Disfunção pré-frontoparietal durante o processamento de informação visuoauditiva em pacientes idosos com esquizofrenia crônica e efeitos da medicação

OBJECTIVES: In first-episode schizophrenia patients, functional magnetic resonance imaging (fMRI) has shown prefronto-parietal dysfunction during acoustic and visual stimulation. The aim of this study was to investigate the prefronto-parietal network in elderly schizophrenia patients using the same paradigm. Additionally, we hypothesized favourable effects on brain activation by the atypical antipsychotic clozapine compared to typical neuroleptics. METHODS: We investigated 18 elderly, chronic schizophrenia patients and 21 elderly healthy controls. Nine schizophrenia patients had been medicated with clozapine and 9 had been receiving typical neuroleptics over decades. In addition to assessments with psychopathological and neuropsychological rating scales we used an acoustic and visual stimulation paradigm in a 1.5 Tesla MRI scanner to investigate BOLD-response in different brain areas. RESULTS: Compared to healthy controls schizophrenia patients showed decreased brain activation in the prefrontal and parietal cortex as well as medial anterior cingulate gyrus compared to healthy controls. In these regions, patients medicated with clozapine showed increased BOLD-response compared to patients treated with typical neuroleptics. DISCUSSION: Our study confirmed prefronto-parietal network disturbances in elderly schizophrenia patients thus pointing to the preservation of brain activation deficits and the influence of neurodevelopmental disturbances in chronic schizophrenia until old-age. CONCLUSION: The atypical antipsychotic clozapine seems to facilitate brain activation even in elderly, chronic schizophrenia patients.OBJETIVOS: Em pacientes com primeiro episódio de esquizofrenia, estudos com ressonância magnética funcional (RMf) têm demonstrado disfunção pré-frontoparietal durante estimulação acústica e visual. O objetivo do presente estudo foi investigar a rede pré-frontoparietal em pacientes idosos com esquizofrenia utilizando o mesmo paradigma. Adicionalmente, foram presumidos efeitos favoráveis na ativação cerebral pelo antipsicótico atípico clozapina em comparação a neurolépticos típicos. MÉTODOS: Foram investigados 18 pacientes com esquizofrenia crônica e 21 controles saudáveis idosos. Nove pacientes com esquizofrenia haviam sido medicados com clozapina e nove haviam recebido neurolépticos típicos por décadas. Concomitantemente às avaliações com escalas psicopatológicas e neuropsicológicas foi utilizado um paradigma de estimulação auditiva e visual em um aparelho de ressonância magnética de 1,5 Tesla para investigar a resposta BOLD em diferentes áreas cerebrais. RESULTADOS: Comparados a controles saudáveis, os pacientes com esquizofrenia apresentaram diminuição na ativação cerebral nos córtices pré-frontal e parietal, assim como no giro do cíngulo anterior medial. Nessas regiões, os pacientes medicados com clozapina apresentaram resposta BOLD aumentada em comparação aos pacientes tratados com neurolépticos típicos. DISCUSSÃO: O presente estudo confirmou a presença de distúrbios na rede pré-frontoparietal em pacientes idosos com esquizofrenia, apontando assim para a preservação de déficits de ativação cerebrais e a influência de distúrbios do desenvolvimento neural em esquizofrenia crônica até a velhice. CONCLUSÃO: O antipsicótico atípico clozapina parece facilitar a ativação de áreas cerebrais mesmo em pacientes idosos com esquizofrenia crônica

Modeling neurocognitive and neurobiological recovery in addiction

This book focuses on "what to know" and "how to apply" information, prioritizing novel principles and delineating cutting-edge assessment, phenotyping and treatment tools

DACC Resting State Functional Connectivity as a Predictor of Pain Symptoms Following Motor Vehicle Crash: A Preliminary Investigation

There is significant heterogeneity in pain outcomes following motor vehicle crashes (MVCs), such that a sizeable portion of individuals develop symptoms of chronic pain months after injury while others recover. Despite variable outcomes, the pathogenesis of chronic pain is currently unclear. Previous neuroimaging work implicates the dorsal anterior cingulate cortex (dACC) in adaptive control of pain, while prior resting state functional magnetic resonance imaging studies find increased functional connectivity (FC) between the dACC and regions involved in pain processing in those with chronic pain. Hyper-connectivity of the dACC to regions that mediate pain response may therefore relate to pain severity. The present study completed rsfMRI scans on N=22 survivors of MVCs collected within two weeks of the incident to test whole-brain dACC-FC as a predictor of pain severity six months later. At two weeks, pain symptoms were predicted by positive connectivity between the dACC and the premotor cortex. Controlling for pain symptoms at two weeks, pain symptoms at six months were predicted by negative connectivity between the dACC and the precuneus. Previous research implicates the precuneus in the individual subjective awareness of pain. Given a relatively small sample size, approximately half of which did not experience chronic pain at six months, findings warrant replication. Nevertheless, this study provides preliminary evidence of enhanced dACC connectivity with motor regions and decreased connectivity with pain processing regions as immediate and prospective predictors of pain following MVC. Perspective: This article presents evidence of distinct neural vulnerabilities that predict chronic pain in motor vehicle crash survivors based on whole-brain connectivity with the dorsal anterior cingulate cortex

Serial longitudinal magnetic resonance imaging data indicate non-linear regional gray matter volume recovery in abstinent alcohol-dependent individuals

The trajectory of regional volume changes during the first year of sustained abstinence in those recovering from an alcohol use disorder is unclear because previous research typically employed only two assessment points. To better understand the trajectory of regional brain volume recovery in treatment-seeking alcohol-dependent individuals (ALC), regional brain volumes were measured after 1 week, 1 month and 7.5 months of sustained abstinence via magnetic resonance imaging at 1.5-T. ALC showed significant volume increases in frontal, parietal and occipital gray matter (GM) and white matter (WM), total cortical GM and total lobar WM, thalamus and cerebellum, and decreased ventricular volume over 7.5 months of abstinence. Volume increases in regional GM were significantly greater over 1 week to 1 month than from 1 month to 7.5 months of abstinence, indicating a non-linear rate of change in regional GM over 7.5 months. Overall, regional lobar WM showed linear volume increases over 7.5 months. With increasing age, smoking ALC showed lower frontal and total cortical GM volume recovery than non-smoking ALC. Despite significant volume increases, ALC showed smaller GM volumes in all regions, except the frontal cortex, than controls after 7.5 months of abstinence. ALC and controls showed no regional WM volume differences at any assessment point. In non-smoking ALC only, increasing regional GM and WM volumes were related to improving processing speed. Findings may indicate a differential rate of recovery of cell types/cellular components contributing to GM and WM volume during early abstinence, and that GM volume deficits persist after 7.5 months of sustained sobriety in this ALC cohort. Regional brain volume recovery in abstinent alcohol dependent individuals (ALC) was measured via magnetic resonance imaging. ALC showed significant volume increases in frontal, parietal, and occipital gray matter (GM), and total cortical GM over 7.5-months of abstinence; these volume changes were greater over 1-week to 1-month than from 1-month to 7.5-months of abstinence; only frontal GM recovered to the level of controls. Smoking ALC showed less recovery in frontal and total cortical GM volume with increasing age than non-smoking ALC

Istraživanje povezanosti stambenog zelenila s neurokognitivnom funkcijom u sredovječnih Bugara

Recent research has indicated that exposure to residential vegetation (“greenness”) may be protective against cognitive decline and may support the integrity of the corresponding brain structures. However, not much is known about these effects, especially in less affluent countries and in middle-aged populations. In this study, we investigated the associations between greenness and neurocognitive function. We used a convenience sample of 112 middle-aged Bulgarians and two cognitive tests: the Consortium to Establish a Registry for Alzheimer’s Disease Neuropsychological Battery (CERADNB) and the Montreal Cognitive Assessment (MoCA). In addition, structural brain imaging data were available for 25 participants. Participants’ home address was used to link cognition scores to the normalised difference vegetation index (NDVI), a measure of overall neighbourhood vegetation level (radii from 100 to 1,000 m). Results indicated that higher NDVI was consistently associated with higher CERAD-NB and MoCA scores across radial buffers and adjustment scenarios. Lower waist circumference mediated the effect of NDVI on CERAD-NB. NDVI100-m was positively associated with average cortical thickness across both hemispheres, but these correlations turned marginally significant (P<0.1) after correction for false discovery rate due to multiple comparisons. In conclusion, living in a greener neighbourhood might be associated with better cognitive function in middle-aged Bulgarians, with lower central adiposity partially accounting for this effect. Tentative evidence suggests that greenness might also contribute to structural integrity in the brain regions regulating cognitive functions. Future research should build upon our findings and investigate larger and more representative population groups.Najnovija istraživanja upućuju na to da izloženost vegetaciji u mjestu stanovanja (“zelenilu”) može usporiti pad kognitivne funkcije te očuvati cjelovitost s njom povezanih moždanih struktura. Međutim, malo se zna o takvom djelovanju zelenila, osobito u siromašnijim zemljama i populacijama srednje životne dobi. Stoga je u ovom istraživanju analizirana povezanost između zelenila i neurokognitivne funkcije na prigodnom uzorku od 122 sredovječna bugarska stanovnika koji su bili podvrgnuti dvama kognitivnim testovima: jednom za utvrđivanje znakova Alzheimerove bolesti (Consortium to Establish a Registry for Alzheimer’s Disease Neuropsychological Battery, krat. CERAD-NB) te drugom za ocjenu kognitivne funkcije (Montreal Cognitive Assessment, krat. MoCA). Osim toga, dostupni su nam bili podaci dobiveni magnetnom rezonancijom moždanih struktura 25 sudionika. Njihove kućne adrese povezane su normaliziranim indeksom razlike u vegetaciji (engl. Normalised Difference Vegetation Index, krat. NDVI) kojim se mjeri razina zelenila u četvrti (u polumjeru od 100 do 1000 m). Rezultati pokazuju da je viši NDVI bez iznimke povezan s višim ocjenama testova CERAD-NB i MoCA kroz sve polumjere i statističke modele prilagođene po različitim kovarijatima. Na tu povezanost zelenila i testova posredno je utjecao opseg struka. NDVI u polumjeru od 100 metara od adrese stanovanja bio je povezan sa srednjom debljinom korteksa u objema moždanim polutkama, ali se ta povezanost pokazala marginalno značajnom (P<0,1) nakon korekcije zbog ocjene lažnoga otkrivanja uslijed višestrukih statističkih usporedbi. Zaključak je da život u zelenijoj četvrti može biti povezan s boljom kognitivnom funkcijom u sredovječnih Bugara te da na nju utječe i manji opseg struka. Naši rezultati također donekle upućuju na to da zelenilo pridonosi strukturnoj cjelovitosti moždanih područja koja upravljaju kognitivnim funkcijama. Buduća bi istraživanja trebala proširiti te rezultate obuhvativši veće i reprezentativnije populacijske skupine

Testing associations between cannabis use and subcortical volumes in two large population-based samples

Background and aims Disentangling the putative impact of cannabis on brain morphology from other comorbid substance use is critical. After controlling for the effects of nicotine, alcohol and multi‐substance use, this study aimed to determine whether frequent cannabis use is associated with significantly smaller subcortical grey matter volumes. Design Exploratory analyses using mixed linear models, one per region of interest (ROI), were performed whereby individual differences in volume (outcome) at seven subcortical ROIs were regressed onto cannabis and comorbid substance use (predictors). Setting Two large population‐based twin samples from the United States and Australia. Participants A total of 622 young Australian adults [66% female; μage = 25.9, standard deviation SD) = 3.6] and 474 middle‐aged US males (μage = 56.1SD = 2.6) of predominately Anglo‐Saxon ancestry with complete substance use and imaging data. Subjects with a history of stroke or traumatic brain injury were excluded. Measurements Magnetic resonance imaging (MRI) and volumetric segmentation methods were used to estimate volume in seven subcortical ROIs: thalamus, caudate nucleus, putamen, pallidum, hippocampus, amygdala and nucleus accumbens. Substance use measurements included maximum nicotine and alcohol use, total life‐time multi‐substance use, maximum cannabis use in the young adults and regular cannabis use in the middle‐aged males. Findings After correcting for multiple testing (P = 0.007), cannabis use was unrelated to any subcortical ROI. However, maximum nicotine use was associated with significantly smaller thalamus volumes in middle‐aged males. Conclusions In exploratory analyses based on young adult and middle‐aged samples, normal variation in cannabis use is unrelated statistically to individual differences in brain morphology as measured by subcortical volume