White and Gray Matter Changes are Associated With Neurocognitive Decline in HIV Infection.

OBJECTIVE: To investigate the relationship between neurocognitive deficits and structural changes on brain magnetic resonance imaging in people living with HIV (PLWH) with good virological control on combination antiretroviral therapy, compared with socioeconomically matched control participants recruited from the same communities. METHODS: Brain magnetic resonance imaging scans, and clinical and neuropsychological data were obtained from virologically controlled PLWH (viral load of <50 c/mL and at least 1 year of combination antiretroviral therapy) and socioeconomically matched control participants. Magnetic resonance imaging was carried out on 3 T scanner with 8-channel head coils and segmented using Classification using Derivative-based Features. Multiple regression analysis was performed to examine the association between brain volume and various clinical and neuropsychiatric parameters adjusting for age, race, and sex. To evaluate longitudinal changes in brain volumes, a random coefficient model was used to evaluate the changes over time (age) adjusting for sex and race. RESULTS: The cross-sectional study included 164 PLWH and 51 controls, and the longitudinal study included 68 PLWH and 20 controls with 2 or more visits (mean 2.2 years, range 0.8-5.1 years). Gray matter (GM) atrophy rate was significantly higher in PLWH compared with control participants, and importantly, the GM and global atrophy was associated with the various neuropsychological domain scores. Higher volume of white matter hyperintensities were associated with increased atherosclerotic cardiovascular disease risk score, and decreased executive functioning and memory domain scores in PLWH. INTERPRETATION: These findings suggest ongoing neurological damage even in virologically controlled participants, with significant implications for clinical management of PLWH. ANN NEUROL 2024;95:941-950.

On presentation of the human cerebral sulci from inside of the cerebrum.

The human cerebral cortex is highly convoluted forming patterns of gyri separated by sulci. The cerebral sulci and gyri are fundamental in cortical anatomy as well as neuroimage processing and analysis. Narrow and deep cerebral sulci are not fully discernible either on the cortical or white matter surface. To cope with this limitation, I propose a new sulci presentation method that employs the inner cortical surface for sulci examination from the inside of the cerebrum. The method has four steps, construct the cortical surface, segment and label the sulci, dissect (open) the cortical surface, and explore the fully exposed sulci from the inside. The inside sulcal maps are created for the left and right lateral, left and right medial, and basal hemispheric surfaces with the sulci parcellated by color and labeled. These three-dimensional sulcal maps presented here are probably the first of this kind created. The proposed method demonstrates the full course and depths of sulci, including narrow, deep, and/or convoluted sulci, which has an educational value and facilitates their quantification. In particular, it provides a straightforward identification of sulcal pits which are valuable markers in studying neurologic disorders. It enhances the visibility of sulci variations by exposing branches, segments, and inter-sulcal continuity. The inside view also clearly demonstrates the sulcal wall skewness along with its variability and enables its assessment. Lastly, this method exposes the sulcal 3-hinges introduced here.

Altered Effective Connectivity Among the Cerebellum and Cerebrum in Patients with Major Depressive Disorder Using Multisite Resting-State fMRI.

Major depressive disorder (MDD) is a serious and widespread psychiatric disorder. Previous studies mainly focused on cerebrum functional connectivity, and the sample size was relatively small. However, functional connectivity is undirected. And, there is increasing evidence that the cerebellum is also involved in emotion and cognitive processing and makes outstanding contributions to the symptomology and pathology of depression. Therefore, we used a large sample size of resting-state functional magnetic resonance imaging (rs-fMRI) data to investigate the altered effective connectivity (EC) among the cerebellum and other cerebral cortex in patients with MDD. Here, from the perspective of data-driven analysis, we used two different atlases to divide the whole brain into different regions and analyzed the alterations of EC and EC networks in the MDD group compared with healthy controls group (HCs). The results showed that compared with HCs, there were significantly altered EC in the cerebellum-neocortex and cerebellum-basal ganglia circuits in MDD patients, which implied that the cerebellum may be a potential biomarker of depressive disorders. And, the alterations of EC brain networks in MDD patients may provide new insights into the pathophysiological mechanisms of depression.

Functional mapping and cooperation between the cerebellum and cerebrum during word reading.

Multiple areas in the cerebellum have been reported to be engaged in reading. However, how these regions cooperate with the reading-related areas in the cerebrum remains unclear. Here, brain images of fifty-two adults were acquired via functional magnetic resonance imaging. By comparing the cerebellar activation across three localization tasks targeting orthographic, phonological, and semantic processing, we first identified three different reading-related areas in the cerebellum, biased toward orthography, phonology, and semantics, respectively. Then, functional connectivity (FC) analyses demonstrated that the mean FC between functionally corresponding areas across the cerebrum and cerebellum was greater than that between noncorresponding areas during silent word reading. FC patterns of functionally corresponding areas could significantly predict reading speed, with the FC driven from orthographic and semantic areas contributing the most. Effective FC analyses further showed that orthographic and semantic areas in the cerebellum had selective and direct connectivity to areas in the cerebrum with similar functional specificity. These results suggest that reading-related areas vary in their functions to reading, and cooperation between areas with corresponding functions was greater than that between noncorresponding areas. These findings emphasize the importance of functional cooperation between the cerebrum and cerebellum during reading from a new perspective.

Discrepancy between clinical presentation and cerebral imaging requires further diagnostic effort.

No abstract available.

Negative bias effects during audiovisual emotional processing in major depression disorder.

Aberrant affective neural processing and negative emotional bias are trait-marks of major depression disorders (MDDs). However, most research on biased emotional perception in depression has only focused on unimodal experimental stimuli, the neural basis of potentially biased emotional processing of multimodal inputs remains unclear. Here, we addressed this issue by implementing an audiovisual emotional task during functional MRI scanning sessions with 37 patients with MDD and 37 gender-, age- and education-matched healthy controls. Participants were asked to distinguish laughing and crying sounds while being exposed to faces with different emotional valences as background. We combined general linear model and psychophysiological interaction analyses to identify abnormal local functional activity and integrative processes during audiovisual emotional processing in MDD patients. At the local neural level, MDD patients showed increased bias activity in the ventromedial prefrontal cortex (vmPFC) while listening to negative auditory stimuli and concurrently processing visual facial expressions, along with decreased dorsolateral prefrontal cortex (dlPFC) activity in both the positive and negative visual facial conditions. At the network level, MDD exhibited significantly decreased connectivity in areas involved in automatic emotional processes and voluntary control systems during perception of negative stimuli, including the vmPFC, dlPFC, insula, as well as the subcortical regions of posterior cingulate cortex and striatum. These findings support a multimodal emotion dysregulation hypothesis for MDD by demonstrating that negative bias effects may be facilitated by the excessive ventral bottom-up negative emotional influences along with incapability in dorsal prefrontal top-down control system.

Coronary artery disease and its impact on the pulsatile brain: A functional NIRS study.

Recent studies have reported that optical indices of cerebral pulsatility are associated with cerebrovascular health in older adults. Such indices, including cerebral pulse amplitude and the pulse relaxation function (PRF), have been previously applied to quantify global and regional cerebral pulsatility. The aim of the present study was to determine whether these indices are modulated by cardiovascular status and whether they differ between individuals with low or high cardiovascular risk factors (LCVRF and HCVRF) and coronary artery disease (CAD). A total of 60 older adults aged 57-79 were enrolled in the study. Participants were grouped as LCVRF, HCVRF, and CAD. Participants were asked to walk freely on a gym track while a near-infrared spectroscopy (NIRS) device recorded hemodynamics data. Low-intensity, short-duration walking was used to test whether a brief cardiovascular challenge could increase the difference of pulsatility indices with respect to cardiovascular status. Results indicated that CAD individuals have higher global cerebral pulse amplitude compared with the other groups. Walking reduced global cerebral pulse amplitude and PRF in all groups but did not increase the difference across the groups. Instead, walking extended the spatial distribution of cerebral pulse amplitude to the anterior prefrontal cortex when CAD was compared to the CVRF groups. Further research is needed to determine whether cerebral pulse amplitude extracted from data acquired with NIRS, which is a noninvasive, inexpensive method, can provide an index to characterize the cerebrovascular status associated with CAD.

Test-retest reliability of approach-avoidance conflict decision-making during functional magnetic resonance imaging in healthy adults.

Neural and behavioral mechanisms during approach-avoidance conflict decision-making are relevant across various psychiatric disorders, particularly anxiety disorders. Studies using approach-avoidance conflict paradigms in healthy adults have identified preliminary neural mechanisms, but findings must be replicated and demonstrated as reliable before further application. This study sought to replicate previous findings and examine test-retest reliability of behavioral (approach behavior, reaction time) and neural (regions of interest [ROIs]) responses during an approach-avoidance conflict task conducted during functional magnetic resonance imaging (fMRI). Thirty healthy adults completed an approach-avoidance conflict task during fMRI on two occasions (mean interval: 17 days; range: 11-32). Effects of task condition during three task phases (decision-making, affective outcome and monetary reward) and intraclass correlation coefficients (ICCs) were calculated across time points. Results replicated that approach behavior was modulated by conflict during decision-making. ROI activations were replicated such that dorsal anterior cingulate cortex (dACC) was modulated by conflict during decision-making, and dACC, striatum, and anterior insula were modulated by valence during affective outcomes (p's <.0083). Approach behavior during conflict demonstrated excellent reliability (ICCs ≥.77). Activation of dACC during conflict decision-making and anterior insula during negative outcomes demonstrated fair reliability (ICCs = .51 and .54), and dACC and striatum activation demonstrated good reliability during negative outcomes (ICCs = .63 and .69). Two additional ROIs (amygdala, left dorsolateral prefrontal cortex) showed good reliability during negative outcomes (ICCs ≥.60). These results characterize several specific behavioral and neuroimaging responses that are replicable and sufficiently reliable during approach-avoidance conflict decision-making to support future utility.

Individual-based morphological brain network organization and its association with autistic symptoms in young children with autism spectrum disorder.

Individual-based morphological brain networks built from T1-weighted magnetic resonance imaging (MRI) reflect synchronous maturation intensities between anatomical regions at the individual level. Autism spectrum disorder (ASD) is a socio-cognitive and neurodevelopmental disorder with high neuroanatomical heterogeneity, but the specific patterns of morphological networks in ASD remain largely unexplored at the individual level. In this study, individual-based morphological networks were constructed by using high-resolution structural MRI data from 40 young children with ASD (age range: 2-8 years) and 38 age-, gender-, and handedness-matched typically developing children (TDC). Measurements were recorded as threefold. Results showed that compared with TDC, young children with ASD exhibited lower values of small-worldness (i.e., σ) of individual-level morphological brain networks, increased morphological connectivity in cortico-striatum-thalamic-cortical (CSTC) circuitry, and decreased morphological connectivity in the cortico-cortical network. In addition, morphological connectivity abnormalities can predict the severity of social communication deficits in young children with ASD, thus confirming an associational impact at the behavioral level. These findings suggest that the morphological brain network in the autistic developmental brain is inefficient in segregating and distributing information. The results also highlight the crucial role of abnormal morphological connectivity patterns in the socio-cognitive deficits of ASD and support the possible use of the aberrant developmental patterns of morphological brain networks in revealing new clinically-relevant biomarkers for ASD.

Evaluation of denoising strategies for task-based functional connectivity: Equalizing residual motion artifacts between rest and cognitively demanding tasks.

In-scanner head motion represents a major confounding factor in functional connectivity studies and it raises particular concerns when motion correlates with the effect of interest. One such instance regards research focused on functional connectivity modulations induced by sustained cognitively demanding tasks. Indeed, cognitive engagement is generally associated with substantially lower in-scanner movement compared with unconstrained, or minimally constrained, conditions. Consequently, the reliability of condition-dependent changes in functional connectivity relies on effective denoising strategies. In this study, we evaluated the ability of common denoising pipelines to minimize and balance residual motion-related artifacts between resting-state and task conditions. Denoising pipelines-including realignment/tissue-based regression, PCA/ICA-based methods (aCompCor and ICA-AROMA, respectively), global signal regression, and censoring of motion-contaminated volumes-were evaluated according to a set of benchmarks designed to assess either residual artifacts or network identifiability. We found a marked heterogeneity in pipeline performance, with many approaches showing a differential efficacy between rest and task conditions. The most effective approaches included aCompCor, optimized to increase the noise prediction power of the extracted confounding signals, and global signal regression, although both strategies performed poorly in mitigating the spurious distance-dependent association between motion and connectivity. Censoring was the only approach that substantially reduced distance-dependent artifacts, yet this came at the great cost of reduced network identifiability. The implications of these findings for best practice in denoising task-based functional connectivity data, and more generally for resting-state data, are discussed.

Genotype-associated cerebellar profiles in ALS: focal cerebellar pathology and cerebro-cerebellar connectivity alterations.

OBJECTIVE: Cerebellar disease burden and cerebro-cerebellar connectivity alterations are poorly characterised in amyotrophic lateral sclerosis (ALS) despite the likely contribution of cerebellar pathology to the clinical heterogeneity of the condition. METHODS: A prospective imaging study has been undertaken with 271 participants to systematically evaluate cerebellar grey and white matter alterations, cerebellar peduncle integrity and cerebro-cerebellar connectivity in ALS. Participants were stratified into four groups: (1) patients testing positive for GGGGCC repeat expansions in C9orf72, (2) patients carrying an intermediate-length repeat expansion in ATXN2, (3) patients without established ALS-associated mutations and (4) healthy controls. Additionally, the cerebellar profile of a single patient with ALS who had an ATXN2 allele length of 62 was evaluated. Cortical thickness, grey matter and white matter volumes were calculated in each cerebellar lobule complemented by morphometric analyses to characterise genotype-associated atrophy patterns. A Bayesian segmentation algorithm was used for superior cerebellar peduncle volumetry. White matter diffusivity parameters were appraised both within the cerebellum and in the cerebellar peduncles. Cerebro-cerebellar connectivity was assessed using deterministic tractography. RESULTS: Cerebellar pathology was confined to lobules I-V of the anterior lobe in patients with sporadic ALS in contrast to the considerable posterior lobe and vermis disease burden identified in C9orf72 mutation carriers. Patients with intermediate ATXN2 expansions did not exhibit significant cerebellar pathology. CONCLUSIONS: Focal rather than global cerebellar degeneration characterises ALS. Pathognomonic ALS symptoms which are typically attributed to other anatomical regions, such as dysarthria, dysphagia, pseudobulbar affect, eye movement abnormalities and cognitive deficits, may be modulated, exacerbated or partially driven by cerebellar changes in ALS.

Subacute cerebellar ataxia following respiratory symptoms of COVID-19: a case report.

BACKGROUND: Severe acute respiratory syndrome virus 2 (SARS-CoV-2) is spreading globally and causes most frequently fever and respiratory symptoms, i.e. Coronavirus disease 2019 (COVID-19), however, distinct neurological syndromes associated with SARS-CoV-2 infection have been described. Among SARS-CoV-2-infections-associated neurological symptoms fatigue, headache, dizziness, impaired consciousness and anosmia/ageusia are most frequent, but less frequent neurological deficits such as seizures, Guillain-Barré syndrome or ataxia may also occur. CASE PRESENTATION: Herein we present a case of a 62-year-old man who developed a subacute cerebellar syndrome with limb-, truncal- and gait ataxia and scanning speech 1 day after clinical resolution of symptomatic SARS-CoV-2 infection of the upper airways. Apart from ataxia, there were no signs indicative of opsoclonus myoclonus ataxia syndrome or Miller Fisher syndrome. Cerebral magnetic resonance imaging showed mild cerebellar atrophy. SARS-CoV-2 infection of the cerebellum was excluded by normal cerebrospinal fluid cell counts and, most importantly, absence of SARS-CoV-2 RNA or intrathecal SARS-CoV-2-specific antibody production. Other causes of ataxia such as other viral infections, other autoimmune and/or paraneoplastic diseases or intoxication were ruled out. The neurological deficits improved rapidly after high-dose methylprednisolone therapy. CONCLUSIONS: The laboratory and clinical findings as well as the marked improvement after high-dose methylprednisolone therapy suggest a post-infectious, immune-mediated cause of ataxia. This report should make clinicians aware to consider SARS-CoV-2 infection as a potential cause of post-infectious neurological deficits with an atypical clinical presentation and to consider high-dose corticosteroid treatment in case that a post-infectious immune-mediated mechanism is assumed.

Abnormal Left-Hemispheric Sulcal Patterns Correlate with Neurodevelopmental Outcomes in Subjects with Single Ventricular Congenital Heart Disease.

Neurodevelopmental abnormalities are the most common noncardiac complications in patients with congenital heart disease (CHD). Prenatal brain abnormalities may be due to reduced oxygenation, genetic factors, or less commonly, teratogens. Understanding the contribution of these factors is essential to improve outcomes. Because primary sulcal patterns are prenatally determined and under strong genetic control, we hypothesized that they are influenced by genetic variants in CHD. In this study, we reveal significant alterations in sulcal patterns among subjects with single ventricle CHD (n = 115, 14.7 ± 2.9 years [mean ± standard deviation]) compared with controls (n = 45, 15.5 ± 2.4 years) using a graph-based pattern-analysis technique. Among patients with CHD, the left hemisphere demonstrated decreased sulcal pattern similarity to controls in the left temporal and parietal lobes, as well as the bilateral frontal lobes. Temporal and parietal lobes demonstrated an abnormally asymmetric left-right pattern of sulcal basin area in CHD subjects. Sulcal pattern similarity to control was positively correlated with working memory, processing speed, and executive function. Exome analysis identified damaging de novo variants only in CHD subjects with more atypical sulcal patterns. Together, these findings suggest that sulcal pattern analysis may be useful in characterizing genetically influenced, atypical early brain development and neurodevelopmental risk in subjects with CHD.

Cerebral Coenurosis of a Long-Tailed Goral, Naemorhedus caudatus, in Korea.

We intended to describe a case of cerebral coenurosis in a long-tailed goral, Naemorhedus caudatus, from Hwacheon-gun, Gangwon-do (Province), in the Korea. The goral, a 10-year-old male, was suffering from neurological symptoms, such as turning the circle to one side without lifting the head straight, and died at 30 days after admission to the wildlife medical rescue center in Chuncheon-si, Gangwon-do. A fluid-filled cyst was detected in the left cerebral hemisphere by computed tomography and magnetic resonance imaging. The cyst removed from the deceased goral was transparent, about 3×3 cm in size, contained a clear fluid and approximately 320 protoscolices invaginating from the internal germinal layer. The protoscolex had 4 suckers and a rostellum with 28 hooklets arranged in 2 rows. By the present study, a case of cerebral coenurosis was first confirmed in a long-tailed goral, N. caudatus, from Gangwon-do, in Korea. The residents frequently exposed in the sylvatic environment should be careful the accidental infections of zoonotic metacestode of Taenia multiceps, Coenurus cerebralis, in Korea.

Analysis of Changes in Microcirculation Parameters of Symmetrical Areas of the Human Head under Conditions of Hypoxic Influences.

The reactions of microcirculation parameters of symmetrical areas of the human head to hypoxic loads were studied. The study was conducted in 10 healthy male volunteers aged 18-19 years. Short-term hypoxia was modeled using a ReOxy Cardio normobaric device (S. A. Aimediq). Synchronous measurements of microcirculation parameters in symmetrical temporal regions of the head at the basal state and immediately after short-term hypoxic exposure were carried out by the method of laser Doppler flowmetry. We evaluated statistical characteristics of perfusion of both sides, as well as regression characteristics of the relationship between changes in the microcirculation parameters and the initial values of these parameters. It was shown that the reaction of the microcirculation parameters in symmetrical regions of the head to hypoxia depends on the initial microcirculation parameters in ipsi- and contralateral sides. 3D graphs were constructed and regression equations describing these relationships were formulated. A new method of geometric sensing is proposed, which allows predicting the direction of reactions to hypoxic effects. The obtained data illustrate the specificity of regulation of microcirculation of paired organs determined by the presence of functional asymmetry. A new method of geometric zoning is proposed, which allows solving the problems of personalized assessments of the state of the microcirculation system in patients.

Right Hemispheric Homologous Language Pathways Negatively Predicts Poststroke Naming Recovery.

Background and Purpose- Stroke is the leading cause of disability in United States, and aphasia is a common sequela after a left hemisphere stroke. Functional imaging and brain stimulation studies show that right hemisphere structures are detrimental to aphasia recovery but evidence from diffusion tensor imaging is lacking. We investigated the role of homologous language pathways in naming recovery after left hemispheric stroke. Methods- Patients with aphasia after a left hemispheric stroke underwent naming assessment using the Boston Naming Test and diffusion tensor imaging at the acute and chronic time points. We analyzed diffusion tensor imaging of right arcuate fasciculus and frontal aslant tracts. We used Wilcoxon rank-sum test to evaluate structural lateralization patterns and partial Spearman correlation/multivariate generalized linear model to determine the role of right arcuate fasciculus and frontal aslant tracts in naming recovery after controlling for confounders. Results were corrected for multiple comparisons. Results- On average, the structural integrity of left language pathways deteriorated more than their right homologs, such that there was rightward lateralization in the chronic stage. Regression/correlation analyses showed that greater preservation of tract integrity of right arcuate fasciculus was associated with poorer naming recovery. Conclusions- Our study provides preliminary evidence that preservation of right homologs of language pathways is associated with poor recovery of naming after a left hemispheric stroke, consistent with previous evidence that maintaining greater reliance on left hemisphere structures is associated with better language recovery.

Effects of Spaceflight on Astronaut Brain Structure as Indicated on MRI.

BACKGROUND: There is limited information regarding the effects of spaceflight on the anatomical configuration of the brain and on cerebrospinal fluid (CSF) spaces. METHODS: We used magnetic resonance imaging (MRI) to compare images of 18 astronauts' brains before and after missions of long duration, involving stays on the International Space Station, and of 16 astronauts' brains before and after missions of short duration, involving participation in the Space Shuttle Program. Images were interpreted by readers who were unaware of the flight duration. We also generated paired preflight and postflight MRI cine clips derived from high-resolution, three-dimensional imaging of 12 astronauts after long-duration flights and from 6 astronauts after short-duration flights in order to assess the extent of narrowing of CSF spaces and the displacement of brain structures. We also compared preflight ventricular volumes with postflight ventricular volumes by means of an automated analysis of T1-weighted MRIs. The main prespecified analyses focused on the change in the volume of the central sulcus, the change in the volume of CSF spaces at the vertex, and vertical displacement of the brain. RESULTS: Narrowing of the central sulcus occurred in 17 of 18 astronauts after long-duration flights (mean flight time, 164.8 days) and in 3 of 16 astronauts after short-duration flights (mean flight time, 13.6 days) (P<0.001). Cine clips from a subgroup of astronauts showed an upward shift of the brain after all long-duration flights (12 astronauts) but not after short-duration flights (6 astronauts) and narrowing of CSF spaces at the vertex after all long-duration flights (12 astronauts) and in 1 of 6 astronauts after short-duration flights. Three astronauts in the long-duration group had optic-disk edema, and all 3 had narrowing of the central sulcus. A cine clip was available for 1 of these 3 astronauts, and the cine clip showed upward shift of the brain. CONCLUSIONS: Narrowing of the central sulcus, upward shift of the brain, and narrowing of CSF spaces at the vertex occurred frequently and predominantly in astronauts after long-duration flights. Further investigation, including repeated postflight imaging conducted after some time on Earth, is required to determine the duration and clinical significance of these changes. (Funded by the National Aeronautics and Space Administration.).

Common and separable neural alterations in substance use disorders: A coordinate-based meta-analyses of functional neuroimaging studies in humans.

Delineating common and separable neural alterations in substance use disorders (SUD) is imperative to understand the neurobiological basis of the addictive process and to inform substance-specific treatment strategies. Given numerous functional MRI (fMRI) studies in different SUDs, a meta-analysis could provide an opportunity to determine robust shared and substance-specific alterations. The present study employed a coordinate-based meta-analysis covering fMRI studies in individuals with addictive cocaine, cannabis, alcohol, and nicotine use. The primary meta-analysis demonstrated common alterations in primary dorsal striatal, and frontal circuits engaged in reward/salience processing, habit formation, and executive control across different substances and task-paradigms. Subsequent sub-analyses revealed substance-specific alterations in frontal and limbic regions, with marked frontal and insula-thalamic alterations in alcohol and nicotine use disorders respectively. Examining task-specific alterations across substances revealed pronounced frontal alterations during cognitive processes yet stronger striatal alterations during reward-related processes. Finally, an exploratory meta-analysis revealed that neurofunctional alterations in striatal and frontal reward processing regions can already be determined with a high probability in studies with subjects with comparably short durations of use. Together the findings emphasize the role of dysregulations in frontostriatal circuits and dissociable contributions of these systems in the domains of reward-related and cognitive processes which may contribute to substance-specific behavioral alterations.