Cortical abnormalities and their cognitive correlates in patients with temporal lobe epilepsy and interictal psychosis

Purpose: To determine whether cortical abnormalities are more severe and widespread in patients with temporal lobe epilepsy (TLE) and interictal psychosis (IP) compared to those with TLE only (NIP) and healthy controls (HC), and to explore the associations between cortical parameters (area, thickness and volume), psychotic symptoms, and cognitive performance. Methods: Twenty‐two patients with IP (9 male; 10 hippocampal sclerosis, HS), 23 TLE nonpsychotic (NIP) patients (11 male; 13 HS) matched for duration of epilepsy and 20 HC participated. Surface‐based morphometry (SBM) was used to measure cortical parameters. Cognition was examined in IP and NIP patients. Associations between cortical parameters and cognition were examined using linear mixed models adjusted by age, gender, and brain volume. Key Findings: IP patients had an earlier onset of epilepsy, more status epilepticus, and worse cognitive performance than NIP patients. In IP patients, cortical thickness was reduced in the inferior frontal gyrus (IFG), and their current IQ was associated with decreases in area, but not thickness, in regions of the frontotemporal cortex. Significance: IP likely reflects the interplay of psychosis‐related genetic factors and the cumulative effects of seizure activity on the brain. Cortical thinning in the IFG, a region implicated in schizophrenia, is likely to be related to seizure activity, whereas changes in IQ, associated with reductions in area of frontotemporal cortex, may be related to the presence of psychosis.     

High-resolution diffusion tensor imaging of the hippocampus in temporal lobe epilepsy

PURPOSE: To assess the quantitative diffusion characteristics of the hippocampus with high-resolution diffusion tensor imaging (DTI) in temporal lobe epilepsy (TLE). METHODS: Thirteen controls and seven unilateral TLE patients (six with hippocampal sclerosis, one with normal magnetic resonance imaging (MRI)) were scanned with DTI using a zonally magnified oblique multislice echo planar imaging (ZOOM-EPI) acquisition. Fractional anisotropy (FA) and mean diffusivity (MD) were measured in the hippocampi. RESULTS: The mean hippocampal MD ipsilateral to the seizure focus was higher than the contralateral MD in patients (p<0.05) and the mean MD in controls (p<0.001). Hippocampal FA ipsilateral to the seizure focus was lower than the mean FA in controls (p<0.05). MD asymmetry indexes were significantly different between the patient and control groups (p<0.01). All six individual HS patients had ipsilateral hippocampal MD >or=2 standard deviations (S.D.) above the control mean. The patient with normal structural MRI had bilaterally low hippocampal FA and high MD. DISCUSSION: High-resolution DTI identifies lateralizing abnormalities of MD and FA in TLE patients. This quantitative data on hippocampal integrity may assist in evaluating TLE patients with normal MRI, and in longitudinal studies.     

A neuropsychological study of patients with temporal lobe epilepsy and chronic interictal psychosis

PURPOSE: To characterize the pattern of cognitive deficits in patients with temporal lobe epilepsy (TLE) and interictal (schizophrenia-like) psychosis and to examine the relationship between neuropsychological deficits and Magnetization transfer imaging. METHODS: Twenty patients with TLE and interictal psychosis were compared to 20 non-psychotic TLE patients. Patients were matched with respect to premorbid IQ, age and conventional MRI findings. A battery of neuropsychological tests was administered. The neuropsychological tests which showed significant group differences were used for correlational analysis with magnetization transfer ratio (MTR) which provides a quantitative measure of macromolecular structural integrity. RESULTS: Patients with interictal psychosis were significantly more impaired on executive and semantic memory tasks than the non-psychotic TLE group. Vocabulary test scores correlated significantly with MTR reduction in the left fusiform gyrus in the psychotic but not the non-psychotic group. DISCUSSION: In this study, patients with TLE and interictal psychosis were more cognitively impaired than non-psychotic TLE patients. Our findings suggest that the cognitive deterioration in these patients may occur as the illness progresses and the causes for this are probably multifactorial. Our study also provides further evidence that MTR may be useful in investigating structural correlates of cognitive impairment.     

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.     

A magnetization transfer imaging study in patients with temporal lobe epilepsy and interictal psychosis.

BACKGROUND: Findings from previous neuropathological and neuroimaging studies in patients with epilepsy and interictal psychosis have been inconclusive, and both focal and widespread brain abnormalities have been reported. Thus, further investigation with advanced in vivo magnetic resonance imaging (MRI) techniques, such as magnetization transfer imaging, capable of detecting more subtle brain abnormalities, is warranted. METHODS: Twenty patients with temporal lobe epilepsy and interictal psychosis were compared with 20 nonpsychotic patients. Patients were matched with respect to conventional MRI findings. Each group comprised of 10 patients with hippocampal sclerosis (6 left, 4 right) and 10 patients without focal lesions on MRI. A voxel-based analysis was used for the group comparisons. RESULTS: Voxel-based analysis revealed significant reductions of magnetization transfer ratio (an index of signal loss derived from magnetization transfer imaging) in the left superior and middle temporal gyri in the psychotic patients for the subgroup of patients with no focal lesions on MRI. There were no significant volumetric differences between the psychotic and nonpsychotic patients. CONCLUSIONS: Focal cortical magnetization transfer ratio abnormalities in the left temporal lobe unrelated to volume changes can be demonstrated in some temporal lobe epilepsy patients with interictal psychosis. Our findings might reflect subtle neuropathological abnormalities that are undetected by conventional MRI.     

Structural brain abnormalities in patients with schizophrenia, epilepsy, and epilepsy with chronic interictal psychosis.

Chronic interictal psychotic syndromes, often resembling schizophrenia, develop in some patients with epilepsy. Although widespread brain abnormalities are recognized as characteristic of schizophrenia, prevailing but controversial hypotheses on the co-occurrence of epilepsy and psychosis implicate left temporal lobe pathology. In this study, quantitative MRI methods were used to address the regional specificity of structural brain abnormalities in patients with epilepsy plus chronic interictal psychosis (E+PSY, n=9) relative to three comparison groups: unilateral temporal lobe epilepsy without chronic psychosis (TLE, n=18), schizophrenia (SCZ, n=46), and healthy control subjects (HC, n=57). Brain measures, derived from a coronal spin-echo MRI sequence, were adjusted for age and cerebral volume. Relative to HC, all patient groups had ventricular enlargement and smaller temporal lobe, frontoparietal, and superior temporal gyrus gray matter volumes, with the extent of these abnormalities greatest in E+PSY. Only TLE had temporal lobe white matter deficits, as well as smaller hippocampi, which were ipsilateral to the seizure focus. Structural brain abnormalities in E+PSY are not restricted to the left temporal lobe. The confluence of cortical gray matter deficits in E+PSY and SCZ suggests salience to chronic psychosis.     

Changes in Regional Cerebral Blood Flow Beyond the Temporal Lobe in Unilateral Temporal Lobe Epilepsy

Summary: Purpose: Single photon emission computed tomography (SPECT) is widely used to evaluate functional abnormalities during the epileptic event. Changes in regional cerebral blood flow (rCBF) are well defined in patients with temporal lobe epilepsy (TLE) undergoing surgical resection. Nonetheless, the interpretation of ictal abnormalities in CBF beyond the temporal lobes has not been carefully addressed.
Methods : We assessed 4 patients with pathologically proven unilateral TLE who had significant ipsilateral frontal hypoperfusion in ictal studies with no other abnormalities but chronic epilepsy accounting for such findings. Patients were assessed as candidates for surgery by interictal EEG, neuropsychological studies, brain magnetic resonance imaging, scalp electrode video-EEG monitoring, and ictal SPECT.
Results : Characteristic hyperperfusion was evident over the temporal lobe ipsilateral to the EEG focus, with significant hypoperfusion over the frontal region in 3 patients. In patient 4, frontal hypoperfusion was not statistically significant.
Conclusions : SPECT demonstrated relative rCBF changes beyond the epileptogenic zone in unilateral TLE. Our findings provide further insight into the pathophysiological changes underlying this condition.     

抑郁症患者脑白质变化初步研究

目的：利用能够提示脑白质纤维完整性的磁共振弥散张量成像（DTI）探讨首发和复发重性抑郁症患者脑白质纤维的变化及其差异。方法：20例重性抑郁症患者（首发9例，复发11例）和20名正常对照者均经常规磁共振成像（MRI）平扫，未发现异常者继续进行DTI和结构MRI（3D）扫描，基于像素的全脑分析技术对DTI数据进行分析。结果：与对照组相比较，抑郁症组白质纤维结构在双侧额中回、右顶下小叶及双侧脑岛等区域白质的各向异性值（FA）显著降低（各脑区P均〈0.001，cluster〉30像素）;与首发抑郁症患者相比较，复发抑郁症患者右侧额上回、右顶叶、中央前回、中央后回及右顶下小叶等区域FA值降低更为显著（各脑区P均〈0.001，cluster〉10像素）。结论：重性抑郁症患者存在脑白质异常，抑郁反复发作会导致脑白质损害进一步加重。     

Chemotherapy‐induced structural changes in cerebral white matter and its correlation with impaired cognitive functioning in breast cancer patients

A subgroup of patients with breast cancer suffers from mild cognitive impairment after chemotherapy. To uncover the neural substrate of these mental complaints, we examined cerebral white matter (WM) integrity after chemotherapy using magnetic resonance diffusion tensor imaging (DTI) in combination with detailed cognitive assessment. Postchemotherapy breast cancer patients (n = 17) and matched healthy controls (n = 18) were recruited for DTI and neuropsychological testing, including the self‐report cognitive failure questionnaire (CFQ). Differences in DTI WM integrity parameters [fractional anisotropy (FA) and mean diffusivity (MD)] between patients and healthy controls were assessed using a voxel‐based two‐sample‐t‐test. In comparison with healthy controls, the patient group demonstrated decreased FA in frontal and temporal WM tracts and increased MD in frontal WM. These differences were also confirmed when comparing this patient group with an additional control group of nonchemotherapy‐treated breast cancer patients (n = 10). To address the heterogeneity observed in cognitive function after chemotherapy, we performed a voxel‐based correlation analysis between FA values and individual neuropsychological test scores. Significant correlations of FA with neuropsychological tests covering the domain of attention and processing/psychomotor speed were found in temporal and parietal WM tracts. Furthermore, CFQ scores correlated negatively in frontal and parietal WM. These studies show that chemotherapy seems to affect WM integrity and that parameters derived from DTI have the required sensitivity to quantify neural changes related to chemotherapy‐induced mild cognitive impairment. Hum Brain Mapp 32:480–493, 2011. © 2010 Wiley‐Liss, Inc.     

Altered white matter integrity in temporal lobe epilepsy: Association with cognitive and clinical profiles

Purpose: Diffusion tensor imaging (DTI) studies have reported substantial white matter abnormalities in patients with temporal lobe epilepsy (TLE). However, limited data exist regarding the extent of white matter tract abnormalities, cognitive effects of these abnormalities, and relationship to clinical factors. The current study examined these issues in subjects with chronic TLE. Methods: DTI data were obtained in 12 TLE subjects and 10 age‐matched healthy controls. Voxel‐wise statistical analysis of fractional anisotropy (FA) was carried out using tract‐based spatial statistics (TBSS). White matter integrity was correlated with cognitive performance and epilepsy‐related clinical parameters. Results: Subjects with TLE, as compared to healthy controls, demonstrated four clusters of reduced FA, in anterior temporal lobe, mesial temporal lobe, and cerebellum ipsilateral, as well as frontoparietal lobe contralateral to the side of seizure onset. Mean FA was positively correlated with delayed memory, in anterior temporal lobe; and immediate memory, in mesial temporal lobe. Lower FA values in the posterior region of corpus callosum were related to earlier age of seizure onset. Conclusion: TLE is associated with widespread disturbances in white matter tracts and these changes have important cognitive and clinical consequences.     

White Matter Abnormalities in Schizophrenia and Schizotypal Personality Disorder

Prior diffusion tensor imaging (DTI) studies examining schizotypal personality disorder (SPD) and schizophrenia, separately have shown that compared with healthy controls (HCs), patients show frontotemporal white matter (WM) abnormalities. This is the first DTI study to directly compare WM tract coherence with tractography and fractional anisotropy (FA) across the schizophrenia spectrum in a large sample of demographically matched HCs (n = 55), medication-naive SPD patients (n = 49), and unmedicated/never-medicated schizophrenia patients (n = 22) to determine whether (a) frontal-striatal-temporal WM tract abnormalities in schizophrenia are similar to, or distinct from those observed in SPD; and (b) WM tract abnormalities are associated with clinical symptom severity indicating a common underlying pathology across the spectrum. Compared with both the HC and SPD groups, schizophrenia patients showed WM abnormalities, as indexed by lower FA in the temporal lobe (inferior longitudinal fasciculus) and cingulum regions. SPD patients showed lower FA in the corpus callosum genu compared with the HC group, but this regional abnormality was more widespread in schizophrenia patients. Across the schizophrenia spectrum, greater WM disruptions were associated with greater symptom severity. Overall, frontal-striatal-temporal WM dysconnectivity is attenuated in SPD compared with schizophrenia patients and may mitigate the emergence of psychosis.Key words: DTI, MRI, schizotypal personality disorder, schizophrenia, psychosis, white matter, genu, cingulum, inferior longitudinal fasciculus     

White matter abnormalities and their impact on attentional performance in adult attention-deficit/hyperactivity disorder

Inattention is the most important behavioral feature of adult patients with attention-deficit/hyperactivity disorder (ADHD). Neuroimaging studies in ADHD have demonstrated abnormalities primarily in the frontostriatal circuitry and were mostly conducted in children. We investigated white matter (WM) integrity in adult ADHD patients and the correlation of WM microstructure and neuropsychological parameters in 37 (21 men) never-medicated adult ADHD patients and 34 age- and gender-matched healthy controls. All subjects underwent clinical interviews, rating scales, and neuropsychological tests of attentional performance. Diffusion tensor imaging (DTI) was acquired, and 12 WM regions-of-interest (ROIs) within the attentional network were chosen. Group differences of mean fractional anisotropy (FA) and mean diffusivity (MD) values were calculated for each ROI, and patients' DTI measures were then correlated with measures of attentional performance. FA values in ADHD patients were significantly reduced in the left inferior longitudinal fasciculus (ILF), while MD values were significantly increased in ADHD patients in the frontal portion of the left frontooccipital fasciculus (IFO). In ADHD patients, MD values were negatively correlated with attentional performance in the left ILF. Our findings provide further support for disturbed frontostriatal structural connectivity and also point to an involvement of the left temporal white matter with an impact on attentional performance.     

Distribution of regional gray matter abnormalities in a pediatric population with temporal lobe epilepsy and correlation with neuropsychological performance

OBJECTIVE: The goals of the work described here were to determine if hippocampal and extrahippocampal atrophy in children with temporal lobe epilepsy (TLE) follows a pattern similar to that in adult patients, and to assess the clinical and neuropsychological relevance of regional brain atrophy in pediatric TLE. METHODS: Children with symptomatic TLE (n=14: 9 with mesial TLE due to hippocampal atrophy and 5 with TLE due to neocortical lesions), healthy children (n=14), and 9 adults with mesial temporal lobe epilepsy (MTLE) were compared using voxel-based morphometry (VBM) of brain magnetic resonance imaging (MRI). The children underwent a comprehensive neuropsychological battery. RESULTS: Children with MTLE with unilateral hippocampal atrophy (n=9) exhibited a significant reduction in gray matter in the hippocampus ipsilateral to the seizure origin and significant atrophy in the ipsilateral cingulate gyrus and contralateral middle frontal lobe. Children with TLE (n=14) exhibited a significant reduction in the gray matter of the ipsilateral hippocampus and parahippocampal gyrus. There was a correlation between gray matter volume in children with TLE and scores on several neuropsychological tests. Atrophy in pediatric patients with MTLE was less extensive than that in adults, and involved the hippocampi and the frontal cortex. CONCLUSIONS: Similar to adult MTLE, pediatric MTLE is associated with hippocampal and extrahippocampal cell loss. However, children display less intense quantifiable gray matter atrophy, which affects predominantly frontal lobe areas. There was a significant association between volume of gray matter in medial temporal and frontal regions and scores on neuropsychological tests. In childhood, TLE and the concomitant cognitive/behavior disturbances are the result of a damaged neural network.     

Frequency and age-related variables in interictal psychoses in localization-related epilepsies

PURPOSE: Several studies have described that patients with temporal lobe epilepsy (TLE) develop psychoses more frequently than patients with extra-temporal localization-related epilepsy (LRE). However, few controlled studies have demonstrated an increased susceptibility to psychosis in TLE patients. As one of a series of multi-center studies on psychosis in epilepsy, we investigated whether the frequency of interictal psychosis differs between types of LRE. METHODS: We reviewed some biological characteristics of 197 PE patients with interictal psychosis and of 456 LRE patients with no history of psychosis. Type of PE was determined as TLE, frontal lobe epilepsy, parietal lobe epilepsy, occipital lobe epilepsy, and multi-lobar epilepsy/undifferentiated lobar epilepsy by clinical symptoms, EEG findings, and neuroimaging. The frequency of psychosis for each type of LRE was compared. Ages at onset of epilepsy and psychosis and the time interval between onset of each were also analyzed. RESULTS: There was no significant correlation between psychosis and epilepsy type (P=0.211). Age-related variables also failed to show any significant differences between LRE types (age at onset of epilepsy, P=0.369; age at onset of psychosis, P=0.852; the time interval, P=0.893). CONCLUSIONS: Patients with LREs as well as with TLE are susceptible to interictal psychosis. The mean ages at onset of symptoms and the interval between onset of epilepsy and onset of psychosis that we observed suggest that patients with LREs, regardless of focus, may share similar processes in the development of psychiatric symptoms.     

The relationship between white matter abnormalities and cognitive functions in new-onset juvenile myoclonic epilepsy

Diffusion tensor imaging (DTI) has revealed evidence of subcortical white matter abnormalities in the frontal area in juvenile myoclonic epilepsy (JME). Decreased fractional anisotropy (FA) and increased mean diffusivity (MD) in the corticothalamic pathway have been detected in adult patients with JME. It has been demonstrated that, in adult patients with JME, frontal dysfunction is related to subcortical white matter damage and decreased volume in frontal cortical gray matter and the thalamus. Many studies have focused on adult patients.Twenty-four patients and 28 controls were evaluated. The group with JME had significantly worse results for the word fluency, trail-B, and Stroop tests that assessed executive functions. A significant decrease in FA values in the dorsolateral prefrontal cortex (DLPFC), the supplementary motor area (SMA), the right thalamus, the posterior cingulate, the corpus callosum anterior, the corona radiata, and the middle frontal white matter (MFWM) and an increase in ADC values in patients with JME were detected. The correlation between FA values in DLPFC and the letter fluency test results was positive, and the correlation with the Stroop and trail-B test results was negative. We found a negative correlation between SMA, anterior thalamus, and MFWM FA values and the trail-B test results and a positive correlation between the SMA, anterior thalamus, and MFWM FA values and the letter fluency test results.We detected white matter and gray matter abnormalities in patients with new-onset JME using DTI. In addition, we determined the relationship between cognitive deficit and microstructural abnormalities by evaluating the correlation between the neuropsychological test battery results and DTI parameters. We evaluated newly diagnosed patients with JME in our study. That leads us to believe that microstructural abnormalities exist from the very beginning of the disease and that they result from the genetic basis of the disease.     

White matter microstructural abnormalities in late-life depression

OBJECTIVE: To evaluate the location and the degree of white matter damage in late-life depression using diffusion tensor imaging (DTI). METHODS: Thirty-one patients with late-life depression and 15 healthy volunteers matched for age, gender and years of education received conventional MRI (magnetic resonance imaging) and MR-diffusion tensor scanning. The fractional anisotropy (FA) values of white matter were measured respectively in frontal and temporal regions and the corpus callosum. RESULTS: FA values were significantly decreased in the frontal (superior and middle frontal gyrus), and temporal (right parahippocampal gyrus) regions of elderly patients with depression compared with healthy controls. CONCLUSION: Microstructural changes in the frontal (superior and middle frontal gyrus) and temporal (right parahippocampal gyrus) areas are associated with late-life depression.     

颞叶内侧结构弥散张量成像及白质纤维束成像在颞叶癫痫诊断中的应用价值

目的 通过磁共振弥散张量成像(DTI)及白质纤维束示踪(DTT)技术定量分析颞叶癫痫患者双侧颞叶内侧结构弥散参数值及局部纤维束变化特点,评价DTI技术对颞叶癫痫的诊断价值.方法 对广州医学院第二附属医院自2010年12月至2011年2月临床诊断为颞叶癫痫的16例患者和20例健康志愿者进行常规MRI及DTI扫描,测量双侧颞叶杏仁体、海马及颞叶皮质的部分各向异性(FA)、相对各向异性(RA)、表观弥散系数(ADC)等数值并进行统计学分析,同时应用DTT技术观察癫痫患者局部纤维束与正常对照者的差异.结果 正常对照者双侧颞叶内侧各结构FA、RA、ADC值比较差异均无统计学意义(P＞0.05).颞叶癫痫患侧、对侧与正常对照者颞叶内侧各结构FA、RA、ADC值比较差异均有统计学意义(P＜0.05),其中ADC值呈颞叶癫痫患侧＞颞叶癫痫对侧＞正常对照者的变化趋势,以海马尾部变化最为显著;而FA、RA值呈颞叶癫痫患侧＜颞叶癫痫对侧＜正常对照者的变化趋势,并且杏仁体、海马体部变化较海马尾部更显著.结论 DTI技术能充分了解癫痫患者颞叶内侧结构的弥散参数值及纤维束变化特点,有助于癫痫病灶定位的准确诊断,同时加深对颞叶内侧结构整体变化的了解亦有助于术前的整体评估及提高手术疗效.     

颞叶癫痫患者磁共振弥散张量成像及记忆损害的研究

目的利用磁共振弥散张量成像技术(DTI)研究颞叶癫痫(TLE)患者脑内微观改变及记忆损害的相关脑区。方法对颞叶癫痫患者15例和健康对照者15例,进行DTI检查,利用韦氏记忆量表检测记忆功能。结果 TLE患者部分各向异性弥散(FA)值降低激活区域有颞叶、边缘叶、扣带回和岛叶,升高区有:额叶、顶叶、枕叶,表观系数(ADC)值升高激活区域在颞叶、额叶、枕叶、顶叶;无ADC值降低区域。与健康者相比,颞叶癫痫患者的记忆商数(MQ)(90.73±19.72)显著下降,P<0.01。对照组FA值在左岛叶、颞叶与MQ值正相关;患者组FA值在右额、顶、枕叶、左顶叶与MQ值正相关,在左颞叶与MQ值负相关。对照组ADC与MQ正相关区域在左边缘叶,与MQ成负相关区域在左顶叶、患者组正相关区域在左、右颞叶。结论初步证实TLE患者的脑内结构变化不局限于颞叶,还包括颞叶外网络结构;TLE患者全脑DTI与MQ存在着相关激活脑区,表明记忆功能损害与脑内相关结构改变有关。     

抑郁症患者弥散张量成像与认知功能的关系

目的:探讨抑郁症患者全脑白质纤维受损状况及其与认知功能的关系.方法:对 24 例抑郁症患者及 30 名健康对照者进行临床测评、常规磁共振成像(MRI)、弥散张量成像(DTI)及神经心理学检查.结果:抑郁症组在左额中回、左额上回、右额内侧回、左楔前叶、左颞上回、右扣带回等区域各向异性(FA)值较对照组显著下降(P＜0.001).抑郁症组威斯康星卡片分类测验(WCST)的分类数、总错误率明显高于对照组(P＜0.01 或 P＜0.05).两组持续注意操作测试(CPT)差异无显著性;抑郁症组 CPT 与 WCST 部分结果均呈负相关(P均＞0.05).结论:DTI 与 WCST 结果的相互印证反映重性抑郁症患者可能存在白质区域神经功能的异常,DTI 技术有助于发现影响认知改变的脑微细结构和功能的异常.     

MRI with diffusion tensor imaging post-mortem at 3.0 T in a patient with frontotemporal dementia

The formalin-fixed brain of a patient with clinically diagnosed frontotemporal dementia (FTD) was examined post-mortem using magnetic resonance imaging (MRI) with diffusion tensor imaging (DTI) at 3.0 T. Frontotemporal atrophy as well as bilateral frontal white matter abnormalities were seen. The white matter changes were slightly more extensive on DTI than on conventional MRI. Correlation with histopathology of the corresponding regions revealed typical frontal lobe degeneration of non-Alzheimer type, with mild frontotemporal degeneration in the outer cortical layers and a moderate frontal white matter gliosis with demyelination. Post-mortem MRI/DTI with histopathologic correlation will enhance our understanding of the basis of white matter changes observed in dementia patients and may improve the in vivo MRI/DTI diagnostic assessment in FTD.