Temporal Lobe Gray Matter Volumes Research Articles

Automated detection of MRI-negative temporal lobe epilepsy with ROI-based morphometric features and machine learning.

Temporal lobe epilepsy (TLE) predominantly originates from the anteromedial basal region of the temporal lobe, and its prognosis is generally favorable following surgical intervention. However, TLE often appears negative in magnetic resonance imaging (MRI), making it difficult to quantitatively diagnose the condition solely based on clinical symptoms. There is a pressing need for a quantitative, automated method for detecting TLE. This study employed MRI scans and clinical data from 51 retrospective epilepsy cases, dividing them into two groups: 34 patients in TLE group and 17 patients in non-TLE group. The criteria for defining the TLE group were successful surgical removal of the epileptogenic zone in the temporal lobe and a favorable postoperative prognosis. A standard procedure was used for normalization, brain extraction, tissue segmentation, regional brain partitioning, and cortical reconstruction of T1 structural MRI images. Morphometric features such as gray matter volume, cortical thickness, and surface area were extracted from a total of 20 temporal lobe regions in both hemispheres. Support vector machine (SVM), extreme learning machine (ELM), and cmcRVFL+ classifiers were employed for model training and validated using 10-fold cross-validation. The results demonstrated that employing ELM classifiers in conjunction with specific temporal lobe gray matter volume features led to a better identification of TLE. The classification accuracy was 92.79%, with an area under the curve (AUC) value of 0.8019. The method proposed in this study can significantly assist in the preoperative identification of TLE patients. By employing this method, TLE can be included in surgical criteria, which could alleviate patient symptoms and improve prognosis, thereby bearing substantial clinical significance.

Longitudinal medial temporal lobe gray matter volume and cognitive changes in late middle‐aged and older adults with treated and non‐treated obstructive sleep apnea

AbstractBackgroundNeuroimaging studies in obstructive sleep apnea (OSA) have found both gray matter atrophy and hypertrophy in medial temporal lobe subregions, the latter probably reflecting edema. Whether and how these changes progress over time when OSA is treated or untreated remains unclear. Here, we investigated gray matter volume changes in medial temporal lobe subregions in treated OSA, untreated OSA and control participants aged > 55 years. We also explored whether the medial temporal lobe volume at baseline could predict cognitive decline.MethodTwenty‐three non‐treated OSA participants (65.8 ±5.4 years) and twenty controls (64.0 ±6.4 years) were evaluated with overnight polysomnography, MRI session and neuropsychological assessment. Twelve OSA participants then started continuous positive airway pressure (CPAP) therapy and used it at least 4 hours per night, 4 nights per week. Eleven participants refused treatment. Participants were evaluated again with MRI and neuropsychology after 18 months. We extracted the entorhinal, hippocampal and parahippocampal volumes using FreeSurfer 7.1. We performed repeated‐measure ANOVAs with Group (treated OSA, untreated OSA and controls) and Time (baseline and follow‐up) on bilateral volumes. We also performed partial correlations between bilateral medial temporal volumes at baseline and changes in cognition (Montreal Cognitive Assessment, score at follow‐up – baseline) in each group separately. Analyses were corrected for age, sex, and total intracranial volume.ResultWe found a significant Group X Time interaction for bilateral parahippocampal volumes (F = 7.2; p = 0.002) where treated OSA participants showed a decreased volume over time (p tukey<0.001), while no changes occurred in the two other groups. Regarding the predictive value of medial temporal lobe volume, in untreated participants, higher bilateral hippocampal volume at baseline was associated with more severe cognitive decline over time (r = ‐0.77; p = 0.01). In treated participants, higher bilateral entorhinal cortex volume at baseline was associated with more cognitive decline (r = ‐0.74; p = 0.035). No associations were found in controls.ConclusionThese preliminary results showed that presenting hypertrophy of the medial temporal lobe subregions at baseline is associated with worse cognitive outcome at 18‐month follow‐up in OSA participants. In the CPAP group, the decrease in parahippocampal volume might represent a reduction in hypertrophy, possibly by limiting edema.

Late‐life social activity moderates the association between temporal lobe atrophy and episodic memory decline

AbstractBackgroundRetirement and loss of important social relationships, including spouse and friends, make older adults more vulnerable to social isolation. Therefore, social activity could be important for older adults in maintaining life satisfaction and everyday functioning. Although several studies found protective roles of social activity against cognitive decline in late life, only a few studies examined the protective effects of social activity using longitudinal data. In this study, the effects of social activity on the relationship between brain aging and cognitive decline in older adults were examined during a four‐year period.MethodThirty‐two older adults with normal cognition (mean age = 70.69, SD: 6.27, mean education = 7.75, SD: 3.94 at baseline) were recruited from the Korean Social Life, Health, and Aging Project (KSHAP). Neuropsychological and brain imaging data, and social survey, were acquired in 2015 and 2019. Elderly Verbal Learning Test (EVLT) performance and cortical volumes from Magnetic Resonance Imaging (MRI) were the main measures of interest. The participants were asked to respond either “yes” or “no” to social survey items, including participation in community senior center events, volunteering for charities, religious activities, socializing events, leisure activities, and community activities. Social activity was explored in terms of level, consistency, and types of social activities. The Computational Anatomy Toolbox (CAT) was used to calculate temporal lobe gray matter volume selected as regions of interest (ROI) for its role in episodic memory. Hierarchical regressions were conducted to examine the effects of social activity on the relationship between temporal lobe atrophy and episodic memory decline.ResultWe found that the temporal lobe atrophy was associated with the delayed recall decline (r = 0.49, p = 0.003). More involvement in social activity at baseline decreased the effects of temporal lobe atrophy on delayed recall decline, controlling for age, sex, education, and self‐rated health as covariates. Further, consistent involvement in social activity, especially volunteering, attenuated the association between temporal lobe atrophy and delayed recall decline.ConclusionThese findings suggest that social activities in late life function as cognitive reserve to buffer against the effects of temporal lobe atrophy on episodic memory decline in older adults.

Associations Between Brain Gray Matter Volumes and Adipose Tissue Metabolism in Healthy Adults.

Gray matter (GM) volume in different brain loci has been shown to vary in obesity and diabetes, and elevated fasting plasma nonesterified fatty acid (NEFA) levels have been suggested as one potential mechanism. The hypothesis presented in this study is that brown adipose tissue (BAT) activity may correlate with GM volume in areas negatively associated with obesity and diabetes. A total of 36 healthy patients (M/F: 12/24, age 39.7 ± 9.4 years, BMI 27.5 ± 5.6 kg/m2 ) were imaged with positron emission tomography using fatty acid analog [18 F]FTHA to measure NEFA uptake and with [15 O]H2 O to measure perfusion during cold exposure, at room temperature during fasting, or during a postprandial state. A 2-hour hyperinsulinemic euglycemic clamp was performed to measure whole-body insulin sensitivity (M value, mean 7.6 ± 3.9 mg/kg/min). T1-weighted magnetic resonance imaging at 1.5 T was performed on all patients. BAT NEFA uptake was associated directly with GM volume in anterior cerebellum and occipital lobe (P ≤ 0.04) when adjusted for age, gender, and intra-abdominal fat volume and with anterior cerebellum, limbic lobe, and temporal lobe GM volumes when adjusted for M value. BAT NEFA metabolism may participate in protection from cognitive degeneration associated with cardiometabolic risk factors, such as central obesity and insulin resistance. Potential causal relationships between BAT activity and GM volumes remain to be examined.

Vitamin D deficiency is associated with decreased cognition independent from the disease status and AD morphology

AbstractBackground25(OH)D deficiency was associated with cognitive impairment and altered brain volumes, namely reduction in white matter and medial temporal lobe and enlargement of lateral ventricles. 25(OH)D deficiency was also associated with the development of Alzheimer's disease (AD). In this study, we aimed to investigate whether 25(OH)D levels are independently associated with cognitive performance and AD‐associated morphology in a mixed sample.MethodThe study was conducted at Hacettepe University Faculty of Medicine, Ankara, Turkey. The participants were chosen from our dementia research database.Demographic variables, 25(OH)D levels, standardized Modified Mini Mental Test (3MS) z‐scores, 1.5 T brain MRI, the data for comorbid medical conditions and current prescription drugs were used as pertinent variables. FreeSurfer v.6.0 was used for automated structural neuroimaging analysis. Based on the previous literature, AD cortical signature, predictive cortical thickness, medial temporal lobe gray matter and mean hippocampal volumes were calculated and used independently to assess AD‐related morphological changes. Cut‐off for 25(OH)D deficiency was accepted as 20 ng/ml. Statistical analyses were conducted using IBM SPSS Statistics 23 for Windows. To assess the predictive power of 25(OH)D, regression models were used with standardized 3MS scores and AD‐related areas as dependent variables. Statistical assumptions were met for all models presented. Funded by TUBITAK 214S048 and Hacettepe University THD 2018‐17363.ResultA total of 210 patients over 55 years of age (47 AD, 15 nonAD dementia, 74 Mild and Subjective Cognitive Impairment, 74 cognitively intact) were included. Mean 25(OH) level was 22.48 ±15.8 ng/ml. 108 participants (51.4%) had 25(OH)D deficiency (AD 57%, nonAD Dementia 60%, SCI/MCI 51%, Control 46%, p>0.5). 25(OH)D deficiency was significantly associated with 3MS scores (χ2 =5.608,df=1,p=0.018). The association was also marginally significant when adjusted for age, diagnosis and medial temporal lobe gray matter volume (Exp(β): 2.472, p=0.05). 25(OH)D levels were not associated with AD‐related morphological changes on multivariate analyses.ConclusionPlasma 25(OH)D levels are associated with cognitive performance regardless of the diagnosis. The effect seems to be independent of AD‐related brain morphological changes. Our results suggest an independent effect of 25(OH)D levels on cognition.

Development and validation of the Uniform Data Set (v3.0) executive function composite score (UDS3-EF).

IntroductionCognitive composite scores offer a means of precisely measuring executive functioning (EF).MethodsWe developed the Uniform Data Set v3.0 EF composite score (UDS3‐EF) in 3507 controls from the National Alzheimer's Coordinating Center dataset using item‐response theory and applied nonlinear and linear demographic adjustments. The UDS3‐EF was validated with other neuropsychological tests and brain magnetic resonance imaging from independent research cohorts using linear models.ResultsFinal model fit was good‐to‐excellent: comparative fit index = 0.99; root mean squared error of approximation = 0.057. UDS3‐EF scores differed across validation cohorts (controls > mild cognitive impairment > Alzheimer's disease‐dementia ≈ behavioral variant frontotemporal dementia; P < 0.001). The UDS3‐EF correlated most strongly with other EF tests (βs = 0.50 to 0.85, Ps < 0.001) and more with frontal, parietal, and temporal lobe gray matter volumes (βs = 0.18 to 0.33, Ps ≤ 0.004) than occipital gray matter (β = 0.12, P = 0.04). The total sample needed to detect a 40% reduction in UDS3‐EF change (n = 286) was ≈40% of the next best measure (F‐words; n = 714).ConclusionsThe UDS3‐EF is well suited to quantify EF in research and clinical trials and offers psychometric and practical advantages over its component tests.

COMT-Val158Met polymorphism modulates antipsychotic effects on auditory verbal hallucinations and temporal lobe gray matter volumes in healthy individuals\u2014symptom relief accompanied by worrisome volume reductions

Investigation of auditory verbal hallucinations (AVHs) in schizophrenics is complicated by psychiatric symptoms. Investigating healthy individuals with AVHs (H-AVHs) can obviate such confounding factors. The objective of this study was to explore the effects of antipsychotic treatment on AVHs and gray matter volumes (GMVs) in H-AVH subjects and whether such are effects are influenced by COMT-Val158Met genotype. Magnetic resonance imaging (MRI) and genotyping studies were completed for 42 H-AVH subjects and 42 well-matched healthy controls (HCs). COMT-Met/Met homozygotes (158th codon) were identified as COMT-Met genotype; COMT-Met/Val heterozygotes and COMT-Val/Val homozygotes were identified as COMT-Val genotype. Data were compared across groups (H-AVH vs. HC, and between genotypes) with two-sample t-tests. The H-AVH COMT-Met group showed a stronger response to antipsychotic treatment than the H-AVH COMT-Val group (p < 0.001). Both H-AVH genotype groups exhibited temporal lobe GMV reductions after treatment, and relative to their respective genotype-matched HC groups. Antipsychotic treatment effects in H-AVH subjects were influenced by COMT-Val158Met genotype and associated with widespread GMV reductions. These findings provide clues for further exploration of treatment targets for AVHs. Treatment associated GMV reductions, however, raise concerns about use of antipsychotics in H-AVH subjects.

The structural brain correlates of callous-unemotional traits in incarcerated male adolescents.

Youth with severe conduct problems impose a significant cost on society by engaging in high levels of antisocial and aggressive behavior. Within this group, adolescents with high levels of callous- unemotional traits have been found to exhibit more severe and persistent patterns of antisocial behavior than youth with severe conduct problems but normative levels of callous-unemotional traits. Existing neuroimaging studies, along with theoretical accounts of psychopathology, suggest that dysfunction within the paralimbic cortex and limbic system may underlie elevated levels of callous-unemotional traits. The present study examines this hypothesis by investigating gray matter correlates associated with callous-unemotional traits. A sample of incarcerated male adolescents (N = 269), were assessed using voxel-based morphometry. Callous-unemotional traits were assessed using the Inventory of Callous-Unemotional traits (Frick 2004). Total callous-unemotional traits were negatively correlated with anterior temporal lobe gray matter volume (GMV). Callous traits in particular exhibited a reliable negative correlation with gray matter volume in nearly every paralimbic brain region examined. Uncaring traits were positively correlated with GMV in the orbitofrontal and anterior cingulate cortices. These findings demonstrate specific neural features within the paralimbic cortex and limbic system that accompany elevated callous-unemotional traits and serves to expand our understanding of pathophysiological mechanisms that may give rise to severe conduct problems in youth.

Anomalous Brain Development Is Evident in Preschoolers With Attention-Deficit/Hyperactivity Disorder.

Attention-deficit/hyperactivity disorder (ADHD) is a common neurological disorder with symptom onset early in childhood. Growing evidence suggests anomalous brain development across multiple brain regions is evident in school-aged children; however, few studies have examined whether such differences are notable in the preschool years when symptom onset typically occurs. High resolution anatomical (MPRAGE) images and cognitive and behavioral measures were analyzed in a total of 90 medication-naïve preschoolers, ages 4-5 years (52 with ADHD, 38 controls; 64.4% boys). Results revealed reductions in bilateral frontal, parietal, and temporal lobe gray matter volumes in children with ADHD relative to typically developing children, with largest effect sizes noted for right frontal and left temporal lobe volumes. Examining frontal lobe sub-regions, the largest between group effect sizes were evident for left orbitofrontal cortex, left primary motor cortex (M1), and left supplementary motor complex (SMC). ADHD-related reductions in specific sub-regions (left prefrontal, left premotor, left frontal eye field, left M1, and right SMC) were significantly correlated with symptom severity, such that higher ratings of hyperactive/impulsive symptoms were associated with reduced cortical volumes. These findings represent the first comprehensive examination of cortical volume in preschool children with ADHD, providing evidence that anomalous brain structure in ADHD is evident very early in development. Furthermore, findings set the stage for developing our understanding of the way in which developmental trajectories of anomalous brain development are associated with the unfolding of symptoms in childhood ADHD. (JINS, 2018, 24, 531-539).

Differences in gray matter volume corresponding to delusion and hallucination in patients with schizophrenia compared with patients who have bipolar disorder.

BackgroundAlthough schizophrenia and bipolar disorder (BD) are classified as different disease entities, they share critical pathognomonic symptoms in terms of hallucination and delusion. Because the characteristics of clinical symptoms are not sufficient to differentiate schizophrenia from BD, several studies have applied brain imaging methods to provide biological evidence of differences. We compared gray matter (GM) volume differences in schizophrenia and BD patients and examined volumetric differences associated with hallucination and delusion in these two groups.MethodsNinety-three schizophrenia patients and 75 BD patients who were followed for at least 3 years in an outpatient department were recruited for this study. Magnetic resonance data from 71 schizophrenia patients and 44 BD patients were obtained using a 3.0 T scanner. Volumetric differences were analyzed using Matlab 8.0.0 and SPM8 software.ResultsThe results showed that delusion symptoms were negatively correlated with GM volume within both frontal and both temporal cortices in the schizophrenia group and were negatively correlated with GM volume within the bilateral frontal cortices in the BD group. Hallucination symptoms were negatively correlated with GM volume within the bilateral frontal, bilateral temporal, and left parietal cortices in the schizophrenia group and were negatively correlated with GM volume within the bilateral frontal, right parietal, occipital, and insular cortices in the BD group.ConclusionDelusions in schizophrenia were correlated with GM volume in multiple brain regions, including the frontal, temporal, and parietal cortices, compared to those in patients with BD. Hallucination was associated with temporal lobe GM volume in patients with schizophrenia and with insular cortex GM volume in patients with BD.

Altered Gray Matter Volume and School Age Anxiety in Children Born Late Preterm

To determine if late preterm (LP) children differ from full term (FT) children in volumes of the cortex, hippocampus, corpus callosum, or amygdala and whether these differences are associated with anxiety symptoms at school-age. LP children born between 34 and 36 weeks gestation and FT children born between 39 and 41 weeks gestation from a larger longitudinal cohort had magnetic resonance imaging scans at school-age. Brain volumes, cortical surface area, and thickness measures were obtained. Anxiety symptoms were assessed using a structured diagnostic interview annually beginning at preschool-age and following the magnetic resonance imaging. LP children (n = 21) had a smaller percentage of total, right parietal, and right temporal lobe gray matter volume than FT children (n = 87). There were no differences in hippocampal, callosal, or amygdala volumes or cortical thickness. LP children also had a relative decrease in right parietal lobe cortical surface area. LP children had greater anxiety symptoms over all assessments. The relationship between late prematurity and school-age anxiety symptoms was mediated by the relative decrease in right temporal lobe volume. LP children, comprising 70% of preterm children, are also at increased risk for altered brain development particularly in the right temporal and parietal cortices. Alterations in the right temporal lobe cortical volume may underlie the increased rate of anxiety symptoms among these LP children. These findings suggest that LP delivery may disrupt temporal and parietal cortical development that persists until school-age with the right temporal lobe conferring risk for elevated anxiety symptoms.

Impaired Insulin Sensitivity as Indexed by the HOMA Score Is Associated With Deficits in Verbal Fluency and Temporal Lobe Gray Matter Volume in the Elderly

OBJECTIVEImpaired insulin sensitivity is linked to cognitive deficits and reduced brain size. However, it is not yet known whether insulin sensitivity involves regional changes in gray matter volume. Against this background, we examined the association between insulin sensitivity, cognitive performance, and regional gray matter volume in 285 cognitively healthy elderly men and women aged 75 years from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study.RESEARCH DESIGN AND METHODSInsulin sensitivity was calculated from fasting serum insulin and plasma glucose determinations using the homeostasis model assessment of insulin resistance (HOMA-IR) method. Cognitive performance was examined by a categorical verbal fluency. Participants also underwent a magnetic resonance imaging (MRI) brain scan. Multivariate analysis using linear regression was conducted, controlling for potential confounders (sex, education, serum LDL cholesterol, mean arterial blood pressure, and abdominal visceral fat volume).RESULTSThe HOMA-IR was negatively correlated with verbal fluency performance, brain size, and temporal lobe gray matter volume in regions known to be involved in speech production (Brodmann areas 21 and 22, respectively). No such effects were observed when examining diabetic (n = 55) and cognitively impaired (n = 27) elderly subjects as separate analyses.CONCLUSIONSThese cross-sectional findings suggest that both pharmacologic and lifestyle interventions improving insulin signaling may promote brain health in late life but must be confirmed in patient studies.

Neuroanatomic Predictors to Prodromal Psychosis in Velocardiofacial Syndrome (22q11.2 Deletion Syndrome): A Longitudinal Study

Up to 30% of young adults with velocardiofacial syndrome (VCFS; 22q11.2 deletion syndrome) develop schizophrenia or psychosis. Identifying the neuroanatomic trajectories that increase risk for psychosis in youth with this genetic disorder is of great interest. We acquired high-resolution anatomic magnetic resonance images and measures of psychiatric function on 72 youth with VCFS, 26 unaffected siblings, and 24 age-matched community control subjects at two time points: between late childhood (mean age 11.9 years) and mid-adolescence (mean age 15.1 years). With the exception of cranial gray matter and orbitofrontal prefrontal cortex, neuroanatomic trajectories in youth with VCFS were comparable to unaffected siblings and community control subjects during this developmental window. However, in youth with VCFS, longitudinal decreases in the volumes of cranial gray and white matter, prefrontal cortex, mesial temporal lobe, and cerebellum were associated with increased combined prodromal symptoms at Time 2. In contrast, only decreases in temporal lobe gray matter volumes (p < .002) and verbal IQ (p < .002) predicted specifically to positive prodromal symptoms of psychosis at Time 2. These findings are in line with studies of non-VCFS individuals at risk for schizophrenia and suggest that early decrements in temporal lobe gray matter may be predictive of increased risk of prodromal psychotic symptoms in youth with VCFS.

Puberty influences medial temporal lobe and cortical gray matter maturation differently in boys than girls matched for sexual maturity.

Sex differences in age- and puberty-related maturation of human brain structure have been observed in typically developing age-matched boys and girls. Because girls mature 1-2 years earlier than boys, the present study aimed at assessing sex differences in brain structure by studying 80 adolescent boys and girls matched on sexual maturity, rather than age. We evaluated pubertal influences on medial temporal lobe (MTL), thalamic, caudate, and cortical gray matter volumes utilizing structural magnetic resonance imaging and 2 measures of pubertal status: physical sexual maturity and circulating testosterone. As predicted, significant interactions between sex and the effect of puberty were observed in regions with high sex steroid hormone receptor densities; sex differences in the right hippocampus, bilateral amygdala, and cortical gray matter were greater in more sexually mature adolescents. Within sex, we found larger volumes in MTL structures in more sexually mature boys, whereas smaller volumes were observed in more sexually mature girls. Our results demonstrate puberty-related maturation of the hippocampus, amygdala, and cortical gray matter that is not confounded by age, and is different for girls and boys, which may contribute to differences in social and cognitive development during adolescence, and lasting sexual dimorphisms in the adult brain.

Suicidality and brain volumes in pediatric epilepsy

This study examined the relationship between suicidal ideation and frontotemporal volumes, particularly orbital frontal gyrus volume, in 51 subjects with epilepsy with a mean age of 9.8 (2.1) years. Structured psychiatric interviews of the children and parents provided information on suicidal behavior and DSM-IV diagnoses. Tissue of 1.5-T MRI scans was segmented, and total brain, frontal lobe, frontal parcellations, and temporal lobe volumes were computed. The 11 subjects with epilepsy with suicidal ideation had significantly smaller right orbital frontal gyrus white matter volumes and larger left temporal lobe gray matter volumes than the 40 children without suicidal thoughts. Given the role of the orbital frontal gyrus in both emotional regulation and epilepsy, these findings highlight the biological underpinnings of suicidal ideation in pediatric epilepsy.

Language and brain volumes in children with epilepsy

In this study the relationship between language skill and frontotemporal volumes was compared in 69 medically treated subjects with epilepsy and 34 healthy children, aged 6.1–16.6 years. Also, whether patients with linguistic deficits had abnormal volumes and atypical associations between volumes and language skills in these brain regions was determined. The children underwent language testing and MRI scans at 1.5 T. Brain tissue was segmented and frontotemporal volumes were computed. Higher mean language scores were significantly associated with larger inferior frontal gyrus, temporal lobe, and posterior superior temporal gyrus gray matter volumes in the epilepsy group and in the children with epilepsy with average language scores. Increased total brain and dorsolateral prefrontal gray and white matter volumes, however, were associated with higher language scores in the healthy controls. Within the epilepsy group, linguistic deficits were related to smaller anterior superior temporal gyrus gray matter volumes and there was a negative association between language scores and dorsolateral prefrontal gray matter volumes. These findings demonstrate abnormal development of language-related brain regions, and imply differential reorganization of brain regions subserving language in children with epilepsy with normal linguistic skills and in those with impaired language.

Thought disorder and frontotemporal volumes in pediatric epilepsy

The aim of this study was to determine if volumes of frontotemporal regions associated with language were related to thought disorder in 42 children, aged 5-16 years, with cryptogenic epilepsy, all of whom had complex partial seizures (CPS). The children with CPS and 41 age- and gender-matched healthy children underwent brain MRI scans at 1.5 T. Tissue was segmented, and total brain, frontal lobe, and temporal lobe volumes were computed. Thought disorder measures, IQ, and seizure information were collected for each patient. The subjects with CPS had more thought disorder, smaller total gray matter and orbital frontal gray matter volumes, as well as larger temporal lobe white matter volumes than the control group. In the CPS group, thought disorder was significantly related to smaller orbital frontal and inferior frontal gray matter volumes, increased Heschl's gyrus gray matter volumes, and smaller superior temporal gyrus white matter volumes. However, significantly larger orbital frontal gyrus, superior temporal gyrus, and temporal lobe gray matter volumes and decreased Heschl's gyrus white matter volumes were associated with thought disorder in the control group. These findings suggest that thought disorder might represent a developmental disability involving frontotemporal regions associated with language in pediatric CPS.

Temporal lobe volume in bipolar disorder: Relationship with diagnosis and antipsychotic medication use

Background We tested for differences in temporal lobe volume in bipolar disorder and the relationship between these volumes and psychotropic medication use. Methods 125 subjects with bipolar disorder and 87 comparison subjects with no psychiatric illness completed clinical interviews and 1.5T MRI brain scans. Temporal lobe volumes were manually traced and segmented into gray matter and white matter volumes using an automated process. General linear models examined the relationship between these volumes and diagnosis as the primary predictor with age, sex, education, and race as copredictors. Secondary analyses incorporated the use of psychotropic medication into the linear models, and parsimonious models developed through backwards regression. Results In initial models, subjects with bipolar disorder exhibited larger temporal lobe white matter bilaterally (left: F 1,211 = 2.86, p = 0.0047; right: F 1,211 = 3.25, p = 0.0014). Current antipsychotic use was significantly associated with larger bilateral temporal lobe white matter volumes (left: F 2,211 = 9.45, p = 0.0001; right: F 2,211 = 10.79, p < 0.0001), wherein bipolar subjects taking antipsychotics had larger volumes than bipolar subjects not taking antipsychotics or healthy comparison subjects. Temporal lobe gray matter volume was not significantly associated with diagnosis or medication use. Limitations Excluding subjects with substance use disorders may limit the study's generalizability. Conclusions These findings indicate that differences in temporal lobe white matter are associated with bipolar disorder and use of antipsychotic medications.

P3-051: Peripheral insulin levels are associated with increased medial temporal lobe gray matter volume in early Alzheimer's disease

P3-051: Peripheral insulin levels are associated with increased medial temporal lobe gray matter volume in early Alzheimer's disease

Relationship of temporal lobe volumes to neuropsychological test performance in healthy children

Ecological validity of neuropsychological assessment includes the ability of tests to predict real-world functioning and/or covary with brain structures. Studies have examined the relationship between adaptive skills and test performance, with less focus on the association between regional brain volumes and neurobehavioral function in healthy children. The present study examined the relationship between temporal lobe gray matter volumes and performance on two neuropsychological tests hypothesized to measure temporal lobe functioning (visual perception—VP; peabody picture vocabulary test, third edition—PPVT-III) in 48 healthy children ages 5–18 years. After controlling for age and gender, left and right temporal and left occipital volumes were significant predictors of VP. Left and right frontal and temporal volumes were significant predictors of PPVT-III. Temporal volume emerged as the strongest lobar correlate with both tests. These results provide convergent and discriminant validity supporting VP as a measure of the “what” system; but suggest the PPVT-III as a complex measure of receptive vocabulary, potentially involving executive function demands.