MRI对颞叶癫痫的定侧诊断的价值

目的 观察颞叶癫痫患者的头颅MRI变化，探讨MRI对颞叶癫痫的定侧诊断价值。方法 采用头颅MRI检查，对40例颞叶癫痢患者及40例正常对照组的海马体积进行测量，将海马萎缩严重侧作为致瘌侧。结果 定量MRI对颞叶癫痢定侧敏感性为72．5％，特异性为85．3％。结论 头颅MRI扫描对颞叶癫痫的定位及定侧有着重要的诊断价值。     

Postoperative memory prediction in left temporal lobe epilepsy: The Wada test is of no added value to preoperative neuropsychological assessment and MRI

The contribution of the Wada test (intracarotid amytal procedure, IAP) to predicting postoperative memory outcome in left temporal lobe epilepsy (LTLE) is becoming increasingly controversial when preoperative neuropsychological evaluation and MRI findings are available. We retrospectively analyzed 59 patients with LTLE who underwent en bloc temporal lobe resection. All patients had valid bilateral IAP test results, complete pre- and postoperative neuropsychological evaluation, and MRI grading on a 5-point scale integrating T 2 signal increase and degree of atrophy. Thirty percent of patients showed postoperative memory decline. Multiple regression analysis revealed that significant predictors of decline [F(2.56) = 22.71, P < 0.001, r² = 0.448] included preoperative memory learning score [t = −5.89, P < 0.001] and MRI classification [t = 3.10, P < 0.003], but not IAP scores. The IAP is of no added value in the prediction of postoperative memory outcome in LTLE in the presence of comprehensive neuropsychological and MRI data.     

磁共振成像阴性颞叶癫痫的临床特点分析

目的探讨磁共振成像(MRI)阴性颞叶癫痫(nonlesional temporal lobe epilepsy,TLE-NL)患者的临床特征、记忆水平和影像学特点。方法纳入2012年9月1日至2017年8月31日在浙江大学医学院附属第二医院确诊的44例单侧TLE-NL患者和53例同期就诊单侧颞叶癫痫伴海马硬化(temporal lobe epilepsy with hippocampal sclerosis,TLE-HS)患者,对TLE-NL和TLE-HS的临床特点进行对比。同时纳入20名健康志愿者作为正常对照组。采用韦氏记忆量表评估患者和对照组记忆功能,并通过高分辨率MRI定量分析海马体积及形态,评估TLE-NL和TLE-HS患者记忆水平和海马体积的改变。结果TLE-NL患者比TLE-HS患者发病年龄更晚[(24.3±12.6)岁与(15.8±10.3)岁;t=3.684,P<0.01],癫痫病程更短[4.00(2.00,8.75)年与14.00(7.50,22.00)年;Z=-4.675,P<0.01],热性惊厥史比例[4.5%(2/44)与62.3%(33/53);χ2=32.270,P<0.01)和药物难治性比例更低[47.7%(21/44)与84.9%(45/53);χ2=15.282,P<0.01)。TLE-NL患者在性别比例、癫痫家族史、致痫灶侧别、先兆发生率、症状学类型及发作频率上与TLE-HS患者类似。TLE-NL患者与正常对照组相比无明显记忆损害(记忆商数:105.2±17.4与103.8±16.2;P=1.000),而TLE-HS患者与正常对照组相比存在明显记忆损害(记忆商数:84.5±20.3与103.8±16.2;P<0.01)。TLE-NL患者海马体积和形态与正常对照组相比无明显改变,而TLE-HS患者存在明显致痫灶同侧海马萎缩[(2953±481)mm3与(4431±505)mm3;P<0.01),形态分析结果提示萎缩以海马头及海马体部明显。结论TLE-NL是一类有别于TLE-HS的颞叶癫痫综合征,具有发病年龄晚、病程短、热性惊厥史少、药物难治性癫痫发生率较低、无明显记忆损害及海马萎缩的临床特点。     

Cross hippocampal influence in mesial temporal lobe epilepsy measured with high temporal resolution functional magnetic resonance imaging

Purpose Mesial temporal lobe epilepsy (mTLE) is a chronic disorder with spontaneous seizures recurring for years, or even decades. Many structural and functional changes have been detected in both the seizure focus and distal regions throughout the brain over this duration that may reflect the development of epileptogenic networks. Resting state functional magnetic resonance imaging (fMRI) connectivity mapping has the potential to elucidate and quantify these networks. The network between the left and right hippocampus may very likely be one of the most susceptible to changes due to long‐term seizure propagation effects. Therefore, the objective of this study was to quantify cross hippocampal influence in mTLE using high temporal resolution fMRI, and to determine its relationship with disease duration. Methods fMRI images were acquired in the resting (interictal) state with 500 ms temporal resolution across the temporal lobes of 19 mTLE patients (13 left, 6 right). The left and right hippocampi were identified on each subject’s images using both structurally defined and functionally defined boundaries. The cross hippocampal influence was quantified in two ways for each pair of regions: (1) the nondirectional hippocampal functional connectivity calculated as the Pearson’s correlation between the average time series in the left and the right hippocampus regions, and (2) the Granger causality (GC) laterality measure, which implies directional influence by determining temporal precedence. Each of these measures was correlated with age, age of onset, and disease duration across subjects to investigate relationship to disease progression. Key Findings The hippocampal connectivity was not significantly different between patients with left and right mTLE using either the structurally or the functionally defined regions. Across all patients, hippocampal connectivity was not correlated significantly with age of onset or duration of disease. However, as duration of disease increased after 10 years (nine patients), the hippocampal connectivity increased linearly. Using the functionally defined regions, the GC laterality was increased in the right mTLE over the left mTLE, indicating that the left hippocampus was influencing the right hippocampus more than the right influencing left. This was also positively correlated with age of onset. Furthermore, like hippocampal connectivity, the relationship between GC laterality and duration of disease changes after 10 years duration of disease. After this duration, the GC laterality was positive in the three of three patients with right mTLE (left influencing right), whereas the GC laterality was negative in five of six patients with left mTLE (right influencing left). Significance This study reveals a relationship between fMRI functional connectivity and causal influence of the left and right hippocampi and duration of disease in mTLE. During the interictal state, the interhemispheric hippocampal connectivity initially is disrupted and then linearly increases as the epilepsy progresses longer than 10 years. This increase in connectivity appears to be due to the hippocampus contralateral to the epileptogenic focus exerting more influence over the ipsilateral hippocampus. These findings may have implications in understanding the functional development of epileptic networks and possibly prediction of surgical outcome of mTLE.     

Combined measurements of hippocampal N-acetyl-aspartate and T2 relaxation time in the evaluation of mesial temporal lobe epilepsy: correlation with clinical severity and memory performances.

PURPOSE: In this study we tried to find a correlation between the clinical severity and memory performances, by comparing proton magnetic resonance (MR) spectroscopy and T2 relaxation time measurements in the hippocampi, in a homogeneous group of 27 patients with unilateral mesial temporal lobe epilepsy with ipsilateral hippocampal sclerosis on MR imaging, with a view to answer the following questions: (a) how sensitive is this approach for the assessment of the apparently normal contralateral hippocampus, (b) do the results relate to the clinical severity, and (c) does it allow evaluation of the degree of hippocampal dysfunction. METHODS: Volume-selective proton MR spectroscopy of the head of both hippocampi was performed at 3 T, by using the PRESS sequence, with an echo time of 135 ms, to estimate NAA/(Cho + Cr) ratios. The relaxation times were measured at 0.28 T, by using a conventional Carr-Purcell-Meiboom-Gill sequence, with a repetition time of 2,000 ms, an echo time of 15 ms, and 48 echoes. RESULTS: The combination of NAA/(Cho + Cr) ratio and T2 relaxation time values was allowed to classify contralateral hippocampus abnormalities in two groups: first, decreased NAA/(Cho + Cr) ratio with strongly increased T2 relaxation time values corresponding to abnormalities observed in sclerotic ipsilateral hippocampi; and second, decreased NAA/(Cho + Cr) ratio with normal or slightly increased T2 relaxation time values. Whereas the NAA/(Cho + Cr) ratio or T2 relaxation time value alone was not correlated with memory performances, their association shows that left hippocampal injury evaluated both by NAA and T2 relaxation time measurements was clearly correlated with verbal memory scores, and right hippocampal injury, with visual memory scores. On the other hand, the maximal seizure frequency reported by the patients was correlated with ipsilateral NAA/(Cho + Cr) ratio and T2 relaxation time values but not with contralateral results. CONCLUSIONS: We showed that the combination of NAA and T2 relaxation time measurements can be used to examine the degree of ipsi- and contralateral hippocampal dysfunction or injuries and their relations with memory performances in the presurgical evaluation of patients.     

Surgical outcome of patients with mesial temporal lobe epilepsy related to hippocampal sclerosis

Seizure outcome in mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) that was evaluated according to a noninvasive protocol was assessed in 165 patients and reported using both Engel's and ILAE classifications. The mean postoperative follow-up was 5.0 +/- 2.7 years. At the end of first year, 77.1% of patients were in Engel-I, and 52.7% were in ILAE-I. Antiepileptic drugs (AEDs) were discontinued in 41 patients (42.7%), all remained seizure-free for >or= 2 years that could be accepted as "cure." Thirty-six patients had recurrences, 19 had running-down phenomena. Anterior temporal lobectomy (ATL) was performed in 27 patients with a better outcome when compared to patients operated by selective anterior hippocampectomy. Clinical risk factors for better and worse outcome, which show some similarity in different reports, seem to veil the main reason, which is the accurate delineation of epileptogenic zone considering the presence of different subgroups and underlying developmental pathologies.     

Hippocampal deformation-based shape analysis in epilepsy and unilateral mesial temporal sclerosis

PURPOSE: To assess shape changes in patients with mesial temporal sclerosis (MTS) and temporal lobe epilepsy (TLE), by using deformation-based hippocampal shape analysis. METHODS: We retrospectively reviewed magnetic resonance imaging (MRI) studies in 30 subjects with unilateral MTS (15 right-sided MTS, 15 left-sided MTS) and TLE. We defined the "average" hippocampus in the right- and left-MTS groups by generating a mean transformation for the 15 deformation images in each group. Further to quantify the difference between the hippocampi, we coregistered the mean transformation of the involved hippocampus (with MTS) to the contralateral hippocampus, considering the left- and right-MTS groups independently. We generated a color "flame" scale showing degrees of outward and inward deviation of the coregistered hippocampi. RESULTS: Both the right- and left-MTS groups showed similar shape changes, with maximal inward deformation in the medial and lateral hippocampal head and the hippocampal tail. However, more extensive involvement was seen in the lateral hippocampal body in the right-MTS group as compared with the left. CONCLUSIONS: Deformation-based hippocampal shape analysis shows specific regions of hippocampal surface anatomy that are most affected in MTS. This technique may aid in detection of clinically significant anatomic abnormalities of the hippocampus in patients with epilepsy.     

Thalamic diffusion and volumetry in temporal lobe epilepsy with and without mesial temporal sclerosis

PURPOSE: As an important connection within the limbic system, considerable attention has been paid to thalamic pathology in temporal lobe epilepsy (TLE). Magnetic resonance imaging (MRI) volumetric studies have yielded variable results and have largely been focused on TLE with mesial temporal sclerosis (TLE+). Diffusion tensor imaging (DTI) provides unique information on microstructure based on the measurement of water diffusion. To date, DTI properties of thalamus have not been well characterized in adult TLE patients with unilateral MTS or without MTS (TLE-). The purpose of this study was to investigate the status of thalamic integrity by using DTI as well as volumetric MRI in adult TLE+ and TLE- patients. METHOD: In 17 unilateral TLE+ patients, 10 TLE- patients and 26 controls, the thalamus was segmented by using an automated atlas-based method. Mean diffusivity (MD), fractional anisotropy (FA) and volume were then quantified from DTI and 3D T1-weighted scans. RESULTS: No significant changes were found in either DTI parameters or volume of thalamus in TLE- patients, as compared to healthy controls. However, both DTI parameters and MRI volumetry showed bilateral thalamic pathology in TLE+ patients, as compared to healthy controls. Also, TLE+ patients showed significant reduction of thalamic volume as compared to TLE- patients. In addition, thalamic FA ipsilateral to seizure focus showed significant correlation with age at onset of epilepsy in TLE+ patients. CONCLUSION: Our finding demonstrates bilateral pathology of thalamus in unilateral TLE+ patients. The discrepancy in thalamic pathology between TLE+ and TLE- patients suggests that along with differences in mesial temporal pathology, TLE+ and TLE- have unique extratemporal structural abnormalities.     

Subfield atrophy pattern in temporal lobe epilepsy with and without mesial sclerosis detected by high-resolution MRI at 4 Tesla: Preliminary results

Purpose:   High-resolution magnetic resonance imaging (MRI) at 4 Tesla depicts details of the internal structure of the hippocampus not visible at 1.5 Tesla, and so allows for in vivo parcellation of different hippocampal subfields. The aim of this study was to test if distinct subfield atrophy patterns can be detected in temporal lobe epilepsy (TLE) with mesial temporal sclerosis (TLE-MTS) and without (TLE-no) hippocampal sclerosis.
Methods:   High-resolution T₂-weighted hippocampal images were acquired in 34 controls: 15 TLE-MTS and 18 TLE-no. Entorhinal cortex (ERC), subiculum (SUB), CA1, CA2, and CA3, and dentate (CA3&DG) volumes were determined using a manual parcellation scheme.
Results:   TLE-MTS had significantly smaller ipsilateral CA1, CA2, CA3&DG, and total hippocampal volume than controls or TLE-no. Mean ipsilateral CA1 and CA3&DG z-scores were significantly lower than ipsilateral CA2, ERC, and SUB z-scores. There were no significant differences between the various subfield or hippocampal z-scores on either the ipsi- or the contralateral side in TLE-no. Using a z-score ≤−2.0 to identify severe volume loss, the following atrophy patterns were found in TLE-MTS: CA1 atrophy, CA3&DG atrophy, CA1 and CA3&DG atrophy, and global hippocampal atrophy. Significant subfield atrophy was found in three TLE-no: contralateral SUB atrophy, bilateral CA3&DG atrophy, and ipsilateral ERC and SUB atrophy.
Discussion:   Using a manual parcellation scheme on 4 Tesla high-resolution MRI, we found the characteristic ipsilateral CA1 and CA3&DG atrophy described in TLE-MTS. Seventeen percent of the TLE-no had subfield atrophy despite normal total hippocampal volume. These findings indicate that high-resolution MRI and subfield volumetry provide superior information compared to standard hippocampal volumetry.     

Clinical patterns of patients with temporal lobe epilepsy and pure amygdalar atrophy

PURPOSE: MRI volumetric measurements (MRIvol) have been proven reliable in determining mesial temporal atrophy in patients with TLE. We attempted to correlate the clinical features with different patterns of hippocampal formation (HF) and amygdala (AM) atrophy in patients with TLE without foreign tissue lesion. METHODS: We studied 65 patients with refractory TLE. They were divided into five groups according to MRIvol results: pure AM atrophy (n = 11, 10 unilateral and one bilateral), unilateral HF atrophy (n = 16), bilateral HF atrophy (n = 12), unilateral AM + HF atrophy (n = 13), and patients with normal volumes of AM and HF (n = 13). MRIvol of AM and HF were performed by using a protocol previously described by Watson et al. (Neurology 1992;42:1743-50). RESULTS: Patients with AM atrophy had later onset of seizures compared with those with unilateral HF atrophy (p < 0.01). History of febrile convulsions (p < 0.0001) and frequent secondarily generalized tonic-clonic seizures (GTCSs) were more often found in patients with HF atrophy compared with those with pure AM atrophy and those with normal volumes (p = 0.04). Prolonged postictal confusion was more often found with AM atrophy (p = 0.05). Memory impairment was more severe in patients with HF atrophy than in those with AM atrophy only or in those with normal volumes (p = 0.03). There were no significant differences among the five groups in the following parameters: age, duration of epilepsy, seizure frequency, and presence and type of aura. CONCLUSIONS: Prolonged postictal confusion appeared to be related to AM atrophy, in keeping with previous clinical observations. These patients also had a lower incidence of early febrile convulsions, older age at epilepsy onset, lower frequency of secondary GTCS, and lesser memory dysfunction compared with patients with hippocampal atrophy.     

Extrahippocampal gray matter loss and hippocampal deafferentation in patients with temporal lobe epilepsy

Purpose: Medial temporal epilepsy (MTLE) is associated with extrahippocampal brain atrophy. The mechanisms underlying brain damage in MTLE are unknown. Seizures may lead to neuronal damage, but another possible explanation is deafferentation from loss of hippocampal connections. This study aimed to investigate the relationship between hippocampal deafferentation and brain atrophy in MTLE. Methods: Three different MRI studies were performed involving 23 patients with unilateral MTLE (8 left and 15 right) and 34 healthy controls: (1) voxel‐based morphometry (VBM), (2) diffusion tensor imaging (DTI) and (3) probabilistic tractography (PT). VBM was employed to define differences in regional gray matter volume (GMV) between controls and patients. Voxel‐wise analyses of DTI evaluated differences in fractional anisotropy (FA), mean diffusivity (MD) and hippocampal PT. Z‐scores were computed for regions‐of‐interest (ROI) GMV and peri‐hippocampal FA and MD (to quantify hippocampal fiber integrity). The relationship between hippocampal deafferentation and regional GMV was investigated through the association between ROI Z scores and hippocampal fiber integrity. Results: Patients with MTLE exhibited a significant reduction in GMV and FA in perihippocampal and limbic areas. There was a decrease in hippocampal PT in patients with MTLE in limbic areas. A significant relationship between loss of hippocampal connections and regional GMV atrophy was found involving the putamen, pallidum, middle and inferior temporal areas, amygdala and ceberellar hemisphere. Discussion: There is a relationship between hippocampal disconnection and regional brain atrophy in MTLE. These results indicate that hippocampal deafferentation plays a contributory role in extrahippocampal brain damage in MTLE.     

Reorganization of verbal and nonverbal memory in temporal lobe epilepsy due to unilateral hippocampal sclerosis

PURPOSE: Patients with temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS) often suffer from material-specific memory impairments. The purpose of this study was to use functional magnetic resonance imaging (fMRI) to study the organization of specific memory functions in these patients. METHODS: We report 14 patients with unilateral TLE and HS, and 10 controls, performing an fMRI memory paradigm of word, picture, and face encoding. RESULTS: Compared with controls, patients with left TLE demonstrated less left MTL and greater right MTL activation and patients with right TLE demonstrated less right MTL and greater left MTL activation. Correlations between fMRI activation and memory performance revealed greater activation in the damaged left hippocampus to be correlated with better verbal memory performance in left TLE patients and greater right hippocampal activation to be correlated with better nonverbal memory in right TLE patients. Conversely, greater fMRI activation in the contralateral hippocampus correlated with worse memory performance. CONCLUSIONS: Our findings suggest that memory function in unilateral TLE is better when it is sustained by activation within the damaged hippocampus and that reorganization to the undamaged MTL is an inefficient process, incapable of preserving memory function.     

The renin-angiotensin system is upregulated in the cortex and hippocampus of patients with temporal lobe epilepsy related to mesial temporal sclerosis

Purpose: As reported by several authors, angiotensin II (AngII) is a proinflammatory molecule that stimulates the release of inflammatory cytokines and activates nuclear factor κB (NFκB), being also associated with the increase of cellular oxidative stress. Its production depends on the activity of the angiotensin converting enzyme (ACE) that hydrolyzes the inactive precursor angiotensin I (AngI) into AngII. It has been suggested that AngII underlies the physiopathological mechanisms of several brain disorders such as stroke, bipolar disorder, schizophrenia, and disease. The aim of the present work was to localize and quantify AngII AT1 and AT2 receptors in the cortex and hippocampus of patients with temporal lobe epilepsy related to mesial temporal sclerosis (MTS) submitted to corticoamygdalohippocampectomy for seizure control.
Method: Immunohistochemistry, Western blot, and real-time PCR techniques were employed to analyze the expression of these receptors.
Results: The results showed an upregulation of AngII AT1 receptor as well as its messenger ribonucleic acid (mRNA) expression in the cortex and hippocampus of patients with MTS. In addition, an increased immunoexpression of AngII AT2 receptors was found only in the hippocampus of these patients with no changes in its mRNA levels.
Discussion: These data show, for the first time, changes in components of renin-angiotensin system (RAS) that could be implicated in the physiopathology of MTS.     

The role of the intracarotid amobarbital procedure in predicting verbal memory decline after temporal lobe resection

PURPOSE: The aim of this study was to compare the utility of baseline neuropsychological measures and scores from the intracarotid amobarbital procedure (IAP) in the prediction of postoperative memory decline in temporal lobe epilepsy surgery patients. METHODS: Logistic regression analyses were used to determine the relation between demographic variables, baseline neuropsychological scores, and scores from the IAP (using mixed verbal and nonverbal stimuli) and postoperative deterioration in verbal learning and verbal recall in 91 patients (48 right, RTL; 43 left, LTL) who had undergone a standard anterior temporal lobe resection for the relief of medically intractable epilepsy and who had been followed up 1 year postoperatively. RESULTS: In the RTL group, the IAP scores were not significant predictors of a postoperative decline in verbal learning or recall. In the LTL group, postoperative decline in verbal learning was associated with good preoperative baseline scores, an older age at the time of surgery, and an unexpected asymmetry on the IAP. Baseline neuropsychological scores and scores from the IAP were associated with a significant postoperative decline in verbal recall in the LTL group. CONCLUSIONS: Scores from the IAP using mixed stimuli were not helpful in the prediction of postoperative verbal memory decline in RTL patients. The significance of IAP scores in predicting verbal memory deficits in LTL patients may be task specific.     

Extent of initial injury determines language lateralization in mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS)

Purpose :  To assess the prevalence and attributes of atypical language lateralization (ALL) in patients with left mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS).
Methods :  We recruited consecutive patients with left MTLE-HS, who had undergone resective surgery and had pathologically proven HS. Based on the Wada test, language lateralization was classified into typical (left hemispheric) or atypical (right hemispheric or codominant). We assessed the attributes of patients with ALL using univariate and multivariate analyses.
Results :  Of 124 patients with left MTLE-HS, 23 (18.5%) had ALL. ALL occurred more frequently in patients with severe initial precipitating injury (IPI), early onset of epilepsy, and a short latent period between IPI and onset of habitual seizures. ALL was more common in patients with bitemporal and extratemporal interictal epileptiform discharges (IEDs) on electroencephalogram (EEG) and extratemporal changes on magnetic resonance imaging (MRI). On multivariate analyses, the age at onset of habitual seizures <6 years, atypical IPI, nonunilateral temporal IEDs, and extratemporal MRI abnormalities independently predicted ALL. The likelihood of ALL was very low (∼1%) when all of these four risk factors were absent, whereas it was very high (>95%), if any three or all four of them were present.
Conclusions :  ALL occurs in one-fifth of patients with left MTLE-HS. ALL is more frequent in those with structural or functional extrahippocampal involvement and early onset of epilepsy interrupting the development of normal language networks. Because ALL is uncommon in those with damage/dysfunction restricted to the hippocampus, the hippocampus itself may have only a limited role in determining language lateralization.     

Contribution of SISCOM imaging in the presurgical evaluation of temporal lobe epilepsy related to dysembryoplastic neuroepithelial tumors

PURPOSE: Dysembryoplastic neuroepithelial tumors (DNTs) are a group of glioneuronal supratentorial and intracortical lesions often associated with the early onset of intractable and crippling partial seizures. They are characterized by their location, multinodular architecture, and heterogeneous cell composition, with a specific glioneuronal element in the specific form. Foci of cortical dysplasia may be associated with the tumoral lesion, and identifying the presence and the extent of cortical dysplasia is not always easy on magnetic resonance images (MRIs). The purpose of this article is to evaluate, retrospectively, the usefulness of ictal single-photon emission computed tomography (SPECT) imaging to assess the presence and the extent of cortical dysplasia associated with DNTs in nine patients with intractable temporal lobe epilepsy related to histopathologically confirmed DNTs. METHODS: The results of the subtraction of ictal and interictal SPECT coregistered to MRI (SISCOM) were compared with the results of the examinations of pathological material after surgery. RESULTS: SISCOM showed a strongly hyperperfused area corresponding anatomically to electroclinical abnormalities and to the location of DNTs on MRI. A circumscribed hyperperfusion was present in DNTs without cortical dysplasia, limited to the location of the tumor on MRI. In cases of associated cortical dysplasia, a widespread hyperperfusion including areas corresponding to normal perilesional regions on MRI was found. CONCLUSIONS: SISCOM, used among presurgical investigations, contributes to detecting cortical dysplasia associated with DNTs. Concordance between the symptomatogenic zone (defined from the medical history and electroclinical data), MRI scans, SISCOM pattern, and complete resection of the epileptic zone was predictive of a good postsurgical outcome.     

Bilateral hippocampal atrophy in temporal lobe epilepsy: effect of depressive symptoms and febrile seizures

Purpose: Neuroimaging studies suggest a history of febrile seizures, and depression, are associated with hippocampal volume reductions in patients with temporal lobe epilepsy (TLE). Methods: We used radial atrophy mapping (RAM), a three‐dimensional (3D) surface modeling tool, to measure hippocampal atrophy in 40 patients with unilateral TLE, with or without a history of febrile seizures and symptoms of depression. Multiple linear regression was used to single out the effects of covariates on local atrophy. Key Findings: Subjects with a history of febrile seizures (n = 15) had atrophy in regions corresponding to the CA1 and CA3 subfields of the hippocampus contralateral to seizure focus (CHC) compared to those without a history of febrile seizures (n = 25). Subjects with Beck Depression Inventory II (BDI‐II) score ≥14 (n = 11) had atrophy in the superoanterior portion of the CHC compared to subjects with BDI‐II <14 (n = 29). Significance: Contralateral hippocampal atrophy in TLE may be related to febrile seizures or depression.     

The relationship between quantitative T2 relaxometry and memory in nonlesional temporal lobe epilepsy

PURPOSE: We investigated the relationship between preoperative quantitative magnetic resonance imaging (MRI) T2 relaxometry and volumetry of the hippocampi and pre- and postoperative verbal memory in temporal lobectomy patients who had nonlesional temporal lobe epilepsy. METHODS: Pre- and postoperative memory data based on the Logical Memory (LM) subtest of the Wechsler Memory Scale-Revised (WMS-R) and the 30-min delayed recall trial of the Rey Auditory Verbal Learning Test (AVLT) were obtained from 26 left and 15 right temporal lobectomy patients. Coronal MRI T2 maps were generated for these 41 temporal lobectomy patients as well as 61 control patients. Hippocampal T2 relaxation times and hippocampal volumes, converted to z scores using control group data, were correlated with neuropsychological performance in the patients. RESULTS: In left temporal lobe-onset patients, high T2 in the left hippocampal body predicted higher LM performance after surgery. Asymmetrically high T2 in the left hippocampal body (i.e., the right-minus-left difference), compared with the right hippocampal body, also predicted higher LM performance after surgery. In right temporal lobe-onset patients, high T2 in the left hippocampal body predicted relatively lower AVLT performance after surgery. Multiple regression analysis in left temporal-onset patients revealed that high T2 in the left hippocampal body together with higher preoperative LM performance predict higher postoperative LM performance. CONCLUSIONS: Our findings suggest that elevated (i.e., abnormal) hippocampal T2 signal is associated with memory ability (or hippocampal functional capacity) independent of MRI-determined hippocampal atrophy. Therefore, our findings support the use of quantitative T2 relaxometry as an independent predictor of verbal memory outcome in both left and right TLE patients who are candidates for temporal lobectomy.