Left Middle Temporal Lobe Research Articles

Progressive gray matter atrophy in parkinsonian variant of multiple system atrophy assessed by using causal structural covariance network.

Multiple system atrophy (MSA), a rare neurodegenerative disease, is usually accompanied by brain morphological alterations. However, the causal relationships between progressive gray matter atrophy in MSA parkinsonian (MSA-P) subtype remain unknown. In total, thirty-five MSA-P patients and thirty-five healthy controls (HC) underwent three-dimensional high-resolution T1-weighted structural imaging and voxel-based morphometry analysis. The causal structural covariance network (CaSCN) of gray matter was assessed to explore the causal relationships in MSA-P. With greater illness duration, the reduction of gray matter was originated from right cerebellum and progressed to bilateral cerebellum, fusiform gyrus, insula, putamen, caudate nucleus, frontal lobe, right angular gyrus, right precuneus, left middle occipital lobe and left inferior temporal lobe, then expanded to midbrain, bilateral para-hippocampus, thalamus, temporal lobe, inferior parietal lobule (IPL), precentral gyrus, postcentral gyrus and middle cingulate cortex. The right cerebellum was revealed to be the core node of the directional network and projected positive causal effects to bilateral cerebellum, caudate nucleus and left IPL. MSA-P patients showed progression of gray matter atrophy over time, with the right cerebellum probably as a primary hub. Furthermore, the early structural vulnerability of cerebellum in MSA-P may play a pivotal role in the modulation of motor and non-motor circuits at the structural level.

Correlations between Immunoinflammatory Factor Levels and Cognitive Functions and Brain Structural Magnetic Resonance Imaging Features among Patients with Primary Schizophrenia.

Schizophrenia is associated with significant cognitive impairment. However, the pathophysiological mechanisms underlying cognitive dysfunction in schizophrenia remain unclear. Based on the latest concept of cognition, immunoinflammatory factors and structural magnetic resonance imaging (sMRI) features of the brain are considered markers of schizophrenia. This study explored the correlations between cognitive function and immunoinflammatory factors and sMRI in primary schizophrenia patients. Non-interventional cross-sectional study was conducted, including 21 patients with primary schizophrenia, who were identified based on the Diagnostic and Statistical Manual, Fifth Edition (DSM-V) and grouped under the observation group. Thirty healthy volunteers with age, gender, hand dominance, and education duration matched with those of the primary schizophrenia patients were recruited to the control group. All subjects underwent sMRI examination. MATRICS consensus cognitive battery (MCCB) was employed to assess the cognitive functions among patients with primary schizophrenia. The levels of serum amyloid A (SAA), monocyte chemoattractant protein 1 (MCP-1), and chitinase-3-like protein 1 (YKL-40) were measured by means of enzyme-linked immunosorbent assay (ELISA). Pearson's correlation analysis was carried out to analyze the correlation between immunoinflammatory factor levels and cognitive functions as well as brain sMRI features. The scores for all MCCB items and the total score for the observation group were apparently lower than those for the control group (p < 0.001), while the YKL-40 and SAA levels were notably higher in the observation group (t = 3.406, p < 0.05; t = 5.656, p < 0.001). Compared to the control group, the observation group exhibited reduced volumes of left and right insular lobes, left and right anterior cingulate cortexes, left and right hippocampi, right parahippocampal gyrus, right amygdala, left inferior occipital lobe, left superior temporal lobe, left temporal pole, and left middle and inferior temporal lobes (p < 0.001). The levels of YKL-40 and SAA were both negatively correlated with MCCB score (r = -0.3668, p = 0.004; r = -0.8495, p < 0.001). The volumes of right insular lobe, left and right anterior cingulate cortexes, right parahippocampal gyrus, right amygdala, and gray matter in left middle temporal lobe were all negatively correlated with the levels of YKL-40 and SAA (p < 0.05). Cognitive impairment in patients with primary schizophrenia is associated with increased serum SAA and YKL-40 levels and decreased gray matter volume.

Communicative impairment and its neural correlates in Alzheimer's disease and frontotemporal dementia.

Communication skills can deteriorate in neurodegenerative diseases such as Alzheimer's disease (AD) and frontotemporal dementia (FTD); however, their clinical assessment and treatment in patient care can be challenging. In the present study, we aimed to quantify the distinctive communication resources and barriers reported by patients and their relatives in AD and FTD and associated these communicative characteristics with clinical parameters, such as the degree of cognitive impairment and atrophy in language-associated brain areas. We assessed self-reported communication barriers and resources in 33 individuals with AD and FTD through an interview on daily-life communication, using the Aachener KOMPASS questionnaire. We correlated reported communication barriers and resources with atrophy from high-resolution 3T brain magnetic resonance imaging, neuropsychological assessment, and neurodegenerative markers from cerebrospinal fluid. Communicative impairment was higher in FTD compared to AD. Increased reported communication barriers in our whole sample were associated with the atrophy rate in the left middle temporal lobe, a critical site within the neuronal language network, and with depressive symptoms as well as the semantic word fluency from neuropsychological assessment. The best model for prediction of communicative impairment included the diagnosis (AD or FTD), semantic word fluency, and depressive symptoms. Our study demonstrates that communication barriers and resources can be successfully assessed via a structured interview based on self-report and report of patients' relatives in practice and are reflected in neuroimaging specific for AD and FTD as well as in further clinical parameters specific for these neurodegenerative diseases. This can potentially open new treatment options for clinical practice and patient care.

Semantic composition in experimental and naturalistic paradigms

Abstract Naturalistic paradigms using movies or audiobooks have become increasingly popular in cognitive neuroscience, but connecting them to findings from controlled experiments remains rare. Here, we aim to bridge this gap in the context of semantic composition in language processing, which is typically examined using a “minimal” two-word paradigm. Using magnetoencephalography (MEG), we investigated whether the neural signatures of semantic composition observed in an auditory two-word paradigm can extend to naturalistic story listening, and vice versa. Our results demonstrate consistent differentiation between phrases and single nouns in the left anterior and middle temporal lobe, regardless of the context. Notably, this distinction emerged later during naturalistic listening. Yet this latency difference disappeared when accounting for various factors in the naturalistic data, such as prosody, word rate, word frequency, surprisal, and emotional content. These findings suggest the presence of a unified compositional process underlying both isolated and connected speech comprehension.

Lower Endogenous Estrogens in APOE4‐Positive Postmenopausal Women Associated with Lower Regional Brain Volumes

AbstractBackgroundDuring the menopause transition, levels of estradiol (E2) ecline. Although these changes are likely key determinants of cognition and brain structure during the menopause transition, how they are related to brain volume in women at elevated risk of Alzheimer’s disease (AD) is not known. We predict associations of endogenous E1 and E2 levels to regional brain volumes will depend on APOE4 carrier status, such that the associations between lower levels of E1 and E2 and lower regional brain volumes will be more positive among APOE4 carriers.MethodsParticipants were enrolled in MsBrain, a cohort study of postmenopausal women (n = 191, mean age 59.4 +/‐ 3.4 years, 45 APOE4 carriers, 84.3% white). Serum E1 and E2 were assessed using liquid chromatography‐tandem mass spectrometry. Cortical volume was measured and segmented by FreeSurfer software using individual T1w MPRAGE images. Cross‐sectional associations of interest were analyzed with APOE4 genotype (carrier versus noncarrier; excluding APOE2)ormone levels, and their interaction, as predictors and regional brain volumes (33 regions per hemisphere) as outcome measures using lme4 Package in R. Models controlled for, years of education, and body mass index.ResultsNeither APOE4 carrier status nor hormone levels were associated with brain volumes . However, significant interactions were observed between APOE4 carrier status and E2 levels in relation to volume of the right (p&lt;.05) and left isthmus cingulate (p&lt;.01), right and left middle temporal lobe (p&lt;.05), and the left posterior cingulate (p&lt;.05), such that the positive association between E2 and regional brain volumes was more positive among APOE4 carriers (Figure 1). Further, there was a significant interaction between APOE4 carrier status and E1 levels in relation to volumes of the right and left inferior parietal lobe (p&lt;.05), right (p&lt;.05) and left isthmus cingulate (p&lt;.05), left cuneus (p&lt;.05), left precuneus (p&lt;.05), and left lingual gyrus (p&lt;.05)(Figure 2).ConclusionAlthough some of these findings would be expected by chance, results suggest that lower levels of endogenous estrogens may be a risk factor for regional brain volume loss in female APOE4 carriers compared to non‐carriers.Supported by NIH RF1AG053504 and R01AG053504 (Thurston &amp; Maki)

Cortical thinning in male obstructive sleep apnoea patients with excessive daytime sleepiness.

Obstructive sleep apnoea is associated with excessive daytime sleepiness due to sleep fragmentation and hypoxemia, both of which can lead to abnormal brain morphology. However, the pattern of brain structural changes associated with excessive daytime sleepiness is still unclear. This study aims to investigate the effects of excessive daytime sleepiness on cortical thickness in patients with obstructive sleep apnoea. 61 male patients with newly diagnosed obstructive sleep apnoea were included in the present study. Polysomnography and structural MRI were performed for each participant. Subjective daytime sleepiness was assessed using the Epworth Sleepiness Scale score. Surface-based morphometric analysis was performed using Statistical Parametric Mapping 12 and Computational Anatomy 12 toolboxes to extract cortical thickness. Using the median Epworth Sleepiness Scale score, patients were divided into the non-sleepiness group and the sleepiness group. The cortical thickness was markedly thinner in the sleepiness group in the left temporal, frontal, and parietal lobe and bilateral pre- and postcentral gyri (pFWE < 0.05). There was a significant negative correlation between the cortical thickness and the Epworth Sleepiness Scale score. After adjusting for age, body mass index, and obstructive sleep apnoea severity, the Epworth Sleepiness Scale score remained an independent factor affecting the cortical thickness of the left middle temporal lobe, transverse temporal and temporal pole. Subjective daytime sleepiness is associated with decreased cortical thickness, and the Epworth Sleepiness Scale score may be of utility as a clinical marker of brain injury in patients with obstructive sleep apnoea.

Abnormal Neural Activity in Different Frequency Bands in Parkinson's Disease With Mild Cognitive Impairment.

Background: Abnormal spontaneous neural activity is often found in patients with Parkinson’s disease with mild cognitive impairment (PD-MCI). However, the frequency dependence of neuronal interaction activities, especially the fractional amplitude of low-frequency fluctuation (fALFF) and degree centrality (DC), in PD-MCI is still unclear. Thus, this study aimed to explore the frequency dependence of PD-MCI based on fALFF and DC maps.Methods: Twenty-four patients with PD-MCI, 42 PD patients with normal cognition (PD-NC), and 33 healthy controls (HCs) were enrolled. Neuropsychological assessments and resting-state functional MRI (rs-fMRI) were performed. The fALFF and DC values in the conventional, slow4 and slow5 frequency bands were compared among the groups.Results: In the conventional frequency band, the DC value in the left precentral area was decreased in PD-MCI patients, while that in the right fusiform area was increased in PD-NC patients compared with HCs. Regarding fALFFs, both the PD-MCI and PD-NC patients had decreased values in the right precentral area compared with those of the HCs. The fALFFs did not differ between PD-MCI and PD-NC patients. The fALFF results in the slow4 subfrequency band were consistent with those in the conventional frequency band. In the slow5 band, the DC value in the left middle temporal lobe was higher in PD-MCI patients than in PD-NC patients and was positively correlated with the performance of the PD-MCI patients on the Montreal Cognitive Assessment (MoCA). Additionally, both PD-MCI and PD-NC patients showed lower fALFF values in the bilateral putamen than the HCs, and the fALFF in the bilateral putamen was negatively correlated with the Hoehn and Yahr stages of PD-MCI. The fALFF in the left putamen was negatively correlated with the scores of PD-MCI patients on the Movement Disorder Society-Unified Parkinson Disease Rating Scale Part III (MDS-UPRDS-III).Conclusion: Our results suggested that abnormal neuronal activities, such as fALFF and DC, are dependent on frequency in PD-MCI. Some subfrequency bands could distinguish PD-MCI from PD. Our findings may be helpful for further revealing the frequency-dependent resting functional disruption in PD-MCI.

Disentangling Semantic Composition and Semantic Association in the Left Temporal Lobe.

Although composing two words into a complex representation (e.g., “coffee cake”) is conceptually different from forming associations between a pair of words (e.g., “coffee, cake”), the brain regions supporting semantic composition have also been implicated for associative encoding. Here, we adopted a two-word magnetoencephalography (MEG) paradigm which varies compositionality (“French/Korean cheese” vs “France/Korea cheese”) and strength of association (“France/French cheese” vs “Korea/Korean cheese”) between the two words. We collected MEG data while 42 English speakers (24 females) viewed the two words successively in the scanner, and we applied both univariate regression analyses and multivariate pattern classification to the source estimates of the two words. We show that the left anterior temporal lobe (LATL) and left middle temporal lobe (LMTL) are distinctively modulated by semantic composition and semantic association. Specifically, the LATL is mostly sensitive to high-association compositional phrases, while the LMTL responds more to low-association compositional phrases. Pattern-based directed connectivity analyses further revealed a continuous information flow from the anterior to the middle temporal region, suggesting that the integration of adjective and noun properties originated earlier in the LATL is consistently delivered to the LMTL when the complex meaning is newly encountered. Taken together, our findings shed light into a functional dissociation within the left temporal lobe for compositional and distributional semantic processing.SIGNIFICANCE STATEMENT Prior studies on semantic composition and associative encoding have been conducted independently within the subfields of language and memory, and they typically adopt similar two-word experimental paradigms. However, no direct comparison has been made on the neural substrates of the two processes. The current study relates the two streams of literature, and appeals to audiences in both subfields within cognitive neuroscience. Disentangling the neural computations for semantic composition and association also offers insight into modeling compositional and distributional semantics, which has been the subject of much discussion in natural language processing and cognitive science.

Causal structural covariance network revealing atrophy progression in Alzheimer's disease continuum.

The structural covariance network (SCN) has provided a perspective on the large‐scale brain organization impairment in the Alzheimer's Disease (AD) continuum. However, the successive structural impairment across brain regions, which may underlie the disrupted SCN in the AD continuum, is not well understood. In the current study, we enrolled 446 subjects with AD, mild cognitive impairment (MCI) or normal aging (NA) from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. The SCN as well as a casual SCN (CaSCN) based on Granger causality analysis were applied to the T1‐weighted structural magnetic resonance images of the subjects. Compared with that of the NAs, the SCN was disrupted in the MCI and AD subjects, with the hippocampus and left middle temporal lobe being the most impaired nodes, which is in line with previous studies. In contrast, according to the 194 subjects with records on CSF amyloid and Tau, the CaSCN revealed that during AD progression, the CaSCN was enhanced. Specifically, the hippocampus, thalamus, and precuneus/posterior cingulate cortex (PCC) were identified as the core regions in which atrophy originated and could predict atrophy in other brain regions. Taken together, these findings provide a comprehensive view of brain atrophy in the AD continuum and the relationships among the brain atrophy in different regions, which may provide novel insight into the progression of AD.

Lexical Influences on Categorical Speech Perception Are Driven by a Temporoparietal Circuit.

Categorical judgments of otherwise identical phonemes are biased toward hearing words (i.e., "Ganong effect") suggesting lexical context influences perception of even basic speech primitives. Lexical biasing could manifest via late stage postperceptual mechanisms related to decision or, alternatively, top-down linguistic inference that acts on early perceptual coding. Here, we exploited the temporal sensitivity of EEG to resolve the spatiotemporal dynamics of these context-related influences on speech categorization. Listeners rapidly classified sounds from a /gɪ/-/kɪ/ gradient presented in opposing word-nonword contexts (GIFT-kift vs. giss-KISS), designed to bias perception toward lexical items. Phonetic perception shifted toward the direction of words, establishing a robust Ganong effect behaviorally. ERPs revealed a neural analog of lexical biasing emerging within ∼200 msec. Source analyses uncovered a distributed neural network supporting the Ganong including middle temporal gyrus, inferior parietal lobe, and middle frontal cortex. Yet, among Ganong-sensitive regions, only left middle temporal gyrus and inferior parietal lobe predicted behavioral susceptibility to lexical influence. Our findings confirm lexical status rapidly constrains sublexical categorical representations for speech within several hundred milliseconds but likely does so outside the purview of canonical auditory-sensory brain areas.

Brain Perfusion Bridges Virtual-Reality Spatial Behavior to TPH2 Genotype for Head Acceleration Events.

Neuroimaging demonstrates that athletes of collision sports can suffer significant changes to their brain in the absence of concussion, attributable to head acceleration event (HAE) exposure. In a sample of 24 male Division I collegiate football players, we examine the relationships between tryptophan hydroxylase 2 (TPH2), a gene involved in neurovascular function, regional cerebral blood flow (rCBF) measured by arterial spin labeling, and virtual reality (VR) motor performance, both pre-season and across a single football season. For the pre-season, TPH2 T-carriers showed lower rCBF in two left hemisphere foci (fusiform gyrus/thalamus/hippocampus and cerebellum) in association with higher (better performance) VR Reaction Time, a dynamic measure of sensory-motor reactivity and efficiency of visual-spatial processing. For TPH2 CC homozygotes, higher pre-season rCBF in these foci was associated with better performance on VR Reaction Time. A similar relationship was observed across the season, where TPH2 T-carriers showed improved VR Reaction Time associated with decreases in rCBF in the right hippocampus/amygdala, left middle temporal lobe, and left insula/putamen/pallidum. In contrast, TPH2 CC homozygotes showed improved VR Reaction Time associated with increases in rCBF in the same three clusters. These findings show that TPH2 T-carriers have an abnormal relationship between rCBF and the efficiency of visual-spatial processing that is exacerbated after a season of high-impact sports in the absence of diagnosable concussion. Such gene-environment interactions associated with behavioral changes after exposure to repetitive HAEs have been unrecognized with current clinical analytical tools and warrant further investigation. Our results demonstrate the importance of considering neurovascular factors along with traumatic axonal injury to study long-term effects of repetitive HAEs.

Abnormalities of the default-mode network homogeneity and executive dysfunction in people with first-episode, treatment-naive left temporal lobe epilepsy.

Converging evidence has demonstrated that there is aberrant connectivity of the default-mode network (DMN) in left temporal lobe epilepsy (lTLE) yet changes in the network homogeneity (NH) of the DMN in people with first-episode, treatment-naive lTLE remains unclear. In this study, we used an NH method to investigate the NH of the DMN in people with first-episode, treatment-naive, lTLE, at rest. We collected resting-state functional magnetic resonance imaging (rs-fMRI), and attention network test (ANT) data from 43 people with lTLE and 42well-matched, healthy control subjects. An NH approach was used to analyze the data. People with lTLE have decreased NH in the right inferior temporal gyrus (ITG) and the left middle temporal lobe (MTG), and increased NH in the bilateral precuneus (PCu) and right inferior parietal lobe (IPL), as compared with the controls. We also found that people with lTLE had a longer executive control reaction time (RT). No significant correlations were found between abnormal NH values and clinical variables in the subjects. These findings suggest that abnormal NH of the DMN exists in lTLE subjects and highlight the significance of the DMN in the pathophysiology of cognitive problems occurring in lTLE.

Is This Within Reach? Left but Not Right Brain Damage Affects Affordance Judgment Tendencies.

The ability to judge accurately whether or not an action can be accomplished successfully is critical for selecting appropriate response options that enable adaptive behaviors. Such affordance judgments are thought to rely on the perceived fit between environmental properties and knowledge of one's current physical capabilities. Little, however, is currently known about the ability of individuals to judge their own affordances following a stroke, or about the underlying neural mechanisms involved. To address these issues, we employed a signal detection approach to investigate the impact of left or right hemisphere injuries on judgments of whether a visual object was located within reach while remaining still (i.e., reachability). Regarding perceptual sensitivity and accuracy in judging reachability, there were no significant group differences between healthy controls (N = 29), right brain damaged (RBD, N = 17) and left brain damaged stroke patients (LBD, N = 17). However, while healthy controls and RBD patients demonstrated a negative response criterion and thus overestimated their reach capability, LBD patients' average response criterion converged to zero, indicating no judgment tendency. Critically, the LBD group's judgment tendency pattern is consistent with previous findings in this same sample on an affordance judgment task that required estimating whether the hand can fit through apertures (Randerath et al., 2018). Lesion analysis suggests that this loss of judgment tendency may be associated with damage to the left insula, the left parietal and middle temporal lobe. Based on these results, we propose that damage to the left ventro-dorsal stream disrupts the retrieval and processing of a stable criterion, leading to stronger reliance on intact on-line body-perceptive processes computed within the preserved bilateral dorsal network.

EEG power spectral analysis reveals tandospirone improves anxiety symptoms in patients with Alzheimer's disease: a prospective cohort study.

BackgroundTo study the efficacy of tandospirone citrate in treating Alzheimer’s disease (AD) patients with anxiety.MethodsThirty mild-to-moderate AD patients with anxiety symptoms were randomly divided into a monotherapy group (donepezil) and a combination therapy group (donepezil and tandospirone). The treatment lasted for 12 weeks. Drug efficacy was regularly assessed using psychological assessment scales and quantitative pharmaco-electroencephalogram (QPEEG) power spectral analysis.ResultsAfter 12 weeks of treatment, the mean Hamilton Anxiety Scale (HAMA) score and mean Neuropsychiatric Inventory (NPI) score of the combination therapy group were 5.13±4.18 and 4.2±5.0, respectively, which was significantly lower compared to baseline and the monotherapy group (all P<0.05). The mean attention score on the Alzheimer’s Disease Assessment Scale-cognitive subscale (ADAS-Cog) was 0.07±0.26 for the combination group, which was significantly lower than that of the monotherapy group (P<0.05). QPEEG revealed that the power values of the δ wave in the right prefrontal lobe, left middle temporal lobe and right posterior temporal lobe decreased in the combination therapy group but not in the monotherapy group. Similarly, the power values of the α2 wave in the right parietal, right posterior temporal and left middle temporal lobes, and the β1 wave power values of left middle temporal and left posterior temporal lobes were also significantly decreased in the combination therapy group, but not in the monotherapy group.ConclusionsTandospirone citrate can significantly improve anxiety symptoms and attention in patients with mild to moderate AD. QPEEG examination might provide a objective way for the efficacy of the tandospirone in anxiety symptoms of the patients with Alzheimer’s disease.

What's behind drawing for an artist with left temporal lobe epilepsy? A multimodal neurophysiological study.

There are few studies in literature reporting drawing as a strong trigger of praxis-induced focal seizures. The aim of the present case report was describing a case of focal epilepsy with praxis induced EEG activation, due to a cavernoma, in the left middle anterior temporal lobe by using a multimodal approach. We combined video-EEG, showing that drawing increased a sustained monomorphic delta activity localized on left anterior temporal region (F7-T1a), diffusing to the vertex (Fz) and the fronto-polar electrodes (F3), with DTI data, showing that the left uncinate fasciculus, connecting the temporal pole to the orbitofrontal cortex, significantly differed from controls. fMRI confirmed that drawing increased activation in these areas. The congruence between findings supports the role of the left uncinated fasciculus linking the temporal lobe to the orbitofrontal cortex in the present focal epilepsy mainly facilitated by drawing.

Combined treatment with escitalopram and memantine increases gray matter volume and cortical thickness compared to escitalopram and placebo in a pilot study of geriatric depression.

BackgroundGeriatric depression with subjective cognitive complaints increases the risk of Alzheimer's Disease (AD). Memantine is a cognitive enhancer used to treat AD. In a 6-month double-blind randomized placebo-controlled trial of escitalopram and memantine (ESC/MEM), ESC/MEM improved cognition at 12 month in geriatric depression (NCT01902004). We now investigated structural neuroplastic changes at 3 months. MethodsForty-one older depressed adults (mean age=70.43, SD=7.33, 26 female) were randomized to receive ESC/MEM or ESC/PBO. Mood scores (Hamilton Depression Rating Scale, HAMD) and high-resolution structural T1-weighted images were acquired at baseline and 3 months. Freesurfer 6.0 for image processing and General Linear Models was used to examine group differences in symmetrized percent change gray matter volume (GMV) and cortical thickness, controlling for age and intracranial volume. Nonparametric tests were used to investigate group differences in mood and subcortical volume change. ResultsAmong 27 completers (ESC/MEM n = 13; ESC/PBO n = 14), 62% achieved remission (HAMD≤6) with ESC/MEM and 43% with ESC/PBO (Fisher's exact p=.45). Change in HAMD did not differ between groups (F(1,23)=0.14, p=.7). GMV and thickness increased more with ESC/MEM than with ESC/PBO in the left middle and inferior temporal lobe, right medial, and lateral orbito-frontal cortex (OFC). Limitationsincluded small sample size, dropout, and the lack of cognitive data at 3 months. ConclusionsAlthough significant group differences in mood improvement were not observed, ESC/MEM resulted in increased GMV and cortical thickness in several brain regions compared to placebo. Larger longitudinal clinical trials can further examine the neuroprotective effect of memantine in geriatric depression.

Interactive effects of gender and sexual orientation on cortical thickness, surface area and gray matter volume: a structural brain MRI study.

Testosterone is thought to play a crucial role in sexual differentiation of the brain, and sexual orientation is programmed into our brain structures even when we are still fetuses. Although gender and sexual orientation differences have been shown respectively in many brain structures, the mechanism underlying the sexual differentiation of the brain is still unknown. The study is to investigate the interactive effects of gender and sexual orientation on cerebral structures in homosexual and heterosexual people. Sexual orientation was evaluated by the Kinsey scale. We collected structural magnetic resonance image (MRI) data of local cortical thickness, surface area, and gray matter volume in all the subjects (29 homosexual and 29 heterosexual men, 17 homosexual and 17 heterosexual women). Statistical maps were generated using a general linear model (GLM) using FreeSurfer's Query, Design, Estimate, Contrast (QDEC) interface. We had sexual orientation and gender as 2 discrete factors with 2 levels, allowing for the generation of the interaction between sexual orientation and gender: homosexual women and heterosexual men versus heterosexual women and homosexual men. Coordinates were in Talairach space. All the cluster sizes were calculated with a P value of 0.01. Results revealed interactions concerning the area and gray matter volume between the factors of sexual orientation and gender. Regarding the thickness, an interaction was not found in any regions of the clusters. Regarding the area, an interaction was found in region of left middle temporal lobe, inferior temporal lobe, lateral occipital lobe, fusiform [(-58.1, -38.6, -14.7), maximum vertex-wise (MV) log10(P) =3.30, cluster size (CS) =1,286.90 mm2], and left rostral middle frontal lobe, pars opercularis, caudal middle frontal lobe [(-37.3, 23.6, 24.8), MV log10(P) =2.92, CS =1,194.40 mm2]. Regarding the gray matter volume, an interaction was found in the region of the left pars opercularis (inferior frontal gyrus) [(-42.9, 6.3, 18.5), MV log10(P) =1.31, CS =526.79 mm2]. The present study extends our understandings of how structural features differ in homosexual men, heterosexual men, homosexual women, and heterosexual women. Furthermore, it highlights the interactions between sexual orientation and gender in the left inferior frontal gyrus, bilateral temporal lobe, and the right rostral anterior cingulate cortex, which are suggested to play a critical role in the sexual differentiation of the human brain.

Combat exposure, posttraumatic stress disorder, and head injuries differentially relate to alterations in cortical thickness in military Veterans.

Combat-exposed Veterans are at increased risk for developing psychological distress, mood disorders, and trauma and stressor-related disorders. Trauma and mood disorders have been linked to alterations in brain volume, function, and connectivity. However, far less is known about the effects of combat exposure on brain health. The present study examined the relationship between severity of combat exposure and cortical thickness. Post-9/11 Veterans (N = 337; 80% male) were assessed with structural neuroimaging and clinically for combat exposure, depressive symptoms, prior head injury, and posttraumatic stress disorder (PTSD). Vertex-wide cortical thickness was estimated using FreeSurfer autosegmentation. FreeSurfer's Qdec was used to examine relationship between combat exposure, PTSD, and prior head injuries on cortical thickness (Monte Carlo corrected for multiple comparisons, vertex-wise cluster threshold of 1.3, p < 0.01). Covariates included age, sex, education, depressive symptoms, nonmilitary trauma, alcohol use, and prior head injury. Higher combat exposure uniquely related to lower cortical thickness in the left prefrontal lobe and increased cortical thickness in the left middle and inferior temporal lobe; whereas PTSD negatively related to cortical thickness in the right fusiform. Head injuries related to increased cortical thickness in the bilateral medial prefrontal cortex. Combat exposure uniquely contributes to lower cortical thickness in regions implicated in executive functioning, attention, and memory after accounting for the effects of PTSD and prior head injury. Our results highlight the importance of examining effects of stress and trauma exposure on neural health in addition to the circumscribed effects of specific syndromal pathology.

Imaging of semantic association judgements reveals areas of functional disruption and compensation remote from lesion in chronic Wernicke's aphasia

Imaging of semantic association judgements reveals areas of functional disruption and compensation remote from lesion in chronic Wernicke's aphasia

Characteristic deterioration of ADAS-Jcog subscale scores and correlations with regional cerebral blood flow reductions in Alzheimer's disease.

The Alzheimer Disease Assessment Scale (Japanese version) cognitive subscale (ADAS-Jcog) is composed of a number of subscale tasks. However, it is not clear which subscale tasks are most susceptible to impairment in Alzheimer's disease (AD) or what is the relationship between reduction in regional cerebral blood flow (rCBF) and decreased ADAS-Jcog scores. Subjects were 32 AD patients, aged 52-86years. We examined the relationship between subscale tasks that showed marked score changes and brain regions that showed reduced rCBF over a 2-year period. rCBF was measured by single-photon emission computed tomography (SPECT) with technetium-99m ethyl cysteinate dimer (99mTc-ECD), and the SPECT imaging data were analyzed with the easy Z-score imaging system (eZIS) and voxel-based stereotactic extraction estimation (vbSEE) methods. Total score of ADAS-Jcog deteriorated from 19.5 ± 7.0 to 35.7 ± 15.2 after 2years. Subscale scores were significantly worse in all fields, particularly in orientation, word recall, remembering test instructions, commands, constructional praxis, and ideational praxis, in that order. Significant correlations were found between (1) word recall and commands and rCBF in the left middle temporal lobe, (2) naming objects/fingers and rCBF in the left temporal (middle, inferior) lobe, and (3) constructional and ideational praxis and rCBF in the right parietal (superior, inferior) lobe, temporal (superior, middle) lobe, angular gyrus, and cingulate gyrus. We identified the brain regions associated with specifically impaired subscales of ADAS-Jcog during progressive deterioration of AD over 2years.