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Frontiers in Integrative Neuroscience 2024Maximal grip strength, a measure of how much force a person's hand can generate when squeezing an object, may be an effective method for understanding potential...
Microstructural neural correlates of maximal grip strength in autistic children: the role of the cortico-cerebellar network and attention-deficit/hyperactivity disorder features.
INTRODUCTION
Maximal grip strength, a measure of how much force a person's hand can generate when squeezing an object, may be an effective method for understanding potential neurobiological differences during motor tasks. Grip strength in autistic individuals may be of particular interest due to its unique developmental trajectory. While autism-specific differences in grip-brain relationships have been found in adult populations, it is possible that such differences in grip-brain relationships may be present at earlier ages when grip strength is behaviorally similar in autistic and non-autistic groups. Further, such neural differences may lead to the later emergence of diagnostic-group grip differences in adolescence. The present study sought to examine this possibility, while also examining if grip strength could elucidate the neuro-motor sources of phenotypic heterogeneity commonly observed within autism.
METHODS
Using high resolution, multi-shell diffusion, and quantitative R1 relaxometry imaging, this study examined how variations in key sensorimotor-related white matter pathways of the proprioception input, lateral grasping, cortico-cerebellar, and corticospinal networks were associated with individual variations in grip strength in 68 autistic children and 70 non-autistic (neurotypical) children (6-11 years-old).
RESULTS
In both groups, results indicated that stronger grip strength was associated with higher proprioceptive input, lateral grasping, and corticospinal (but not cortico-cerebellar modification) fractional anisotropy and R1, indirect measures concordant with stronger microstructural coherence and increased myelination. Diagnostic group differences in these grip-brain relationships were not observed, but the autistic group exhibited more variability particularly in the cortico-cerebellar modification indices. An examination into the variability within the autistic group revealed that attention-deficit/hyperactivity disorder (ADHD) features moderated the relationships between grip strength and both fractional anisotropy and R1 relaxometry in the premotor-primary motor tract of the lateral grasping network and the cortico-cerebellar network tracts. Specifically, in autistic children with elevated ADHD features (60% of the autistic group) stronger grip strength was related to higher fractional anisotropy and R1 of the cerebellar modification network (stronger microstructural coherence and more myelin), whereas the opposite relationship was observed in autistic children with reduced ADHD features.
DISCUSSION
Together, this work suggests that while the foundational elements of grip strength are similar across school-aged autistic and non-autistic children, neural mechanisms of grip strength within autistic children may additionally depend on the presence of ADHD features. Specifically, stronger, more coherent connections of the cerebellar modification network, which is thought to play a role in refining and optimizing motor commands, may lead to stronger grip in children with more ADHD features, weaker grip in children with fewer ADHD features, and no difference in grip in non-autistic children. While future research is needed to understand if these findings extend to other motor tasks beyond grip strength, these results have implications for understanding the biological basis of neuromotor control in autistic children and emphasize the importance of assessing co-occurring conditions when evaluating brain-behavior relationships in autism.
PubMed: 38808069
DOI: 10.3389/fnint.2024.1359099 -
Arthritis Research & Therapy May 2024Diffusion kurtosis imaging (DKI) and neurite orientation dispersion and density imaging (NODDI) provide more comprehensive and informative perspective on microstructural...
BACKGROUND
Diffusion kurtosis imaging (DKI) and neurite orientation dispersion and density imaging (NODDI) provide more comprehensive and informative perspective on microstructural alterations of cerebral white matter (WM) than single-shell diffusion tensor imaging (DTI), especially in the detection of crossing fiber. However, studies on systemic lupus erythematosus patients without neuropsychiatric symptoms (non-NPSLE patients) using multi-shell diffusion imaging remain scarce.
METHODS
Totally 49 non-NPSLE patients and 41 age-, sex-, and education-matched healthy controls underwent multi-shell diffusion magnetic resonance imaging. Totally 10 diffusion metrics based on DKI (fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity, mean kurtosis, axial kurtosis and radial kurtosis) and NODDI (neurite density index, orientation dispersion index and volume fraction of the isotropic diffusion compartment) were evaluated. Tract-based spatial statistics (TBSS) and atlas-based region-of-interest (ROI) analyses were performed to determine group differences in brain WM microstructure. The associations of multi-shell diffusion metrics with clinical indicators were determined for further investigation.
RESULTS
TBSS analysis revealed reduced FA, AD and RK and increased ODI in the WM of non-NPSLE patients (P < 0.05, family-wise error corrected), and ODI showed the best discriminative ability. Atlas-based ROI analysis found increased ODI values in anterior thalamic radiation (ATR), inferior frontal-occipital fasciculus (IFOF), forceps major (F_major), forceps minor (F_minor) and uncinate fasciculus (UF) in non-NPSLE patients, and the right ATR showed the best discriminative ability. ODI in the F_major was positively correlated to C3.
CONCLUSION
This study suggested that DKI and NODDI metrics can complementarily detect WM abnormalities in non-NPSLE patients and revealed ODI as a more sensitive and specific biomarker than DKI, guiding further understanding of the pathophysiological mechanism of normal-appearing WM injury in SLE.
Topics: Humans; Female; White Matter; Male; Adult; Lupus Erythematosus, Systemic; Diffusion Tensor Imaging; Middle Aged; Diffusion Magnetic Resonance Imaging; Young Adult; Brain
PubMed: 38807248
DOI: 10.1186/s13075-024-03344-3 -
Journal of Cardiovascular Magnetic... May 2024Novel treatment strategies are needed to improve the structure and function in the myocardium post infarction. In vitro-matured pluripotent stem cell-derived...
BACKGROUND
Novel treatment strategies are needed to improve the structure and function in the myocardium post infarction. In vitro-matured pluripotent stem cell-derived cardiomyocytes (PSC-CMs), have been shown to be a promising regenerative strategy. We hypothesized that mature PSC-CMs will have anisotropic structure and improved cell alignment when compared to immature PSC-CMs using magnetic resonance imaging (MRI) in a guinea pig model of cardiac injury.
METHODS
Guinea pigs (n=16) were cryoinjured on day -10, followed by transplantation of either 10 polydimethylsiloxane-matured PSC-CMs (PDMS, n=6) or 10 immature tissue culture plastic-generated PSC-CMs (TCP, n=6) on day 0. Vehicle (sham-treated) subjects were injected with a pro-survival cocktail devoid of cells (n=4), while healthy controls (n=4) did not undergo cryoinjury or treatment. Animals were sacrificed on either day +14 or day +28 post transplantation. Animals were imaged ex vivo on a 7T Bruker MRI. A 3D Diffusion Tensor Imaging sequence was used to quantify structure via fractional anisotropy (FA), mean diffusivity (MD) and myocyte alignment measured by the standard deviation of the transverse angle (TA).
RESULTS
MD and FA of mature PDMS grafts demonstrated anisotropy that were not significantly different than the healthy control hearts (MD=1.1 ± 0.12 ×10 mm/s vs. 0.93 ± 0.01 ×10 mm/s, p=0.4 and FA=0.22±0.05 vs. 0.26±0.001, p=0.5). Immature TCP grafts exhibited significantly higher MD than the healthy control (1.3 ± 0.08 ×10 mm/s, p<0.05) and significantly lower FA than the control (0.12±0.02, p< 0.05) but were not different from mature PDMS grafts in this small cohort. TA of healthy controls showed low variability and were not significantly different than mature PDMS grafts (p=0.4) while immature TCP grafts were significantly different (p<0.001).
DISCUSSION
DTI parameters of mature graft tissue trended towards that of the healthy myocardium, indicating the grafted cardiomyocytes may have a similar phenotype to healthy tissue. Contrast-enhanced MR images corresponded well to histological staining, demonstrating a non-invasive method of localizing the repopulated cardiomyocytes within the scar.
CONCLUSIONS
The DTI measures within graft tissue were indicative of anisotropic structure, and showed greater myocyte organization compared to the scarred territory. These findings show that MRI is a valuable tool to assess structural impacts of regenerative therapies.
PubMed: 38795790
DOI: 10.1016/j.jocmr.2024.101045 -
Journal of Clinical Medicine May 2024To determine whether early structural brain trajectories predict early childhood neurodevelopmental deficits in complex CHD patients and to assess relative cumulative...
To determine whether early structural brain trajectories predict early childhood neurodevelopmental deficits in complex CHD patients and to assess relative cumulative risk profiles of clinical, genetic, and demographic risk factors across early development. : Term neonates with complex CHDs were recruited at Texas Children's Hospital from 2005-2011. Ninety-five participants underwent three structural MRI scans and three neurodevelopmental assessments. Brain region volumes and white matter tract fractional anisotropy and radial diffusivity were used to calculate trajectories: perioperative, postsurgical, and overall. Gross cognitive, language, and visuo-motor outcomes were assessed with the Bayley Scales of Infant and Toddler Development and with the Wechsler Preschool and Primary Scale of Intelligence and Beery-Buktenica Developmental Test of Visual-Motor Integration. Multi-variable models incorporated risk factors. Reduced overall period volumetric trajectories predicted poor language outcomes: brainstem ((β, 95% CI) 0.0977, 0.0382-0.1571; = 0.0022) and white matter (0.0023, 0.0001-0.0046; = 0.0397) at 5 years; brainstem (0.0711, 0.0157-0.1265; = 0.0134) and deep grey matter (0.0085, 0.0011-0.0160; = 0.0258) at 3 years. Maternal IQ was the strongest contributor to language variance, increasing from 37% at 1 year, 62% at 3 years, and 81% at 5 years. Genetic abnormality's contribution to variance decreased from 41% at 1 year to 25% at 3 years and was insignificant at 5 years. Reduced postnatal subcortical-cerebral white matter trajectories predicted poor early childhood neurodevelopmental outcomes, despite high contribution of maternal IQ. Maternal IQ was cumulative over time, exceeding the influence of known cardiac and genetic factors in complex CHD, underscoring the importance of heritable and parent-based environmental factors.
PubMed: 38792464
DOI: 10.3390/jcm13102922 -
BMC Medical Imaging May 2024Magnetic Resonance Imaging (MRI)-based imaging techniques are useful for assessing white matter (WM) structural and microstructural integrity in the context of infection... (Review)
Review
BACKGROUND
Magnetic Resonance Imaging (MRI)-based imaging techniques are useful for assessing white matter (WM) structural and microstructural integrity in the context of infection and inflammation. The purpose of this scoping review was to assess the range of work on the use of WM neuroimaging approaches to understand the impact of congenital and perinatal viral infections or exposures on the developing brain.
METHODS
This scoping review was conducted according to the Arksey and O' Malley framework. A literature search was performed in Web of Science, Scopus and PubMed for primary research articles published from database conception up to January 2022. Studies evaluating the use of MRI-based WM imaging techniques in congenital and perinatal viral infections or exposures were included. Results were grouped by age and infection.
RESULTS
A total of 826 articles were identified for screening and 28 final articles were included. Congenital and perinatal infections represented in the included studies were cytomegalovirus (CMV) infection (n = 12), human immunodeficiency virus (HIV) infection (n = 11) or exposure (n = 2) or combined (n = 2), and herpes simplex virus (HSV) infection (n = 1). The represented MRI-based WM imaging methods included structural MRI and diffusion-weighted and diffusion tensor MRI (DWI/ DTI). Regions with the most frequently reported diffusion metric group differences included the cerebellar region, corticospinal tract and association fibre WM tracts in both children with HIV infection and children who are HIV-exposed uninfected. In qualitative imaging studies, WM hyperintensities were the most frequently reported brain abnormality in children with CMV infection and children with HSV infection.
CONCLUSION
There was evidence that WM imaging techniques can play a role as diagnostic and evaluation tools assessing the impact of congenital infections and perinatal viral exposures on the developing brain. The high sensitivity for identifying WM hyperintensities suggests structural brain MRI is a useful neurodiagnostic modality in assessing children with congenital CMV infection, while the DTI changes associated with HIV suggest metrics such as fractional anisotropy have the potential to be specific markers of subtle impairment or WM damage in neuroHIV.
Topics: Humans; White Matter; Magnetic Resonance Imaging; Female; Pregnancy; Infant, Newborn; Brain; Cytomegalovirus Infections; HIV Infections; Neuroimaging; Diffusion Tensor Imaging; Pregnancy Complications, Infectious; Infant; Virus Diseases
PubMed: 38783187
DOI: 10.1186/s12880-024-01282-9 -
Human Brain Mapping Jun 2024In this study we explore the spatio-temporal trajectory and clinical relevance of microstructural white matter changes within and beyond subcortical stroke lesions...
In this study we explore the spatio-temporal trajectory and clinical relevance of microstructural white matter changes within and beyond subcortical stroke lesions detected by free-water imaging. Twenty-seven patients with subcortical infarct with mean age of 66.73 (SD 11.57) and median initial NIHSS score of 4 (IQR 3-7) received diffusion MRI 3-5 days, 1 month, 3 months, and 12 months after symptom-onset. Extracellular free-water and fractional anisotropy of the tissue (FA) were averaged within stroke lesions and the surrounding tissue. Linear models showed increased free-water and decreased FA in the white matter of patients with subcortical stroke (lesion [free-water/FA, mean relative difference in %, ipsilesional vs. contralesional hemisphere at 3-5 days, 1 month, 3 months, and 12 months after symptom-onset]: +41/-34, +111/-37, +208/-26, +251/-18; perilesional tissue [range in %]: +[5-24]/-[0.2-7], +[2-20]/-[3-16], +[5-43]/-[2-16], +[10-110]/-[2-12]). Microstructural changes were most prominent within the lesion and gradually became less pronounced with increasing distance from the lesion. While free-water elevations continuously increased over time and peaked after 12 months, FA decreases were most evident 1 month post-stroke, gradually returning to baseline values thereafter. Higher perilesional free-water and higher lesional FA at baseline were correlated with greater reductions in lesion size (rho = -0.51, p = .03) in unadjusted analyses only, while there were no associations with clinical measures. In summary, we find a characteristic spatio-temporal pattern of extracellular and cellular alterations beyond subcortical stroke lesions, indicating a dynamic parenchymal response to ischemia characterized by vasogenic edema, cellular damage, and white matter atrophy.
Topics: Humans; Male; Aged; Female; Middle Aged; Ischemic Stroke; White Matter; Diffusion Magnetic Resonance Imaging; Longitudinal Studies; Water; Brain; Anisotropy
PubMed: 38780442
DOI: 10.1002/hbm.26722 -
Parkinsonism & Related Disorders May 2024Identifying biomarkers reflecting cellular dysfunctions in early Parkinson's disease patients (ePD) is needed to develop targeted therapeutic strategies. We aimed to...
INTRODUCTION
Identifying biomarkers reflecting cellular dysfunctions in early Parkinson's disease patients (ePD) is needed to develop targeted therapeutic strategies. We aimed to determine if cellular energetic dysfunction related to increased brain sodium concentration would be co-located to microstructural alterations and iron deposition in ePD.
METHODS
We prospectively included 12 ePD (mean disease duration 20.0 ± 10.2 months) and 13 healthy controls (HC), scanned with a 7 T H and Na MRI. Complementary voxel-based and region-based assessments were performed, the latter utilizing a high-resolution multimodal template we created (combining quantitative T maps (qT1), transverse relaxation rate (R2*), quantitative magnetic susceptibility mapping (QSM) images) from 200 subjects. This template allowed a precise multiparametric assessment of sodium concentration, QSM, R*, qT, mean diffusivity, and fractional anisotropy values. A two-sided p-value<0.05 was considered statistically significant after the Bonferroni correction.
RESULTS
Relative to HC, ePD showed significantly higher sodium concentration in left Substantia nigra (SN) pars reticulata (46.13 mM ± 3.52 vs 38.60 mM ± 6.10, p = 0.038), a subpart of the SN pars compacta (SNc) and ventral tegmental area, Putamen, Globus Pallidum external, accumbens nucleus and claustrum. Significantly increased QSM and R2* values, and decreased T values, were limited to the Nigrosomes 1 (Nig) and right SNc (all p < 0.05). QSM values in the Nig were significantly correlated to UPDRS-III scores (r = 0.91,p < 0.001).
CONCLUSION
In ePD, brain sodium accumulation was broad and dissociated from iron accumulation. As with iron accumulation, a sodium-related pathophysiological approach could lead to identifying potential new therapeutic agents and deserves further investigation.
PubMed: 38776725
DOI: 10.1016/j.parkreldis.2024.106996 -
Journal of Athletic Training May 2024Structural evidence for corticospinal tract (CST) abnormality between patients with ACLR and healthy controls, and the relationships between CST structure and clinical...
CONTEXT
Structural evidence for corticospinal tract (CST) abnormality between patients with ACLR and healthy controls, and the relationships between CST structure and clinical features of the patients (e.g., objective sensorimotor outcomes, postoperative duration) are lacking.
OBJECTIVES
To investigate whether the structural features of CST 1) differ between patients with ACLR and healthy controls, and 2) were associated with clinical features in patients following ACLR.
DESIGN
Cross-sectional study.
SETTING
Sports medicine laboratory.
PATIENTS OR OTHER PARTICIPANTS
Twenty-six patients who had undergone ACLR and twenty-six healthy controls were enrolled in this cross-sectional investigation.
MAIN OUTCOME MEASURE(S)
Using the CST as the region of interest, we performed diffusion tensor imaging to measure the microstructure of white matter tracts. Between-group comparisons and correlation analyses with clinical features in patients with ACLR were performed.
RESULTS
The patients with ACLR showed significant, moderate lower fractional anisotropy (FA, Cohen's d = -0.666, 95% CIs -1.221 to -0.104), lower axial diffusivity (AD, Cohen's d = -0.526, 95% CIs -1.077 to 0.030), and higher radial diffusivity (RD, Cohen's d = 0.514, 95% CIs -0.042 to 1.064) when compared to that of healthy controls, with the RD values being significantly correlated with the postoperative duration (r = 0.623, p < 0.001) after controlling the age, sex, and BMI in patients with ACLR.
CONCLUSIONS
This study revealed that patients with ACLR have impaired integrity (lower FA values and higher RD values) in the CST contralateral to the ACLR injured limb in comparison with healthy controls. Decreased integrity (higher RD) of the CST in patients was significantly associated with longer postoperative duration, which hinted that impaired structural integrity of the CST may be a maladaptive process of neuroplasticity in ACLR.
PubMed: 38775129
DOI: 10.4085/1062-6050-0380.23 -
Brain and Behavior May 2024Using correlation tractography, this study aimed to find statistically significant correlations between white matter (WM) tracts in participants with obstructive sleep...
INTRODUCTION
Using correlation tractography, this study aimed to find statistically significant correlations between white matter (WM) tracts in participants with obstructive sleep apnea (OSA) and OSA severity. We hypothesized that changes in certain WM tracts could be related to OSA severity.
METHODS
We enrolled 40 participants with OSA who underwent diffusion tensor imaging (DTI) using a 3.0 Tesla MRI scanner. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD), and quantitative anisotropy (QA)-values were used in the connectometry analysis. The apnea-hypopnea index (AHI) is a representative measure of the severity of OSA. Diffusion MRI connectometry that was used to derive correlational tractography revealed changes in the values of FA, MD, AD, RD, and QA when correlated with the AHI. A false-discovery rate threshold of 0.05 was used to select tracts to conduct multiple corrections.
RESULTS
Connectometry analysis revealed that the AHI in participants with OSA was negatively correlated with FA values in WM tracts that included the cingulum, corpus callosum, cerebellum, inferior longitudinal fasciculus, fornices, thalamic radiations, inferior fronto-occipital fasciculus, superior and posterior corticostriatal tracts, medial lemnisci, and arcuate fasciculus. However, there were no statistically significant results in the WM tracts, in which FA values were positively correlated with the AHI. In addition, connectometry analysis did not reveal statistically significant results in WM tracts, in which MD, AD, RD, and QA values were positively or negatively correlated with the AHI.
CONCLUSION
Several WM tract changes were correlated with OSA severity. However, WM changes in OSA likely involve tissue edema and not neuronal changes, such as axonal loss. Connectometry analyses are valuable tools for detecting WM changes in sleep disorders.
Topics: Humans; Sleep Apnea, Obstructive; Diffusion Tensor Imaging; Male; Female; Middle Aged; Adult; White Matter; Severity of Illness Index; Brain
PubMed: 38773829
DOI: 10.1002/brb3.3541 -
BioRxiv : the Preprint Server For... May 2024Magnetic resonance elastography (MRE) is a promising neuroimaging technique to probe tissue microstructure, which has revealed widespread softening with loss of...
Magnetic resonance elastography (MRE) is a promising neuroimaging technique to probe tissue microstructure, which has revealed widespread softening with loss of structural integrity in the aging brain. Traditional MRE approaches assume mechanical isotropy. However, white matter is known to be anisotropic from aligned, myelinated axonal bundles, which can lead to uncertainty in mechanical property estimates in these areas when using isotropic MRE. Recent advances in anisotropic MRE now allow for estimation of shear and tensile anisotropy, along with substrate shear modulus, in white matter tracts. The objective of this study was to investigate age-related differences in anisotropic mechanical properties in human brain white matter tracts for the first time. Anisotropic mechanical properties in all tracts were found to be significantly lower in older adults compared to young adults, with average property differences ranging between 0.028-0.107 for shear anisotropy and between 0.139-0.347 for tensile anisotropy. Stiffness perpendicular to the axonal fiber direction was also significantly lower in older age, but only in certain tracts. When compared with fractional anisotropy measures from diffusion tensor imaging, we found that anisotropic MRE measures provided additional, complementary information in describing differences between the white matter integrity of young and older populations. Anisotropic MRE provides a new tool for studying white matter structural integrity in aging and neurodegeneration.
PubMed: 38766139
DOI: 10.1101/2024.05.08.593260