The effect of meditation on brain structure: cortical thickness mapping and diffusion tensor imaging

A convergent line of neuroscientific evidence suggests that meditation alters the functional and structural plasticity of distributed neural processes underlying attention and emotion. The purpose of this study was to examine the brain structural differences between a well-matched sample of long-term meditators and controls. We employed whole-brain cortical thickness analysis based on magnetic resonance imaging, and diffusion tensor imaging to quantify white matter integrity in the brains of 46 experienced meditators compared with 46 matched meditation-naïve volunteers. Meditators, compared with controls, showed significantly greater cortical thickness in the anterior regions of the brain, located in frontal and temporal areas, including the medial prefrontal cortex, superior frontal cortex, temporal pole and the middle and interior temporal cortices. Significantly thinner cortical thickness was found in the posterior regions of the brain, located in the parietal and occipital areas, including the postcentral cortex, inferior parietal cortex, middle occipital cortex and posterior cingulate cortex. Moreover, in the region adjacent to the medial prefrontal cortex, both higher fractional anisotropy values and greater cortical thickness were observed. Our findings suggest that long-term meditators have structural differences in both gray and white matter.     

Regionally localized thinning of the cerebral cortex in schizophrenia

BACKGROUND: Schizophrenia is characterized by small reductions in cortical gray matter volume, particularly in the temporal and prefrontal cortices. The question of whether cortical thickness is reduced in schizophrenia has not been addressed using magnetic resonance imaging (MRI) techniques. Our objectives were to test the hypothesis that cortical thinning in patients with schizophrenia (relative to control subjects) is greater in temporal and prefrontal regions of interest (ROIs) than in control ROIs (superior parietal, calcarine, postcentral, central, and precentral cortices), and to obtain an unbiased estimate of the distribution of cortical thinning in patients (relative to controls) by constructing mean and statistical cortical thickness difference maps. METHODS: Participants included 33 right-handed outpatients receiving medication and meeting DSM-IV criteria for schizophrenia and 32 healthy volunteers, matched on age and parental socioeconomic status. After high-resolution MRI scans, models of the gray-white and pial surfaces were generated for each individual's cortex, and the distance between these 2 surfaces was used to compute cortical thickness. A surface-based averaging technique that aligned the main cortical folds across individuals allowed between-group comparisons of thickness within ROIs, and at multiple, uniformly sampled loci across the cortical ribbon. RESULTS: Relative to controls, patients showed greater cortical thinning in temporal-prefrontal ROIs than in control ROIs, as revealed by a significant (P<.009) interaction between group and region type. Cortical thickness difference maps revealed significant (at P<.05, corrected) thinning within the orbitofrontal cortices bilaterally; the inferior frontal, inferior temporal, and occipitotemporal cortices on the left; and within the medial temporal and medial frontal cortices on the right. Superior parietal and primary somatosensory and motor cortices were relatively spared, even at subthreshold significance levels. CONCLUSIONS: Patients with chronic schizophrenia showed widespread cortical thinning that particularly affected the prefrontal and temporal cortices. This thinning might reflect underlying neuropathological abnormalities in cortical structure.     

Structural correlates of Openness and Intellect: Implications for the contribution of personality to creativity

Openness/Intellect (i.e., openness to experience) is the Big Five personality factor most consistently associated with individual differences in creativity. Recent psychometric evidence has demonstrated that this factor consists of two distinct aspects—Intellect and Openness. Whereas Intellect reflects perceived intelligence and intellectual engagement, Openness reflects engagement with fantasy, perception, and aesthetics. We investigated the extent to which Openness and Intellect are associated with variations in brain structure as measured by cortical thickness, area, and volume (N = 185). Our results demonstrated that Openness was correlated inversely with cortical thickness and volume in left middle frontal gyrus (BA 6), middle temporal gyrus (MTG, BA 21), and superior temporal gyrus (BA 41), and exclusively with cortical thickness in left inferior parietal lobule (BA 40), right inferior frontal gyrus (IFG, BA 45), and MTG (BA 37). When age and sex were statistically controlled for, the inverse correlations between Openness and cortical thickness remained statistically significant for all regions except left MTG, whereas the correlations involving cortical volume remained statistically significant only for left middle frontal gyrus. There was no statistically significant correlation between Openness and cortical area, and no statistically significant correlation between Intellect and cortical thickness, area, or volume. Our results demonstrate that individual differences in Openness are correlated with variation in brain structure—particularly as indexed by cortical thickness. Given the involvement of the above regions in processes related to memory and cognitive control, we discuss the implications of our findings for the possible contribution of personality to creative cognition.     

Voxel-based morphometry detects cortical atrophy in the Parkinson variant of multiple system atrophy.

To determine magnetic resonance imaging (MRI) patterns of brain atrophy in parkinsonian syndromes, we applied voxel-based morphometry (VBM) to segmented gray matter, white matter, and cerebrospinal fluid compartments of T(1)-weighted brain volumes of 12 patients with probable multiple system atrophy-parkinson variant (MSA-P) and 12 Parkinson's disease patients, comparing them with 12 normal controls matched for age. In comparison to controls, a cortical atrophy pattern was observed in MSA-P patients with significant clusters of volume loss in primary sensorimotor cortices bilateral, supplementary motor areas bilateral, right premotor cortex, prefrontal cortex bilateral (middle frontal gyri) and insular cortices bilateral; subcortical atrophy occurred bilaterally in caudate nuclei and putamen as well as in the midbrain. Furthermore, an enlargement of the cerebrospinal fluid compartment was found in the lateral ventricles, third ventricle, perimesencephalic and cerebellomedullar cavities. In PD patients, significant atrophy only occurred in left caudate head with enlargement of left lateral ventricle. Comparing MSA-P to PD patients, MSA-P showed a similar cortical pattern of atrophy as compared to controls. We conclude that VBM reveals selective cortical atrophy in patients with MSA-P affecting primary and higher order motor areas as well as prefrontal and insular cortices. Further studies are required to determine clinical and/or subclinical correlates of cortical atrophy in MSA-P.     

Late-life depression and microstructural abnormalities in dorsolateral prefrontal cortex white matter

OBJECTIVE: The purpose of this study was to determine whether microstructural abnormalities in the white matter of the dorsolateral prefrontal cortex are associated with late-life depression. METHOD: Seventeen elderly depressed subjects were compared with 16 elderly subjects who were not depressed. Diffusion tensor imaging was used to measure the fractional anisotropy of the white matter in the dorsolateral prefrontal cortex's superior and middle frontal gyri bilaterally and in the left occipital lobe as a control region. The authors compared results between groups while controlling for age, sex, and comorbid medical disorders. RESULTS: Even after controlling for age, sex, hypertension, and heart disease, the authors found significantly lower fractional anisotropy values in the right superior frontal gyrus white matter of depressed patients than comparison subjects. CONCLUSIONS: Microstructural changes in the white matter of the right superior frontal gyrus are associated with late-life depression. Further work is needed to determine how these changes contribute to depression outcomes.     

Increased Cortical Thickness in Professional On-Line Gamers

Objective

The bulk of recent studies have tested whether video games change the brain in terms of activity and cortical volume. However, such studies are limited by several factors including cross-sectional comparisons, co-morbidity, and short-term follow-up periods. In the present study, we hypothesized that cognitive flexibility and the volume of brain cortex would be correlated with the career length of on-line pro-gamers.

Methods

High-resolution magnetic resonance scans were acquired in twenty-three pro-gamers recruited from StarCraft pro-game teams. We measured cortical thickness in each individual using FreeSurfer and the cortical thickness was correlated with the career length and the performance of the pro-gamers.

Results

Career length was positively correlated with cortical thickness in three brain regions: right superior frontal gyrus, right superior parietal gyrus, and right precentral gyrus. Additionally, increased cortical thickness in the prefrontal cortex was correlated with winning rates of the pro-game league. Increased cortical thickness in the prefrontal and parietal cortices was also associated with higher performance of Wisconsin Card Sorting Test.

Conclusion

Our results suggest that in individuals without pathologic conditions, regular, long-term playing of on-line games is associated with volume changes in the prefrontal and parietal cortices, which are associated with cognitive flexibility.     

Normal variation in behavioral adjustment relates to regional differences in cortical thickness in children

Neuroanatomical correlates of developmental psychopathology such as attention deficit hyperactivity and conduct disorder have been identified. The majority of studies point to lesser gray matter in psychopathology, often involving prefrontal cortices. The goal of this study was to test whether similar neural correlates exist for behavioral variance in healthy children and adolescents. A large sample (n = 106) aged 8–19 years underwent MR scanning and their parents completed the Strength and Difficulties Questionnaire. The relationships between cortical thickness and conduct problems and hyperactivity/inattention scale scores were investigated throughout the cerebrum. No associations were found between normal variance in hyperactivity/inattention and cortical thickness. Normal variance in conduct problems was associated with thinner left hemisphere prefrontal and supramarginal cortices. Relationships between conduct problems and cortical thickness interacted with age, with the greatest differences in cortical thickness seen in the younger children. These interactions were observed in the anterior cingulate, orbitofrontal, middle and superior frontal, as well as lateral and medial temporal cortices. In conclusion, the results indicate neurobiological continuity between symptoms of conduct problems within the normal range, and conduct disorder. Relationships of thinner cortices and conduct problems were primarily seen in younger children, and appeared to decrease with age, indicative of different maturational trajectories in the groups. The long-term consequences are unknown, and the results point to a need for longitudinal studies of developmental trajectories of neuroanatomical foundations of behavioral adjustment.     

3D mapping of mini-mental state examination performance in clinical and preclinical Alzheimer disease

The Mini-mental State Examination (MMSE) is a brief cognitive screening instrument frequently used to track Alzheimer disease (AD) progression. We investigated the structural neuroimaging correlates of MMSE performance in patients with clinical and preclinical AD. We analyzed structural magnetic resonance imaging data from 29 probable AD and 5 MCI patients who later converted to probable AD using an advanced 3D cortical mapping technique. MMSE scores were entered as covariates in a general linear model that predicted the gray matter density at each cortical surface point. The results were corrected for multiple comparisons by permutation testing. The global permutation-corrected significance for the maps linking gray matter loss and cognitive decline was P=0.005 for the left and P=0.012 for the right hemisphere. Strongest correlations between MMSE score and gray matter integrity were seen in the entorhinal, parahippocampal, precuneus, superior parietal, and subgenual cingulate/orbitofrontal cortices. Significant correlations were also seen bilaterally in the temporal, the middle frontal and the left angular and supramarginal gyri. As a global cognitive measure, MMSE depends on the integrity of widely distributed cortical areas in both brain hemispheres with left-sided predominance.     

White matter integrity and cortical metabolic associations in aging and dementia

BackgroundStudies show that white matter hyperintensities, regardless of location, primarily affect frontal lobe metabolism and function. This report investigated how regional white matter integrity (measured as fractional anisotropy [FA]) relates to brain metabolism, to unravel the complex relationship between white matter changes and brain metabolism.ObjectiveTo elucidate the relationship between white matter integrity and gray matter metabolism using diffusion tensor imaging and fluorodeoxyglucose-positron emission tomography in a cohort of 16 subjects ranging from normal to demented (age, >55 years).MethodsMean FA values from white matter regions underlying the medial prefrontal, inferior-lateral prefrontal, parietal association, and posterior temporal areas and the corpus callosum were regressed with glucose metabolism (by positron emission tomography), using statistical parametric mapping (P < 0.005; voxel cluster, >100). Regional cerebral glucose metabolism was the primary outcome measure. According to our hypothesis, those hypometabolic cortical regions affected by Alzheimer's disease would correlate with a lower FA of associated tracks.ResultsOur data show inter-regional positive correlations between FA and gray matter metabolism for the prefrontal cortex, temporal, and parietal regions. Our results suggest that left prefrontal FA is associated with left temporal and parietal metabolism. Further, left posterior temporal FA correlated with left prefrontal metabolism. Finally, bilateral parietal FA correlated with bilateral temporal metabolism.ConclusionsThese regions are associated with cognitive processes affected in Alzheimer's disease and cerebrovascular disease, suggesting a link with white matter degeneration and gray matter hypometabolism. Therefore, cortical function and white matter degeneration are related in aging and dementia.     

Mapping inter-regional connectivity of the entire cortex to characterize major depressive disorder: a whole-brain diffusion tensor imaging tractography study

Diffusion tensor imaging (DTI) can be used to study the organization of brain white matter noninvasively. The aim of this study was to present a proof of concept for integrating DTI with high-resolution anatomical (T1) images to map and assess inter-regional connectivity across the entire cortex in a cohort of healthy participants and compared with patients with major depressive disorder. We used MRI data of 23 patients and 23 matched controls, assessed as part of baseline testing in the International Study to Predict Optimized Treatment in Depression (iSPOT-D). Freesurfer was used to analyze the T1 images to automatically label 35 gyral-based areas for each hemisphere. DTI tractography was performed to parcellate intercortical tracts using each of these areas in seed-target combinations. We quantified fractional anisotropy, number-of-fiber connections, and fiber path length for each DTI connection, with the goal of identifying the best measure or combination of measures to characterize major depression. The best classification accuracy for the individual measures was achieved using the number-of-fibers data, whereas the combination model provided a slight improvement. The most discriminant features between the two groups were for white matter associated with the limbic, frontal, and thalamic projection fibers and as part of cortical connections between the left inferior temporal and the postcentral cortex; the left parstriangularis and the left superior frontal; the left cuneus and the corpus callosum; the left lingual and the right lateral occipital, the right superior parietal and the right superior temporal cortices; and the right inferior parietal and the right insula and postcentral cortices.     

Regional cerebral cortical thinning in bipolar disorder

OBJECTIVE: This study was conducted to explore differences in cortical thickness between subjects with bipolar disorder and healthy comparison subjects using cortical surface-based analysis. METHODS: Brain magnetic resonance images were acquired from 25 subjects with bipolar disorder and 21 healthy comparison subjects. Cortical surface-based analysis was conducted using the Freesurfer application. Group differences in cortical thickness, defined by the distance from gray/white boundary to the pial surface, were assessed using statistical difference maps. RESULTS: Subjects with bipolar disorder exhibited significantly decreased cortical thickness in left cingulate cortex, left middle frontal cortex, left middle occipital cortex, right medial frontal cortex, right angular cortex, right fusiform cortex and bilateral postcentral cortices, relative to healthy comparison subjects (all p < 0.001). Duration of illness in bipolar subjects was inversely correlated with the cortical thickness of the left middle frontal cortex. CONCLUSIONS: Cortical thinning was present in multiple prefrontal cortices in bipolar disorder. There was also cortical thinning in sensory and sensory association cortices, which has not been reported in previous studies using region-of-interest or voxel-based morphometry methods. Cortical thinning observed in the current study may be related to impairment of emotional, cognitive, and sensory processing in bipolar disorder but longitudinal studies will be necessary to test this hypothesis.     

Sustained attention is associated with right superior longitudinal fasciculus and superior parietal white matter microstructure in children

Sustained attention develops during childhood and has been linked to the right fronto‐parietal cortices in functional imaging studies; however, less is known about its relation to white matter (WM) characteristics. Here we investigated whether the microstructure of the WM underlying and connecting the right fronto‐parietal cortices was associated with sustained attention performance in a group of 76 typically developing children aged 7–13 years. Sustained attention was assessed using a rapid visual information processing paradigm. The two behavioral measures of interest were the sensitivity index d′ and the coefficient of variation in reaction times (RT_CV). Diffusion‐weighted imaging was performed. Mean fractional anisotropy (FA) was extracted from the WM underlying right dorsolateral prefrontal (DLPFC) and parietal cortex (PC), and the right superior longitudinal fasciculus (SLF), as well as equivalent anatomical regions‐of‐interest (ROIs) in the left hemisphere and mean global WM FA. When analyzed collectively, right hemisphere ROIs FA was significantly associated with d′ independently of age. Follow‐up analyses revealed that only FA of right SLF and the superior part of the right PC contributed significantly to this association. RT_CV was significantly associated with right superior PC FA, but not with right SLF FA. Observed associations remained significant after controlling for FA of equivalent left hemisphere ROIs or global mean FA. In conclusion, better sustained attention performance was associated with higher FA of WM in regions connecting right frontal and parietal cortices. Further studies are needed to clarify to which extent these associations are driven by maturational processes, stable characteristics and/or experience. Hum Brain Mapp 34:3216–3232, 2013. © 2012 Wiley Periodicals, Inc.     

Genetic and environmental influences on cortical thickness among 14-year-old twins

The overall volume of the brain has been found to be under relatively strong genetic control, but the relative strength of genetic and environmental factors on between-person variations in regional cortical thickness in adolescence is still not well understood. Here, we analyzed structural MRI data from 108 14-year-old healthy twins (54 females/54 males) to determine the relative contributions of genes and the environment toward regional variations in gray matter thickness across the cortex. After extracting cortical thickness values at a high spatial resolution, an A/C/E structural equation model that divides the variations into additive genetic (A), shared (C), and unique (E) environmental components was fitted. There was considerable regional variability in the magnitude of genetic influences on cortical thickness after controlling for sex. Regions with genetic contributions of greater than 80% were observed in the prefrontal cortex, predominantly in the bilateral dorsolateral and mesial superior frontal regions. No region showed prominent shared environmental influences, but unique environmental influences of over 80% were found in parietal association regions. The genetic variance for cortical thickness in adolescents in prefrontal regions overlapped with previous findings in adults. However, the unique environmental effects observed in multimodal parietal association cortices with converging inputs from visual, auditory, somatosensory regions, and neighboring secondary association cortices suggest that these regional variations are more shaped by experience and could form targets for early interventions in youth with behavioral disorders.     

Comparable cortical activation with inferior performance in women during a novel cognitive inhibition task

Men are hypothesised to perform better than women at tasks requiring cognitive inhibition. The present study applied whole-brain functional magnetic resonance imaging to investigate the neural correlates of cognitive inhibition using a novel task, requiring detection of numbers decreasing in numerical order, in relation to sex. The study involved 19 young healthy subjects (9 men, 10 women). Behavioural sex differences favouring men were found on the inhibition, but not on the automatization (i.e. detection of numbers increasing in numerical order), condition of the task. Significant areas of activation associated with cognitive inhibition included the right inferior prefrontal and bilateral dorsolateral prefrontal cortices, left inferior and superior parietal lobes, and bilateral temporal regions across men and women. No brain region was significantly differently activated in men and women. Our findings demonstrate that (a) cognitive inhibition is dependent on intact processes within frontal and parietal regions, and (b) women show inferior cognitive inhibition despite of comparable activation to men in relevant regions. Equated behavioural performance may elicit sex differences in brain activation.     

Maturation of white matter is associated with the development of cognitive functions during childhood

In the human brain, myelination of axons continues until early adulthood and is thought to be important for the development of cognitive functions during childhood. We used diffusion tensor MR imaging and calculated fractional anisotropy, an indicator of myelination and axonal thickness, in children aged between 8 and 18 years. Development of working memory capacity was positively correlated with fractional anisotropy in two regions in the left frontal lobe, including a region between the superior frontal and parietal cortices. Reading ability, on the other hand, was only correlated with fractional anisotropy in the left temporal lobe, in the same white matter region where adults with reading disability are known to have lower fractional anisotropy. Both the temporal and the frontal regions were also correlated with age. These results show that maturation of white matter is an important part of brain maturation during childhood, and that maturation of relatively restricted regions of white matter is correlated with development of specific cognitive functions.     

Effects of age on prefrontal subregions and hippocampal volumes in young and middle‐aged healthy humans

There are limited data available regarding the effects of age and sex on discrete prefrontal gray and white matter volumes or posterior and anterior hippocampal volumes in healthy humans. Volumes of the superior frontal gyrus, anterior cingulate gyrus, and orbital frontal lobe were computed manually from contiguous magnetic resonance (MR) images in 83 (39M/44F) healthy humans (age range = 16–40) and segmented into gray and white matter. Volumes of the posterior and anterior hippocampal formation were also computed with reliable separation of the anterior hippocampal formation from the amygdala. There were significant age‐by‐tissue type interactions for the superior frontal gyrus and orbital frontal lobe such that gray matter within these regions correlated significantly and inversely with age. In contrast, no significant age effects were evident within regional white matter volumes. Analysis of hippocampal volumes indicated that men had larger volumes of the anterior, but not posterior hippocampal formation compared to women even following correction for total brain size. These data highlight age effects within discrete prefrontal cortical gray matter regions in young and middle aged healthy humans and suggest that the white matter comprising these regions may be more resistant to age effects. Furthermore, understanding the potential role of sex and age in mediating prefrontal cortical and hippocampal volumes may have strong relevance for psychiatric disorders such as schizophrenia that have implicated neurodevelopmental abnormalities within frontotemporal circuits in their pathogenesis. Hum Brain Mapp 34:2129–2140, 2013. © 2012 Wiley Periodicals, Inc.     

Widespread Cortical Thinning Is a Robust Anatomical Marker for Attention-Deficit/Hyperactivity Disorder

ObjectiveThis cross-sectional study sought to confirm the presence and regional profile of previously reported changes in laminar cortical thickness in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) compared with typically developing control subjects.MethodHigh-resolution magnetic resonance images were obtained from 22 (19 male and 3 female subjects; mean age 11.7 years) children and adolescents with ADHD and 22 age- and sex-matched control subjects (mean age 11.7 years). Brain tissue volumes were estimated for each subject. Cortical pattern matching methods were used to sample measures of laminar thickness at high spatial frequency across homologous regions of the cortex. Volume and thickness measures were compared across diagnostic groups with and without controlling for general intelligence. False discovery rate correction confirmed regional results.ResultsThe subjects with ADHD exhibited significant reductions in overall brain volume, gray matter volume, and mean cortical thickness compared with the controls, whereas white matter volumes were significantly increased in ADHD. Highly significant cortical thinning (false discovery rate-corrected p < .0006) was observed over large areas of the frontal, temporal, parietal, and occipital association cortices and aspects of motor cortex but not within the primary sensory regions.ConclusionsCortical thickness reductions present a robust neuroanatomical marker for child and adolescent ADHD. Observations of widespread cortical thinning expand on earlier cross-sectional findings and provide further evidence to support that the neurobiological underpinnings of ADHD extend beyond prefrontal and subcortical circuits.     

阿尔茨海默病脑白质葡萄糖代谢异常分析

目的探讨阿尔茨海默病(AD)脑白质葡萄糖代谢异常的意义。方法纳入33例符合美国精神障碍诊断与统计手册-第四版(DSM-IV)AD诊断标准的患者和健康对照20名,进行脑正电子发射断层成像(PET)检查。应用SPM软件对PET图像进行分析。结果①与健康对照相比,AD患者有广泛的白质葡萄糖代谢减低,减低较为明显的区域有右侧额叶皮质下白质、左侧额叶上中回皮质下白质(P<0.001);另外,AD患者左侧额叶内侧回皮质下白质、左侧枕叶楔回皮质下白质葡萄糖代谢增强(P<0.001);②与不伴有精神行为症状(BPS)的AD患者(16例)相比,伴有BPS的AD患者(17例)在左右枕叶中回、右侧枕叶楔回、右侧顶下小叶、左侧颞叶梭形回、左侧额叶内侧回等脑区的皮质下白质葡萄糖代谢增强(P<0.001);而左右额叶中央旁回、右侧额叶上回和中回、左侧颞叶上回等脑区的皮质下白质葡萄糖代谢减低(P<0.001)。结论AD有广泛的白质脑葡萄糖代谢异常,有无BPS的AD白质代谢异常不同。     

Correlations between MRI-assessed volumes of the thalamus and cortical Brodmann's areas in schizophrenia

BACKGROUND: We compared the thalamic-cortical volumetric correlational patterns in patients with schizophrenia and normal comparison subjects, and evaluated their relations to outcome. METHODS: High-resolution MR images were acquired in patients with schizophrenia (n=106) and normal comparison subjects (n=42). Patients were divided into good-outcome (n=52) and poor-outcome (Kraepelinian, n=54) subtypes based on their ability for self-care. Correlations between the relative gray and white matter volumes of the individual cortical Brodmann's areas and five dorsoventral levels of the thalamus were assessed. RESULTS: Compared to normal subjects, schizophrenia patients lacked significant thalamic gray matter volume correlations with the prefrontal and medial temporal cortical regions in the right hemisphere, and with frontal, cingulate, posterior parietal and occipital regions in the left hemisphere, while normal white matter volume cortical-thalamic correlations along the cingulate gyrus and in the temporal lobe were not found in schizophrenia patients in both hemispheres. In contrast to both normal comparison subjects and good-outcome group, schizophrenia patients with poor outcomes showed significant bilateral gray matter volume correlations between the dorsal thalamus and ventral prefrontal cortex, while the group differences in the white matter volume correlations were mostly restricted to the cingulate arch. CONCLUSIONS: Whereas patients with schizophrenia exhibit deficiencies in cortical-thalamic correlational patterns, poor outcome is associated with abnormal interregional correlations not observed in either normal subjects or patients with good outcomes. This latter finding may be explained by a core neurodevelopmental disturbance that results in aberrant cortical-thalamic connectivity in poor-outcome schizophrenia.     

Widespread cortical thinning in children with frontal lobe epilepsy

Purpose: Spread of seizure activity outside the frontal lobe due to cortico‐cortical connections can result in alteration in the cortex beyond the frontal lobe in children with intractable frontal lobe epilepsy (FLE). The aim of this study was to identify regions of reduced cortical thickness in children with intractable FLE. Methods: High‐resolution volumetric T₁‐weighted imaging was performed on 17 children with FLE, who were being evaluated for epilepsy surgery, and 26 age‐matched healthy controls. The cortical thickness of 12 patients with left FLE and 5 patients with right FLE was compared to controls. The clusters of cortical thinning were regressed against age of seizure onset, duration of epilepsy, seizure frequency, and number of medications. Key Findings: In children with left FLE, cortical thinning was present in the left superior frontal, paracentral, precuneus, cingulate, inferior parietal, supramarginal, postcentral, and superior temporal gyri, as well as in the right superior and middle frontal, medial orbitofrontal, supramarginal, postcentral, banks of superior temporal sulcus, and parahippocampal gyri. In children with right FLE, cortical thinning was present in the right precentral, postcentral, transverse temporal, parahippocampal, lingual, and lateral occipital gyri, as well as in the left superior frontal, inferior parietal, postcentral, superior temporal, posterior cingulate, and lingual gyri. In children with left FLE, following exclusion of one outlier, there was no significant association between age at seizure onset, duration of epilepsy, seizure frequency and number of medications with clusters of cortical thinning. In children with right FLE, age at seizure onset, duration of epilepsy, frequency of seizures, and number of medications were not associated with clusters of cortical thinning within the right and left hemispheres. Significance: Cortical changes were present in the frontal and extrafrontal cortex in children with intractable FLE. These changes may be related to spread of seizure activity, large epileptogenic zones involving both frontal and extrafrontal lobes, and development of secondary epileptogenic zones that over time lead to cortical abnormality. Further studies correlating cortical changes with neurocognitive measures are needed to determine if the cortical changes relate to cognitive function.