Resting-state functional connectivity of the vermal and hemispheric subregions of the cerebellum with both the cerebral cortical networks and subcortical structures

Learning to play badminton altered resting-state activity and functional connectivity of the cerebellar sub-regions in adults

Previous studies have shown that sport experts are different from novices in functions and structures of the cerebellar sub-regions and the functional connectivity (FC) associated with the cerebellum, suggesting the role of the cerebellum on motor skill learning (MSL). However, the manipulation of individuals with different motor skills fails to exclude the effects of innate talents. In addition, individuals with higher motor skills often start with the MSL in their young ages. It is still unclear whether the effects regarding the cerebellum would be shown at one's adult age. The present study was to directly alter individuals' motor skills to investigate whether MSL (taking learning to play badminton as an example) in adulthood influences resting-state activity in the cerebellum. To this end, young adults without ball training experience were recruited as participants and were assigned randomly into the experimental group and the control group. Participants in the experimental group were asked to attend a badminton training course for 12 weeks, while the control group did not regularly attend any ball sports during this period. Resting-state functional magnetic resonance imaging (fMRI) was recorded before and after the training. Results showed that compared to the control group, the experimental group had smaller amplitude of low-frequency fluctuation (ALFF) in right cerebellar hemispheric VI and left VIII after training. For the experimental group, right hemispheric VIII had a stronger FC with left hemispheric IV-V, cerebellar vermal IX, left middle cingulate gyrus and right hippocampus after training. Taken together, these findings suggested that MSL, at least learning to play badminton in adulthood, reduces resting-state activity in different sub-regions in the cerebellum but increases FC between sub-regions of the cerebellum as well as between sub-regions of the cerebellum and cerebral cortices (e.g., middle cingulate cortex and hippocampus).

The Cerebellar Cognitive Affective/Schmahmann Syndrome: a Task Force Paper

Sporadically advocated over the last two centuries, a cerebellar role in cognition and affect has been rigorously established in the past few decades. In the clinical domain, such progress is epitomized by the "cerebellar cognitive affective syndrome" ("CCAS") or "Schmahmann syndrome." Introduced in the late 1990s, CCAS reflects a constellation of cerebellar-induced sequelae, comprising deficits in executive function, visuospatial cognition, emotion-affect, and language, over and above speech. The CCAS thus offers excellent grounds to investigate the functional topography of the cerebellum, and, ultimately, illustrate the precise mechanisms by which the cerebellum modulates cognition and affect. The primary objective of this task force paper is thus to stimulate further research in this area. After providing an up-to-date overview of the fundamental findings on cerebellar neurocognition, the paper substantiates the concept of CCAS with recent evidence from different scientific angles, promotes awareness of the CCAS as a clinical entity, and examines our current insight into the therapeutic options available. The paper finally identifies topics of divergence and outstanding questions for further research.

The Cerebellar Cognitive Affective Syndrome in Ataxia-Telangiectasia

Ataxia-telangiectasia (AT) is an autosomal recessive, multisystem disease causing cerebellar ataxia, mucocutaneous telangiectasias, immunodeficiency, and malignancies. A pilot study reported cognitive and behavioral manifestations characteristic of the cerebellar cognitive affective / Schmahmann syndrome (CCAS). We set out to test and further define these observations because a more comprehensive understanding of the spectrum of impairments in AT is essential for optimal management. Twenty patients (12 males; 9.86 ± 5.5 years, range 4.3 to 23.2) were grouped by age: AT-I (toddlers and preschoolers, n = 7, 4.3-5.9 years), AT-II (school children, n = 7, 5.9-9.8 years), AT-III (adolescents/young adults, n = 6, 12.6-23.2 years). Standard and experimental tests investigated executive, linguistic, visual-spatial, and affective/social-cognitive domains. Results were compared to standard norms and healthy controls. Cognitive changes in AT-I were limited to mild visual-spatial disorganization. Spatial deficits were greater in AT-II, with low average scores on executive function (auditory working memory), expressive language (vocabulary), academic abilities (math, spelling, reading), social cognition (affect recognition from faces), and emotional/psychological processing. Full Scale IQ scores were low average to borderline impaired. AT-III patients had the greatest level of deficits which were evident particularly in spatial skills, executive function (auditory working memory, sequencing, word/color interference, set-shifting, categorization errors, perseveration), academic achievement, social cognition (affect recognition from faces), and behavioral control. Full Scale IQ scores in this group fell in the impaired range, while language was borderline impaired for comprehension, and low average for expression. Cognitive deficits in AT at a young age are mild and limited to visual-spatial functions. More widespread cognitive difficulties emerge with age and disease progression, impacting executive function, spatial skills, affect, and social cognition. Linguistic processing remains mildly affected. Recognition of the CCAS in children with AT may facilitate therapeutic interventions to improve quality of life.

The cerebellum under stress

Stress-related psychiatric conditions are one of the main causes of disability in developed countries. They account for a large portion of resource investment in stress-related disorders, become chronic, and remain difficult to treat. Research on the neurobehavioral effects of stress reveals how changes in certain brain areas, mediated by a number of neurochemical messengers, markedly alter behavior. The cerebellum is connected with stress-related brain areas and expresses the machinery required to process stress-related neurochemical mediators. Surprisingly, it is not regarded as a substrate of stress-related behavioral alterations, despite numerous studies that show cerebellar responsivity to stress. Therefore, this review compiles those studies and proposes a hypothesis for cerebellar function in stressful conditions, relating it to stress-induced psychopathologies. It aims to provide a clearer picture of stress-related neural circuitry and stimulate cerebellum-stress research. Consequently, it might contribute to the development of improved treatment strategies for stress-related disorders.

Developmental Changes in Task-Induced Brain Deactivation in Humans Revealed by a Motor Task

Performing tasks activates relevant brain regions in adults while deactivating task-irrelevant regions. Here, using a well-controlled motor task, we explored how deactivation is shaped during typical human development and whether deactivation is related to task performance. Healthy right-handed children (8-11 years), adolescents (12-15 years), and young adults (20-24 years; 20 per group) underwent functional magnetic resonance imaging with their eyes closed while performing a repetitive button-press task with their right index finger in synchronization with a 1-Hz sound. Deactivation in the ipsilateral sensorimotor cortex (SM1), bilateral visual and auditory (cross-modal) areas, and bilateral default mode network (DMN) progressed with development. Specifically, ipsilateral SM1 and lateral occipital deactivation progressed prominently between childhood and adolescence, while medial occipital (including primary visual) and DMN deactivation progressed from adolescence to adulthood. In adults, greater cross-modal deactivation in the bilateral primary visual cortices was associated with higher button-press timing accuracy relative to the sound. The region-specific deactivation progression in a developmental period may underlie the gradual promotion of sensorimotor function segregation required in the task. Task-induced deactivation might have physiological significance regarding suppressed activity in task-irrelevant regions. Furthermore, cross-modal deactivation develops to benefit some aspects of task performance in adults.

Cerebellar atrophy and its contribution to motor and cognitive performance in multiple system atrophy

Objective

Neuroanatomical differences in the cerebellum are among the most consistent findings in multiple system atrophy (MSA) patients. This study performed a detailed cerebellar morphology in MSA patients and its two subtypes: MSA-P (parkinson's symptoms predominate) and MSA-C (cerebellar symptoms predominant), and their relations to profiles of motor and cognitive deficits.

Materials and methods

Structure MRI data were acquired from 63 healthy controls and 61 MSA patients; voxel-based morphometry and the Spatially Unbiased Infratentorial Toolbox cerebellar atlas were performed to identify the cerebellar gray volume changes in MSA and its subtypes. Further, the gray matter changes were correlated with the clinical motor/cognitive scores.

Results

Patients with MSA exhibited widespread loss of cerebellar volume bilaterally, relative to healthy controls. In those with MSA-C, gray matter loss was detected from anterior (bilateral lobule IV-V) to posterior (bilateral crus I/II, bilateral lobule IX, left lobule VIII) cerebellar lobes. Lower anterior cerebellar volume negatively correlated with disease duration and motor performance, whereas posterior lobe integrity positively correlated with cognitive assessment. In patients with MSA-P, atrophy of anterior lobe (bilateral lobules IV-V) and posterior lobe in part (left lobule VI, bilateral IX) was evident; and in left cerebellar lobule IX, gray matter loss negatively correlated with motor scores. Direct comparison of MSA-P and MSA-C group outcomes showed divergence in right cerebellar crus II only.

Conclusions

Our data suggest that volumetric abnormalities of cerebellum contribute substantially to motor and cognitive performance in patients with MSA. In patients with MSA-P and MSA-C, affected regions of cerebellum differed.

•

Cerebellum atrophy contributed substantially to motor and cognitive behavior in MSA.

•

Lower cerebellum IV-V volume was correlated with MSA-C disease duration and severity

•

Cerebellum atrophy in one side may imply symptoms onset on contralateral

The role of the cerebellum in adaptation: ALE meta-analyses on sensory feedback error

It is widely accepted that unexpected sensory consequences of self‐action engage the cerebellum. However, we currently lack consensus on where in the cerebellum, we find fine‐grained differentiation to unexpected sensory feedback. This may result from methodological diversity in task‐based human neuroimaging studies that experimentally alter the quality of self‐generated sensory feedback. We gathered existing studies that manipulated sensory feedback using a variety of methodological approaches and performed activation likelihood estimation (ALE) meta‐analyses. Only half of these studies reported cerebellar activation with considerable variation in spatial location. Consequently, ALE analyses did not reveal significantly increased likelihood of activation in the cerebellum despite the broad scientific consensus of the cerebellum's involvement. In light of the high degree of methodological variability in published studies, we tested for statistical dependence between methodological factors that varied across the published studies. Experiments that elicited an adaptive response to continuously altered sensory feedback more frequently reported activation in the cerebellum than those experiments that did not induce adaptation. These findings may explain the surprisingly low rate of significant cerebellar activation across brain imaging studies investigating unexpected sensory feedback. Furthermore, limitations of functional magnetic resonance imaging to probe the cerebellum could play a role as climbing fiber activity associated with feedback error processing may not be captured by it. We provide methodological recommendations that may guide future studies.

Neocerebellar Crus I Abnormalities Associated with a Speech and Language Disorder Due to a Mutation in FOXP2

Bilateral volume reduction in the caudate nucleus has been established as a prominent brain abnormality associated with a FOXP2 mutation in affected members of the 'KE family', who present with developmental orofacial and verbal dyspraxia in conjunction with pervasive language deficits. Despite the gene's early and prominent expression in the cerebellum and the evidence for reciprocal cerebellum-basal ganglia connectivity, very little is known about cerebellar abnormalities in affected KE members. Using cerebellum-specific voxel-based morphometry (VBM) and volumetry, we provide converging evidence from subsets of affected KE members scanned at three time points for grey matter (GM) volume reduction bilaterally in neocerebellar lobule VIIa Crus I compared with unaffected members and unrelated controls. We also show that right Crus I volume correlates with left and total caudate nucleus volumes in affected KE members, and that right and total Crus I volumes predict the performance of affected members in non-word repetition and non-verbal orofacial praxis. Crus I also shows bilateral hypo-activation in functional MRI in the affected KE members relative to controls during non-word repetition. The association of Crus I with key aspects of the behavioural phenotype of this FOXP2 point mutation is consistent with recent evidence of cerebellar involvement in complex motor sequencing. For the first time, specific cerebello-basal ganglia loops are implicated in the execution of complex oromotor sequences needed for human speech.

Structural Variability in the Human Brain Reflects Fine-Grained Functional Architecture at the Population Level

Human brain structure topography is thought to be related in part to functional specialization. However, the extent of such relationships is unclear. Here, using a data-driven, multimodal approach for studying brain structure across the lifespan (N = 484, n = 260 females), we demonstrate that numerous structural networks, covering the entire brain, follow a functionally meaningful architecture. These gray matter networks (GMNs) emerge from the covariation of gray matter volume and cortical area at the population level. We further reveal fine-grained anatomical signatures of functional connectivity. For example, within the cerebellum, a structural separation emerges between lobules that are functionally connected to distinct, mainly sensorimotor, cognitive and limbic regions of the cerebral cortex and subcortex. Structural modes of variation also replicate the fine-grained functional architecture seen in eight well defined visual areas in both task and resting-state fMRI. Furthermore, our study shows a structural distinction corresponding to the established segregation between anterior and posterior default-mode networks (DMNs). These fine-grained GMNs further cluster together to form functionally meaningful larger-scale organization. In particular, we identify a structural architecture bringing together the functional posterior DMN and its anticorrelated counterpart. In summary, our results demonstrate that the relationship between structural and functional connectivity is fine-grained, widespread across the entire brain, and driven by covariation in cortical area, i.e. likely differences in shape, depth, or number of foldings. These results suggest that neurotrophic events occur during development to dictate that the size and folding pattern of distant, functionally connected brain regions should vary together across subjects.SIGNIFICANCE STATEMENT Questions about the relationship between structure and function in the human brain have engaged neuroscientists for centuries in a debate that continues to this day. Here, by investigating intersubject variation in brain structure across a large number of individuals, we reveal modes of structural variation that map onto fine-grained functional organization across the entire brain, and specifically in the cerebellum, visual areas, and default-mode network. This functionally meaningful structural architecture emerges from the covariation of gray matter volume and cortical folding. These results suggest that the neurotrophic events at play during development, and possibly evolution, which dictate that the size and folding pattern of distant brain regions should vary together across subjects, might also play a role in functional cortical specialization.

Local-to-distant development of the cerebrocerebellar sensorimotor network in the typically developing human brain: a functional and diffusion MRI study

Sensorimotor function is a fundamental brain function in humans, and the cerebrocerebellar circuit is essential to this function. In this study, we demonstrate how the cerebrocerebellar circuit develops both functionally and anatomically from childhood to adulthood in the typically developing human brain. We measured brain activity using functional magnetic resonance imaging while a total of 57 right-handed, blindfolded, healthy children (aged 8-11 years), adolescents (aged 12-15 years), and young adults (aged 18-23 years) (n = 19 per group) performed alternating extension-flexion movements of their right wrists in precise synchronization with 1-Hz audio tones. We also collected their diffusion MR images to examine the extent of fiber maturity in cerebrocerebellar afferent and efferent tracts by evaluating the anisotropy-sensitive index of hindrance modulated orientational anisotropy (HMOA). During the motor task, although the ipsilateral cerebellum and the contralateral primary sensorimotor cortices were consistently activated across all age groups, the functional connectivity between these two distant regions was stronger in adults than in children and adolescents, whereas connectivity within the local cerebellum was stronger in children and adolescents than in adults. The HMOA values in cerebrocerebellar afferent and efferent tracts were higher in adults than in children (some were also higher than in adolescents). The results indicate that adult-like cerebrocerebellar functional coupling is not completely achieved during childhood and adolescence, even for fundamental sensorimotor brain function, probably due to anatomical immaturity of cerebrocerebellar tracts. This study clearly demonstrated the principle of "local-to-distant" development of functional brain networks in the human cerebrocerebellar sensorimotor network.

Is there an "antisocial" cerebellum? Evidence from disorders other than autism characterized by abnormal social behaviours

The cerebellum is a hindbrain structure which involvement in functions not related to motor control and planning is being increasingly recognized in the last decades. Studies on Autism Spectrum Disorders (ASD) have reported cerebellar involvement on these conditions characterized by social deficits and repetitive motor behavior patterns. Although such an involvement hints at a possible cerebellar participation in the social domain, the fact that ASD patients present both social and motor deficits impedes drawing any firm conclusion regarding cerebellar involvement in pathological social behaviours, probably influenced by the classical view of the cerebellum as a purely "motor" brain structure. Here, we suggest the cerebellum can be a key node for the production and control of normal and particularly aberrant social behaviours, as indicated by its involvement in other neuropsychiatric disorders which main symptom is deregulated social behaviour. Therefore, in this work, we briefly review cerebellar involvement in social behavior in rodent models, followed by discussing the findings linking the cerebellum to those other psychiatric conditions characterized by defective social behaviours. Finally, possible commonalities between the studies and putative underlying impaired functions will be discussed and experimental approaches both in patients and experimental animals will also be proposed, aimed at stimulating research on the role of the cerebellum in social behaviours and disorders characterized by social impairments, which, if successful, will definitely help reinforcing the proposed cerebellar involvement in the social domain.

Altered resting-state functional connectivity of the cerebellum in schizophrenia

Structural and functional abnormalities of the cerebellum in schizophrenia have been reported. Most previous studies investigating resting-state functional connectivity (rsFC) have relied on a priori restrictions on seed regions or specific networks, which may bias observations. In this study, we aimed to elicit the connectivity alterations of the cerebellum in schizophrenia in a hypothesis-free approach. Ninety-five schizophrenia patients and 93 sex- and age-matched healthy controls underwent resting-state functional magnetic resonance imaging (fMRI). A voxel-wise data-driven method, resting-state functional connectivity density (rsFCD), was used to investigate cerebellar connectivity changes in schizophrenia patients. Regions with altered rsFCD were chosen as seeds to perform seed-based resting-state functional connectivity (rsFC) analyses. We found that schizophrenia patients exhibited decreased rsFCD in the right hemispheric VI; moreover, this cerebellar region showed increased rsFC with the prefrontal cortex and subcortical nuclei and decreased rsFC with the visual cortex and sensorimotor cortex. In addition, some rsFC changes were associated with positive symptoms. These findings suggest that abnormalities of the cerebellar hub and cerebellar-subcortical-cortical loop may be the underlying mechanisms of schizophrenia.

Reduction in gray matter of cerebellum in schizophrenia and its influence on static and dynamic connectivity

Pathophysiological and atrophic changes in the cerebellum have been well-documented in schizophrenia. Reduction of gray matter (GM) in the cerebellum was confirmed across cognitive and motor cerebellar modules in schizophrenia. Such abnormalities in the cerebellum could potentially have widespread effects on both sensorimotor and cognitive symptoms. In this study, we investigated how reduction change in the cerebellum affects the static and the dynamic functional connectivity (FC) between the cerebellum and cortical/subcortical networks in schizophrenia. Reduction of GM in the cerebellum was confirmed across the cognitive and motor cerebellar modules in schizophrenic subjects. Results from this study demonstrates that the extent of reduction of GM within cerebellum correlated with increased static FCs between the cerebellum and the cortical/subcortical networks, including frontoparietal network (FPN), and thalamus in patients with schizophrenia. Decreased GM in the cerebellum was also associated with a declined dynamic FC between the cerebellum and the FPN in schizophrenic subjects. The severity of patients' positive symptom was related to these structural-functional coupling score of cerebellum. These findings identified potential cerebellar driven functional changes associated with positive symptom deficits. A post hoc analysis exploring the effect of changed FC within cerebellum, confirmed that a significant positive relationship, between dynamic FCs of cerebellum-thalamus and intracerebellum existed in patients, but not in controls. The reduction of GM within the cerebellum might be associated with modulation of cerebellum-thalamus, and contributes to the dysfunctional cerebellar-cortical communication in schizophrenia. Our results provide a new insight into the role of cerebellum in understanding the pathophysiological of schizophrenia.

Aberrant intra and inter network resting state functional connectivity in thyrotoxicosis

Thyroid hormones epigenetically play an important role in the regularisation of neural networks and in neural differentiation during brain development. The present study aimed to explore the intra and inter network resting state functional connectivity changes underlying the neurobehavioural symptoms in thyrotoxicosis. To understand the pathophysiological changes, we investigated the correlation between functional connectivity and clinical and behavioural measures. Twenty-eight freshly diagnosed thyrotoxicosis patients suffering with symptoms such as palpitation, loss of weight, trembling and heat intolerance from days to weeks and 28 healthy controls were recruited for the study. Thyrotoxicosis patients showed significantly decreased functional connectivity in sensorimotor network, fronto-temporal network, default mode network, right fronto-parietal network, left fronto-parietal network and salience network. Inter network functional connectivity was significantly reduced between the basal ganglia network and sensorimotor network and increased between the salience network and fronto-temporal network in thyrotoxicosis. Cognitive functions such as visual retention, recognition of objects, mental balance and performance on neuropsychological tests (ie, the Bender Gestalt test, Nahar-Benson test and Mini Mental State Examination) also showed significant decline in thyrotoxicosis patients. The altered intrinsic resting state functional connectivity might underlie these cognitive deficits. The increased functional connectivity between the salience network and fronto-temporal network suggests the recruitment of additional neuronal circuitry needed to compensate for the neuropathology in the primary neural network in thyrotoxicosis.

Sensorineural hearing loss and cognitive impairments: Contributions of thalamus using multiparametric MRI

BACKGROUND

The thalamus is an integrative hub conveying sensory information between cortical areas and related to cognition. However, alterations of the thalamus following partial hearing deprivation remains unknown.

PURPOSE

To investigate the modifications of the thalamus and its seven subdivisions in terms of structure, function, and perfusion in subjects with sensorineural hearing loss (SNHL), as well as their associations with SNHL-induced cognitive impairments.

STUDY TYPE

Cross-sectional study.

SUBJECTS

Thirty-seven bilateral long-term SNHL patients and 38 well-matched controls.

FIELD STRENGTH

3 T/BOLD, T₁ -weighted imaging, arterial spin labeling (ASL).

ASSESSMENT

Quantitative measurements in the thalamus and subdivisions were obtained, including the relative volume, fractional amplitude of low-frequency fluctuation (fALFF) within slow 5 (0.01-0.027 Hz), slow 4 (0.027-0.073 Hz), and combined frequency (0.01-0.073 Hz), as well as the whole-brain functional connectivity. Twenty-five SNHL patients and 20 controls underwent ASL scanning. Then correlation analysis was computed between all significant changes and cognition tests.

STATISTICAL TESTS

Continuous and categorical variables were compared by independent-sample t-test and chi-square test, respectively. Quantitative MRI measurement comparisons were corrected for multiple comparison, and functional connectivity (FC) analysis used two-sample t-test with false-discovery rate correction. Area under the curve (AUC) in receiver operating characteristic curve analysis was applied to evaluate the power of alterations in differentiating SNHL and controls.

RESULTS

No significant difference in the relative volume and perfusion of seven thalamus subdivisions were observed, but a decrease in fALFF in SNHL. SNHL showed reduced thalamic connectivity with the cerebellum lobule VIII, ventral anterior cingulate cortex, insula, superior temporal gyrus, media temporal gyrus, medial frontal gyrus, Heschl's gyrus, and temporal pole. And some FC abnormalities exhibited positive correlations with cognitive tests and high discriminative power (0.8 < AUC < 1) in two groups.

DATA CONCLUSION

SNHL led to decreased thalamic activity and widespread weakened connectivity with other brain areas.

LEVEL OF EVIDENCE

2 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019;50:787-797.

Reorganization of the somatosensory pathway after subacute incomplete cervical cord injury

Objective

The main purpose of the present study was to investigate the possible somatosensory-related brain functional reorganization after traumatic spinal cord injury (SCI).

Methods

Thirteen patients with subacute incomplete cervical cord injury (ICCI) and thirteen age- and sex-matched healthy controls (HCs) were recruited. Eleven patients and all the HCs underwent both sensory task-related brain functional scanning and whole brain structural scanning on a 3.0 Tesla MRI system, and two patients underwent only structural scanning; the process of structural scanning was completed on thirteen patients, while functional scanning was only applied to eleven patients. We performed sensory task-related functional MRI (fMRI) to investigate the functional changes in the brain. In addition, voxel-based morphometry (VBM) was applied to explore whether any sensory-related brain structural changes occur in the whole brain after SCI.

Results

Compared with HCs, ICCI patients exhibited decreased activation in the left postcentral gyrus (postCG), the brainstem (midbrain and right pons) and the right cerebellar lobules IV-VI. Moreover, a significant positive association was found between the activation in the left PostCG and the activation in both the brainstem and the right cerebellar lobules IV-VI. Additionally, the decrease in gray matter volume (GMV) was detected in the left superior parietal lobule (SPL). The decrease of white matter volume (WMV) was observed in the right temporal lobe, the right occipital lobe, and the right calcarine gyrus. No structural change in the primary sensory cortex (S1), the secondary somatosensory cortex (S2) or the thalamus was detected.

Conclusion

These functional and structural findings may demonstrate the existence of an alternative pathway in the impairment of somatosensory function after SCI, which consists of the ipsilateral cerebellum, the brainstem and the contralateral postCG. It provides a new theoretical basis for the mechanism of sensory-related brain alteration in SCI patients and the rehabilitation therapy based on this pathway in the future.

•

We found that sensory-related brain reorganization may not occur in the thalamus in patients with ICCI.

•

We found that brain structural reorganization did not occur in the S1 or the S2 in patients with ICCI.

•

We observed that SCI can cause brain structural reorganization in non-sensory-related areas.

•

We observed that an alternative pathway may exist in the impairment of somatosensory function after SCI.

Reduced Resting State Neural Activity in the Right Orbital Part of Middle Frontal Gyrus in Anxious Depression

BACKGROUND

Anxious depression (AD), which is generally recognized as a common clinical subtype of major depressive disorder (MDD), holds distinctive features compared with unanxious depression (UAD). However, the neural mechanism of AD still remains unrevealed. To give insight to it, we compared resting-state functional magnetic resonance amplitude of low-frequency fluctuation (ALFF) and functional connectivity (FC) between AD and UAD patients.

METHOD

The data were collected from 60 AD patients, 38 UAD patients, and 60 matched healthy controls. The ALFF and seed-based FC were examined. Pearson correlations were computed between ALFF/FC and clinical measures.

RESULTS

In Comparison with the UAD group, the ALFF value of the right orbital part of middle frontal gyrus (RO-MFG) decreased in AD group. Specifically, the ALFF values of the RO-MFG were negatively correlated with retardation factor scores in AD group (r = -0.376, p = 0.003).

CONCLUSIONS

AD patients exhibited disturbed intrinsic brain function compared with UAD patients. The decreased activity of the RO-MFG is indicative of the alterations involved in the neural basis of AD.

Stridor-related gray matter alterations in multiple system atrophy: A pilot study

INTRODUCTION

The neuroanatomical substrate of stridor associated with Multiple System Atrophy (MSA) remains unclear. We evaluated stridor-related gray matter (GM) changes in MSA.

METHODS

36 MSA patients underwent standardized nocturnal video-polysomnography and brain MRI. Differences in GM density between MSA patients with and without stridor and a sample of 22 matched healthy controls were evaluated with Voxel Based Morphometry protocol supplemented by a specific tool (SUIT) for analysing infratentorial structures.

RESULTS

Stridor was confirmed in 14 patients (10 MSA-cerebellar variant; 10 M; mean ± SD age = 61.6 ± 8.9years; disease duration = 5.2 ± 2.9years) and absent in 22 (11 MSA-cerebellar variant; 18 M; age = 61.4 ± 9.9years; disease duration = 4.8 ± 3.4years). Compared to MSA without stridor, patients with stridor showed higher GM density in the cerebellum (p < 0.05, corrected for the MSA-cerebellar variant and uncorrected when considering both MSA-variants) and lower in the striatum (p < 0.05, uncorrected).

CONCLUSIONS

This preliminary study has demonstrated for the first time in MSA stridor-related GM changes in striatal and cerebellar regions. Abnormalities in these regions were previously reported in dystonic disorders affecting laryngeal muscles, suggesting the hypothesis that stridor pathophysiology is dystonia-related. These results need however to be confirmed in a larger sample of patients.

Anxious brain networks: A coordinate-based activation likelihood estimation meta-analysis of resting-state functional connectivity studies in anxiety

Anxiety and anxiety disorders are associated with specific alterations to functional brain networks, including intra-networks and inter-networks. Given the heterogeneity within anxiety disorders and inconsistencies in functional network differences across studies, identifying common patterns of altered brain networks in anxiety is imperative. Here, we conducted an activation likelihood estimation meta-analysis of resting-state functional connectivity studies in anxiety and anxiety disorders (including 835 individuals with different levels of anxiety or anxiety disorders and 508 controls). Results show that anxiety can be characterized by hypo-connectivity of the affective network with executive control network (ECN) and default mode network (DMN), as well as decoupling of the ECN with the DMN. The connectivity within the salience network and its connectivity with sensorimotor network are also attenuated. These results reveal consistent dysregulations of affective and cognitive control related networks over networks related to emotion processing in anxiety and anxiety disorders. The current findings provide an empirical foundation for an integrated model of brain network alterations that are common across anxiety and anxiety disorders.

Aberrant Cerebellar-Cerebral Functional Connectivity in Children and Adolescents With Autism Spectrum Disorder

The cerebellum, which forms widespread functional networks with many areas in the cerebral cortices and subcortical structures, is one of the brain regions most consistently reported to exhibit neuropathological features in patients with autism spectrum disorder (ASD). However, cerebellar functional connectivity (FC) studies in patients with ASD have been very sparse. Using resting state functional connectivity (rsFC) analysis, we investigated the FC of the hemispheric/vermal subregions and the dentate nucleus of the cerebellum with the cerebral regions in 36 children and adolescents [16 participants with ASD, 20 typically developing (TD) participants, age: 6–15 years]. Furthermore, an independent larger sample population (42 participants with ASD, 88 TD participants, age: 6–15 years), extracted from the Autism Brain Imaging Data Exchange (ABIDE) II, was included for replication. The ASD group showed significantly increased or decreased FC between “hubs” in the cerebellum and cerebral cortices, when compared with the TD group. Findings of aberrant FCs converged on the posterior hemisphere, right dentate nucleus, and posterior inferior vermis of the cerebellum. Furthermore, these aberrant FCs were found to be related to motor, executive, and socio-communicative functions in children and adolescents with ASD when we examined correlations between FC and behavioral measurements. Results from the original dataset were partially replicated in the independent larger sample population. Our findings suggest that aberrant cerebellar–cerebral FC is associated with motor, socio-communicative, and executive functions in children and adolescents with ASD. These observations improve the current knowledge regarding the neural substrates that underlie the symptoms of ASD.

Altered baseline activity and connectivity associated with cognitive impairment following acute cerebellar infarction: A resting-state fMRI study

The aims of this study were to investigated the changes of brain function and cognitive function in patients with acute posterior cerebellar infarction using the functional magnetic resonance imaging (fMRI) tecniques: fractional amplitude of low-frequency fluctuation (fALFF) and functional connectivity (FC). Forty acute cerebellar infarction patients and 40 healthy controls were included. The differences of fALFF were compared. The regions showed significant differences were set as regions of interest (ROIs), and then the FC values between ROIs and the whole brain were analysed. Pearson correlation analysis was used to understand the correlation between FC values and cognitive function scores. The results showed significant group differences in fALFF values in the four brain regions, including the right frontal lobe, left hippocampus, right cingulate gyrus and cerebellum posterior lobe. Pearson correlation analysis suggested that abnormal alterations in the left hippocampus and right cingulate gyrus may play a core role in the cognitive impairment associated with cerebellar infarction. The changes of fALFF and FC values in related brain area from cerebellar stroke complement and enrich our understanding of cerebellar involvement in cognition involved in cognitive performance.

Abnormal intrinsic cerebro-cerebellar functional connectivity in un-medicated patients with bipolar disorder and major depressive disorder

OBJECTIVE

The cerebellum plays an important role in depression. Cerebro-cerebellar circuits have been found to show aberrance in bipolar disorder (BD) and major depressive disorder (MDD). However, whether the cerebro-cerebellar connectivity contributes equally to the pathologic mechanisms of BD and MDD remains unknown.

METHODS

We recruited 33 patients with MDD, 32 patients with BD, and 43 healthy controls (HC). We selected six seed regions (three per hemisphere) in the cerebrum, corresponding to the affective, cognitive control, and default mode networks, to establish cerebro-cerebellar functional connectivity maps.

RESULTS

Relative to the HC, both the BD and MDD patients exhibited weaker negative connectivity between the right subgenual anterior cingulate cortex and the cerebellar vermis IV_V (pBD = 0.03, pMDD = 0.001) and weaker positive connectivity between the left precuneus and the left cerebellar lobule IX (pBD = 0.043, pMDD = 0.000). Moreover, the MDD patients showed weaker positive connectivity in the left precuneus-left cerebellar lobule IX circuit than the BD patients (p = 0.049). In addition, the BD patients showed weaker positive connectivity in the right dorsolateral prefrontal cortex-left cerebellar lobule Crus Ι circuit compared to the HC (p = 0.002) or the MDD patients (p = 0.013). Receiver operating characteristic curves analyses showed that the altered cerebro-cerebellar connectivities could be used to distinguish the patients from the HC with relatively high accuracy.

CONCLUSIONS

Our findings suggested that differences in connectivity of cerebro-cerebellar circuits, which are involved in affective or cognitive functioning, significantly contributed to BD and MDD.

The role of the cerebellum in drug-cue associative memory: functional interactions with the medial prefrontal cortex

Drug-induced Pavlovian memories are thought to be crucial for drug addiction because they guide behaviour towards environments with drug availability. Drug-related memory depends on persistent changes in dopamine-glutamate interactions in the medial prefrontal cortex (mPFC), basolateral amygdala, nucleus accumbens core and hippocampus. Recent evidence from our laboratory indicated that the cerebellum is also a relevant node for drug-cue associations. In the present study, we tested the role that specific regions of the cerebellum and mPFC play in the acquisition of cocaine-induced preference conditioning. Quinolinic acid was used to manage a permanent deactivation of lobule VIII in the vermis prior to conditioning. Additionally, lidocaine was infused into the prelimbic and infralimbic (IL) cortices for reversible deactivation before every training session. The present findings show, for the first time, that the cerebellum and mPFC might act together in order to acquire drug-cue Pavlovian associations. Either a dorsal lesion in lobule VIII or an IL deactivation encouraged cocaine-induced preference conditioning. Moreover, simultaneous IL-cerebellar deactivation prevented the effect of either of the separate deactivations. Therefore, similar to the IL cortex, neural activity in the cerebellum may be crucial for ensuring inhibitory control of the expression of cocaine-related memories.

Altered cerebellar functional connectivity in remitted bipolar disorder: A resting-state functional magnetic resonance imaging study

OBJECTIVES

Several recent studies have reported a strong association between the cerebellar structural and functional abnormalities and psychiatric disorders. However, there are no studies to investigate possible changes in cerebellar functional connectivity in bipolar disorder. This study aimed to examine the whole-brain functional connectivity pattern of patients with remitted bipolar disorder II, in particular in the cerebellum.

METHODS

A total of 25 patients with remitted bipolar disorder II and 25 controls underwent resting-state functional magnetic resonance imaging and neuropsychological tests. Voxel-wise whole-brain connectivity was analyzed using a graph theory approach: functional connectivity strength. A seed-based resting-state functional connectivity analysis was further performed to investigate abnormal functional connectivity pattern of those regions with changed functional connectivity strength.

RESULTS

Remitted bipolar disorder II patients had significantly decreased functional connectivity strength in the bilateral posterior lobes of cerebellum (mainly lobules VIIb/VIIIa). The seed-based functional connectivity analyses revealed decreased functional connectivity between the right posterior cerebellum and the default mode network (i.e. right posterior cingulate cortex/precuneus and right superior temporal gyrus), bilateral hippocampus, right putamen, left paracentral lobule and bilateral posterior cerebellum and decreased functional connectivity between the left posterior cerebellum and the right inferior parietal lobule and bilateral posterior cerebellum in patients with remitted bipolar disorder II.

CONCLUSION

Our results suggest that cerebellar dysconnectivity, in particular distributed cerebellar-cerebral functional connectivity, might be associated with the pathogenesis of bipolar disorder.

Oxytocin differentially modulates specific dorsal and ventral striatal functional connections with frontal and cerebellar regions

Interactions between oxytocin and the basal ganglia are central in current overarching conceptualizations of its broad modulatory effects on behavior. Whereas evidence from animal models emphasizes the critical role of the ventral striatum in the behavioral effects of oxytocin, region-specific contributions of the basal ganglia have not been systematically explored in humans. The present study combined the randomized placebo-controlled administration of oxytocin versus placebo in healthy men (n = 144) with fMRI-based resting-state functional connectivity to determine the modulatory role of oxytocin on the major basal ganglia pathways. Oxytocin specifically increased connectivity between ventral striatal and pallidal nodes with upstream frontal regions, whereas it decreased the strengths of downstream pathways between the dorsal striatum and posterior cerebellum. These pathways have previously been implicated in salience, reward and behavioral flexibility, thus shaping goal-directed behavior. Given the importance of aberrant striatal intrinsic organization in autism, addiction and schizophrenia the present findings may suggest new mechanistic perspectives for the therapeutic potential of oxytocin in these disorders.

Voxel-based meta-analysis of gray and white matter volume abnormalities in spinocerebellar ataxia type 2

OBJECTIVE

To identify the consistent findings from the whole-brain voxel-based morphometry (VBM) studies on spinocerebellar ataxia type 2 (SCA2).

METHODS

The whole-brain VBM studies comparing SCA2 patients and healthy controls (HCs) were systematically searched in PubMed, Embase databases from January 2000 to June 2017. The coordinates with significant differences in gray matter (GM) and white matter (WM) between SCA2 patients and HCs were extracted separately from each cluster. A meta-analysis was performed using anisotropic effect size-based signed differential mapping (AES-SDM) software.

RESULTS

A total of five studies with 65 SCA2 patients and 124 HCs were included in the GM meta-analysis. Four of the five studies with 50 SCA2 patients and 109 HCs were included in the WM meta-analysis. Significant and consistent GM volume reductions were detected in bilateral cerebellar hemispheres, cerebellar vermis, the right fusiform gyrus, the right parahippocampal gyrus, and the right lingual gyrus. The WM volume reductions were observed in bilateral cerebellar hemispheres, cerebellar vermis, middle cerebellar peduncles, pons, and bilateral cortico-spinal projections. The findings of the study remained largely unchanged in jackknife sensitivity analysis.

CONCLUSIONS

The consistent findings from our meta-analysis showed that GM volume reductions in SCA2 patients were not limited in cerebellum while significant WM volume reductions widely existed in cerebellum and pyramidal system. The findings provide morphological basis for further studies on SCA2.

Cerebellum and cognition in progressive MS patients: functional changes beyond atrophy?

BACKGROUND

The cerebellum is a predilection site of pathology in progressive multiple sclerosis (PMS) patients, contributing to cognitive deficits. Aim of this study was to investigate lobular cerebellar functional connectivity (FC) in PMS patients in relation to cognition.

METHODS

In this cross-sectional study, resting state fMRI analysis was carried out on 29 PMS patients (11 males, mean age 51.2 ± 11.9 years) and 22 age- and sex-matched healthy controls (HC) (11 males, mean age 49.6 ± 8.8 years). Data were analyzed with a seed-based approach, with four different seeds placed at the level of cerebellar Lobule VI, Crus I, Crus II and Lobule VIIb, accounting for cerebellar structural damage. Cognitive status was assessed with the BICAMS battery. Correlations between fMRI data and clinical variables were probed with the Spearman correlation coefficient.

RESULTS

When testing FC differences between PMS and HC without taking into account cerebellar structural damage, PMS patients showed a reduction of FC between Crus II/Lobule VIIb and the right frontal pole (p = 0.001 and p = 0.002, respectively), with an increased FC between Lobule VIIb and the right precentral gyrus (p < 0.001). After controlling for structural damage, PMS patients still showed a reduced FC between Crus II and right frontal pole (p = 0.005), as well as an increased FC between Lobule VIIb and right precentral gyrus (p = 0.003), with the latter showing an inverse correlation with BVMT scores (r = - 0.393; p = 0.03).

CONCLUSION

PMS patients show cerebellar FC rearrangements that are partially independent from cerebellar structural damage, and are likely expression of a maladaptive functional rewiring.

The cerebellum in fear and anxiety-related disorders

Fear and anxiety-related disorders are highly prevalent psychiatric conditions characterized by avoidant and fearful reactions towards specific stimuli or situations, which are disproportionate given the real threat such stimuli entail. These conditions comprise the most common mental disorder group. There are a high proportion of patients who fail to achieve remission and the presence of high relapse rates indicate the therapeutic options available are far from being fully efficient. Despite an increased understanding the neural circuits underlying fear and anxiety-related behaviors in the last decades, a factor that could be partially contributing to the lack of adequate therapies may be an insufficient understanding of the core features of the disorders and their associated neurobiology. Interestingly, the cerebellum shows connections with fear and anxiety-related brain areas and functional involvement in such processes, but explanations for its role in anxiety disorders are lacking. Therefore, the aims of this review are to provide an overview of the neural circuitry of fear and anxiety and its connections to the cerebellum, and of the animal studies that directly assess an involvement of the cerebellum in these processes. Then, the studies performed in patients suffering from anxiety disorders that explore the cerebellum will be discussed. Finally, we'll propose a function for the cerebellum in these disorders, which could guide future experimental approaches to the topic and lead to a better understanding of the neurobiology of anxiety-related disorders, ultimately helping to develop more effective treatments for these conditions.

Participation of the caudal cerebellar lobule IX to the dorsal attentional network

BACKGROUND

We seeked for specific cerebellar contribution within the dorsal attentional network (DAN), using Independent Component Analysis (ICA).

METHODS

ICA-based analysis was performed on brain resting-state functional images of 19 volunteers.

RESULTS

We confirmed that DAN includes bilaterally: lobules VI-VII (crus I) and VIIB-VIIIA, as previously reported by Region-Of-Interest (ROI)-based functional connectivity studies. We also found that lobule IX (tonsillae), and as well as the superior and, likely, inferior colliculi. Also belong to DAN. The part of lobule IX in relation to DAN is located more caudally and laterally, and less extensive than the more rostral part of this lobule belonging to the default-mode network (DMN).

CONCLUSION

Rostral and caudal tonsillae partake in the DMN and DAN, respectively. The latter could subserve either eye movement control in relation to the oculomotor parieto-frontal network, partially congruent with the DAN, or more cognitive functions due to functional reallocation within the DAN.

Functional MRI signal fluctuations highlight altered resting brain activity in Huntington's disease

The fractional Amplitude of Low Frequency Fluctuations (fALFF) and the degree of local synchronization (Regional Homogeneity - ReHo) of resting-state BOLD signal have been suggested to map spontaneous neuronal activity and local functional connectivity, respectively. We compared voxelwise, independent of atrophy, the fALFF and ReHo patterns of 11 presymptomatic (ps-HD) and 28 symptomatic (sHD) Huntington's disease mutation carriers, with those of 40 normal volunteers, and tested their possible correlations with the motor and cognitive subscores of the Unified Huntington's Disease Rating Scale. In sHD patients, fALFF was mainly reduced bilaterally in parietal lobes (right precuneus being already affected in psHD), and in superior frontal gyri, and increased bilaterally in cerebellar lobules VI, VIII and IX, as well as in the right inferior temporal gyrus. In sHD, and to a lesser extent in psHD, ReHo was bilaterally reduced in putamina, cerebellar lobules III to VI, and superior medial frontal gyri, and increased in both psHD and sHD in fronto-basal cortices, and in the right temporal lobe. fALFF correlated inversely with cognitive scores in lobule IX of the cerebellum (mainly with total Stroop score, p < 0.0001), and in the medial portions of both thalami. These results are consistent with a reduced neuronal activity in the cortical components of the executive networks, known to be affected in Huntington's Disease, and with reduced local functional integration in subcortical and cerebellar components of the sensori-motor network. Cerebellar clusters of significant correlation of fALFF with executive function scores may be related to compensatory mechanisms.

Altered cerebro-cerebellum resting-state functional connectivity in HIV-infected male patients

In addition to the role of planning and executing movement, the cerebellum greatly contributes to cognitive process. Numerous studies have reported structural and functional abnormalities in the cerebellum for HIV-infected patients, but little is known about the altered functional connectivity of particular cerebellar subregions and the cerebrum. Therefore, this study aimed to explore the resting-state functional connectivity (rsFC) changes of the cerebellum and further analyze the relationship between the rsFC changes and the neuropsychological evaluation. The experiment involved 26 HIV-infected men with asymptomatic neurocognitive impairment (ANI) and 28 healthy controls (HC). We selected bilateral hemispheric lobule VI and lobule IX as seed regions and mapped the whole-brain rsFC for each subregion. Results revealed that right lobule VI showed significant increased rsFC with the anterior cingulate cortex (ACC) in HIV-infected subjects. In addition, the correlation analysis on HIV-infected subjects illustrated the increased rsFC was negatively correlated with the attention/working memory score. Moreover, significantly increased cerebellar rsFCs were also observed in HIV-infected patients related to right inferior frontal gyrus (IFG) and right superior medial gyrus (SMG) while decreased rsFC was just found between right lobule VI and the left hippocampus (HIP). These findings suggested that, abnormalities of cerebro-cerebellar functional connectivity might be associated with cognitive dysfunction in HIV-infected men, particularly working memory impairment. It could also be the underlying mechanism of ANI, providing further evidence for early injury in the neural substrate of HIV-infected patients.

Cerebellar Neural Circuits Involving Executive Control Network Predict Response to Group Cognitive Behavior Therapy in Social Anxiety Disorder

Some intrinsic connectivity networks including the default mode network (DMN) and executive control network (ECN) may underlie social anxiety disorder (SAD). Although the cerebellum has been implicated in the pathophysiology of SAD and several networks relevant to higher-order cognition, it remains unknown whether cerebellar areas involved in DMN and ECN exhibit altered resting-state functional connectivity (rsFC) with cortical networks in SAD. Forty-six patients with SAD and 64 healthy controls (HC) were included and submitted to the baseline resting-state functional magnetic resonance imaging (fMRI). Seventeen SAD patients who completed post-treatment clinical assessments were included after group cognitive behavior therapy (CBT). RsFC of three cerebellar subregions in both groups was assessed respectively in a voxel-wise way, and these rsFC maps were compared by two-sample t tests between groups. Whole-brain voxel-wise regression was performed to examine whether cerebellar connectivity networks can predict response to CBT. Lower rsFC circuits of cerebellar subregions compared with HC at baseline (p < 0.05, corrected by false discovery rate) were revealed. The left Crus I rsFC with dorsal medial prefrontal cortex was negatively correlated with symptom severity. The clinical assessments in SAD patients were significantly decreased after CBT. Higher pretreatment cerebellar rsFC with angular gyrus and dorsal lateral frontal cortex corresponded with greater symptom improvement following CBT. Cerebellar rsFC circuits involving DMN and ECN are possible neuropathologic mechanisms of SAD. Stronger pretreatment cerebellar rsFC circuits involving ECN suggest potential neural markers to predict CBT response.

Alteration in intrinsic and extrinsic functional connectivity of resting state networks associated with subclinical hypothyroid

Subclinical hypothyroidism (SCH) is characterized by mild elevation of thyroid stimulating hormone (TSH) (range 5-10 μIU/ml) and normal free triiodothyronine (FT3) and free thyroxine (FT4). The cognitive function impairment is well known in thyroid disorders such as hypothyroidism and hyperthyroidism, but little is known about deficits in brain functions in SCH subjects. Also, whether hormone-replacement treatment is necessary or not in SCH subjects is still debatable. In order to have an insight into the cognition of SCH subjects, intrinsic and extrinsic functional connectivity (FC) of the resting state networks (RSNs) was studied. For resting state data analysis we used an unbiased, data-driven approach based on Independent Component Analysis (ICA) and dual-regression that can emphasize widespread changes in FC without restricting to a set of predefined seeds. 28 SCH subjects and 28 matched healthy controls (HC) participated in the study. RSN analysis showed significantly decreased intrinsic FC in somato-motor network (SMN) and right fronto-parietal attention network (RAN) and increased intrinsic FC in default mode network (DMN) in SCH subjects as compared to control subjects. The reduced intrinsic FC in the SMN and RAN suggests neuro-cognitive alterations in SCH subjects in the corresponding functions which were also evident from the deficit in the neuropsychological performance of the SCH subjects on behavioural tests such as digit span, delayed recall, visual retention, recognition, Bender Gestalt and Mini-Mental State Examination (MMSE). We also found a significant reduction in extrinsic network FC between DMN and RAN; SMN and posterior default mode network (PDMN); and increased extrinsic FC between SMN and anterior default mode network (ADMN) in SCH subjects as compared to controls. An altered extrinsic FC in SCH suggests functional reorganization in response to neurological disruption. The partial correlation analysis between intrinsic and extrinsic RSNs FC and neuropsychological performances as well as clinical indices give interesting insights into brain-behavior relationship in SCH subjects. This article is protected by copyright. All rights reserved.

Resting-state fMRI signals in offspring of parents with bipolar disorder at the high-risk and ultra-high-risk stages and their relations with cognitive function

BACKGROUND

Bipolar disorder (BD) has been associated with dysfunctional resting-state brain functioning. However, it is still not known whether the aberrant functioning occurs and predict cognitive functioning before illness onset.

AIMS

We examined the resting-state regional and network dysfunctioning, and their correlates with neurocognitive performance, in the high-risk (HR) and ultra-high-risk (UHR) stages of bipolar disorder.

METHODS

Using amplitude of low-frequency fluctuations (ALFF), region homogeneity (ReHo) and hypothesis-driven region-of-interest (ROI)-based connectivity, we examined resting-state fMRI data of 8- to 25-year-old healthy offspring (HR, n = 28) and offspring with subthreshold syndromes (UHR, n = 22) of a BD parent, and age-matched healthy controls without any personal or family psychopathology (HC, n = 46). Participants' neurocognitive profiles were assessed using the MATRICS Consensus Cognitive Battery (MCCB).

RESULTS

ALFF signals in the left putamen and right rolandic operculum were lower in the HR group compared to the HC group. In contrast, ALFF signals were increased in the UHR group in the right middle pars orbitalis of the inferior frontal gyrus, right calcarine sulcus and right cerebellum. Connectivities between the right amygdala and left inferior temporal gyrus, between the left hippocampus and inferior occipital gyrus, and between the left hippocampus and middle pars orbitalis gyrus were decreased in the HR group compared to the HC group. In UHR versus HC group, connectivity between the right amygdala and the left hippocampus and left insula was increased, and connectivity between the left hippocampus and the left insula and the cerebellum was also increased. Among cognitive measures, processing speed was positively correlated with ALFF signals in the left putamen in the HR offspring. In the UHR offspring, processing speed, attention, and verbal learning/memory were positively correlated with the functional connectivity between the left hippocampus and cerebellum.

CONCLUSIONS

Offspring of parents with BD in the HR and UHR stages show largely non-overlapping patterns of atypical resting-state signals and functional connectivity that predicted cognitive functioning, possibly reflecting inherited abnormalities and/or complimentary reactions.

Research note: a resting-state, cerebello-amygdaloid intrinsically connected network

Background

Previous ROI-based functional connectivity studies found functional coherence between cerebellum and cerebral amygdale, at rest. Moreover, some neurospychiatric symptoms were accompanied by abnormal activations of these two brain areas. Therefore, the aim of the study was to identify a putative, resting-state intrinsically connected cerebello-amygdaloid network.

Methods

ICA-based analysis was performed on brain resting-state functional images of 15 volunteers.

Results

The first ICA spatial component corresponded to a circuit including: dentate nuclei, lobules VI and VIII, the basolateral amygdala, the substantia nigra, the posterior insula, claustrum and the parietal opercule.

Conclusion

A new intrinsically connected network linking cerebellum and amygdala is described, which could be in charge of sensorimotor, emotional and motivational integration of somesthesic stimuli before recruiting more specialized circuits such as ventral striatum or attentional and salience networks.

Hormonal Cycle and Contraceptive Effects on Amygdala and Salience Resting-State Networks in Women with Previous Affective Side Effects on the Pill

The mechanisms linking ovarian hormones to negative affect are poorly characterized, but important clues may come from the examination of the brain's intrinsic organization. Here, we studied the effects of both the menstrual cycle and oral contraceptives (OCs) on amygdala and salience network resting-state functional connectivity using a double-blind, randomized, and placebo-controlled design. Hormone levels, depressive symptoms, and resting-state functional connectivity were measured in 35 healthy women (24.9±4.2 years) who had previously experienced OC-related negative affect. All participants were examined in the follicular phase of a baseline cycle and in the third week of the subsequent cycle during treatment with either a combined OC (30 μg ethinyl estradiol/0.15 mg levonorgestrel) or placebo. The latter time point targeted the midluteal phase in placebo users and steady-state ethinyl estradiol and levonorgestrel concentrations in OC users. Amygdala and salience network connectivity generally increased with both higher endogenous and synthetic hormone levels, although amygdala-parietal cortical connectivity decreased in OC users. When in the luteal phase, the naturally cycling placebo users demonstrated higher connectivity in both networks compared with the women receiving OCs. Our results support a causal link between the exogenous administration of synthetic hormones and amygdala and salience network connectivity. Furthermore, they suggest a similar, potentially stronger, association between the natural hormonal variations across the menstrual cycle and intrinsic network connectivity.

Cerebellar Contributions to Major Depression

Extending beyond the motor domain, the cerebellum is involved in various aspects of cognition and affect. Multidisciplinary evidence has demonstrated topographic organization of higher-order cognitive functions within the cerebellum. We here review recent neuroimaging research that indicates cerebellar contributions to major depressive disorder (MDD). At the structural level, increased volume of lobule IX has been demonstrated in MDD patients, independent of acute or remitted disease state. Successful treatment with electroconvulsive therapy has been associated with increased lobule VIIA volume in depressed patients. At the functional level, connectivity analyses have shown reduced cerebro-cerebellar coupling of lobules VI and VIIA/B with prefrontal, posterior parietal, and limbic regions in patients with MDD. As a limitation, most of this evidence is based on smaller patient samples with incomplete phenotypic and neuropsychological characterization and with heterogenous medication. Some studies did not apply cerebellum-optimized data analysis protocols. Taken together, MDD pathophysiology affects distinct subregions of the cerebellum that communicate with cortical networks subserving cognitive and self-referential processing. This mini-review synthesizes research evidence from cerebellar structural and functional neuroimaging in depression, and provides future perspectives for neuroimaging of cerebellar contributions to MDD.

Disrupted Cerebellar Connectivity With the Central Executive Network and the Default-Mode Network in Unmedicated Bipolar II Disorder

Objective: Bipolar disorder (BD) is a common psychiatric disease. Although structural and functional abnormalities of the cerebellum in BD patients have been reported by recent neuroimaging studies, the cerebellar-cerebral functional connectivity (FC) has not yet been examined. The present study aims to investigate the FC between the cerebellum and cerebrum, particularly the central executive network (CEN) and the default-mode network (DMN) in bipolar II disorder (BD II). Methods: Ninety-four patients with unmedicated BD II depression and 100 healthy controls (HCs) underwent the resting-state functional magnetic resonance imaging. Seed-based connectivity analyses were performed using cerebellar seeds previously identified as being involved in the CEN (bilateral Crus Ia) and DMN (bilateral Crus Ib). Results: Compared with HCs, BD II depression patients appeared decreased FC in the right Crus Ia-left dorsal lateral prefrontal cortex (dlPFC) and -left anterior cingulate cortex (ACC), the right Crus Ib-left medial prefrontal cortex (mPFC), -left middle temporal gyrus (MTG), and -left inferior temporal gyrus (ITG). No altered FC between the left Crus Ia or Crus Ib and the cerebral regions was found. Conclusions: Patients with BD II depression showed disrupted FC between the cerebellum and the CEN (mainly in the left dlPFC and ACC) and DMN (mainly in the left mPFC and temporal lobe), suggesting the significant role of the cerebellum-CEN and -DMN connectivity in the pathogenesis of BD.

Topography of the cerebellum in relation to social brain regions and emotions

In the last few decades, an increasing number of studies have focused on better characterizing the cerebellar functions beyond motor control, including emotional and social domains. Anatomic and functional evidence strongly contributes to delineating the cerebellar functional subdivisions and their integration with cerebral functional networks strictly related to emotional regulation and social functioning, thus suggesting a model of cerebellar organization that resembles that of the cerebral cortex. Overcoming the traditional segregation of cerebrocerebellar networks in sensorimotor/cognitive functional modules, during emotional/social processes, the cerebellar activity reflects a domain-specific mentalizing functionality that is strongly connected with corresponding mentalizing networks in the cerebrum. Additionally, the cerebrocerebellar organization has been shown to have a specific functional and maturational trajectory that is only in part dependent on a structural maturational process and that is protracted from an early stage of life through adolescence and adulthood, when the mature control networks involve both segregation and integration of the brain regions that comprise them. Altogether, these findings underscore the importance of regional functional differences within the cerebellum in relation to emotional and social processing and raise questions about the clinical implication of cerebellar injury on emotional/social behaviors, both in the developing and the adult brain.

Auditory attention in autism spectrum disorder: An exploration of volumetric magnetic resonance imaging findings

Studies have shown that individuals with autism spectrum disorder (ASD) tend to perform significantly below typically developing individuals on standardized measures of attention, even when controlling for IQ. The current study sought to examine within ASD whether anatomical correlates of attention performance differed between those with average to above-average IQ (AIQ group) and those with low-average to borderline ability (LIQ group) as well as in comparison to typically developing controls (TDC). Using automated volumetric analyses, we examined regional volume of classic attention areas including the superior frontal gyrus, anterior cingulate cortex, and precuneus in ASD AIQ (n = 38) and LIQ (n = 18) individuals along with 30 TDC. Auditory attention performance was assessed using subtests of the Test of Memory and Learning (TOMAL) compared among the groups and then correlated with regional brain volumes. Analyses revealed group differences in attention. The three groups did not differ significantly on any auditory attention-related brain volumes; however, trends toward significant size-attention function interactions were observed. Negative correlations were found between the volume of the precuneus and auditory attention performance for the AIQ ASD group, indicating larger volume related to poorer performance. Implications for general attention functioning and dysfunctional neural connectivity in ASD are discussed.

Changes in cerebellar functional connectivity and autonomic regulation in cancer patients treated with the Neuro Emotional Technique for traumatic stress symptoms

PURPOSE

A growing number of research studies have implicated the cerebellum in emotional processing and regulation, especially with regard to negative emotional memories. However, there currently are no studies showing functional changes in the cerebellum as a result of treatment for traumatic stress symptoms. The Neuro Emotional Technique (NET) is an intervention designed to help improve symptoms related to traumatic stress using an integrative approach that combines emotional, cognitive, and motor processing, with a particular focus on autonomic nervous system regulation. In this study, we evaluated whether the NET intervention alters functional connectivity in the brain of patients with traumatic stress symptoms associated with a cancer-related event. We hypothesized that the NET intervention would reduce emotional and autonomic reactivity and that this would correlate with connectivity changes between the cerebellum and limbic structures as well as the brain stem.

METHODS

We enrolled patients with a prior cancer diagnosis who experienced distressing cancer-related memories associated with traumatic stress symptoms of at least 6 months in duration. Participants were randomized to either the NET intervention or a waitlist control. To evaluate the primary outcome of neurophysiological effects, all participants received resting-state functional blood oxygen level-dependent (BOLD) magnetic resonance imaging (rs-fMRI) before and after the NET intervention. In addition, autonomic reactivity was measured using heart rate response to the traumatic stimulus. Pre/post comparisons were performed between the NET and control groups.

RESULTS

The results demonstrated significant changes in the NET group, as compared to the control group, in the functional connectivity between the cerebellum (including the vermis) and the amygdala, parahippocampus, and brain stem. Likewise, participants receiving the NET intervention had significant reductions in autonomic reactivity based on heart rate response to the traumatic stimulus compared to the control group.

CONCLUSIONS

This study is an initial step towards establishing a neurological signature of treatment effect for the NET intervention. Specifically, functional connectivity between the cerebellum and the amygdala and prefrontal cortex appear to be associated with a reduction in autonomic reactivity in response to distressing cancer-related memories.

IMPLICATIONS FOR CANCER SURVIVORS

This study contributes to the understanding of possible mechanisms by which interventions like NET may help reduce emotional distress in cancer patients who suffer from traumatic stress symptoms.

Body Sway Increases After Functional Inactivation of the Cerebellar Vermis by cTBS

Balance stability correlates with cerebellar vermis volume. Furthermore, the cerebellum is involved in precise timing of motor processes by fine-tuning the sensorimotor integration. We tested the hypothesis that any cerebellar action in stance control and in timing of visuomotor integration for balance is impaired by continuous theta-burst stimulation (cTBS) of the vermis. Ten subjects stood quietly and underwent six sequences of 10-min acquisition of center of foot pressure (CoP) data after cTBS, sham stimulation, and no stimulation. Visual shifts from eyes closed (EC) to eyes open (EO) and vice versa were presented via electronic goggles. Mean anteroposterior and mediolateral CoP position and oscillation, and the time delay at which body sway changed after visual shift were calculated. CoP position under both EC and EO condition was not modified after cTBS. Sway path length was greater with EC than EO and increased in both visual conditions after cTBS. CoP oscillation was also larger with EC and increased under both visual conditions after cTBS. The delay at which body oscillation changed after visual shift was longer after EC to EO than EO to EC, but unaffected by cTBS. The time constant of decrease or increase of oscillation was longer in EC to EO shifts, but unaffected by cTBS. Functional inactivation of the cerebellar vermis is associated with increased sway. Despite this, cTBS does not detectably modify onset and time course of the sensorimotor integration process of adaptation to visual shifts. Cerebellar vermis normally controls oscillation, but not timing of adaptation to abrupt changes in stabilizing information.

Consensus Paper: Cerebellum and Emotion

Over the past three decades, insights into the role of the cerebellum in emotional processing have substantially increased. Indeed, methodological refinements in cerebellar lesion studies and major technological advancements in the field of neuroscience are in particular responsible to an exponential growth of knowledge on the topic. It is timely to review the available data and to critically evaluate the current status of the role of the cerebellum in emotion and related domains. The main aim of this article is to present an overview of current facts and ongoing debates relating to clinical, neuroimaging, and neurophysiological findings on the role of the cerebellum in key aspects of emotion. Experts in the field of cerebellar research discuss the range of cerebellar contributions to emotion in nine topics. Topics include the role of the cerebellum in perception and recognition, forwarding and encoding of emotional information, and the experience and regulation of emotional states in relation to motor, cognitive, and social behaviors. In addition, perspectives including cerebellar involvement in emotional learning, pain, emotional aspects of speech, and neuropsychiatric aspects of the cerebellum in mood disorders are briefly discussed. Results of this consensus paper illustrate how theory and empirical research have converged to produce a composite picture of brain topography, physiology, and function that establishes the role of the cerebellum in many aspects of emotional processing.

A Meta-analysis of Voxel-based Brain Morphometry Studies in Obstructive Sleep Apnea

Gray matter (GM) anomalies may represent a critical pathology underlying obstructive sleep apnea (OSA). However, the evidence regarding their clinical relevance is inconsistent. We conducted a meta-analysis of voxel-based morphometry (VBM) studies of patients with OSA to identify their brain abnormalities. A systematic search was conducted based on PRISMA guidelines, and a meta-analysis was performed using the anisotropic effect-size-based algorithms (ASE-SDM) to quantitatively estimate regional GM changes in patients with OSA. Fifteen studies with 16 datasets comprising 353 untreated patients with OSA and 444 healthy controls were included. Our results revealed GM reductions in the bilateral anterior cingulate/paracingulate gyri (ACG/ApCG), left cerebellum (lobules IV/V and VIII), bilateral superior frontal gyrus (SFG, medial rostral part), right middle temporal gyrus (MTG), and right premotor cortex. Moreover, GM reductions in the bilateral ACG/ApCG were positively associated with body mass index (BMI) and age among patients with OSA, and GM reductions in the SFG (medial rostral part) were negatively associated with Epworth sleepiness scale (ESS) scores and sex (male). These abnormalities may represent structural brain underpinnings of neurocognitive abnormalities and respiratory-related abnormalities in OSA. In particular, this study adds to Psychoradiology, which is a promising subspecialty of clinical radiology mainly for psychiatric disorders.