Reduction In Cortical Thickness Research Articles

Internalizing symptoms in intractable pediatric epilepsy: Structural and functional brain correlates

Internalizing disorders (i.e., depression and anxiety) are common comorbidities in people with epilepsy. In adults with epilepsy, comorbid depression or anxiety is associated with worse seizure control and reduced quality of life, and may be linked to specific neural biomarkers. Less is known about brain correlates of internalizing symptoms in pediatric populations. In the current study, we performed a retrospective analysis of 45 youth between the ages of 6 and 18 years old with intractable epilepsy. Individuals were evaluated for internalizing symptoms on the Child Behavior Checklist (CBCL) and underwent magnetic resonance (MR) and fluorodeoxyglucose (FDG)-positron emission tomography (PET) imaging as part of the clinical evaluation for surgical treatment of epilepsy. Forty-two percent of patients experienced clinically significant internalizing symptoms based on parent report. Compared with individuals who scored in the normal range, youth with clinical levels of internalizing problems showed overall reductions in cortex volume, as well as widespread reductions in cortical thickness and functional activation in the bilateral occipital/parietal lobe, left temporal regions, and left inferior frontal cortex on MR and PET scans. There were no group differences in amygdala or hippocampus volumes, nor other patient- or illness-related variables such as age, sex, or the type, lateralization, or duration of epilepsy. Results suggest that high rates of internalizing disorders are present in youth with refractory epilepsy. Multifocal reductions in cortical thickness and function may be nonspecific risk factors for clinically meaningful internalizing symptoms in youth with chronic epilepsy. As such, the presence of broad cortical thinning and reduced glucose uptake upon radiological examination may warrant more focused clinical evaluation of psychological symptoms.

Brain morphological alterations of cerebral cortex and subcortical nuclei in high-tension glaucoma brain and its associations with intraocular pressure.

To investigate brain morphological alterations of high-tension glaucoma patients and explore the association between brain morphological changes and elevated intraocular pressure. Thirty-six patients with high-tension glaucoma and 20 healthy controls were collected and underwent structural MRI scan. Surface-based morphometry and voxel-based morphometry were applied to assess cortical thickness and subcortical gray matter volume of the enrolled subjects. The association between brain morphometry and intraocular pressure was assessed by partial correlation. Compared with healthy controls, high-tension glaucoma patients showed decreased cortical thickness in the bilateral superior temporal gyrus, bilateral superior parietal gyrus, bilateral lateral occipital gyrus, left fusiform gyrus, left medial orbitofrontal gyrus, right precentral gyrus, and right superior frontal gyrus (p < 0.05). High-tension glaucoma patients also showed reduced gray matter volume in the right hippocampus, bilateral putamen, and bilateral thalamus (p < 0.05). In addition, brain morphological correlates of mean intraocular pressure were found in the left rostral middle frontal gyrus, right precentral gyrus, and left postcentral gyrus in high-tension glaucoma group (p < 0.05). High-tension glaucoma patients experienced morphological reduction in the visual and nonvisual areas throughout the entire brain. Elevated intraocular pressure may contribute to the reduction of cortical thickness in certain areas in the progression of the disease.

Murine maternal dietary restriction affects neural Humanin expression and cellular profile.

To understand the cellular basis for the neurodevelopmental effects of intrauterine growth restriction (IUGR), we examined the global and regional expression of various cell types within murine (Mus musculus) fetal brain. Our model employed maternal calorie restriction to 50% daily food intake from gestation day 10-19, producing IUGR offspring. Offspring had smaller head sizes with larger head:body ratios indicating a head sparing IUGR effect. IUGR fetuses at embryonic day 19 (E19) had reduced nestin (progenitors), β-III tubulin (immature neurons), Glial fibrillary acidic protein (astrocytes), and O4 (oligodendrocytes) cell lineages via immunofluorescence quantification and a 30% reduction in cortical thickness. No difference was found in Bcl-2 or Bax (apoptosis) between controls and IUGR, though qualitatively, immunoreactivity of doublecortin (migration) and Ki67 (proliferation) was decreased. In the interest of examining a potential therapeutic peptide, we next investigated a novel pro-survival peptide, mouse Humanin (mHN). Ontogeny examination revealed highest mHN expression at E19, diminishing by postnatal day 15 (P15), and nearly absent in adult (3months). Subanalysis by sex at E19yielded higher mHN expression among males during fetal life, without significant difference between sexes postnatally. Furthermore, femaleIUGR mice at E19had a greater increase in cortical mHN versus the male fetus over their respective controls. We conclude that maternal dietary restriction-associated IUGR interferes with neural progenitors differentiating into the various cellular components populating the cerebral cortex, and reduces cerebral cortical size. mHN expression is developmental stage and sex specific, with IUGR, particularly in the females, adaptively increasing its expression toward mediating a pro-survival approach against nutritional adversity.

P.095 Increased peripheral inflammation in schizophrenia is associated with worse cognitive performance and related cortical thickness reductions

While the biological substrates of brain and behavioural changes in persons with schizophrenia remain unclear, increasing evidence implicates that inflammation is involved. In schizophrenia, including first-episode psychosis and anti-psychotic naive patients, there are numerous reports of increased peripheral inflammation, cognitive deficits and neuropathologies such as cortical thinning. Research defining the relationship between inflammation and schizophrenia symptomatology and neuropathology is needed. Therefore, we analysed the level of C-reactive protein (CRP), a peripheral inflammation marker, and its relationship with cognitive functioning in a cohort of 644 controls and 499 schizophrenia patients. In a subset of individuals who underwent MRI scanning (99 controls and 194 schizophrenia cases), we tested if serum CRP was associated with cortical thickness. CRP was significantly increased in schizophrenia patients compared to controls, co-varying for age, sex, overweight/obesity and diabetes (p < 0.006E-10). In schizophrenia, increased CRP was mildly associated with worse performance in attention, controlling for age, sex and education (R =- 0.15, p = 0.001). Further, increased CRP was associated with reduced cortical thickness in three regions related to attention: the caudal middle frontal, the pars opercularis and the posterior cingulate cortices, which remained significant after controlling for multiple comparisons (all p < 0.05). Together, these findings indicate that increased peripheral inflammation is associated with deficits in cognitive function and brain structure in schizophrenia, especially reduced attention and reduced cortical thickness in associated brain regions. Using CRP as a biomarker of peripheral inflammation in persons with schizophrenia may help to identify vulnerable patients and those that may benefit from adjunctive anti-inflammatory treatments.

Differences in neuroimaging features of early- versus late-onset nonfluent/agrammatic primary progressive aphasia

This study investigated distinct neuroimaging features measured by cortical thickness and subcortical structural shape abnormality in early-onset (EO, onset age <65 years) and late-onset (LO, onset age ≥65 years) nonfluent/agrammatic variant of primary progressive aphasia (nfvPPA) patients. Cortical thickness and subcortical structural shape analyses were performed using a surface-based method from 38 patients with nfvPPA and 76 cognitively normal individuals. To minimize the effects of physiological aging, we used W-scores in comparisons between the groups. The EO-nfvPPA group exhibited more extensive cortical thickness reductions predominantly in the left perisylvian, lateral and medial prefrontal, temporal, posterior cingulate, and precuneus regions than the LO-nfvPPA group. The EO-nfvPPA group also exhibited significantly greater subcortical structural shape abnormality than the LO-nfvPPA group, mainly in the left striatum, hippocampus, and amygdala. Our findings suggested that there were differences in neuroimaging features between these groups by the age of symptom onset, which might be explained by underlying heterogeneous neuropathological differences or the age-related brain reserve hypothesis.

An overlapping pattern of cerebral cortical thinning is associated with both positive symptoms and aggression in schizophrenia via the ENIGMA consortium.

Positive symptoms are a useful predictor of aggression in schizophrenia. Although a similar pattern of abnormal brain structures related to both positive symptoms and aggression has been reported, this observation has not yet been confirmed in a single sample. To study the association between positive symptoms and aggression in schizophrenia on a neurobiological level, a prospective meta-analytic approach was employed to analyze harmonized structural neuroimaging data from 10 research centers worldwide. We analyzed brain MRI scans from 902 individuals with a primary diagnosis of schizophrenia and 952 healthy controls. The result identified a widespread cortical thickness reduction in schizophrenia compared to their controls. Two separate meta-regression analyses revealed that a common pattern of reduced cortical gray matter thickness within the left lateral temporal lobe and right midcingulate cortex was significantly associated with both positive symptoms and aggression. These findings suggested that positive symptoms such as formal thought disorder and auditory misperception, combined with cognitive impairments reflecting difficulties in deploying an adaptive control toward perceived threats, could escalate the likelihood of aggression in schizophrenia.

Effects of hypertension on cerebral cortical thickness alterations in patients with type 2 diabetes

AimsAlthough hypertension (HTN) is the high comorbidity of Type 2 diabetes mellitus (T2DM) and known to be a vascular risk factor for brain damage, the effects of HTN on brain function in T2DM patients are not well understood. Present study was performed to investigate whether HTN might accelerate the Cerebral cortical thickness (CT) alterations in patients with T2DM. MethodsWe enrolled 35 participants with only T2DM, 25 T2DM patients with HTN (HT2DM) and 28 healthy controls (HCs). The cognitive function was assessed and brain image data was collected then the CT was calculated for each participant. Partial correlations between the CT of each brain region and standard laboratory testing data and neuropsychological scale scores were also analyzed. Multivariable regression analysis was performed to evaluated the vascular risk factors and brain regions with different CT in HT2DM patients. ResultsCognitive impairment is associated with thinning of the cerebral cortical thickness reduction in T2DM patients. CT thinning in the left inferior parietal lobe, left posterior cingulate and right precuneus were observed in HT2DM group relative to only T2DM group. Furthermore, the CT decreasing in the right precuneus was negatively correlated with duration of HTN. ConclusionThe current study revealed that coexistent HTN may accelerate the CT reduction in T2DM patients.

Vdr expression in osteoclast precursors is not critical in bone homeostasis

The long-recognized role of the vitamin D endocrine system is to maintain stable serum calcium concentrations, which are ensured by a complex interplay between parathyroid gland, kidney, intestine, and bone. However, although VDR is expressed in osteoclastogenic cells, the contribution of VDR-mediated signaling to osteoclast differentiation and activity remains undefined. We therefore deleted Vdr expression efficiently and specifically in myeloid cells by use of M lysozyme-driven Cre expression, which targets granulocytes, monocytes, macrophages and osteoclasts (Vdrmyel− mice). Bone and calcium homeostasis were investigated under basal conditions and in conditions of increased bone remodeling, by feeding Vdrmyel− and Vdrmyel+ (wildtype) mice either a normal (1%) or a low (0.02%) calcium diet from weaning onwards. Vdrmyel− mice developed normally and were normocalcemic at the age of 8 weeks, both at the normal and the low calcium diet. No differences in trabecular or cortical bone mass were observed between Vdrmyel− mice and their wildtype littermates. Dietary calcium restriction resulted in a comparable reduction of trabecular bone mass (40%) and cortical thickness (48%) in Vdrmyel− and Vdrmyel+ mice, pointing to a massive transfer of calcium from the bone to the serum. In agreement with these results, osteoclastic differentiation of hematopoietic cells of Vdrmyel− mice, either induced by M-CSF and RANKL, or cocultured with osteoblasts, occurred as efficiently as osteoclastogenesis from Vdrmyel+ mice. In conclusion, our data do not support a role for osteoclastic Vdr signaling in the control of bone homeostasis.

Accelerated cortical thinning within structural brain networks is associated with irritability in youth.

Irritability is an important dimension of psychopathology that spans multiple clinical diagnostic categories, yet its relationship to patterns of brain development remains sparsely explored. Here, we examined how transdiagnostic symptoms of irritability relate to the development of structural brain networks. All participants (n = 137, 83 females) completed structural brain imaging with 3 Tesla MRI at two timepoints (mean age at follow-up: 21.1 years, mean inter-scan interval: 5.2 years). Irritability at follow-up was assessed using the Affective Reactivity Index, and cortical thickness was quantified using Advanced Normalization Tools software. Structural covariance networks were delineated using non-negative matrix factorization, a multivariate analysis technique. Both cross-sectional and longitudinal associations with irritability at follow-up were evaluated using generalized additive models with penalized splines. The False Discovery Rate (q < 0.05) was used to correct for multiple comparisons. Cross-sectional analysis of follow-up data revealed that 11 of the 24 covariance networks were associated with irritability, with higher levels of irritability being associated with thinner cortex. Longitudinal analyses further revealed that accelerated cortical thinning within nine networks was related to irritability at follow-up. Effects were particularly prominent in brain regions implicated in emotion regulation, including the orbitofrontal, lateral temporal, and medial temporal cortex. Collectively, these findings suggest that irritability is associated with widespread reductions incortical thickness and accelerated cortical thinning, particularly within thefrontal and temporal cortex. Aberrant structural maturation of regions important for emotional regulation may in part underlie symptoms of irritability.

A single-nucleotide polymorphism influences brain morphology in drug-naïve patients with major depressive disorder.

ObjectiveRecently, a genome-wide association study successfully identified genetic variants associated with major depressive disorder (MDD). The study identified 17 independent single-nucleotide polymorphisms (SNPs) significantly associated with diagnosis of MDD. These SNPs were predicted to be enriched in genes that are expressed in the central nervous system and function in transcriptional regulation associated with neurodevelopment. The study aimed to investigate associations between 17 SNPs and brain morphometry using magnetic resonance imaging (MRI) in drug-naïve patients with MDD and healthy controls (HCs).MethodsForty-seven patients with MDD and 42 HCs were included. All participants underwent T1-weighted structural MRI and genotyping. The genotype–diagnosis interactions associated with regional cortical thicknesses were evaluated using voxel-based morphometry for the 17 SNPs.ResultsRegarding rs301806, an SNP in the RERE genomic regions, we found a significant difference in a genotype effect in the right-lateral orbitofrontal and postcentral lobes between diagnosis groups. After testing every possible diagnostic comparison, the genotype–diagnosis interaction in these areas revealed that the cortical thickness reductions in the MDD group relative to those in the HC group were significantly larger in T/T individuals than in C-carrier ones. For the other SNPs, no brain area was noted where a genotype effect significantly differed between the two groups.ConclusionsWe found that a RERE gene SNP was associated with cortical thickness reductions in the right-lateral orbitofrontal and postcentral lobes in drug-naïve patients with MDD. The effects of RERE gene polymorphism and gene–environment interactions may exist in brain structures of patients with MDD.

Clinical, Structural, and Neuropathological Features of Olfactory Dysfunction in Patients with Alzheimer's Disease.

We explored changes in clinical features and neuropathological mechanisms underlying olfactory dysfunction (OD) in 60 patients with Alzheimer's disease (AD). Olfactory function was evaluated using the Sniffin' Sticks test and a threshold discrimination identification (TDI) score. Based on the TDI score, we divided patients according to the presence or absence of OD (AD-OD and AD-NOD, respectively). Cognitive and neuropsychiatric symptoms were evaluated by a series of rating scales. The volumes and cortical thickness of the thalamus, hippocampus, and amygdala were measured using structural magnetic resonance imaging. Neuropathological protein levels in cerebrospinal fluid were measured. The frequency of OD was 50%. TDI scores were lower in the AD-OD group than in the AD-NOD group (p < 0.001). Compared with the AD-NOD group, the AD-OD group showed greater cognitive function impairments (p < 0.001), and daily living activities were more severely compromised (p = 0.019). The AD-OD group had lower hippocampal and amygdala volumes (p = 0.025, p = 0.030, respectively) and a more pronounced reduction in cortical thickness (p = 0.010). The total tau level was lower in the AD-OD group than the AD-NOD group (p = 0.040). Lower Mini-Mental State Examination scores and thinner AD-signature cortices were associated with lower TDI scores (OR = 0.826, p < 0.001; OR = 1.433, p = 0.008). Overall, in AD patients, the impairments in olfactory discrimination and identification seem to be more correlated with cognitive levels. OD in AD may be an indicator of pathological cognitive decline and structural changes.

Age moderates the relationship between cortical thickness and cognitive performance

Findings from cross-sectional and longitudinal magnetic resonance imaging (MRI) studies indicate that cortical thickness declines across the adult lifespan, with regional differences in rate of decline. Global and regional thickness have also been found to co-vary with cognitive performance. Here we examined the relationships between age, mean cortical thickness, and associative recognition performance across three age groups (younger, middle-aged and older adults; total n = 133). Measures of cortical thickness were obtained using a semi-automated method. Older age was associated with decreased memory performance and a reduction in mean cortical thickness. After controlling for the potentially confounding effects of head motion, mean cortical thickness was negatively associated with associative memory performance in the younger participants, but was positively correlated with performance in older participants. A similar but weaker pattern was evident in the relationships between cortical thickness and scores on four cognitive constructs derived from a neuropsychological test battery. This pattern is consistent with prior findings indicating that the direction of the association between cortical thickness and cognitive performance reverses between early and later adulthood. In addition, head motion was independently and negatively correlated with associative recognition performance in younger and middle-aged, but not older, participants, suggesting that variance in head motion is determined by multiple factors that vary in their relative influences with age.

Potential effectiveness of exenatide in experimentally-induced osteoporosis

Aim of the workTo study the possible protective and therapeutic effects of exenatide on experimentally-induced osteoporosis in adult ovariectomized female albino rats. Materials and methodsThe study included 40 mature female albino rats, matched for age and weight (150–250 gm). Osteoporosis was experimentally-induced by bilateral ovariectomy (OVX) and the animals were left untreated for 6 weeks. Rats were divided into 4 groups: Sham group (group-I), ovariectomized (OVX) non-treated (group-II), prophylactic exenatide (group-III: received 1 μg/kg/d SC for 6 weeks immediately after ovariectomy) and treated group-IV (Left untreated for 6 weeks after ovariectomy then received treatment for 8 weeks) was subdivided into subgroup-IVa: treated with exenatide in a dose of 1 μg/kg/d SC and subgroup IVb: treated with vitamin Din a dose 0.25 µg/day orally for 5 days/week. Serum bone-specific alkaline phosphatase (BsALP) level was measured and bone histomorphometry assessed. ResultsNon-treated rats showed a significant elevation of BsALP level by 182%, reduction of cortical thickness by 36% and osteocyte number by 29% compared to Sham group-I. Rats of prophylactic exenatide, therapeutic exenatide and therapeutic vitamin D showed a significant reduction of BsALP level by 62.4%,62.5% and 62.2%, respectively, increase of the cortical thickness by 38.7%, 29.4% and40.9% respectively and osteocyte number by 29%,26% and 42%, respectively compared to OVX non-treated group-II. The mean BsALP in group IV improved to levels comparable to Sham group-I. There was no significant difference in all previous results between groups-III and IVa or IVb. ConclusionExenatide has a potential prophylactic and therapeutic role in the management postmenopausal osteoporosis. The non-inferiority of exenatide to vitamin D in treatment of osteoporosis is deduced.

Cortical morphometry in anorexia nervosa: An out-of-sample replication study.

BackgroundAcute anorexia nervosa (AN) is frequently accompanied by reduced global cortical volume. Investigations of local cortical alterations in AN have revealed widespread reduction in cortical thickness, gyrification, and curvature. The aim of the present study was to combine data from two previous studies to replicate previous findings.MethodologyMagnetic resonance imaging (MRI) images from 46 adult women with AN and 54 age‐matched healthy comparison (HC) women were analysed using FreeSurfer. Group differences in cortical volume and local cortical measures, including gyrification, curvature, thickness, and area, were examined controlling for dataset and age.ResultsThe AN group had reduced global cortical volume relative to the HC group. The AN group also had reduction in local cortical gyrification, small localised clusters of reduced cortical thickness, in the occipital and parietal cortices, and surface area in the frontal and temporal cortices. The AN group also had increased cortical thickness in the ACC relative to the HC participants.ConclusionsThe present findings replicate and validate previous findings of reduced global cortical volume and local gyrification in acute AN. The findings highlight the need for further investigation of local cortical folding, thickness, and surface area in AN to gain further insight into the biological underpinnings of AN.

Evidence for Network-Based Cortical Thickness Reductions in Schizophrenia.

Cortical thickness reductions in schizophrenia are irregularly distributed across multiple loci. The authors hypothesized that cortical connectivity networks would explain the distribution of cortical thickness reductions across the cortex, and, specifically, that cortico-cortical connectivity between loci with these reductions would be exceptionally strong and form an interconnected network. This hypothesis was tested in three cross-sectional schizophrenia cohorts: first-episode psychosis, chronic schizophrenia, and treatment-resistant schizophrenia. Structural brain images were acquired for 70 patients with first-episode psychosis, 153 patients with chronic schizophrenia, and 47 patients with treatment-resistant schizophrenia and in matching healthy control groups (N=57, N=168, and N=54, respectively). Cortical thickness was compared between the patient and respective control groups at 148 regions spanning the cortex. Structural connectivity strength between pairs of cortical regions was quantified with structural covariance analysis. Connectivity strength between regions with cortical thickness reductions was compared with connectivity strength between 5,000 sets of randomly chosen regions to establish whether regions with reductions were interconnected more strongly than would be expected by chance. Significant (false discovery rate corrected) and widespread cortical thickness reductions were found in the chronic schizophrenia (79 regions) and treatment-resistant schizophrenia (106 regions) groups, with more circumscribed reductions in the first-episode psychosis group (34 regions). Cortical thickness reductions with the largest effect sizes were found in frontal, temporal, cingulate, and insular regions. In all cohorts, both the patient and healthy control groups showed significantly increased structural covariance between regions with cortical thickness reductions compared with randomly selected regions. Brain network architecture can explain the irregular topographic distribution of cortical thickness reductions in schizophrenia. This finding, replicated in three distinct schizophrenia cohorts, suggests that the effect is robust and independent of illness stage.

Influence of Implant Length and Associated Parameters Upon Biomechanical Forces in Finite Element Analyses: A Systematic Review.

The aim of this systematic review is to provide an overview of finite element analyses comparing standard and short dental implants concerning biomechanical properties and to detect the most relevant parameters affecting periimplant stress concentrations. After screening the literature and assessment of studies, 36 studies were included in this review. Eighty-three percent of the studies state that short dental implants have to bear higher stress concentrations compared with standard length implants. At the same time, 44% of articles note that implant diameter can be considered a more effective design parameter than implant length to reduce stress concentrations and to avoid an overload of periimplant bone. Regardless of implant dimension, in all studies, the highest stress concentrations are found in the cortical section around the upper part of the implant. Unaffected of bone quality, implant diameter is found to play a key role to minimize periimplant stress concentrations. Concerning stress reduction implant length gains increasing relevance with decreasing bone density. Furthermore, splinting of short implants constitute an appropriate tool to avoid crestal overloading.

Alterations in white matter microstructure and cortical thickness in individuals at ultra-high risk of psychosis: A multimodal tractography and surface-based morphometry study

There is increasing evidence of white matter (WM) and grey matter pathology in subjects at ultra-high risk of psychosis (UHR), although a limited number of diffusion-weighted magnetic resonance imaging (DW-MRI) and surface-based morphometry (SBM) studies have revealed anatomically inconsistent results. The present multimodal study applies tractography and SBM to analyze WM microstructure, whole-brain cortical anatomy, and potential interconnections between WM and grey matter abnormalities in UHR subjects. Thirty young male UHR patients and 30 healthy controls underwent DW-MRI and T1-weighted MRI. Fractional anisotropy; mean, radial, and axial diffusivity in 18 WM tracts; and vertex-based cortical thickness, area, and volume were analyzed. We found increased radial diffusivity in the left anterior thalamic radiation and reduced bilateral thickness across the frontal, temporal, and parietal cortices. No correlations between WM and grey matter abnormalities were identified. These results provide further evidence that WM microstructure abnormalities and cortical anatomical changes occur in the UHR state. Disruption of structural connectivity in the prefrontal-subcortical circuitry, likely caused by myelin pathology, and cortical thickness reduction affecting the networks presumably involved in processing and coordination of external and internal information streams may underlie the widespread deficits in neurocognitive and social functioning that are consistently reported in UHR subjects.

Converging function, structure, and behavioural features of emotion regulation in very preterm children.

Children born very preterm (VPT; <32 weeks' gestational age) are at high risk for emotional regulation and social communication impairments. However, the underlying neurobiological correlates of these difficulties remain poorly understood. Using a multimodal approach, including both magnetoencephalographic and structural magnetic resonance imaging, we investigated the functional, structural, and behavioural characteristics of socio-emotional processing in 19 school-age children born VPT and 21 age-matched term-born (TB) children (7-13 years). Structural MRI analyses were conducted on a subset of these groups (16 VPT and 21 age-matched TB). Results showed that the inhibition of aversive socio-emotional stimuli was associated with a sustained reduction of right frontoparietal functional brain activity in children born VPT children. Moreover, whole brain structural analyses showed that reductions of cortical thickness or volume in these regions were associated with poor socio-emotional performance in children born VPT. Hence, our results suggest that functional and structural alterations encompassing the frontoparietal areas might be a biological marker of less efficient emotion regulation processes/performance in school-age children born VPT. These findings open up novel avenues to investigate the potential impact of such atypicalities, and in particular, those related to the atypical maturation of the medial prefrontal regions, on the frequent development of psychiatric disorders in this vulnerable population.

T99. Reduction of Frontal and Temporal Cortical Thickness in Patients With Suicidal Behavior but Not With Suicidal Ideation Only

Abnormalities in fronto-parietal and temporal regions, substrates of cognitive control, decision-making, and emotional regulation deficits have been linked to suicidal thoughts and behavior. However, the structural changes are generally examined in the context of presence of lifetime suicidal events (ideation and attempt). In this study, we aimed to extricate the structural differences between individuals with recent and remote suicidal thoughts and behavior.

Differential sensitivity of structural, diffusion, and resting-state functional MRI for detecting brain alterations and verbal memory impairment in temporal lobe epilepsy.

Temporal lobe epilepsy (TLE) is known to affect large-scale gray and white matter networks, and these network changes likely contribute to the verbal memory impairments observed in many patients. In this study, we investigate multimodal imaging patterns of brain alterations in TLE and evaluate the sensitivity of different imaging measures to verbal memory impairment. Diffusion tensor imaging (DTI), volumetric magnetic resonance imaging (vMRI), and resting-state functional MRI (rs-fMRI) were evaluated in 46 patients with TLE and 33 healthy controls to measure patterns of microstructural, structural, and functional alterations, respectively. These measurements were obtained within the white matter directly beneath neocortex (ie, superficial white matter [SWM]) for DTI and across neocortex for vMRI and rs-fMRI. The degree to which imaging alterations within left medial temporal lobe/posterior cingulate (LMT/PC) and left lateral temporal regions were associated with verbal memory performance was evaluated. Patients with left TLE and right TLE both demonstrated pronounced microstructural alterations (ie, decreased fractional anisotropy [FA] and increased mean diffusivity [MD]) spanning the entire frontal and temporolimbic SWM, which were highly lateralized to the ipsilateral hemisphere. Conversely, reductions in cortical thickness in vMRI and alterations in the magnitude of the rs-fMRI response were less pronounced and less lateralized than the microstructural changes. Both stepwise regression and mediation analyses further revealed that FA and MD within SWM in LMT/PC regions were the most robust predictors of verbal memory, and that these associations were independent of left hippocampal volume. These findings suggest that microstructural loss within the SWM is pronounced in patients with TLE, and injury to the SWM within the LMT/PC region plays a critical role in verbal memory impairment.