry: Normative data in the Indian population.

Background:Mesial temporal sclerosis (MTS) is the most common cause of temporal lobe epilepsy. Quantitative analysis of the hippocampus using volumetry is commonly being used in the diagnosis of MTS and is being used as a marker in prognostication of seizure control. Although normative data for hippocampal volume (HV) is available for the western population, no such data is available for the Indian population.Aim:The aim of the study was to establish normative data for HV for the Indian population, which can aid in the accurate diagnosis of MTS.Materials and Methods:Magnetic resonance imaging (MRI) scans of 200 healthy volunteers were acquired using a 3 Tesla (3T) MRI scanner. Manual segmentation and volumetry was done using Siemens Syngo software. The data was analyzed using two tailed t-test to detect associations between HV and age, gender, and education. The data so obtained was also correlated with the data available from the rest of the world.Results:A mean HV of 2.411 cm3 (standard deviation -0.299) was found in the study, which was significantly smaller when compared to the data from the western population. The right hippocampus was larger than the left, with a mean volume of 2.424 cm3 and 2.398 cm3, respectively. HV was detected to be significantly higher in males. No association was found between HV and age and education.Conclusion:The values obtained in this study may be adopted as a standard in the evaluation of patients with intractable epilepsy.

The Irish epilepsy surgery experience: Long-term follow-up

Aim To assess the long-term seizure outcome of Irish patients who underwent resective surgery for refractory epilepsy since 1975. We also wished to determine the impact of pathology and surgical technique (with particular reference to neocorticectomy) on seizure outcome. Methods A retrospective review of medical notes, radiological and histopathological records, was undertaken between 1975 and 2005. Missing data was supplemented by telephone calls to patients. One hundred and ninety-nine patients suited the criteria for inclusion and had at least 1-year follow-up (1–24 years, mean 7.0 years). Engel's criteria were used to classify seizure outcome at 1, 2, 5, 10, 15 and >15 years follow-up. Results The percentage of patients seizure free at 2, 5, 10, 15 and >15 years were, 56.6%, 41.4%, 44%, 25% and 31.3%, respectively. Of patients with a pathologically confirmed diagnosis of mesial temporal sclerosis, 55.6% were seizure free at 10 years. Equivalent figures for tumour were 62.5%, for cortical dysplasia, 34.8%, for those without any demonstrable pathologic abnormality, 50%, for dual pathology, 50% and for all others, 33.3%. Of those with 10 years or greater follow-up only 20% of neocorticectomy patients were in Engel class 1, compared with an average of 58.5% for the other surgical techniques. Conclusion Seizure freedom rates for Irish Patients were comparable to other large retrospective studies. Patients who underwent selective procedures tended to do better than those undergoing lobar resections, in keeping with international trends. The surgical technique unique to the Irish cohort, temporal necocorticectomy, had the worst long-term outcome.

Esclerosis mesial temporal en pediatría: espectro clínico. Nuestra experiencia de 19 años

Mesial temporal sclerosis (MTS) is defined as neuron loss and gliosis in the hippocampus and adjacent structures. Here we report on our 19 years' experience in dealing with this condition.A retrospective, descriptive study was conducted of patients diagnosed with MTS between May 1990 and January 2009.A diagnosis of MTS was established in 16 cases (62.5% males). By location these cases were distributed as follows: 12 were unilateral (seven left temporal and five right) and four were bilateral. It was associated to cortical dysplasia in six patients (37.5%) and to hippocampal arachnoid cysts in two other cases. As regards possible causations, in one case herpes simplex encephalitis was suspected; in three cases, a prenatal cerebral vascular pathology; and in three others, prenatal infection by cytomegalovirus. The distribution of the clinical spectrum was as follows: five patients with isolated clinical epilepsy; one with isolated psychomotor retardation or mental retardation (PMR-MR); one with isolated autism spectrum disorder (ASD); three with epilepsy associated to PMR-MR; one with epilepsy associated to ASD; two with PMR-MR and ASD; and two with the triad consisting of epilepsy together with PMR-MR and ASD. In one case, MTS was discovered in migraine studies, without any other symptoms. Crises were controlled with monotherapy in all the patients who received antiepileptic treatment except in three, one of whom required surgery.The definitive diagnosis of MTS is pathologic, but the latest neuroimaging techniques have allowed a very reliable approximate diagnosis to be reached. It may be associated to other malformative disorders, such as focal cortical dysplasia or cysts. MTS can be observed in epilepsy (whether refractory or not), but also in ASD, PMR-MR or asymptomatic patients.

Mesial temporal sclerosis in children

Mesial temporal sclerosis is the most frequent cause of drug-resistant temporal lobe epilepsy but has a satisfactory response to surgery, and is considered infrequent in children. To evaluate the clinical, electrographic and radiological spectrum of the disease in children. Retrospective study by review of charts of 44 children with a diagnosis of mesial temporal sclerosis on magnetic resonance imaging, attended at the "Hospital das Clínicas" of the University of São Paulo Faculty of Medicine. Febrile seizure was identified in the history of 54% of the patients. Injuries at the left side predominated in patients with schooling difficulties (p=0.049), in those with first seizures between six months and five years (p=0.021) and in those with complex febrile seizure (p=0.032). Thirteen patients were submitted to surgery and of these, eight remained without seizures. Febrile seizure may be related in a more direct way to the presence of left-side mesial temporal sclerosis.

Clinicopathologic findings in mesial temporal sclerosis treated with gamma knife radiotherapy

Mesial temporal sclerosis (MTS) is the most common cause of medically intractable temporal lobe epilepsy. Histologic findings include hippocampal atrophy with neuronal loss in the dentate, CA1, and CA3/CA4 regions with gliosis. The conventional treatment of patients with intractable epilepsy secondary to MTS has been surgical excision. Gamma knife radiotherapy (GKR) has recently been suggested as a less invasive alternative to surgery. To date, the histologic changes that occur in this setting after GKR have not been well described. The clinicopathologic features of 4 patients with MTS who received GKR and underwent subsequent surgical resection or autopsy were retrospectively reviewed. The study group is composed of 4 patients (3 women, 1 men) with ages 55, 48, 22, and 20 years, respectively, at the time of GKR. There were 2 patients who had a history of infantile febrile seizures, and 2 who had a central nervous infection during infancy. All 4 patients had a long-standing (13-36 years) history of temporal lobe seizures resistant to medical management. Imaging studies, electroencephalogram, and surgical specimens all confirmed the diagnosis of MTS. The oldest of the 4 patients died 1 month after receiving GKR, presumably because of post-gamma knife persistent seizure complications. The postmortem neuropathology on this patient was unremarkable for any radiation effect changes but showed evidence of MTS. The remaining 3 patients underwent surgical resection for persistent seizures at 18, 22, and 20 months, respectively, post-gamma knife. These 3 surgical specimens showed variable degrees of radiation effect changes in the temporal lobe, hippocampus, and amygdala, including chronic (lymphocytes and macrophages) perivascular inflammation (3/3), vascular sclerosis (3/3), foci of edema with necrosis (3/3; extensive in 2 patients), reactive astrocytosis (3/3), microglial proliferation (1/3), and microcalcifications (1/3). Patients with MTS who underwent GKR can develop typical radiation changes over time. Treatment of individuals with MTS via GKR may not always be adequate in controlling seizures. Radiation therapy effect may contribute to persistent seizures after GKR in some patients with MTS.

Race/Ethnicity, Sex, and Socioeconomic Status as Predictors of Outcome After Surgery for Temporal Lobe Epilepsy

Several risk factors have been attributed to seizure recurrence after surgery. It is unknown whether race/ethnicity plays a role in outcome. To evaluate whether race/ethnicity plays a role in seizure recurrence after surgery. Cohort study. We evaluated data obtained from the epilepsy centers at the University of Alabama at Birmingham and New York University, New York, NY. All patients included had a diagnosis of mesial temporal sclerosis and underwent temporal lobectomy. Occurrence of seizure after surgery was registered 1 year after surgery. We used multiple logistic regression analysis to model the presence of seizure recurrence after surgery and generated odds ratios (ORs) for seizure recurrence after surgery for African American and Hispanic patients relative to white patients. An unadjusted model incorporated only race/ethnicity as the independent variable, and an adjusted model included socioeconomic status, age, duration of epilepsy, education, history of febrile seizures, sex, handedness, lateralization of epileptogenic focus, and number of antiepileptics as the independent variables. Two hundred fifty-two patients underwent surgical treatment with pathological confirmation of mesial temporal sclerosis. No differences were found between racial/ethnic groups in terms of seizure recurrence in any models. For African American patients, the ORs were 0.9 (95% confidence interval [CI], 0.4-2.1) for the unadjusted model and 0.8 (95% CI, 0.3-2.0) for the adjusted model; for Hispanic patients, the ORs were 1.6 (95% CI, 0.8-3.2) for the unadjusted model and 1.1 (95% CI, 0.5-2.6) for the adjusted model, relative to white patients. Our data suggest that although sex appears to play a role in the outcomes of surgery for temporal lobe epilepsy, race and socioeconomic status do not.

Race/ethnicity: a predictor of temporal lobe epilepsy surgery outcome?

The success of epilepsy surgery in temporal lobe epilepsy reaches a 64% rate of seizure freedom, based on a randomized control trial. Observational studies from epilepsy centers worldwide indicate seizure freedom rates up to 93% when the etiology is unilateral hippocampal sclerosis. Several risk factors are attributed to the recurrence of seizures following the surgical procedure. Nonetheless, whether race influences the outcome of temporal lobe surgery is unknown. The purpose of this study was to evaluate if race plays a role in outcome following surgery. Data were obtained from the discharge database of the University of Alabama at Birmingham video/EEG monitoring unit, between 1998 and 2003, as well as the clinical charts. Seizure recurrence was evaluated 1 year following surgery. The sample consisted of all patients with a primary diagnosis of mesial temporal sclerosis (MTS) who underwent anterior temporal lobectomy. Multiple logistic regression analysis was used to model the presence of seizure recurrence after anterior temporal lobectomy for MTS. Two sets of logistic regression models were estimated to generate odds ratios (ORs) for seizure recurrence after an anterior temporal lobectomy for African-Americans or other possible ethnic/racial group present relative to non-Hispanic Caucasians. The first model incorporated only ethnicity as the independent variable and generated unadjusted ORs for seizure recurrence following the surgical procedure. The second set included the independent variables: duration of epilepsy, history of febrile seizures, lateralization of epileptogenic focus, handedness, and age. Seventy patients underwent surgical treatment and all of them had pathologic confirmation of MTS. Follow-up information for six was not available. Analysis of the remaining 64 patients revealed that African-Americans were more likely than non-Hispanic Caucasians to have seizure recurrence after surgery (OR=2.1, 95% CI=0.6-8.0). After potential confounders (duration of epilepsy, history of febrile seizures, lateralization of epileptogenic focus, handedness, and age) were controlled, this finding did not change (OR=1.7, 95% CI=0.3-10.7). Our data suggest that race may be an important factor related to seizure outcome following temporal lobectomy.

Mesial Temporal Sclerosis and Psychiatric Symptoms: A Case Report

We present the history of a woman with mesial temporal sclerosis (MTS) who was diagnosed with a psychotic depression before the correct diagnosis was made. The atypical course and some specific features raised doubt on the initial diagnosis. This case demonstrates the difficulty making a diagnosis of MTS.

Magnetic resonance imaging detection of mesial temporal sclerosis in children

The objective of this study was to investigate the prevalence and clinical characteristics of mesial temporal sclerosis as diagnosed by brain magnetic resonance imaging in children. A total of 390 consecutive brain magnetic resonance imaging studies in children were reviewed for evidence of mesial temporal sclerosis. Subsequently, the magnetic resonance imaging scans and charts of patients with mesial temporal sclerosis were reviewed and their clinical details were evaluated. The magnetic resonance imaging studies had been performed for multiple indications, including seizures, headache, and developmental problems. In children, the prevalence of mesial temporal sclerosis among all brain magnetic resonance imaging studies was 3.1% (12 of 390 studies) and 12.1% (12 of 99 studies) among all brain magnetic resonance imaging studies performed for seizures. These children all presented with a history of seizure disorder, often had other medical problems, and histopathology (when available) nearly always (5 of 6 patients) confirmed their magnetic resonance imaging diagnosis of mesial temporal sclerosis. The prevalence of mesial temporal sclerosis is low among all pediatric patients who had magnetic resonance imaging brain studies. All our mesial temporal sclerosis patients had clinical seizures; i.e., it was never an “incidental finding”. Children with mesial temporal sclerosis often had comorbid conditions, and the diagnosis of mesial temporal sclerosis made by magnetic resonance imaging was accurate when compared with the available histopathology.

MRI evidence of mesial temporal sclerosis in subjects without seizures

The identification of mesial temporal sclerosis (MTS) on magnetic resonance imaging (MRI) is critical in the evaluation for temporal lobectomy. The purpose of this study was to estimate the prevalence of MTS by MRI in the general population.We reviewed the charts of patients undergoing MRI scans over an 18-month period. In order to be included, patients had to have no history of seizures, and the MRIs had to read as ‘normal’. Patients were excluded if there was a history of seizures, mental illness, or alcohol abuse, and if they had a family history of seizures. Ages had to be from 5 to 50 years. All patients had MRI scans performed in three planes on 1.5 T systems. MRI diagnosis of MTS was based on standard visual diagnostic criteria analyzing: (1) hippocampal atrophy and (2) increased hippocampal T2 signal. Out of 375 charts reviewed, 204 met the inclusion criteria. Of the 204, 29 (14%) had abnormal and asymmetric mesial temporal structures consistent with a diagnosis of unilateral MTS. Nineteen (9.3%) had hippocampal atrophy only, two (1%) had T2 signal abnormalities, and eight (4%) met both criteria. There are some ‘false positives’ and MRI evidence for MTS is only meaningful in the proper clinical context.

Usefulness of Fluid Attenuated Inve rsion Re c overy(FLAIR) Image

Purpose : To determine the usefulness of fluid attenuated inversion recovery(FLAIR) imaging for the in detec-tion of high signal intensity of hippocampus or amygdala in mesial temporal sclerosis (MTS), compared with that of turbo spin-echo T2-weighted imaging. Materials and Methods : Two neuroradiologists independently analyzed randomly mixed MR images of 20 le-sions of 17 patients in whom MTS had been diagnosed, and ten normal controls. All subjects underwent both who performed both FLAIR and turbo spin-echo T2-weighted imaging, in a blind fashion. In order to deter-mine hippocampal morphology, oblique coronal images perpendicular to the long axis of the hippocampus were obtained. The detection rate of high signal intensity in hippocampus or amygdala, the radiologists ’preferred imaging sequence, and intersubject consistency of detection were evaluated. Signal intensity in hip-pocampus or amygdala was considered high if substantially higher than signal intensity in the cortex of adja-cent temporo-parietal lobe. Results : In all normal controls, FLAIR and spin-echo T2-weighted images showed normal signal intensity in hippocampus or amygdala. In MTS, the mean detection rate of high signal intensity in hippocampus or amyg-dala, as seen on FLAIR images was 93%, compared with 43% on spin-echo T2-weighted images. In all cases in which signal intensity on FLAIR images was normal, signal intensity on spin-echo T2-weighted images was al-so normal. The radiologists preferred the contrast properties of FLAIR to those of spin-echo T2-weighted images. Conclusion : In the diagnosis of MTS using MRI, FLAIR images are more useful for the detection of high signal intensity of hippocampus or amygdala than are spin-echo T2-weighted images. In the diagnosis of MTS, FLAIR imaging is therefore a suitable alternative to spin-echo T2-weighted imaging.

Corpora Amylacea

Mesial temporal sclerosis (MTS) is the most frequently encountered abnormality in temporal lobectomies performed for medically intractable seizure disorders. The pathologic diagnosis of MTS relies on the identification of neuronal loss affecting various regions of the hippocampus. However, neuronal loss is often difficult to assess, particularly in lobectomies that are not performed en bloc. Because of this difficulty the presence of hippocampal pathology is often indeterminate. In this report we describe our experience with 73 temporal lobectomies performed for seizure disorders. In 58%, increased numbers of corpora amylacea (CoA) were found in association with MTS. The relationship between CoA and the pathogenetic mechanisms underlying MTS remains speculative. However, the association between MTS and corpora amylacea is important to recognize since the identification of abundant numbers of CoA provides a marker for MTS that can be useful in cases in which neuronal loss and gliosis are difficult to assess. For this purpose, it is strongly recommended that tissues resected from the hippocampus and amygdala for temporal lobe epilepsy be stained with LFB-PAS to highlight CoA.