Cortical Gray Matter Thickness and Volume Changes and Their Association with Memory Functions in Hyperthyroid Patients.

INTRODUCTION: Hyperthyroidism, characterized by excessive thyroid hormone production, is a common endocrine disorder that affects various physiological processes, including brain function. Recent advancements in neuroimaging techniques have enabled researchers to investigate structural alterations in the brain associated with hyperthyroidism. This study aimed to examine regional cortical thickness and cortical volume differences across the brain between hyperthyroid patients and control subjects. METHODS: We examined localized cortical thicknesses and volumes in 34 hyperthyroid patients and 35 control subjects with high-resolution T1-weighted images using FreeSurfer software and assessed group differences with analysis of covariance (covariates: age, sex, education, and total intracranial volume). Spearman and partial correlations were performed between clinical variables and cortical thicknesses/volumes and between neuropsychological scores and cortical thicknesses/volumes, respectively. RESULTS: Hyperthyroid patients exhibited significantly increased cortical thickness in bilateral superior temporal and superior frontal gyri, along with higher cortical volumes in various regions, including the right superior temporal gyrus, right superior parietal gyrus, right rostral and caudal middle frontal gyrus, and left superior frontal gyrus. Notably, thyroid hormones (fT3, fT4) correlated positively with cortical thicknesses and volumes in the superior temporal gyrus and superior frontal gyrus. Additionally, recognition memory scores negatively correlated with the right superior temporal gyrus and right superior frontal gyrus cortical thickness. CONCLUSION: The observed cortical thickening and increased cortical volume in specific brain areas provide new insights into the pathophysiological mechanism associated with brain impairment in hyperthyroidism.

Importance of familial predisposition to heart failure to the risk of anthracycline-related cardiotoxicity: A nationwide study.

BACKGROUND: Anthracycline-based chemotherapy has improved the prognosis of various malignancies, but increases the long-term risk of heart failure (HF). Identification of patients at risk prior to treatment initiation is warranted. Therefore, the aim of this study was to evaluate if a familial predisposition to HF increases the risk of anthracycline related HF. METHODS: Using nationwide Danish registries, all patients treated with anthracycline from 2004 to 16 were identified. The primary outcome was long-term HF risk. First-degree relatives were identified in the Danish Family Registry and exposure was defined as a first-degree biological relative with prior HF. Risk of HF was evaluated in a cumulative incidence function and the association in a multivariable Cox regression model. RESULTS: A total of 11,651 patients (median age 49.1 years (IQR: 43.6-53.7), 12.2% male) were included after exclusion of 46 with preanthracycline HF. Median follow-up was 3.8 years (IQR 1.9-6.4). In the group with a first-degree relative with HF (n = 1,608) 35 patients (2.2%) were diagnosed with HF vs 133 (1.3%) in the group without a first-degree relative with HF (n = 10,043), corresponding to incidence rates per 1,000 patient-years of 5.2 (CI:3.8-7.3) vs 3.0 (CI:2.5-3.5). The cumulative incidence of HF after 10 years was higher in the first-degree relative group (3.2% vs 2.0%, P = .004); adjusted hazard ratio 1.53 (CI:1.05-2.23, P = .03). CONCLUSION: In this nationwide register-based study having a first-degree relative with HF was associated with increased risk of anthracycline related HF, suggesting that attention towards family predisposition may be warranted when estimating the risk of anthracycline related cardiotoxicity.

Prognosis of acute coronary syndrome stratified by cancer type and status - a nationwide cohort study.

BACKGROUND: To investigated the prognosis of the most prevalent cancers (breast-, gastrointestinal-, and lung cancer), according to cancer status (i.e., active-, non-active-, history of-, and no cancer), following first-time of acute coronary syndrome (ACS). METHODS: Danish nationwide registers were used to identify patients with first-time ACS from 2000-2018. Patients were stratified according to cancer type and status. Hazard ratios (HR) estimated by adjusted Cox regression models for 1year all-cause mortality reported. Further absolute risks of 1year cardiovascular versus non-cardiovascular death and 30-day cumulative incidence of coronary angiograms (CAG) was estimated, using the Aalen-Johansen non-parametric method, with competing risk of death. RESULTS: We identified 150,478 (95.7%) with no cancer, 2,370 (1.5%) with history of cancer, 2,712 (1.7%) with non-active cancer and 1,704 (1.1%) with active cancer. Cancer patients were older with more comorbidities than patients with no cancer. When compared with no cancer, we found HRs (95% confidence intervals) of 1.71 (1.44-2.02), 2.47 (2.23-2.73) and 4.22 (3.87-4.60) correspondingly for active breast-, gastrointestinal-, and lung cancer. Increased HRs were also found for non-active cancers, but not for history of cancer. Cardiovascular disease was the leading cause of death in all patients. Among patients with active breast-, gastrointestinal-, and lung cancer 43%, 43%, and 31% underwent CAG, correspondingly, compared with 77% of patients without cancer. CONCLUSIONS: Active- and non-active cancers were associated with an increased 1-year all-cause mortality compared with patients with history of cancer and no cancer. Cardiovascular disease was the leading cause of death; notably CAG was less frequently performed in cancer patients.

Acute metabolic alterations in the hippocampus are associated with decreased acetylation after blast induced TBI.

INTRODUCTION: Blast induced Traumatic brain injury (BI-TBI) is common among military personnels as well as war affected civilians. In the war zone, people can also encounter repeated exposure of blast wave, which may affect their cognition and metabolic alterations. OBJECTIVE: In this study we assess the metabolic and histological changes in the hippocampus of rats at 24 h post injury. METHOD: Rats were divided into four groups: (i) Sham; (ii) Mild TBI (mi); (iii) Moderate TBI (mo); and (iv) Repetitive mild TBI (rm TBI) and then subjected to different intensities of blast exposure. Hippocampal tissues were collected after 24 h of injury for proton nuclear magnetic resonance spectroscopy (1H NMR spectroscopy) and immunohistochemical (IHC) analysis. RESULTS: The metabolic alterations were found in the hippocampal tissue samples and these alterations showed significant change in glutamate, N-Acetylaspartic acid (NAA), acetate, creatine, phosphoethanolamine (PE), ethanolamine and PC/choline concentrations in rmTBI rats only. IHC studies revealed that AH3 (Acetyl histone) positive cells were decreased in rm TBI tissue samples in comparison to other TBI groups and sham rats. This might reflect an epigenetic alteration due to repeated blast exposure at 24 h post injury. Additionally, astrogliosis was observed in miTBI and moTBI hippocampal tissue while no change was observed in rmTBI tissues. CONCLUSION: The present study reports altered acetylation in the presence of altered metabolism in hippocampal tissue of blast induced rmTBI at 24 h post injury. Mechanistic understanding of these intertwined processes may help in the development of better therapeutic pathways and agents for blast induced TBI in near future.

Treated periodontitis and recurrent events after first-time myocardial infarction: A Danish nationwide cohort study.

AIM: To investigate the association between previous periodontal treatment and recurrent events after first-time myocardial infarction (MI). MATERIALS AND METHODS: From the Danish nationwide registries, patients with first-time MI between 2000 and 2015 were divided into three groups according to oral health care within 1 year prior to first-time MI. A multiple logistic regression model provided adjusted odds ratios (ORs) with 95% confidence intervals (CIs) to assess the 3-year risk of major adverse cardiovascular events (MACE). RESULTS: A total of 103,949 patients were included. Patients with treated periodontitis (PD) prior to first-time MI had an adjusted 3-year risk of MACE similar to patients presumed periodontally healthy (OR 0.97 [95% CI 0.92-1.03]). Patients with no prior dental visits were significantly older, had more comorbidities and showed significantly increased adjusted 3-year risks of MACE (OR 1.47 [95% CI 1.42-1.52]), cardiovascular death (OR 1.71 [95% CI 1.64-1.78]) and heart failure (OR 1.13 [95% CI 1.07-1.20]) compared with patients presumed periodontally healthy. CONCLUSIONS: Patients with treated PD 1 year prior to first-time MI had a similar risk of recurrent cardiovascular events as patients presumed periodontally healthy. No dental visit prior to first-time MI was an independent risk factor for recurrent events.

The risk of cardiac events in patients receiving immune checkpoint inhibitors: a nationwide Danish study.

AIMS: The study aimed to estimate the risk of cardiac events in immune checkpoint inhibitor (ICI)-treated patients with lung cancer or malignant melanoma. METHODS AND RESULTS: The study included consecutive patients with lung cancer or malignant melanoma in 2011-17 nationwide in Denmark. The main composite outcome was cardiac events (arrhythmia, peri- or myocarditis, heart failure) or cardiovascular death. Absolute risks were estimated and the association of ICI and cardiac events was analysed in multivariable Cox models. We included 25 573 patients with lung cancer. Of these, 743 were treated with programmed cell death-1 inhibitor (PD1i) and their 1-year absolute risk of cardiac events was 9.7% [95% confidence interval (CI) 6.8-12.5]. Of the 13 568 patients with malignant melanoma, 145 had PD1i and 212 had cytotoxic T-lymphocyte-associated protein-4 inhibitor (CTLA-4i) treatment. Their 1-year risks were 6.6% (1.8-11.3) and 7.5% (3.7-11.3). The hazard rates of cardiac events were higher in patients with vs. without ICI treatment. Within 6 months from 1st ICI administration, the hazard ratios were 2.14 (95% CI 1.50-3.05) in patients with lung cancer and 4.30 (1.38-13.42) and 4.93 (2.45-9.94) in patients with malignant melanoma with PD1i and CTLA-4i, respectively. After 6 months, HRs were 2.26 (1.27-4.02) for patients with lung cancer and 3.48 (1.91-6.35) for patients with malignant melanoma and CTLA-4i. CONCLUSIONS: Among patients with lung cancer and malignant melanoma, ICI treated had increased rates of cardiac events. The absolute risks were higher in these data compared with previous pharmacovigilance studies (e.g. 1.8% peri-/myocarditis 1-year risk).

Oxidative stress contributes to cerebral metabolomic profile changes in animal model of blast-induced traumatic brain injury.

INTRODUCTION: Blast-induced neurotrauma (BINT) has been recognized as the common mode of traumatic brain injury amongst military and civilian personnel due to an increased insurgent activity domestically and abroad. Previous studies from this laboratory have identified three major pathological events following BINT which include blood brain barrier disruption the earliest event, followed by oxidative stress and neuroinflammation as secondary events occurring a few hours following blast. OBJECTIVES: Our recent studies have also identified an increase in oxidative stress mediated by the activation of superoxide producing enzyme NADPH oxidase (NOX) in different brain regions at varying levels with neurons displaying higher oxidative stress (NOX activation) compared to any other neural cell. Since neurons have higher energy demands in brain and are more prone to oxidative damage, this study evaluated the effect of oxidative stress on blast-blast induced changes in metabolomics profiles in different brain regions. METHODS: Animals were exposed to mild/moderate blast injury (180 kPa) and examined the metabolites of energy metabolism, amino acid metabolism as well as the profiles of plasma membrane metabolites in different brain regions at different time points (24 h, 3 day and 7 day) after blast using 1H NMR spectroscopy. Effect of apocynin, an inhibitor of superoxide producing enzyme NADPH oxidase on cerebral metabalomics profiles was also examined. RESULTS: Several metabolomic profile changes were observed in frontal cortex and hippocampus with concomitant decrease in energy metabolism. In addition, glutamate/glutamine and other amino acid metabolism as well as metabolites involved in plasma membrane integrity were also altered. Hippocampus appears metabolically more vulnerable than the frontal cortex. A post-treatment of animals with apocynin, an inhibitor of NOX activation significantly prevented the changes in metabolite profiles. CONCLUSION: Together these studies indicate that blast injury reduces both cerebral energy and neurotransmitter amino acid metabolism and that oxidative stress contributes to these processes. Thus, strategies aimed at reducing oxidative stress can have a therapeutic benefit in mitigating metabolic changes following BINT.

Atrial fibrillation and anticoagulation in patients with breast cancer.

Objectives. To examine the long-term risk of thromboembolism and bleeding in patients with atrial fibrillation comparing patients with and without recent breast cancer in subgroups with or without anticoagulation therapy, respectively. Design. Using nationwide registries, patients with breast cancer from 1998-2015 and subsequent atrial fibrillation within 3 years were stratified on anticoagulation and matched 1:3 on age, sex and comorbidities with atrial fibrillation patients without breast cancer. Risks of thromboembolism and bleeding were estimated by Aalen-Johansen and multivariable cox regression models. Results. Atrial fibrillation patients with and without anticoagulation were matched, respectively (201 and 525 with breast cancer matched with 603 and 1,575 without breast cancer). In patients with CHA2DS2-VASc-score >1 and anticoagulation the three years risks of thromboembolism were 4.2% (95% confidence interval (CI) 1.1-7.3) and 3.2% (CI 1.5-4.9) in patients with and without breast cancer. The risks of bleeding were 5.3% (CI 1.7-8.9) and 5.1% (CI 3.0-7.1), respectively. Breast cancer was associated with a similar risk of thromboembolism in patients with and without anticoagulation, respectively (Hazard ratio (HR) 1.10, CI 0.63-1.92 and HR 1.11, CI 0.82-1.50) and a similar risk of bleeding in patients with and without anticoagulation, respectively (HR 1.01, CI 0.56-1.84 and HR 0.85, CI 0.57-1.27) compared with the matched controls. Conclusions. Breast cancer was not associated with altered risk of thromboembolism or bleeding in patients with atrial fibrillation irrespective of treatment with anticoagulation. Our analyses suggest that atrial fibrillation diagnosed in patients with breast cancer should be considered as primary atrial fibrillation.

Susceptibility of wild and colonized Anopheles stephensi to Plasmodium vivax infection.

BACKGROUND: As much as 80% of global Plasmodium vivax infections occur in South Asia and there is a shortage of direct studies on infectivity of P. vivax in Anopheles stephensi, the most common urban mosquito carrying human malaria. In this quest, the possible effects of laboratory colonization of mosquitoes on infectivity and development of P. vivax is of interest given that colonized mosquitoes can be genetically less divergent than the field population from which they originated. METHODS: Patient-derived P. vivax infected blood was fed to age-matched wild and colonized An. stephensi. Such a comparison requires coordinated availability of same-age wild and colonized mosquito populations. Here, P. vivax infection are studied in colonized An. stephensi in their 66th-86th generation and fresh field-caught An. stephensi. Wild mosquitoes were caught as larvae and pupae and allowed to develop into adult mosquitoes in the insectary. Parasite development to oocyst and sporozoite stages were assessed on days 7/8 and 12/13, respectively. RESULTS: While there were batch to batch variations in infectivity of individual patient-derived P. vivax samples, both wild and colonized An. stephensi were roughly equally susceptible to oocyst stage Plasmodium infection. At the level of sporozoite development, significantly more mosquitoes with sporozoite load of 4+ were seen in wild than in colonized populations.

Altered metabolites of the rat hippocampus after mild and moderate traumatic brain injury - a combined in vivo and in vitro 1 H-MRS study.

Traumatic brain injury (TBI) has been shown to affect hippocampus-associated learning, memory and higher cognitive functions, which may be a consequence of metabolic alterations. Hippocampus-associated disorders may vary depending on the severity of injury [mild TBI (miTBI) and moderate TBI (moTBI)] and time since injury. The underlying hippocampal metabolic irregularities may provide an insight into the pathological process following TBI. In this study, in vivo and in vitro proton magnetic resonance spectroscopy (1 H-MRS) data were acquired from the hippocampus region of controls and TBI groups (miTBI and moTBI) at D0 (pre-injury), 4 h, Day 1 and Day 5 post-injury (PI). In vitro MRS results indicated trauma-induced changes in both miTBI and moTBI; however, in vivo MRS showed metabolic alterations in moTBI only. miTBI and moTBI showed elevated levels of osmolytes indicating injury-induced edema. Altered levels of citric acid cycle intermediates, glutamine/glutamate and amino acid metabolism indicated injury-induced aberrant bioenergetics, excitotoxicity and oxidative stress. An overall similar pattern of pathological process was observed in both miTBI and moTBI, with the distinction of depleted N-acetylaspartate levels (indicating neuronal loss) at 4 h and Day 1 and enhanced lactate production (indicating heightened energy depletion leading to the commencement of the anaerobic pathway) at Day 5 in moTBI. To the best of our knowledge, this is the first study to investigate the hippocampus metabolic profile in miTBI and moTBI simultaneously using in vivo and in vitro MRS.

Dynamics of Plasmodium vivax sporogony in wild Anopheles stephensi in a malaria-endemic region of Western India.

BACKGROUND: In global efforts to track mosquito infectivity and parasite elimination, controlled mosquito-feeding experiments can help in understanding the dynamics of parasite development in vectors. Anopheles stephensi is often accepted as the major urban malaria vector that transmits Plasmodium in Goa and elsewhere in South Asia. However, much needs to be learned about the interactions of Plasmodium vivax with An. stephensi. As a component of the US NIH International Center of Excellence for Malaria Research (ICEMR) for Malaria Evolution in South Asia (MESA), a series of membrane-feeding experiments with wild An. stephensi and P. vivax were carried out to better understand this vector-parasite interaction. METHODS: Wild An. stephensi larvae and pupae were collected from curing water in construction sites in the city of Ponda, Goa, India. The larvae and pupae were reared at the MESA ICEMR insectary within the National Institute of Malaria Research (NIMR) field unit in Goa until they emerged into adult mosquitoes. Blood for membrane-feeding experiments was obtained from malaria patients at the local Goa Medical College and Hospital who volunteered for the study. Parasites were counted by Miller reticule technique and correlation between gametocytaemia/parasitaemia and successful mosquito infection was studied. RESULTS: A weak but significant correlation was found between patient blood gametocytaemia/parasitaemia and mosquito oocyst load. No correlation was observed between gametocytaemia/parasitaemia and oocyst infection rates, and between gametocyte sex ratio and oocyst load. When it came to development of the parasite in the mosquito, a strong positive correlation was observed between oocyst midgut levels and sporozoite infection rates, and between oocyst levels and salivary gland sporozoite loads. Kinetic studies showed that sporozoites appeared in the salivary gland as early as day 7, post-infection. CONCLUSIONS: This is the first study in India to carry out membrane-feeding experiments with wild An. stephensi and P. vivax. A wide range of mosquito infection loads and infection rates were observed, pointing to a strong interplay between parasite, vector and human factors. Most of the present observations are in agreement with feeding experiments conducted with P. vivax elsewhere in the world.

Potential for differentiation of glioma recurrence from radionecrosis using integrated 18F-fluoroethyl-L-tyrosine (FET) positron emission tomography/magnetic resonance imaging: A prospective evaluation.

PURPOSE: To assess the utility of 18F-fluoroethyl-L-tyrosine (FET) positron emission tomography/magnetic resonance imaging (PET/MRI) in distinguishing recurrence from radionecrosis. MATERIALS AND METHODS: Thirty-two patients (25 males, 7 females) of glioma who had already undergone surgery/chemoradiotherapy and had enhancing brain lesions suspicious of recurrence were evaluated using integrated 18F-FET PET/MRI, and followed up with histopathology or clinical follow-up and/or MRI/PET/MRI imaging. Manually drawn regions of interest over areas of maximal enhancement or FET uptake were used to calculate tumor to background ratios [TBRmax, TBRmean], choline: creatine ratio [Cho: Cr ratio], normalized relative cerebral blood volume [N rCBVmean] and apparent diffusion coefficient [ADCmean]. Correlations were evaluated using Pearson's coefficient. Accuracy of each parameter was calculated using independent t-test and receiver operator curve (ROC) analysis while utility of all four parameters together using multivariate analysis of variance (MANOVA) for differentiating recurrence vs. radionecrosis was evaluated. Positive histopathology and imaging/clinical follow up served as the gold standard. RESULTS: Twenty-four of the 32 patients were diagnosed with recurrent disease and 8 with radiation necrosis. Significant correlations were observed between TBRmaxand N rCBVmean (ρ =0.503; P = 0.003), TBRmean, and N rCBVmean (ρ =0.414; P = 0.018), TBRmaxand ADCmean (ρ = -0.52; P = 0.002), and TBRmeanand ADCmean(ρ = -0.518; P = 0.002). TBRmax, TBRmean, ADCmean, Cho: Cr ratios, and N rCBVmeanwere significant in differentiating recurrence from radiation necrosis with an accuracy of 94.1%, 88.2%, 80.4%, 96.4%, and 89.9%, respectively. MANOVA indicated that combination of all parameters demonstrated better evaluation of recurrence vs. necrosis than any single parameter. The diagnostic accuracy, sensitivity, and specificity using all MRI parameters were 93.75%, 96%, and 85.7%, and using all FET PET/MRI parameters was 96.87%, 100%, and 85.7%, respectively. CONCLUSIONS: Synergetic effect of multiple MR parameters evaluated together in addition to FET PET uptake highlights the fact that integrated 18F-FET PET/MRI might have the potential to impact management of patients with glioma by timely and conclusive recognition of true recurrence from radiation necrosis.

Genochondromatosis type I: A clinicoradiological study of four family members.

Genochondromatosis is an extremely rare autosomal dominant disorder, which manifests during childhood and tends to regress in adult life. The bony lesions are symmetrically distributed with characteristic localization at the metaphysis of proximal humerus and distal femur. Two types have been described based on the involvement of clavicle. Usually asymptomatic, sometimes patients may present with pathological fractures. In this communication, we describe four members of a family with Genochondromatosis type I, with some additional clinical and radiological findings not reported previously.

Estimation of radiation dose to patients from (18) FDG whole body PET/CT investigations using dynamic PET scan protocol.

BACKGROUND & OBJECTIVES: There is a growing concern over the radiation exposure of patients from undergoing 18FDG PET/CT (18F-fluorodeoxyglucose positron emission tomography/computed tomography) whole body investigations. The aim of the present study was to study the kinetics of 18FDG distributions and estimate the radiation dose received by patients undergoing 18FDG whole body PET/CT investigations. METHODS: Dynamic PET scans in different regions of the body were performed in 49 patients so as to measure percentage uptake of 18FDG in brain, liver, spleen, adrenals, kidneys and stomach. The residence time in these organs was calculated and radiation dose was estimated using OLINDA software. The radiation dose from the CT component was computed using the software CT-Expo and measured using computed tomography dose index (CTDI) phantom and ionization chamber. As per the clinical protocol, the patients were refrained from eating and drinking for a minimum period of 4 h prior to the study. RESULTS: The estimated residence time in males was 0.196 h (brain), 0.09 h (liver), 0.007 h (spleen), 0.0006 h (adrenals), 0.013 h (kidneys) and 0.005 h (stomach) whereas it was 0.189 h (brain), 0.11 h (liver), 0.01 h (spleen), 0.0007 h (adrenals), 0.02 h (kidneys) and 0.004 h (stomach) in females. The effective dose was found to be 0.020 mSv/MBq in males and 0.025 mSv/MBq in females from internally administered 18FDG and 6.8 mSv in males and 7.9 mSv in females from the CT component. For an administered activity of 370 MBq of 18FDG, the effective dose from PET/CT investigations was estimated to be 14.2 mSv in males and 17.2 mSv in females. INTERPRETATION & CONCLUSIONS: The present results did not demonstrate significant difference in the kinetics of 18FDG distribution in male and female patients. The estimated PET/CT doses were found to be higher than many other conventional diagnostic radiology examinations suggesting that all efforts should be made to clinically justify and carefully weigh the risk-benefit ratios prior to every 18FDG whole body PET/CT scan.

Impact of fasting glucose on electrocardiographic left ventricular hypertrophy in an elderly general population.

OBJECTIVE: To evaluate relationships between fasting plasma glucose (FPG), other cardiovascular risk markers and left ventricular hypertrophy (LVH) as detected by electrocardiography. METHODS: Subjects were selected randomly from groups defined by FPG. Traditional risk markers were assessed. LVH was defined by either Cornell voltage-duration product (CP) or Sokolow-Lyon voltage combination (SL), and univariate and multivariable regressions were performed in search of explanatory factors for the presence of LVH and the values of CP and SL. RESULTS: Of the 1759 subjects included, 1007 had a history of cardiovascular disease and/or medical treatment, while 752 subjects appeared to be healthy. We found an independent association between FPG and LVH (odds ratio 1.152, p = 0.042] as well as continuous CP (beta = 0.126, p = 0.007) in healthy men. As expected, we found an association between systolic blood pressure and LVH (odds ratio 1.020, p < 0.001) among healthy subjects, but only in subjects with FPG < 6 mmol/l (p = 0.04 for interaction). CONCLUSIONS: We found an independent association between FPG and LVH in healthy men, and no potentiating effect by FPG on the impact of hypertension.

What will long-term care be like in 2040?

Many innovative long-term care models can now be found in nursing homes, assisted living, and community home care settings. Key forces that will shape the future include the aging of the baby-boomer generation, personal choice, concerns about quality, new technologies, dementia research, payment issues, financial pressures, and workforce needs.

Altered DTI scalars in the hippocampus are associated with morphological and structural changes after traumatic brain injury.

Blunt and diffuse injury is a highly prevalent form of traumatic brain injury (TBI) which can result in microstructural alterations in the brain. The blunt impact on the brain can affect the immediate contact region but can also affect the vulnerable regions like hippocampus, leading to functional impairment and long-lasting cognitive deficits. The hippocampus of the moderate weight drop injured male rats was longitudinally assessed for microstructural changes using in vivo MR imaging from 4 h to Day 30 post-injury (PI). The DTI analysis found a prominent decline in the apparent diffusion coefficient (ADC), radial diffusivity (RD), and axial diffusivity (AD) values after injury. The perturbed DTI scalars accompanied histological changes in the hippocampus, wherein both the microglia and astrocytes showed changes in the morphometric parameters at all timepoints. Along with this, the hippocampus showed presence of Aß positive fibrils and neurite plaques after injury. Therefore, this study concludes that TBI can lead to a complex morphological, cellular, and structural alteration in the hippocampus which can be diagnosed using in vivo MR imaging techniques to prevent long-term functional deficits.

Differential diagnosis of parkinsonian syndromes using F-18 fluorodeoxyglucose positron emission tomography.

INTRODUCTION: Positron emission tomography (PET) imaging with F-18 fluorodeoxyglucose (FDG) has been used to identify characteristic patterns of regional glucose metabolism in patients with idiopathic Parkinson's disease (IPD) and the atypical parkinsonian syndromes of progressive supranuclear palsy (PSP), multiple system atrophy (MSA), and corticobasal syndrome (CBS). We undertook this study to assess the utility of fluorodeoxyglucose-PET in the differential diagnosis of individual patients with clinical parkinsonism. "Visual" and "computer-supported" reading of the fluorodeoxyglucose-PET scans were used for image interpretation and compared with each other. METHODS: One hundred thirty-six parkinsonian patients were referred from movement disorder clinics in specialty neurology centers for the fluorodeoxyglucose-PET study. Imaging-based diagnosis was obtained by visual assessment of individual scans by a PET physician blinded to the clinical diagnosis and also by computer-assisted interpretation using statistical parametric mapping (SPM) analysis. The results were compared with a 2-year follow-up clinical assessment made by a movement disorder specialist. RESULTS: Concordance of visual evaluation of fluorodeoxyglucose-PET with clinical diagnosis was achieved in 91.7% of patients scanned, 97.6% IPD, 80% MSA, 76.6% PSP, and 100% CBS. Blinded computer assessment using SPM was concordant with the clinical diagnosis in 91% of cases evaluated (90.4% IPD, 80% MSA, 93.3% PSP, and 100% CBS). CONCLUSIONS: Fluorodeoxyglucose-PET performed at the time of initial referral for parkinsonism is useful for the differential diagnosis of IPD, PSP, MSA, and CBS. Computer-assisted methods can be used for objective evaluation especially when expert readers are not available.

Camouflage Detection and Its Association with Cognitive Style: A Functional Connectivity Study.

Background: Individual differences exist in performance in tasks that require visual search, such as camouflage detection (CD). Field dependence/independence (FD/I), as assessed using the Group Embedded Figures Test (GEFT), is an extensively studied dimension of cognitive style that classifies participants based on their visual perceptual styles. Materials and Methods: In the present study, we utilized fMRI on 46 healthy participants to investigate the underlying neural mechanisms specific to the cognitive styles of FD/FI while performing a CD task using both activation magnitude and an exploratory functional connectivity (FC) analysis. Group differences between high and low performers on the two extremes of the accuracy continuum of GEFT were studied. Results: No statistically significant group differences were observed using whole-brain voxel-wise comparison. However, the exploratory FC analysis revealed an enhanced communication between various regions subserving the cognitive traits required for visual search by FI participants over and above their FD counterparts. Conclusion: These enhanced connectivities suggest additional recruitment of cognitive functions to provide computational support that might facilitate superior performance in CD task by the participants who display a field-independent cognitive style.