Volume Of Nucleus Research Articles

Assessing changes in brain structure in new-onset children with acute lymphoblastic leukemia.

Brain structure injury was presented in acute lymphoblastic leukemia (ALL) after treatment; however, its alterations in new-onset stage are still unclear. We aim to explore white matter (WM) and grey matter (GM) alterations using surface-based morphometry (SBM) and tract-based spatial statistics (TBSS) in new-onset pediatric ALL. Thirty-five ALL and 33 typically developing (TD) children were prospectively recruited and underwent three-dimensional T1-weighted and diffusion tensor (DTI) imaging. DTI metrics, cortical GM features, anddeep GM nuclei volume were compared between groups differences. In ALL, the only increased FA in the body of corpus callosum (PFWE-corrected = 0.023) and left superior corona radiata (PFWE-corrected = 0.045) were presented. Relative to TDs, pediatric ALL presented a significant decrease in cortical surface area (CSA), thickness (CT), and volume in orbital gyri, supramarginal gyrus, middle temporal gyrus, and superior temporal gyrus (all CWP = 0.01). Additionally, increased CT and CSA were found in lingual gyrus and left sulcus intermedius primus, respectively (all CWP = 0.01). Smaller volumes in pediatric ALL were observed in bilateral thalamus, caudate, hippocampus, and right putamen (PFDR-corrected < 0.05). Widespread brain structural abnormalities were found in new-onset pediatric ALL, which suggest disease itself can cause brain structural injury. This study revealed the altered white matter integrity and gray matter morphology characteristics in childhood acute lymphoblastic leukemia on new-onset stage. It is suggested that there may be structural impairment before chemotherapy. MRI is a sensitive way for early detection on brain structural damage in childhood acute lymphoblastic leukemia.

Caudate nucleus volume in medicated and unmedicated patients with early- and adult-onset schizophrenia

The caudate nucleus is a part of the striatum, and striatal hyperdopaminergia is considered central to the pathophysiology of schizophrenia. How caudate volume is affected in schizophrenia and what role antipsychotics play remains unclear. In early-onset schizophrenia (EOS), where psychosis emerges during a neurodevelopmentally critical phase, the caudate may exhibit a heightened vulnerability to the effects of antipsychotic medications. We hypothesized effects of both antipsychotic medication use and age of onset on caudate in schizophrenia. We included adult patients with EOS (n = 83) and adult-onset schizophrenia (AOS) (n = 246), adult healthy controls (HC, n = 774), adolescent patients with non-affective psychosis (n = 56) and adolescent HC (n = 97). We obtained T1-weighted MRI scans using a 1.5T Siemens scanner and General Electric 3T scanners. In our main analysis, we tested for main and interaction effects of diagnosis and current antipsychotic medication use on caudate volume. Adult patients with EOS (p < 0.001) and AOS (p = 0.002) had both larger caudate than HC. Age of onset (EOS/AOS) interacted with antipsychotic use (p = 0.004) which was associated with larger caudate in EOS (p < 0.001) but not in AOS (p = 0.654). Conversely, among medicated patients only, EOS had larger caudate than AOS (p < 0.001). No other subcortical structures showed differences between medicated EOS and AOS. Medicated adolescent patients with non-affective psychosis and medicated adult patients with EOS showed similar caudate volumes. The results may indicate a schizophrenia-related and a medication-induced caudate increase, the latter restricted to patients with EOS and possibly occurring already in adolescence shortly after disease onset.

Investigating the genetic relationship of intracranial and subcortical brain volumes with depression and other psychiatric disorders

Abstract Depression is one of the most common mental health disorders worldwide, yet its neurobiological mechanisms remain poorly understood. Structural brain differences in subcortical limbic regions are thought to be implicated in the pathology of depression. We leveraged genome-wide association studies (GWAS) summary-level data to explore the molecular pathways underlying the relationship between genetic risk for depression and intracranial and subcortical brain volumes measured via magnetic resonance imaging. At the whole-genome level, we identified a negative genetic correlation (rG) between depression and the volume of the ventral diencephalon (rG = -0.08), which remained significant after adjusting for multiple testing. We observed nominal (P &amp;lt; 0.05) positive genetic correlations between depression and the volumes of the caudate nucleus (rG = 0.06) and the putamen (rG = 0.06), while hippocampal volume displayed a negative genetic correlation (rG = -0.06) with depression. Pairwise GWAS analyses uncovered 104 genome segments with genetic variants influencing the aetiology of depression and at least one brain volume at the local genetic level. Gene association analyses of these genomic segments suggest putative links with dopamine neurotransmission, mesocorticolimbic functional connectivity, GABAergic transmission, and the insulin signalling pathway. Sensitivity analyses showed that the volume of the ventral diencephalon is also negatively correlated with bipolar disorder and schizophrenia; however, most of the genes associated with depression and brain volumes are specific for depression and do not replicate when investigating bipolar disorder or schizophrenia with brain volumes. We observed negative phenotypic correlations between depression and intracranial and subcortical brain volumes. Overall, our findings contribute to our understanding of the neurobiology of depression and suggest that, besides the known role of the hippocampus, other subcortical structures might also play essential roles in the aetiology of depression.

Association between subcortical nuclei volume changes and cognition in preschool-aged children with tetralogy of Fallot after corrective surgery: a cross-sectional study

BackgroundNeurocognitive disorders frequently occur in patients with cyanotic congenital heart disease (CCHD) because of the hemodynamic abnormalities induced by preoperative cardiac structural changes. We aimed to evaluate subcortical nuclei volume changes and cognition in postoperative tetralogy of Fallot (TOF) children, and analyze their relationship with preoperative cardiac structural changes.MethodsThis case-control study involved thirty-six children with repaired TOF and twenty-nine healthy controls (HCs). We utilized three-dimensional (3D) T1-weighted high-resolution structural images alongside the Wechsler Preschool and Primary Scale of Intelligence-Fourth Edition (WPPSI-IV) to evaluate the cognitive differences between the TOF and HC group.ResultsWe observed notable differences in subcortical nuclei volume between the TOF and HC group, specifically in the left amygdala nucleus (LAM, TOF: 1292.60 ± 155.57; HC: 1436.27 ± 140.62, p < 0.001), left thalamus proper nucleus (LTHA, TOF: 6771.54 ± 666.03; HC: 7435.36 ± 532.84, p < 0.001), and right thalamus proper nucleus (RTHA, TOF: 6514.61 ± 715.23; HC: 7162.94 ± 554.60, p < 0.001). Furthermore, a diminished integrity of LAM ( β:-19.828, 95% CI: -36.462, -3.193), which showed an inverse relationship with the size of the preoperative ventricular septal defect (VSD), correlated with lower working memory indices in children with TOF.ConclusionsOur findings indicate that subcortical nuclei structural injuries possibly potentially stemming from cardiac anatomical abnormalities, are associated with impaired working memory in preschool-aged children with TOF. The LAM in particular may serve as a potential biomarker for neurocognitive deficits in TOF, offering predictive value for future neurodevelopmental outcomes, and shedding light on the neurophysiological mechanisms of these cognitive impairments.

Photoperiodism, testosterone and adult neurogenesis in canaries (Serinus canaria).

Domestic strains of canaries (Serinus canaria) variably respond to photoperiod changes and apparently stay in breeding state for extended periods. Fife Fancy canaries are supposed to be similar to the native species living at 27-39° north where photoperiod significantly changes across the year. Our birds showed reproductive cycles when exposed to light regimes mimicking the annual cycle of photoperiod. However after 6 months in short days (SD: 8L:16D), males developed large testes, as observed by X-ray tomography, and intense singing. Switching to long days (LD: 16L:8D) did not further increase song rate nor testes size but increased song duration, number of syllables per song, and trill occurrence frequency. No sign of regression was observed after 12 weeks in LD but return to SD produced a rapid decrease in testes size and singing activity below values in birds maintained throughout in SD. Fife Fancy thus does not seem to develop absolute but only relative refractoriness. The relatively high singing activity expressed by SD-photosensitive males does not seem to depend on high testosterone (T) concentrations. Singing did not correlate with plasma testosterone (T). Treatment with ATD + Flutamide only marginally decreased song rate and did not affect song quality nor song control nuclei volume. These birds are either supersensitive to low T levels or their reproductive physiology is activated by other mechanisms. Neurogenesis is increased by T and by LD but the function of new neurons incorporated in HVC is poorly understood. We developed a procedure based on X-ray focal irradiation to deplete neural progenitors adjacent to HVC and study the functional consequences. The decrease in neurogenesis increased the variability of T-induced songs in females and decreased their bandwidth. Neurogenesis in HVC thus plays a role in song production and X-ray focal irradiation represents an excellent tool to analyze adult neurogenesis.

Association between ossific nucleus volume changes and postoperative avascular necrosis risk in children with developmental dysplasia of the hip

This study aimed to investigate the correlation between ossific nucleus volume and avascular necrosis (AVN) in pediatric patients diagnosed with developmental dysplasia of the hip (DDH). Analyzing 211 cases, including 119 open reduction (OR) and 92 closed reduction (CR) procedures, we quantified ossific nucleus volume using magnetic resonance imaging (MRI). Categorizing the OR group based on ossific nucleus volume revealed no statistically significant difference in AVN incidence. Similarly, in the CR cohort, there was no significant discrepancy in AVN occurrence between subgroups with or without the ossific nucleus. Logistic regression in CR identified the international hip dysplasia institute (IHDI) grade as a significant AVN risk factor (p = 0.007). IHDI grades 3 and 4 exhibited a 6.94 times higher likelihood of AVN compared to grades 1 and 2. Across CR and OR, neither initial age nor ossific nucleus volume emerged as AVN risk factors. In conclusion, ossific nucleus volume does not pose a risk for AVN in DDH children undergoing CR or OR, emphasizing the clinical significance of IHDI grading in predicting AVN risk during CR and the importance of early intervention to prevent treatment delays.

Multimodal magnetic resonance longitudinal study on the deep gray matter in multiple sclerosis patients with teriflunomide

Disease-modifying therapies (DMTs) are used in an increasing number of patients with multiple sclerosis (MS). However, whether DMTs have intrinsic effects on deep gray matter (DGM) microstructure and atrophy is still poorly understood. In this study, we described the quantitative susceptibility values (QSV) and diffusion kurtosis imaging (DKI) metrics of DGM in relapsing–remitting MS (RRMS) patients and their association with cognitive deficits. We recruited 62 patients with RRMS receiving DMTs and 30 patients with RRMS not receiving DMTs underwent MRI on a 3T scanner. Fractional anisotropy (FA), kurtosis fractional anisotropy (KFA), mean diffusivity (MD), mean kurtosis (MK), QSV and volumes of bilateral caudate nucleus (CAU), amygdala (AMYG), putamen (PUT), hippocampus (Hipp), globus pallidus (GP) and thalamus (THA) were measured. Correlation analysis was performed between those image indexes with longitudinal significant changes and clinical neurological scores, including Expanded Disability Status Scale (EDSS), Digit Span Testand (DST), Symbol Digit Modalities Test (SDMT), Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Significant longitudinal increases in FA, KFA and MK values were found in both groups in bilateral CAU, AMYG, PUT, Hipp, GP and THA (all p < 0.005). MD values of the right of CAU in the two groups were significant longitudinal increase (p = 0.009, p = 0.047); MD values of the right of GP (p = 0.042), the left of THA (p = 0.003), the right of THA (p = 0.001) in treated MS were significant longitudinal decrease; There were no significant longitudinal changes between treated and untreated groups in normalized deep gray matter volume. For QSV, longitudinal increase in the right of PUT (p = 0.022) in the treated MS group and in the left of Hipp (p = 0.045) in the untreated MS group. The QSV and DKI measures were highly correlated with cognitive and disability tests. The treated RRMS patients showed different longitudinal changes of MD value and QSV with untreated in several DGM regions, and these differences were correlated with cognitive and microstructural integrity.

Comparison of facial skin ageing in healthy Asian and Caucasian females quantified by in vivo line-field confocal optical coherence tomography 3D imaging.

Quantitative biomarkers of facial skin aging were investigated in 109 healthy Asian female volunteers, aged 20 to 70 years. In vivo 3D Line-field Confocal Optical Coherence Tomography (LC-OCT) imaging, enhanced by Artificial Intelligence (AI)-based quantification algorithms, was utilized to compute various metrics, including stratum corneum thickness (SC), viable epidermal (VE) thickness, and Dermal-Epidermal Junction (DEJ) undulation along with cellular metrics for the temple, cheekbone, and mandible. Comparison with data from a cohort of healthy Caucasian volunteers revealed similarities in the variations of stratum corneum and viable epidermis layers, as well as cellular shape and size with age in both ethnic groups. However, specific findings emerged, such as larger, more heterogeneous nuclei in both layers, demonstrated by an increase in nuclei volume and their standard deviation, and increased network atypia, all showing significant age-related variations. Caucasian females exhibited a flatter and more homogeneous epidermis, evidenced by a decreased standard deviation of the number of layers, and a less dense cellular network with fewer cells per layer, indicated by a decrease in cell surface density. Ethnicity-wise comparisons highlighted distinct biological features specific to each population. Asian individuals showed significantly higher DEJ undulation, higher compactness, and lower cell network atypia compared to their Caucasian counterparts across age groups. Differences in stratum corneum and viable epidermal thickness on the cheekbone were also significant. LC-OCT 3D imaging provides valuable insights into the aging process in different populations and underscores inherent biological differences between Caucasian and Asian female volunteers.

Gray matter structural alterations of cortico-striato-thalamo-cortical loop in familial Paroxysmal Kinesigenic Dyskinesia

BackgroundPrevious studies have indicated that patients with Paroxysmal Kinesigenic Dyskinesia (PKD) exhibit reduced gray matter volume in certain brain regions within the cortico-striato-thalamo-cortical (CSTC) loop. However, a comprehensive investigation specifically targeting the CSTC loop in PKD has never been conducted. ObjectivesTo provide evidence for the involvement of the CSTC loop in the pathogenesis of PKD from the perspective of structural alterations, this study carried out a surface-based morphometry (SBM), voxel-based morphometry (VBM), and structural covariance networks (SCN) combined analysis in familial PKD patients. MethodsA total of 8 familial PKD patients and 10 healthy family members were included in the study and underwent Brain MRI examinations. Based on 3D T1 MPRAGE data, neuroimaging metrics of cortical thickness from SBM, subcortical nuclei volume from VBM, and covariance coefficient from SCN were used to systematically investigate the brain structural alterations along the CSTC loop of PKD patients. ResultsA significant decrease in the average cortical thickness of the left S1 region in the PKD group was observed. The volumes of subcortical nuclei, including the thalamus, putamen, and globus pallidus were reduced, with a pronounced effect observed in the bilateral putamen. And the structural covariance connection between the left putamen and the left globus pallidus was significantly strengthened. ConclusionsThe study confirms the involvement of the CSTC loop in the pathogenesis of PKD from the perspective of structural alterations, and the findings may provide potential targets for objective diagnosis and therapeutic monitoring of PKD.

Subjective well-being can be predicted by caudate volume and promotion focus.

It is well-known that the caudate nucleus is associated with motivational behaviors and subjective well-being. However, no longitudinal studies have examined the relationship between brain structure, behavioral orientations, and subjective well-being. This study analyzes data from our previous longitudinal study to examine whether future subjective well-being can be predicted by the volume of the caudate nucleus. We also examined whether behavioral orientation, based on the regulatory focus theory showing two orientations-promotion and prevention focus-was related to the volume of the caudate nucleus. Voxel-based morphometry analysis indicated that the left caudate volume was positively associated with rating scores for future subjective well-being and promotion orientation. Further, mediation analysis indicated that promotion orientation significantly mediated the relationship between future subjective well-being and left caudate volume. The findings indicate that future subjective well-being can be predicted by the volume of the left caudate nucleus, and that this relationship is mediated by promotion focus orientation.

Cortical and subcortical gray matter abnormalities in mild cognitive impairment

Gray matter changes are thought to be closely related to cognitive decline in mild cognitive impairment (MCI) patients. The study aimed to explore cortical and subcortical structural alterations in MCI and their association with cognitive assessment. 24 MCI patients and 22 normal controls (NCs) were included. Voxel-based morphometry (VBM), vertex-based shape analysis and surface-based morphometry (SBM) analysis were applied to explore subcortical nuclei volume, shape and cortical morphology. Correlations between structural changes and cognition were explored using spearman correlation analysis. Support vector machine (SVM) classification evaluated MCI identification accuracy. MCI patients showed significant atrophy in the left thalamus, left hippocampus, left amygdala, right pallidum, right hippocampus, along with inward deformation in the left amygdala. SBM analysis revealed that MCI group exhibited shallower sulci depth in the left hemisphere and increased cortical gyrification index (GI) in the right frontal gyrus. Correlation analysis showed the positive correlation between right hippocampus volume and episodic memory, while negative correlation between the altered GI and memory performance in MCI group. SVM analysis demonstrated superior performance of sulci depth and GI derived from SBM in MCI identification. When combined with cortical and subcortical metrics, SVM achieved a peak accuracy of 89 % in distinguishing MCI from NC. The study reveals significant gray matter structural changes in MCI, suggesting their potential role in underlying functional differences and neural mechanisms behind memory impairment in MCI.

Cholinergic nucleus degeneration and its association with gait impairment in Parkinson’s disease

BackgroundThe contribution of cholinergic degeneration to gait disturbance in Parkinson’s disease (PD) is increasingly recognized, yet its relationship with dopaminergic-resistant gait parameters has been poorly investigated. We investigated the association between comprehensive gait parameters and cholinergic nucleus degeneration in PD.MethodsThis cross-sectional study enrolled 84 PD patients and 69 controls. All subjects underwent brain structural magnetic resonance imaging to assess the gray matter density (GMD) and volume (GMV) of the cholinergic nuclei (Ch123/Ch4). Gait parameters under single-task (ST) and dual-task (DT) walking tests were acquired using sensor wearables in PD group. We compared cholinergic nucleus morphology and gait performance between groups and examined their association.ResultsPD patients exhibited significantly decreased GMD and GMV of the left Ch4 compared to controls after reaching HY stage > 2. Significant correlations were observed between multiple gait parameters and bilateral Ch123/Ch4. After multiple testing correction, the Ch123/Ch4 degeneration was significantly associated with shorter stride length, lower gait velocity, longer stance phase, smaller ankle toe-off and heel-strike angles under both ST and DT condition. For PD patients with HY stage 1–2, there were no significant degeneration of Ch123/4, and only right side Ch123/Ch4 were corrected with the gait parameters. However, as the disease progressed to HY stage > 2, bilateral Ch123/Ch4 nuclei showed correlations with gait performance, with more extensive significant correlations were observed in the right side.ConclusionsOur study demonstrated the progressive association between cholinergic nuclei degeneration and gait impairment across different stages of PD, and highlighting the potential lateralization of the cholinergic nuclei’s impact on gait impairment. These findings offer insights for the design and implementation of future clinical trials investigating cholinergic treatments as a promising approach to address gait impairments in PD.

Consistently lower volumes across thalamus nuclei in very premature-born adults

Lasting thalamus volume reduction after preterm birth is a prominent finding. However, whether thalamic nuclei volumes are affected differentially by preterm birth and whether nuclei aberrations are relevant for cognitive functioning remains unknown.Using T1-weighted MR-images of 83 adults born very preterm (≤ 32 weeks’ gestation; VP) and/or with very low body weight (≤ 1,500 g; VLBW) as well as of 92 full-term born (≥ 37 weeks’ gestation) controls, we compared thalamic nuclei volumes of six subregions (anterior, lateral, ventral, intralaminar, medial, and pulvinar) across groups at the age of 26 years. To characterize the functional relevance of volume aberrations, cognitive performance was assessed by full-scale intelligence quotient using the Wechsler Adult Intelligence Scale and linked to volume reductions using multiple linear regression analyses.Thalamic volumes were significantly lower across all examined nuclei in VP/VLBW adults compared to controls, suggesting an overall rather than focal impairment. Lower nuclei volumes were linked to higher intensity of neonatal treatment, indicating vulnerability to stress exposure after birth. Furthermore, we found that single results for lateral, medial, and pulvinar nuclei volumes were associated with full-scale intelligence quotient in preterm adults, albeit not surviving correction for multiple hypotheses testing.These findings provide evidence that lower thalamic volume in preterm adults is observable across all subregions rather than focused on single nuclei. Data suggest the same mechanisms of aberrant thalamus development across all nuclei after premature birth.

O-307 Decrease of human sperm hypercondensed chromatin volume after slow freezing revealed by three-dimensional (3D) nuclear morphometry

Abstract Study question Are the 3D morphometry parameters of the human sperm nucleus affected by slow freezing? Summary answer The slow freezing-thawing cycle induces significant alterations on hypercondensed nucleus zone by reducing its volume and splits it into several small zones. What is known already Sperm cryopreservation is an essential technique for infertility care, but it seems to highly affect the genetic and epigenetic integrity of sperm nuclei with poorly identified mechanisms. Moreover, it is known that sperm nuclear alterations may be involved in pregnancy failures. Therefore, sperm nuclear biomarkers are an essential issue to assess the outcome of ART procedures when frozen sperm is used. Thereby, 3D visualization of chromatin is a good way to understand modifications in the organization and composition of sperm chromatin after a slow freezing procedure. Study design, size, duration Ten semen of patients were analyzed (Germetheque biobank) after informed consent. Standard semen parameters, DNA fragmentation, chromatin decondensation, sperm telomere length (STL) and 3D nuclear morphometry were performed before and after slow freezing. Morphometric measurements were performed from a digital representation of the sperm nucleus in 3 dimensions that allow us to measure the volume, flatness and elongation of each sperm nucleus and characterize hypercondensed zones, with live/dead spermatozoa distinction. Participants/materials, setting, methods After addition of cryoprotective medium v/v (Cryosperm®), sperm was frozen with a programmable freezer (NanoDigitcool®). Standards sperm parameters were measured in accordance with WHO guidelines 2021, DNA fragmentation by flow cytometry TUNEL assay, chromatin decondensation by epifluorescent microscopy with Chromomycin A3 and STL using qPCR. 3D nuclear representation was performed by a z-axis image acquisition series of DAPI/PI stained slides with optigrid epifluorescent microscopy. Analyses were carried out using the NucleusJ2.0 software with NODeJ plugin. Main results and the role of chance Freezing induces an alteration of sperm vitality (p &amp;lt; 0.0001) and progressive and total motility (p &amp;lt; 0.001 and p &amp;lt; 0.0001 respectively) and an increase in the percentage of sperm with DNA fragmentation (18.30% fresh vs 31.6% frozen, p &amp;lt; 0.05). We did not observe a modification of the median volume of the sperm nucleus before and after freezing (37.15 [IC = 36.5;38.14] and 37.10 [33.27;37.78] µm3 respectively), as the same for flatness and elongation (2.48 vs. 2.50 a.u. and 2.04 vs. 2.04 a.u. respectively). Nevertheless, five samples showed significant alterations of nucleus volume (p &amp;lt; 0.0001), due to diminution of flatness and more or less elongated. A significant decrease of the total volume of the hypercondensed chromatin zone was observed after freezing (0.94 [0.84;0.99] before vs. 0.61 [0.53;0.69] µm3 after freezing-thawing, p &amp;lt; 0.0001), with an effect size of -1.48 [-2.10; -0.86]. Decrease of total volume of hypercondensed region was measured homogeny in all the samples tested, particularly on live (1.00 vs. 0.68 µm3 respectively, p &amp;lt; 0.0001) compared with dead spermatozoa (0.72 vs. 0.57 µm3, p &amp;lt; 0.05). We showed also a significant increase of the number of hypercondensed zones in each nucleus (p &amp;lt; 0.001), reflecting a split into several parts of the hypercondensed chromatin. Limitations, reasons for caution A 3D-FISH analysis would allow to characterize the hypercondensed chromatin portion, probably as heterochromatin and which we suspect to be the nucleus ring. Moreover, a chromosomes specific marking would allow for the identification of whether whole chromosomes or specific parts of chromosomes (centromeres or telomeres) are affected by this decompaction. Wider implications of the findings This study is the first to make exacts measurements of human sperm nucleus because of a non-decondensing method. We demonstrate that slow freezing affects hypercondensed chromatin probably through a decondensation and modification of the nucleus-specific organization. This new assessment will allow a better proficiency of men fertility preservation techniques. Trial registration number NCT04715828

Tracking longitudinal thalamic volume changes during early stages of SCA1 and SCA2

PurposeSpinocerebellar ataxia SCA1 and SCA2 are adult-onset hereditary disorders, due to triplet CAG expansion in their respective causative genes. The pathophysiology of SCA1 and SCA2 suggests alterations of cerebello-thalamo-cortical pathway and its connections to the basal ganglia. In this framework, thalamic integrity is crucial for shaping efficient whole-brain dynamics and functions. The aims of the study are to identify structural changes in thalamic nuclei in presymptomatic and symptomatic SCA1 and SCA2 patients and to assess disease progression within a 1-year interval.Material and methodsA prospective 1-year clinical and MRI assessment was conducted in 27 presymptomatic and 23 clinically manifest mutation carriers for SCA1 and SCA2 expansions. Cross-sectional and longitudinal changes of thalamic nuclei volume were investigated in SCA1 and SCA2 individuals and in healthy participants (n = 20).ResultsBoth SCA1 and SCA2 patients had significant atrophy in the majority of thalamic nuclei, except for the posterior and partly medial nuclei. The 1-year longitudinal evaluation showed a specific pattern of atrophy in ventral and posterior thalamus, detectable even at the presymptomatic stage of the disease.ConclusionFor the first time in vivo, our exploratory study has shown that different thalamic nuclei are involved at different stages of the degenerative process in both SCA1 and SCA2. It is therefore possible that thalamic alterations might significantly contribute to the progression of the disease years before overt clinical manifestations occur.

Volumetric and functional connectivity changes of the thalamic nuclei in different stages of Alzheimer’s disease

ObjectiveMemory processes known to be impaired in Alzheimer’s disease (AD) are maintained by a large-scale neurocognitive network with subcortical components, including the thalamus. Therefore, we aimed to examine the volumetric and functional changes of the thalamic nuclei at different scales across AD stages. MethodsMRI data of patients diagnosed with 20 AD dementia (ADD), 30 amnestic mild cognitive impairment (MCI), and 30 subjective cognitive impairment (SCI) were used. Volumetric and functional connectivity analyzes were performed by dividing the thalamus into anterior, medial, posterior, lateral and intralaminar nucleus groups and their specific subnuclei. ResultsIn the course of AD, the volume of the medial group nuclei, especially the mediodorsal medial magnocellular (MDm) nucleus, decreases. Medial group nuclei and MDm functional connectivity with frontal areas were decreased both in ADD and MCI compared to SCI group, while both of them increased their functional connectivity with visual areas in the ADD group compared to the MCI group. ConclusionsOur study suggests that the medial group of the thalamus, and specifically the MDm, may be affected in AD. SignificanceSpecific thalamic nuclei may be a critical anatomical region for investigating structural and functional changes in AD.

Subcortical Brain Volumes and Neurocognitive Function in Children With Perinatal HIV Exposure: A Population-Based Cohort Study in South Africa.

Children who are HIV-exposed and uninfected (HEU) are at risk for early neurodevelopmental impairment. Smaller basal ganglia nuclei have been reported in neonates who are HEU compared to HIV-unexposed (HU); however, neuroimaging studies outside infancy are scarce. We examined subcortical brain structures and associations with neurocognition in children who are HEU. This neuroimaging study was nested within the Drakenstein Child Health Study birth cohort in South Africa. We compared (T1-weighted) magnetic resonance imaging-derived subcortical brain volumes between children who were HEU (n = 70) and HU (n = 92) at age 2-3 years using linear regression. Brain volumes were correlated with neurodevelopmental outcomes measured with the Bayley Scales of Infant and Toddler Development III. Compared to HU children, on average children who were HEU had 3% lower subcortical grey matter volumes. Analyses of individual structures found smaller volume of the putamen nucleus in the basal ganglia (-5% difference, P = .016) and the hippocampus (-3% difference, P = .044), which held on adjustment for potential confounders (P < .05). Maternal viremia and lower CD4 count in pregnancy were associated with smaller child putamen volumes. Children who were HEU had lower language scores than HU; putamen and hippocampus volumes were positively correlated with language outcomes. Overall, children who are HEU had a pattern of smaller subcortical volumes in the basal ganglia and hippocampal regions compared to HU children, which correlated with language function. Findings suggest that optimizing maternal perinatal HIV care is important for child brain development. Further studies are needed to investigate underlying mechanisms and long-term outcomes.

Relationship Between Excessive Daytime Sleepiness and Caudate Nucleus Volume in Patients with Subjective Cognitive Decline: A Study from the SILCODE Using the Volbrain.

Excessive daytime sleepiness (EDS) and caudate nucleus volume alterations have been linked to Alzheimer's disease (AD), but their relationship remains unclear under the context of subjective cognitive decline (SCD). This study aimed to investigate the relationship between EDS and caudate nucleus volume in patients with SCD. The volume of entire brain was measured in 170 patients with SCD, including 37 patients with EDS and 133 non-EDS, from the Sino Longitudinal Study on Cognitive Decline (SILCODE). Participants underwent a comprehensive assessment battery, including neuropsychological and clinical evaluations, blood tests, genetic analysis for APOE ɛ4, and structural MRI scans analyzed using the fully automated segmentation tool, volBrain. Patients with EDS had significantly increased volume in the total and left caudate nucleus compared to non-EDS. The most significant cognitive behavioral factor associated with caudate nucleus volume in the EDS was the Auditory Verbal Learning Test-recognition. These findings suggest that EDS may be associated with alterations in caudate nucleus volume, particularly in the left hemisphere, in the context of SCD. Further research is necessary to understand the underlying mechanisms of this relationship and its implications for clinical management.

Alteration in amygdala subfield volumes and their association with cognition in mild cognitive impairment.

The amygdala has an important role in cognitive and affective functions. The involvement of amygdala and related limbic structures is implicated in many aspects of memory and emotion in mild cognitive impairment (MCI). In the present study, we aimed to compare the volumetric measurements of amygdala and its subfields as well as their association with cognitive functions in stable MCI (sMCI). We performed Addenbrooke's cognitive examination III (ACE-III) test, as well as high-resolution T1-weighted images from 31 participants with sMCI and 31 age-matched healthy controls. The amygdala subfield volumes were extracted using Freesurfer software, and group differences were assessed using general linear model (GLM) with age, gender, education and estimated intracranial volume (ICV) as covariates. Partial correlation was also calculated between cognitive scores and volumes of amygdala subfields in healthy controls and sMCI participants controlling for estimated ICV. sMCI participants exhibited significantly reduced volumes in most of the right amygdala subfields, including basal nucleus, accessory basal nucleus, central nucleus, medial nucleus, corticoamygdaloid transition area, and whole amygdala, as well as significantly reduced right amygdala/hippocampus ratio compared to healthy controls. In addition, our results revealed statistically significant positive correlations between ACE memory scores and the volumes of right central nucleus, right medial nucleus, right cortical nucleus, and the right whole amygdala, in sMCI. Our findings revealed volumetric reductions in most of the right amygdala subfields along with its association with the memory functions in sMCI. These findings provide valuable insights into the underlying anatomical factors contributing to neurocognitive symptoms in MCI.

Evaluation of Scatterer Parameters From Ultrasound Scattering Models Taking Into Account Scattering From Nuclei and Cells of Cell-Pellet Biophantoms and Ex Vivo Tumors.

The Quantitative Ultrasound backscatter coefficient provides the capability to evaluate tissue microstructure parameters. Tissue-based scatterer parameters are extracted using ultrasound scattering models. It is challenging to correlate ultrasound scatterer parameters of tissue structures from optical-measured histology, possibly because of inappropriate scattering models or the presence of multiple scatterers. The objective of this study is to pursue the quantification of pertinent scatterer parameters with scattering models that consider ultrasound scattering from nuclei and cells. The concentric sphere model (CSM) and the structure factor model adapted for two types of scatterers (SFM2) are evaluated for cell-pellet biophantoms and ex vivo tumors of four cell lines: 4T1, JC, LMTK, and MAT. The structure factor model (SFM) was used for comparison. CSM and SFM2 provided scatterer parameters closer to histology (lower relative errors) for nucleus and cell radii and volume fractions than SFM but were not always accompanied by lower dispersion of the scatterer distribution (lower coefficient of variation). CSM and SFM2 quantified cell and nucleus radius and volume fraction parameters with lower relative error compared to SFM. For tumors, CSM provided better results than SFM2.