Cerebellar Gray Matter Volume Research Articles

P584. Low Premorbid Cognitive Function in Psychosis is Associated With Smaller Cognitive and Motor Cerebellar Regions

Prominent neural models hypothesize that the cerebellum contributes to psychosis pathophysiology and may be developmental in nature. Studies find smaller cerebellar grey matter volume, with recent region-specific studies noting robust effects in posterior (‘cognitive’-related) lobules in schizophrenia. Whether these deficits are associated with clinical phenotypes, including cognitive impairment, remains unclear.

Increased Cerebellar Gray Matter Volume in Athletes: A Voxel-Wise Coordinate-Based Meta-Analysis

ABSTRACT Purpose: The purpose of this systematic review and meta-analysis study was to investigate distinct brain structural characteristics in athletes as compared with those in non-athletes by quantifying regional gray matter (GM) volume changes using voxel-based morphometry analysis based on a whole-brain approach.Methods: The systematic literature search was conducted from November 1, 2020 to October 18, 2021 via the two search engines including the PubMed and Web of Science. We included 13 studies that reported GM volume data in 229 athletes as compared 219 non-athletes based on the whole-brain analysis with specific three-dimensional coordinates in a standard stereotactic space. Thus, we performed a coordinate-based meta-analysis using the seed-based d mapping via permutation of subject images methods.Result: The coordinate-based meta-analysis reported that the athletes significantly reveal greater regional GM volume across right cerebellar lobules IV–V and Brodmann area 37 regions than those in the non-athletes with minimal levels of heterogeneity and publication bias between the included studies. The subgroup analyses show that greater GM volume for athletes in closed-skill sports appeared across the right cerebellar hemispheric lobules VIII and the right cingulum than those for non-athletes.Conclusion: These cumulative findings from multiple brain imaging studies suggest potential brain plasticity evidence in the athletes who experienced extensive motor training.

Cerebellar Structure and Cognitive Ability in Psychosis

BackgroundDysconnectivity theories, combined with advances in fundamental cognitive neuroscience, have led to increased interest in characterizing cerebellar abnormalities in psychosis. Smaller cerebellar gray matter volume has been found in schizophrenia spectrum disorders. However, the course of these deficits across illness stage, specificity to schizophrenia (vs. psychosis more broadly), and relationship to clinical phenotypes, primarily cognitive impairment, remain unclear. MethodsThe Spatially Unbiased Infratentorial toolbox, a gold standard for analyzing human neuroimaging data of the cerebellum, was used to quantify cerebellar volumes and conduct voxel-based morphometry on structural magnetic resonance images obtained from 574 individuals (249 schizophrenia spectrum, 108 bipolar with psychotic features, 217 nonpsychiatric control). Analyses examining diagnosis (schizophrenia spectrum, bipolar disorder), illness stage (early, chronic), and cognitive effects on cerebellum structure in psychosis were performed. ResultsCerebellar structure in psychosis did not differ significantly from healthy participants, regardless of diagnosis and illness stage (effect size = 0.01–0.14). In contrast, low premorbid cognitive functioning was associated with smaller whole and regional cerebellum volumes, including cognitive (lobules VI and VII, Crus I, frontoparietal and attention networks) and motor (lobules I–IV, V, and X; somatomotor network) regions in psychosis (effect size = 0.36−0.60). These effects were not present in psychosis cohorts with average estimated premorbid cognition. ConclusionsCerebellar structural abnormalities in psychosis are related to lower premorbid cognitive functioning implicating early antecedents, atypical neurodevelopment, or both in cerebellar dysfunction. Future research focused on identifying the impact of early-life risk factors for psychosis on the development of the cerebellum and cognition is warranted.

Comparing brain asymmetries independently of brain size

Studies examining cerebral asymmetries typically divide the l-R Measure (e.g., Left–Right Volume) by the L + R Measure to obtain an Asymmetry Index (AI). However, contrary to widespread belief, such a division fails to render the AI independent from the L + R Measure and/or from total brain size. As a result, variations in brain size may bias correlation estimates with the AI or group differences in AI. We investigated how to analyze brain asymmetries in to distinguish global from regional effects, and report unbiased group differences in cerebral asymmetries in the UK Biobank (N = 40, 028).We used 306 global and regional brain measures provided by the UK Biobank. Global gray and white matter volumes were taken from Freesurfer ASEG, subcortical gray matter volumes from Freesurfer ASEG and subsegmentation, cortical gray matter volumes, mean thicknesses, and surface areas from the Destrieux atlas applied on T1-and T2-weighted images, cerebellar gray matter volumes from FAST FSL, and regional white matter volumes from Freesurfer ASEG.We analyzed the extent to which the L + R Measure, Total Cerebral Measure (TCM, e.g., Total Brain Volume), and l-R TCM predict regional asymmetries. As a case study, we assessed the consequences of omitting each of these predictors on the magnitude and significance of sex differences in asymmetries.We found that the L + R Measure, the TCM, and the l-R TCM predicted the AI of more than 89% of regions and that their relationships were generally linear. Removing any of these predictors changed the significance of sex differences in 33% of regions and the magnitude of sex differences across 13–42% of regions. Although we generally report similar sex and age effects on cerebral asymmetries to those of previous large-scale studies, properly adjusting for regional and global brain size revealed additional sex and age effects on brain asymmetry.

Post-Concussive Vestibular Dysfunction Is Related to Injury to the Inferior Vestibular Nerve.

Symptoms of vestibular dysfunction such as dizziness and vertigo are common after sports-related concussions (SRC) and associated with a worse outcome and a prolonged recovery. Vestibular dysfunction after SRC can be because of an impairment of the peripheral or central neural parts of the vestibular system. The aim of the present study was to establish the cause of vestibular impairment in athletes with SRC who have persisting post-concussive symptoms (PPCS). We recruited 42 participants—21 athletes with previous SRCs and PPCS ≥6 months and 21 healthy athletic age- and sex-matched controls—who underwent symptom rating, a detailed test battery of vestibular function and 7T magnetic resonance imaging with diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) of cerebellar white matter tracts, and T1-weighted imaging for cerebellar volumetrics. Vestibular dysfunction was observed in 13 SRC athletes and three controls (p = 0.001). Athletes with vestibular dysfunction reported more pronounced symptoms on the Dizziness Handicap Inventory (DHI; p < 0.001) and the Hospital Anxiety and Depression Scale (HADS; p < 0.001). No significant differences in DTI metrics were found, while in DKI two metrics were observed in the superior and/or inferior cerebellar tracts. Cerebellar gray and white matter volumes were similar in athletes with SRC and controls. Compared with controls, pathological video head impulse test results (vHIT; p < 0.001) and cervical vestibular evoked myogenic potentials (cVEMP; p = 0.002) were observed in athletes with SRC, indicating peripheral vestibular dysfunction and specifically suggesting injury to the inferior vestibular nerve. In athletes with persisting symptoms after SRC, vestibular dysfunction is associated with injury to the inferior vestibular nerve.

Cerebellar Grey Matter Volumes in Reactive Aggression and Impulsivity in Healthy Volunteers

Several lines of evidence point towards the involvement of the cerebellum in reactive aggression. In addition to the posterior cerebellar hemisphere, the vermis has been suggested to play a prominent role in impulse regulation. In the present study, we set out to further examine the relationships between cerebellar grey matter volumes, aggression, and impulsivity in 201 healthy volunteers. 3 T structural magnetic resonance imaging scans were acquired to investigate grey matter volumes of the cerebellar vermis and the anterior and posterior lobules. Aggression was assessed with the Buss–Perry Aggression Questionnaire and impulsivity was measured with the Barratt Impulsiveness Scale-11. Results showed that impulsivity was positively associated with grey matter volumes of the cerebellar vermis and inversely correlated with grey matter volumes of the right posterior lobule. In addition, smaller volumes of the right posterior lobules were associated with higher physical aggression. Exploratory analyses indicated that for the right hemisphere, this association was driven by grey matter volumes of lobules VIIb and VIIIa. Our findings provide correlational evidence in healthy volunteers for the involvement of the cerebellar vermis and posterior lobules in a cortico-limbic-cerebellar circuit of aggression.

Neuropsychological correlates of cerebellar volumes in multiple sclerosis: an MRI volumetric analysis study.

The hallmark of Multiple Sclerosis (MS) pathophysiology is the damage to the myelin sheath around axons. The cerebellum is a predilection site for demyelination with a well-recognized role in motor and a rather understudied contribution to cognitive functions. The aim of this study is to investigate patterns of cerebellar grey and white matter pathology, expressed as reduced volume, as well as cortical thickness and their potential contribution to cognitive performance and disability status of patients with MS. 24 patients with MS underwent extensive neuropsychological assessment using paper and pencil tests and the Brain Health Assessment (BHA) tablet-based battery. Cerebellar lobular volumes and thickness were calculated using a volumetric analysis with automated segmentation of the cerebellum and its lobules. The main findings are a reduction of cerebellar grey matter (CGMV) and white matter volumes (CWMV) in lobule X and a widespread cerebellar cortical thinning in patients. Overall disease severity and neurological disability, assessed with the Expanded Disability Status Severity Scale, was correlated with fatigue and information processing speed tasks, but not with CGMV and CWMV. CWMV and CGMV of lobule I-II was negatively correlated with information processing speed, as well as visuospatial memory tests and, finally, inverse cortical thinning associations were noted between the whole cerebellum, lobule I-II, lobule III, lobule VI, Crus I, lobule VIIIA and information processing speed and verbal fluency tasks. The inverse associations observed may represent a compensatory mechanism activated in MS engaging additional high-level cortical areas functionally interconnected with the damaged cerebellum, in order to cope with the cognitive demands of a task.

Altered cerebellar gray matter and cerebellar-cortex resting-state functional connectivity in patients with bipolar disorder Ⅰ

BackgroundBipolar disorder (BP) is a common psychiatric disorder characterized by extreme fluctuations in mood. Recent studies have indicated the involvement of cerebellum in the pathogenesis of BP. However, no study has focused on the precise role of cerebellum exclusively in patients with bipolar I disorder (BP-I). MethodsForty-five patients with BP-I and 40 healthy controls were recruited. All subjects underwent clinical evaluation and Magnetic Resonance diffusion Tension Imaging scans. For structural images, we used a spatially unbiased infratentorial template toolbox to isolate the cerebellum and then preformed voxel-based morphometry (VBM) analyses to assess the difference in cerebellar gray matter volume (GMV) between the two groups. For the functional images, we chose the clusters that survived from VBM analysis as seeds and performed functional connectivity (FC) analysis. Between-group differences were assessed using the independent Students t test or the nonparametric Mann‐Whitney U Test. For multiple comparisons, the results were further corrected with Gaussian random field (GRF) approach (voxel-level P < 0.001, cluster-level P < 0.05). ResultsCompared with healthy controls, BP-I patients showed significantly decreased GMV in left lobule V and left lobule VI (P < 0.05, GRF corrected). The FC of cerebellum with bilateral superior temporal gyrus, bilateral insula, bilateral rolandic operculum, right putamen, and left precentral gyrus was disrupted in BP-I patients (P < 0.05, GRF corrected). ConclusionsBP-I patients showed decreased cerebellar GMV and disrupted cerebellar-cortex resting-state FC. This suggests that cerebellar abnormalities may play an important role in the pathogenesis of BP-I.

Cerebellar pathology in motor neuron disease: neuroplasticity and neurodegeneration.

Amyotrophic lateral sclerosis is a relentlessly progressive multi-system condition. The clinical picture is dominated by upper and lower motor neuron degeneration, but extra-motor pathology is increasingly recognized, including cerebellar pathology. Post-mortem and neuroimaging studies primarily focus on the characterization of supratentorial disease, despite emerging evidence of cerebellar degeneration in amyotrophic lateral sclerosis. Cardinal clinical features of amyotrophic lateral sclerosis, such as dysarthria, dysphagia, cognitive and behavioral deficits, saccade abnormalities, gait impairment, respiratory weakness and pseudobulbar affect are likely to be exacerbated by co-existing cerebellar pathology. This review summarizes in vivo and post mortem evidence for cerebellar degeneration in amyotrophic lateral sclerosis. Structural imaging studies consistently capture cerebellar grey matter volume reductions, diffusivity studies readily detect both intra-cerebellar and cerebellar peduncle white matter alterations and functional imaging studies commonly report increased functional connectivity with supratentorial regions. Increased functional connectivity is commonly interpreted as evidence of neuroplasticity representing compensatory processes despite the lack of post-mortem validation. There is a scarcity of post-mortem studies focusing on cerebellar alterations, but these detect pTDP-43 in cerebellar nuclei. Cerebellar pathology is an overlooked facet of neurodegeneration in amyotrophic lateral sclerosis despite its contribution to a multitude of clinical symptoms, widespread connectivity to spinal and supratentorial regions and putative role in compensating for the degeneration of primary motor regions.

Late chronotype is linked to greater cortical thickness in the left fusiform and entorhinal gyri

ABSTRACT Humans can be classified as early, intermediate and late chronotypes based on their preferred sleep and wakefulness patterns. Eveningness is associated with increased risk of developing several psychiatric conditions, such as major depressive and addictive disorders, however, the anatomical basis of chronotype distinctions, which might predispose to the above conditions, remains largely unexplored. Using magnetic resonance imaging data from 113 healthy young adults (71 females), we aimed to correlate individual chronotype scores with cortical thickness, as well as subcortical and cerebellar grey matter volume. The results revealed one cluster located in the left fusiform and entorhinal gyri showing increased cortical thickness with increasing preference for eveningness. These structures are well positioned to mediate well-established chronotype differences in affective processing, i.e. increased negative affect in late chronotypes. Furthermore, in line with the earlier findings, we found no differences in subcortical and cerebellar grey matter volume. Thus, our study confirms that circadian preference is associated with specific structural cortical substrates and provides a potential anatomical basis for differential affective functioning in morning- and evening-oriented individuals, bridging the gap between brain structure and function.

Associations between neurofilament light-chain protein, brain structure, and chronic kidney disease.

Background:Neurofilament light chain (NfL) protein is a blood-based marker of neuroaxonal injury. We sought to 1) compare plasma NfL levels in children with chronic kidney disease (CKD) and healthy peers, 2) characterize the relationship between NfL level and kidney function, and 3) evaluate NfL as a predictor of abnormal brain structure in CKD.Methods:Sixteen children with CKD due to congenital kidney anomalies and 23 typically developing peers were included. Plasma NfL was quantified using single-molecule array immunoassay. Participants underwent structural magnetic resonance imaging. Multiple linear regression models were used to evaluate the association between plasma NfL levels, kidney function, and brain structure.Results:An age × group interaction was identified whereby NfL levels increased with age in the CKD group only (estimate = 0.65; CI = 0.08–1.22; p = 0.026). Decreased kidney function was associated with higher NfL levels (estimate = −0.10; CI = −0.16 to −0.04; p = 0.003). Lower cerebellar gray matter volume predicted increased plasma NfL levels (estimate = −0.00024; CI = −0.00039–0.00009; p = 0.004) within the CKD group.Conclusion:Children with CKD show accelerated age-related increase in NfL levels. NfL level is associated with lower kidney function and abnormal brain structure in CKD.

Emotion recognition in individuals with cocaine use disorder: the role of abstinence length and the social brain network.

Emotion recognition is impaired in drug addiction. However, research examining the effects of cocaine use on emotion recognition yield mixed evidence with contradictory results potentially reflecting varying abstinence durations. Therefore, we investigated emotion recognition and its neural correlates in individuals with cocaine use disorder (CUD) parsed according to abstinence duration. Emotion recognition performance was compared between current cocaine users (CUD + , n = 28; cocaine-positive urine), short-term abstainers (CUD-ST, n = 23; abstinence < 6months), long-term abstainers (CUD-LT, n = 20; abstinence ≥ 6months), and controls (n = 45). A sample subset (n = 73) underwent structural magnetic resonance imaging to quantify regional gray matter volume (GMV) using voxel-based morphometry. CUD + demonstrated greater difficulty recognizing happiness than CUD-ST and controls, and sadness and fear compared to controls (p < 0.01). For fear, CUD-ST also performed worse than controls (p < 0.01), while no differences emerged between CUD-LT and controls. Whole-brain analysis revealed lower GMV in the bilateral cerebellum in CUD + compared to CUD-LT and controls; a similar pattern was observed in the amygdala (CUD + < CUD-LT) (pFWE < 0.01). Collapsed across all participants, poorer recognition for happiness was associated with lower right cerebellar GMV (pFWE < 0.05). Emotion recognition is impaired with current cocaine use, and selective deficits (in fear) may persist with up to 6months of abstinence. Lower cerebellar GMV may underlie deficits in positive emotion recognition. Interventions targeting emotional-social-cognitive deficits, especially among active users, may enhance treatment success for individuals with CUD.

Effects of Short- and Long-Term Aerobic-Strength Training and Determinants of Walking Speed in the Elderly

Background/Aims: Walking speed (WS) is an objective measure of physical capacity and a modifiable risk factor of morbidity and mortality in the elderly. In this study, we (i) determined effects of 3-month supervised aerobic-strength training on WS, muscle strength, and habitual physical activity; (ii) evaluated capacity of long-term (21 months) training to sustain higher WS; and (iii) identified determinants of WS in the elderly. Methods: Volunteers (F 48/M 14, 68.4 ± 7.1 years) completed either 3-month aerobic-strength (3 × 1 h/week, n = 48) or stretching (active control, n = 14) intervention (study A). Thirty-one individuals (F 24/M 7) from study A continued in supervised aerobic-strength training (2 × 1 h/week, 21 months) and 6 (F 5/M 1) became nonexercising controls. Results: Three-month aerobic-strength training increased preferred and maximal WS (10-m walk test, p < 0.01), muscle strength (p < 0.01) and torque (p < 0.01) at knee extension, and 24-h habitual physical activity (p < 0.001), while stretching increased only preferred WS (p < 0.03). Effect of training on maximal WS was most prominent in individuals with baseline WS between 1.85 and 2.30 m·s−1. Maximal WS measured before intervention correlated negatively with age (r = −0.339, p = 0.007), but this correlation was weakened by the intervention (r = −0.238, p = 0.06). WS progressively increased within the first 9 months of aerobic-strength training (p < 0.001) and remained elevated during 21-month intervention (p < 0.01). Cerebellar gray matter volume (MRI) was positively associated with maximal (r = 0.54; p < 0.0001) but not preferred WS and explained >26% of its variability, while age had only minor effect. Conclusions: Supervised aerobic-strength training increased WS, strength, and dynamics of voluntary knee extension as well as habitual physical activity in older individuals. Favorable changes in WS were sustainable over the 21-month period by a lower dose of aerobic-strength training. Training effects on WS were not limited by age, and cerebellar cortex volume was the key determinant of WS.

Machine learning classifier to identify clinical and radiological features relevant to disability progression in multiple sclerosis

ObjectivesTo evaluate the accuracy of a data-driven approach, such as machine learning classification, in predicting disability progression in MS.MethodsWe analyzed structural brain images of 163 subjects diagnosed with MS acquired at two different sites. Participants were followed up for 2–6 years, with disability progression defined according to the expanded disability status scale (EDSS) increment at follow-up. T2-weighted lesion load (T2LL), thalamic and cerebellar gray matter (GM) volumes, fractional anisotropy of the normal appearing white matter were calculated at baseline and included in supervised machine learning classifiers. Age, sex, phenotype, EDSS at baseline, therapy and time to follow-up period were also included. Classes were labeled as stable or progressed disability. Participants were randomly chosen from both sites to build a sample including 50% patients showing disability progression and 50% patients being stable. One-thousand machine learning classifiers were applied to the resulting sample, and after testing for overfitting, classifier confusion matrix, relative metrics and feature importance were evaluated.ResultsAt follow-up, 36% of participants showed disability progression. The classifier with the highest resulting metrics had accuracy of 0.79, area under the true positive versus false positive rates curve of 0.81, sensitivity of 0.90 and specificity of 0.71. T2LL, thalamic volume, disability at baseline and administered therapy were identified as important features in predicting disability progression. Classifiers built on radiological features had higher accuracy than those built on clinical features.ConclusionsDisability progression in MS may be predicted via machine learning classifiers, mostly evaluating neuroradiological features.

Design-based stereological study of the guinea-pig (Cavia porcellus) cerebellum.

Guinea pigs have proved useful as experimental animal models in studying cerebellar anatomical and structural alterations in human neurological disease; however, they are also currently acquiring increasing veterinary interest as companion animals. The morphometric features of the normal cerebellum in guinea pigs have not been previously investigated using stereology. The objective of the present work was to establish normal volumetric and quantitative stereological parameters for cerebellar tissues in guinea pigs, by means of unbiased design-based stereology. Cerebellar total volume, gray and white matter volume fractions, molecular and granular layers volume fractions, cerebellar surface area, Purkinje cellular and nuclear volumes, and the Purkinje cell total count were stereologically estimated. For this purpose, cerebellar hemispheres from six adult male guinea pigs were employed. Isotropic, uniform random sections were obtained by applying the orientator method, and subsequently processed for light microscopy. The cerebellar total volume, the white and grey matter volume fractions, and the molecular and granular layer volumes were estimated using the Cavalieri's principle and the point counting system. The cerebellar surface area was estimated through the use of test lines; Purkinje cellular and nuclear volumes were analysed using the nucleator technique, whereas the Purkinje cell total count was obtained by means of the optical disector technique. The mean±standard deviation total volume of a guinea-pig cerebellar hemisphere was 0.11±0.01cm3 . The mean volumetric proportions occupied by the gray and white matters were, respectively, 78.0±2.6% and 22.0±2.6%, whereas their mean absolute volumes were found to be 0.21±0.02cm3 and 0.059±0.006cm3 . The volumes of the molecular and granular layers were estimated at 112.4±20.6mm3 and 104.4±7.3mm3 , whereas their mean thicknesses were calculated to be 0.184±0.020mm and 0.17±0.02mm. The molecular and granular layers accounted for 40.7±3.9% and 37.4±1.8% of total cerebellar volume respectively. The surface area of the cerebellum measured 611.4±96.8mm2 . Purkinje cells with a cellular volume of 3210.1µm3 and with a nuclear volume of 470.9µm3 had a higher incidence of occurrence. The mean total number of Purkinje cells for a cerebellar hemisphere was calculated to be 253,090±34,754. The morphometric data emerging from the present study provide a set of reference data which might prove valuable as basic anatomical contribution for practical applications in veterinary neurology.

Changes in Resting-State Functional Connectivity of Cerebellum in Amnestic Mild Cognitive Impairment and Alzheimer's Disease: A Case-Control Study.

This case-control study is aimed to investigate the correlation of altered functional connectivity (FC) in cerebellum with cognitive impairment in amnestic mild cognitive impairment (aMCI) and Alzheimer’s disease (AD). The morphometric and resting-state FC MRI analysis including 46 participants with AD, 32 with aMCI and 42 age-matched normal controls (NCs) were conducted. We compared the cerebellar gray matter volume and cerebellar FC with cerebral cortical regions among three groups. To investigate the relationship of cerebellar FC with cognition, we measure the correlation of significant altered FC and individual cognitive domain. No significant morphometric differences of cerebellum was observed across three groups. The patients with AD had weaker cerebral cortical FCs in bilateral Crus I and left VIIb compared to NCs, and in bilateral Crus I compared to patients with aMCI. For patients with aMCI, the weaker FC were found between right Crus I, left VIIb and cerebral cortical regions compared to NCs. The strength of left cerebellar FC positively correlated with specific cognitive subdomains, including memory, executive function, visuospatial function, and global cognition in AD and aMCI. These findings demonstrated the alteration of cerebellar FC with cerebral cortical regions, and the correlation of cerebellar FC and cognitive impairment in AD and aMCI.

The cerebellum could serve as a potential imaging biomarker of dementia conversion in patients with amyloid-negative amnestic mild cognitive impairment.

As part of network-specific neurodegeneration, changes in cerebellar gray matter (GM) volume and impaired cerebello-cerebral functional networks have been reported in Alzheimer disease (AD). Compared with healthy controls, a volume loss in the cerebellum has been observed in patients with continuum of AD. However, little is known about the anatomical or functional changes in patients with clinical AD but no brain amyloidosis. We aimed to identify the relationship between cerebellar volume and dementia conversion of amyloid-negative mild cognitive impairment (MCI). This study was a retrospective cohort study of patients over the age 50 years with amyloid-negative amnestic MCI who visited the memory clinic of Asan Medical Center with no less than a 36-month follow-up period. All subjects underwent detailed neuropsychological tests, 3 T brain magnetic resonance imaging scans including three-dimensional T1 imaging, and fluorine-18[F18 ]-florbetaben amyloid positron emission tomography scans. A spatially unbiased atlas template of the cerebellum and brainstem was used for analyzing cerebellar GM volume. During the 36months of follow-up, 39 of 107 (36.4%) patients converted to dementia from amnestic MCI. The converter group had more severe impairments in all visual memory tasks. In terms of volumetric analysis, reduced crus I/II volume adjusted with total intracranial volume, and age was observed in the converter group. Significant cerebellar GM atrophy involving the bilateral crus I/II may be a novel imaging biomarker for predicting dementia progression in amyloid-negative amnestic MCI patients.

Structural and Functional Changes in the Cerebellum and Brainstem in Patients with Benign Paroxysmal Positional Vertigo.

Benign paroxysmal positional vertigo (BPPV) is one of the most common peripheral vestibular diseases. Since the peripheral vestibular system connects with the cerebellum via the brainstem, repeated episodic vertigo may result in progressive structural and functional changes in the cerebellum and brainstem. In the present work, voxel-based morphometry (VBM) of T1-weighted images and resting-state functional magnetic resonance imaging (fMRI) in 32 patients with BPPV and 32 matched healthy controls were used to assess cerebellar and brainstem anatomical and spontaneous resting-state brain activity alterations associated with BPPV. We used a spatially unbiased infratentorial template toolbox in combination with VBM to analyze cerebellar and brainstem gray matter volume (GMV), fractional amplitude of low-frequency fluctuations (fALFF), and regional homogeneity (ReHo). Patients with BPPV showed decreased GMV in the right cerebellum posterior lobe/cerebellar tonsil extending to the cerebellum anterior lobe and pons relative to healthy controls. BPPV patients also exhibited significantly higher fALFF values in the right pons and left pons and higher ReHo values in the left cerebellum posterior lobe/Crus2 than the controls. Furthermore, the fALFF z-scores in the pons were positively correlated with the duration of vertigo at baseline and dizziness visual analog scale scores 1 week after canalith repositioning procedures (CRPs). BPPV patients exhibited structural and functional changes in the cerebellum and pons, which may reflect the adaptation and plasticity of these anatomical structures after repeated attacks of episodic vertigo. These results indicate that the changes in pons function may be closely related to residual dizziness after CRPs.

Cerebellar volumes and language functions in school-aged children born very preterm.

Volumes of cerebellar posterior lobes have been associated with cognitive skills, such as language functioning. Children born very preterm (VPT) often have language problems. However, only total cerebellar volume has been associated with language functioning, with contradicting results. The objective of this study was to ascertain whether total cerebellar structures or specific posterior lobular structures are associated with language ability of school-aged VPT children. This is a prospective cohort study of 42 school-aged VPT children without major handicaps. Structural MRI was performed and the cerebellum segmentation pipeline was used for segmentation of separate lobules. Narrative retelling assessment was performed and language content and language structure scores were extracted. Linear regression analyses were used to associate language scores with whole gray matter (GM) cerebellar volume and right Crus I+II GM volume. Whole cerebellar GM volume was not significantly associated with language content nor with language structure; however, right Crus I+II GM volume was significantly associated with language content (β = 0.192 (CI = 0.033, 0.351), p = 0.020). GM volume of Crus I+II appears to be associated with language functions in school-aged VPT children without major handicaps, while whole cerebellar volume is not. This study showed the importance of studying cerebellar lobules separately, rather than whole cerebellar volume only, in relation to VPT children's language functions. GM volume of Crus I+II is associated with semantic language functions in school-aged very preterm children without overt brain injury, whereas whole cerebellar volume is not. This study showed the importance of studying cerebellar lobules separately, rather than whole cerebellar volume only, in relation to very preterm children's language functions. This study might impact future research in very preterm children. Lobular structures rather than whole cerebellar structures should be the region of interest in relation to language functions.

Effects of Thyroid Status on Regional Brain Volumes: A Diagnostic and Genetic Imaging Study in UK Biobank.

BackgroundThyroid hormone is essential for optimal human neurodevelopment and may modify the risk of attention-deficit/hyperactivity disorder (ADHD). However, the brain structures involved are unknown and it is unclear if the adult brain is also susceptible to changes in thyroid status.MethodsWe used International Classification of Disease-10 codes, polygenic thyroid scores at different thresholds of association with thyroid traits (PT-values), and image-derived phenotypes in UK Biobank (n = 18 825) to investigate the effects of a recorded diagnosis of thyroid disease and genetic risk for thyroid status on cerebellar and subcortical gray matter volume. Regional genetic pleiotropy between thyroid status and ADHD was explored using the GWAS-pairwise method.ResultsA recorded diagnosis of hypothyroidism (n = 419) was associated with significant reductions in total cerebellar and pallidum gray matter volumes (β [95% CI] = −0.14[−0.23, −0.06], P = 0.0005 and β [95%CI] = −0.12 [−0.20, −0.04], P = 0.0042, respectively), mediated in part by increases in body mass index. While we found no evidence for total cerebellar volume alterations with increased polygenic scores for any thyroid trait, opposing influences of increased polygenic scores for hypo- and hyperthyroidism were found in the pallidum (PT < 1e−3: β [95% CI] = −0.02 [−0.03, −0.01], P = 0.0003 and PT < 1e−7: β [95% CI] = 0.02 [0.01, 0.03], P = 0.0003, respectively). Neither hypo- nor hyperthyroidism showed evidence of regional genetic pleiotropy with ADHD.ConclusionsThyroid status affects gray matter volume in adults, particularly at the level of the cerebellum and pallidum, with potential implications for the regulation of motor, cognitive, and affective function.