The Role of the Cerebellar and Vestibular Networks in Anxiety Disorders and Depression: the Internal Model Hypothesis

Edge-centric connectome-genetic markers of bridging factor to comorbidity between depression and anxiety

Depression-anxiety comorbidity is commonly attributed to the occurrence of specific symptoms bridging the two disorders. However, the significant heterogeneity of most bridging symptoms presents challenges for psychopathological interpretation and clinical applicability. Here, we conceptually established a common bridging factor (cb factor) to characterize a general structure of these bridging symptoms, analogous to the general psychopathological p factor. We identified a cb factor from 12 bridging symptoms in depression-anxiety comorbidity network. Moreover, this cb factor could be predicted using edge-centric connectomes with robust generalizability, and was characterized by connectome patterns in attention and frontoparietal networks. In an independent twin cohort, we found that these patterns were moderately heritable, and identified their genetic connectome-transcriptional markers that were associated with the neurobiological enrichment of vasculature and cerebellar development, particularly during late-childhood-to-young-adulthood periods. Our findings revealed a general factor of bridging symptoms and its neurobiological architectures, which enriched neurogenetic understanding of depression-anxiety comorbidity.

Why is vestibular migraine associated with many comorbidities?

Vestibular migraine (VM) is a usual trigger of episodic vertigo. Patients with VM often experience spinning, shaking, or unsteady sensations, which are usually also accompanied by photophobia, phonophobia, motor intolerance, and more. VM is often associated with a number of comorbidities. Recurrent episodes of VM can affect the patient's emotions, sleep, and cognitive functioning to varying degrees. Patients with VM may be accompanied by adverse moods such as anxiety, fear, and depression, which can gradually develop into anxiety disorders or depressive disorders. Sleep disorders are also a common concomitant symptom of VM, which significantly lower patients' quality of life. The influence of anxiety disorders and sleep disorders may reduce cognitive functions of VM, such as visuospatial ability, attention, and memory decline. Clinically, it is also common to see VM comorbid with other vestibular disorders, making the diagnosis more difficult. VM episodes are relieved but lingering, in which case VM may coexist with persistent postural-perceptual dizziness (PPPD). Anxiety may be an important bridge between recurrent VM and PPPD. The clinical manifestations of VM and Meniere's disease (MD) overlap considerably, and those who meet the diagnostic criteria for both can be said to have VM/MD comorbidity. VM can also present with positional vertigo, and some patients with VM present with typical benign paroxysmal positional vertigo (BPPV) nystagmus on positional testing. In this paper, we synthesize and analyze the pathomechanisms of VM comorbidity by reviewing the literature. The results show that it may be related to the extensive connectivity of the vestibular system with different brain regions and the close connection of the trigeminovascular system with the periphery of the vestibule. Therefore, it is necessary to pay attention to the diagnosis of comorbidities in VM, synthesize its pathogenesis, and give comprehensive treatment to patients.

Unveiling perinatal depression: A dual-network EEG analysis for diagnosis and severity assessment

Perinatal depression (PD), which affects about 10-20 percent of women, often goes unnoticed because related symptoms frequently overlap with those commonly experienced during pregnancy. Moreover, identifying PD currently depends heavily on the use of questionnaires, and objective biological indicators for diagnosis has yet to be identified. This research proposes a safe and non-invasive method for diagnosing PD and aims to delve deeper into its underlying mechanism. Considering the non-invasiveness and clinical convenience of electroencephalogram (EEG) for mothers-to-be and fetuses, we collected the resting-state scalp EEG of pregnant women (with PD/healthy) at the 38th week of gestation. To compensate for the low spatial resolution of scalp EEG, source analysis was first applied to project the scalp EEG to the cortical-space. Afterwards, cortical-space networks and large-scale networks were constructed to investigate the mechanism of PD from two different level. Herein, differences in the two distinct types of networks between PD patients and healthy mothers-to-be were explored, respectively. We found that the PD patients illustrated decreased network connectivity in the cortical-space, while the large-scale networks revealed weaker connections at cerebellar area. Further, related spatial topological features derived from the two different networks were combined to promote the recognition of pregnant women with PD from those healthy ones. Meanwhile, the depression severity at patient level was effectively predicted based on the combined spatial topological features as well. These findings consistently validated that the two kinds of networks indeed played off each other, which thus helped explore the underlying mechanism of PD; and further verified the superiority of the combination strategy, revealing its reliability and potential in diagnosis and depression severity evaluation.

Gender differences in major depressive disorder at different ages: a REST-meta-MDD project-based study

BACKGROUND

Major depressive disorder (MDD) is a highly heterogeneous disease, with differences in clinical manifestations among depression patients based on onset ages and genders. The neural mechanisms underlying these differences remain unclear. In this study, we utilized resting state functional imaging data from a large sample database and adopted the ReHo method to investigate gender differences in local brain function in MDD patients across different onset age groups.

METHODS

The study included 364 MDD patients and 695 healthy participants who were part of the REST-meta-MDD project. Regional homogeneity (ReHo) assessed gender disparities in MDD and healthy individuals within groups delineated by gender and onset age (young group: 18-29 years; middle-aged group: 30-45 years).

RESULTS

Among the young MDD groups, there were significant gender differences in the right superior frontal gyrus, right inferior frontal gyrus, left superior temporal gyrus, and right superior parietal lobule, with male MDD patients having higher ReHo values compared to females. When compared to healthy males, male MDD patients exhibited elevated ReHo values in the right superior parietal lobule. In the middle-aged groups, a marked ReHo difference was observed in the bilateral cerebellum posterior lobe, with female MDD patients showing higher ReHo values.

CONCLUSIONS

The functional mechanisms of MDD differ between genders and show distinct variations across different onset age groups. These findings underscore the importance of developing personalized interventions that address the unique needs of MDD patients, tailored to their gender and age, and necessitate the development of antidepressant medications targeted at each gender-age subgroup.

Proprioception, Emotion and Social Responsiveness in Children with Developmental Disorders: An Exploratory Study in Autism Spectrum Disorder, Cerebral Palsy and Different Neurodevelopmental Situations

Proprioception has long been linked with emotional dysregulation in neurotypical adults. Neuropediatric disorders such as autism spectrum disorder (ASD) and cerebral palsy (CP) are distinct entities and yet both present with deficits and challenges in sensory processing and the regulation of emotions. This study aimed to explore the relationship between proprioception and emotional-social performance in children and to compare proprioception and emotional-social performance in different underlying neurodevelopmental conditions. For this purpose, this cross-sectional study included 42 children with ASD, 34 children with CP and 50 typically developing peers. Proprioceptive acuity, proprioceptive reactive behavior as well as emotion regulation and social responsiveness were assessed. The results show a significant correlation between proprioceptive deficits and emotional difficulties in this pediatric sample, with distinct proprioceptive impairment patterns according to the underlying neurological disorder. Children with CP showed significant emotional knowledge deficits, while children with ASD predominantly showed challenges in social responsiveness. These data thus suggest a differentiated impact of proprioception on emotional-social performance in neurodevelopmental disorders and highlight proprioception as a potential therapeutic target for balancing emotion regulation in children with neurodevelopmental conditions.

Associations between benign paroxysmal positional vertigo and seven mental disorders: a two-sample Mendelian randomization study

Background

The association between benign paroxysmal positional vertigo (BPPV) and various mental disorders is still controversial. This study used the Mendelian randomization (MR) method to clarify the correlation between BPPV and seven mental disorders (bipolar disorder, depression, anxiety disorder, schizophrenia, suicidality, neuroticism, and mood swings) to aid in the exploration of BPPV complications and prevention and early treatment of mental disorders.

Methods

The datasets for BPPV and seven mental disorders were obtained from genome-wide association studies (GWASs). Two-sample MR was used to analyze the correlation between exposure (BPPV) and various outcomes (bipolar disorder, depression, anxiety disorder, schizophrenia, suicidality, neuroticism, and mood swings). A reverse MR study was also performed. The inverse variance weighting (IVW) method, the MR-Egger method, the simple mode method, the weighted mode method, and the weighted median method were selected.

Results

The MR analysis and the reverse MR analysis results did not reveal significant associations between BPPV and bipolar disorder, depression, anxiety disorder, schizophrenia, suicidal tendencies, neuroticism, and mood swings. Interestingly, neuroticism (IVW: OR = 1.142, 95% CI: 1.059-1.231, P = 0.001; P-MR-PRESSO adjustment = 0.0002) and mood swings (IVW: OR = 3.119, 95% CI: 1.652-5.884, P = 0.0004) may have a significant association with BPPV. After MR-PRESSO adjustment, there was no horizontal pleiotropy or heterogeneity, and a significant association between neuroticism, mood swings, and BPPV has still been suggested.

Conclusion

We conducted MR analysis on genetic data from European populations and discovered a causal relationship between BPPV and the seven mental disorders. Our research findings suggest that BPPV may not have a significant causal relationship with bipolar disorder, depression, anxiety disorder, schizophrenia, or suicidal tendencies. However, neuroticism and mood swings may be risk factors for BPPV.

Motor Dysfunctions in Fibromyalgia Patients: The Importance of Breathing

The classification of fibromyalgia (FM) is not always immediate and simple, with the time from the first diagnosis, compared to the onset of symptoms, of a few years. Currently, we do not have instrumental or biochemical tests considered as gold standards; the clinician will make a diagnosis of FM based on the patient's medical history and subjective assessment. The symptoms can involve physical, cognitive and psychological disorders, with the presence of pain of different origins and classifications: nociplastic, nociceptive and neuropathic pain. Among the symptoms highlighted, postural disorders and neuromotor uncoordination emerge, whose functional dysfunctions can increase the mortality and morbidity rate. An alteration of the diaphragm muscle could generate such functional motor problems. Considering that the current literature underestimates the importance of breathing in FM, the article aims to highlight the relationship between motor and diaphragmatic difficulties in the patient, soliciting new points of view for the clinical and therapeutic framework.

Central vestibular networking for sensorimotor control, cognition, and emotion

PURPOSE OF REVIEW

The aim of this study was to illuminate the extent of the bilateral central vestibular network from brainstem and cerebellum to subcortical and cortical areas and its interrelation to higher cortical functions such as spatial cognition and anxiety.

RECENT FINDINGS

The conventional view that the main function of the vestibular system is the perception of self-motion and body orientation in space and the sensorimotor control of gaze and posture had to be developed further by a hierarchical organisation with bottom-up and top-down interconnections. Even the vestibulo-ocular and vestibulo-spinal reflexes are modified by perceptual cortical processes, assigned to higher vestibulo-cortical functions. A first comparative fMRI meta-analysis of vestibular stimulation and fear-conditioning studies in healthy participants disclosed widely distributed clusters of concordance, including the prefrontal cortex, anterior insula, temporal and inferior parietal lobe, thalamus, brainstem and cerebellum. In contrast, the cortical vestibular core region around the posterior insula was activated during vestibular stimulation but deactivated during fear conditioning. In recent years, there has been increasing evidence from studies in animals and humans that the central vestibular system has numerous connections related to spatial sensorimotor performance, memory, and emotion. The clinical implication of the complex interaction within various networks makes it difficult to assign some higher multisensory disorders to one particular modality, for example in spatial hemineglect or room-tilt illusion.

SUMMARY

Our understanding of higher cortical vestibular functions is still in its infancy. Different brain imaging techniques in animals and humans are one of the most promising methodological approaches for further structural and functional decoding of the vestibular and other intimately interconnected networks. The multisensory networking including cognition and emotion determines human behaviour in space.

Compensatory strategies after an acute unilateral vestibulopathy: a prospective observational study

PURPOSE

In case of an acute unilateral vestibulopathy (UVP), compensatory strategies such as restoration and adaptation will lead to a decrease in intensity of the symptoms. Although measurements of compensatory strategies are available, currently, an overview taking the different strategies into account is lacking. The objectives of this study are to explore compensatory strategies and to investigate the association between compensatory strategies and patient characteristics.

METHODS

Restoration was objectified by the vestibulo-ocular reflex (VOR) gain on the video head impulse test, and adaptation-consisting of visual, multisensory, and behavioral substitution-was objectified by the Visual Vertigo Analog Scale (VVAS), Antwerp Vestibular Compensation Index (AVeCI), and Perez and Rey score (PR score), respectively. Adequate restoration and adaptation levels were interpreted as follows: VOR gain > 0.80, VVAS ≤ 40%, AVeCI > 0 and PR score ≤ 55.

RESULTS

Sixty-two UVP patients, 34 men and 28 women, were included with an average age of 52.1 ± 17.3 years. At 10.5 ± 1.4 weeks after onset, 41.9% of the UVP patients reached adequate restoration levels and 58.1-86.9% reached adequate adaptation levels. Furthermore, significant associations were found between (1) restoration status and UVP etiology [Odds Ratio (OR) with 95% CI: 4.167 {1.353;12.828}] and balance performance (OR: 4.400 {1.258;15.386}), (2) visual sensory substitution status and perceived handicap (OR: 8.144 {1.644;40.395}), anxiety (OR: 10.000 {1.579;63.316}) and depression (OR: 16.667 {2.726;101.896}), and (3) behavioral substitution status and balance performance (OR: 4.143 {1.341;12.798}).

CONCLUSION

UVP patients with adequate compensatory strategies presented with better balance performance, lower perceived handicap, and lower anxiety and depression scores.

Altered brain function and structure pre- and post- COVID-19 infection: a longitudinal study

BACKGROUND

Evidence indicates that the SARS-CoV-2 virus can infect the brain, resulting in central nervous system symptoms. However, there is a lack of a longitudinal imaging study investigating the impact of Coronavirus disease 2019 (COVID-19) infection on brain function. Consequently, this study aimed to fill this knowledge gap using functional magnetic resonance imaging (fMRI).

METHODS

Twenty-one participants underwent two resting-state fMRI scans before and after infection. The amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) were assessed to identify the brain function changes. Additionally, voxel-based morphometry (VBM) was utilized to assess changes in brain structure. Subsequently, brain regions that showed significant differences were identified as regions of interest (ROI) in functional connectivity analysis (FC).

RESULTS

After infection, ALFF was increased in the bilateral paracentral lobe and postcentral gyrus while decreased in the bilateral precuneus. Moreover, ReHo was decreased in the cerebellar vermis, accompanied by a decrease in FC with the bilateral postcentral gyrus. Furthermore, gray matter volume (GMV) reduction was observed in the left thalamus. The results of the correlation analysis revealed a negative correlation between ALFF values in the bilateral precuneus and scores on the self-rating anxiety scale (SAS) in pre- and post-infection datasets.

CONCLUSION

Neuroimaging alterations may occur before the manifestation of clinical symptoms, indicating that the functioning of the motor and sensory systems, as well as their connection, might be affected following infection. This alteration can potentially increase the potential of maladaptive responses to environmental stimuli. Furthermore, patients may be susceptible to future emotional disorders.

Fear avoidance beliefs, anxiety, and depression in healthy individuals and persons with vestibular disorders across cultures

Background/introduction

In persons with vestibular disorders, disturbed vestibular input and accompanying dizziness can be associated with anxiety or depression. To avoid dizziness, persons with vestibular disorders can develop mal-adaptive fear avoidance behaviors which can negatively influence daily life functioning. The aims of this study were to (1) document different psychological factors in patients with vestibular disorders and healthy adults across cultures and (2) to assess the convergent validity of the 9-item Vestibular Activities Avoidance Instrument (VAAI), which quantifies fear avoidance beliefs.

Methods

Psychological factors and disability were measured in Dutch-speaking healthy adults and English- and Dutch-speaking persons with vestibular disorders using the VAAI, the Dizziness Handicap Inventory (DHI), the Hospital Anxiety and Depression Scale (HADS) and the Activities-Specific Balance Confidence Scale (ABC). The convergent validity of the VAAI was investigated by performing correlation analyses between the VAAI, the DHI, the HADS, and the ABC.

Results

A total of 151 Dutch-speaking healthy adults, 404 English-speaking participants with vestibular disorders, and 126 Dutch-speaking participants with vestibular disorders were included. Participants with vestibular disorders presented with higher levels of fear avoidance beliefs (VAAI), perceived disability (DHI), anxiety and depression (HADS), and lower confidence during balance activities (ABC) compared to healthy adults. Regarding the convergent validity of the VAAI, there were moderate to strong correlation coefficients (r = 0.39-0.74) between fear avoidance and the DHI, HADS, and ABC in participants with vestibular disorders.

Conclusions

Participants with vestibular disorders report a higher psychological burden compared to healthy adults. These results emphasize the importance of assessing psychological factors in persons with vestibular disorders. In addition, evidence was provided for convergent validity, supporting the VAAI as a valid outcome measure across cultures.

Anxiety and physical impairment in patients with central vestibular disorders

BACKGROUND

There is increasing evidence for close interrelations between vestibular and emotional brain networks. A study in patients with bilateral peripheral vestibulopathy (BVP) showed relatively low vertigo-related anxiety (VRA), despite high physical impairment. The current working hypothesis proposes the integrity of the peripheral vestibular system as a prerequisite for development of VRA. Here we contribute by evaluating VRA and vestibular-related handicap in central vestibular disorders.

METHODS

Of 6396 patients presenting in a tertiary vertigo centre, 306 were identified with four clear central vestibular disorders: pure cerebellar ocular motor disorder (COD; 61), cerebellar ataxia (CA; 63), atypical parkinsonian syndromes (APS; 28), vestibular migraine (VM; 154). Their results of the Vertigo Handicap Questionnaire (VHQ), with its subscales for anxiety and handicapped activity, were compared to those of 65 BVP patients. Postural instability was measured on a force-plate. Multivariate linear regression was used to adjust for patient demographics.

RESULTS

Patients with chronic central vestibular disorders (COD, CA, APS) had relatively low VRA levels comparable to those in BVP, independent of increased handicapped activity or postural instability. Only VM patients showed significantly higher VRA, although their activity impairment and postural instability were lowest. No significant differences within chronic central vestibular disorders were found for VRA and subjective activity impairment.

CONCLUSIONS

Subjective and objective vestibular-related impairment are not necessarily correlated with vestibular-related anxiety in central vestibular disorders. Our findings rather support the hypothesis that, in addition to an intact peripheral, an intact central vestibular system could also serve as a prerequisite to develop specific VRA.

The Cerebellum's Role in Affective Disorders: The Onset of Its Social Dimension

Major Depressive Disorder (MDD) and Bipolar Disorder (BD) are the most frequent mental disorders whose indeterminate etiopathogenesis spurs to explore new aetiologic scenarios. In light of the neuropsychiatric symptoms characterizing Cerebellar Cognitive Affective Syndrome (CCAS), the objective of this narrative review is to analyze the involvement of the cerebellum (Cbm) in the onset of these conditions. It aims at detecting the repercussions of the Cbm activities on mood disorders based on its functional subdivision in vestibulocerebellum (vCbm), pontocerebellum (pCbm) and spinocerebellum (sCbm). Despite the Cbm having been, for decades, associated with somato-motor functions, the described intercellular pathways, without forgiving the molecular impairment and the alteration in the volumetric relationships, make the Cbm a new important therapeutic target for MDD and BD. Given that numerous studies have showed its activation during mnestic activities and socio-emotional events, this review highlights in the Cbm, in which the altered external space perception (vCbm) is strictly linked to the cognitive-limbic Cbm (pCbm and sCbm), a crucial role in the MDD and BD pathogenesis. Finally, by the analysis of the cerebellar activity, this study aims at underlying not only the Cbm involvement in affective disorders, but also its role in social relationship building.

The effect of accompanying anxiety and depression on patients with different vestibular syndromes

Objective

This study aims to investigate the situation of vertigo disorder combined with anxiety and depression in patients with different types of vestibular syndrome.

Methods

A total of 330 patients with vertigo in otolaryngology outpatient department were selected, and clinical information such as age, gender, and scores of Dizziness handicap inventory (DHI), Generalized anxiety disorder-7 (GAD-7), and Patient Health Questionnaire-9 (PHQ-9) were collected. Analyzed the differences among acute vestibular syndrome (AVS), episodic vestibular syndrome (EVS) and chronic vestibular syndrome (CVS) in terms of age, gender, comorbid anxiety and depression, and the multivariate ordered logistic regression analysis was used to evaluate the relationship between the above factors and the degree of vertigo disorder.

Results

The three types of vestibular syndrome had no significant difference in age composition, sex composition, anxiety and depression. There was no significant difference in the probability of anxiety and depression among vertigo patients of different ages and genders. The total score of vertigo disorder and each sub-item score were higher in patients with anxiety and depression. Patients with anxiety mainly manifested in EVS and CVS, while patients with depression mainly manifested in EVS and AVS. The probability of increased vertigo in anxious patients was 4.65 times that of non-anxious patients, and the probability of increased vertigo in depressed patients was 3.49 times that of non-depressed patients. Age and gender had no statistically significant effect on the degree of vertigo. In patients with EVS, anxiety and depression had a significant effect on the degree of vertigo; in patients with CVS, anxiety had a significant effect on the degree of vertigo, but depression had no significant effect.

Conclusion

Age and gender do not significantly affect the degree of vertigo disorder and mental state in various vestibular syndromes. Instead, anxiety and depression are the risk factors for aggravating the degree of vertigo disorder, and manifest differently in each type of vestibular syndrome. Therefore, it is necessary to use a quick scale tool to conduct a standardized screening of the psychological status of patients with vertigo.

Structural connectome alterations in anxious dogs: a DTI-based study

Anxiety and fear are dysfunctional behaviors commonly observed in domesticated dogs. Although dogs and humans share psychopathological similarities, little is known about how dysfunctional fear behaviors are represented in brain networks in dogs diagnosed with anxiety disorders. A combination of diffusion tensor imaging (DTI) and graph theory was used to investigate the underlying structural connections of dysfunctional anxiety in anxious dogs and compared with healthy dogs with normal behavior. The degree of anxiety was assessed using the Canine Behavioral Assessment & Research Questionnaire (C-BARQ), a widely used, validated questionnaire for abnormal behaviors in dogs. Anxious dogs showed significantly decreased clustering coefficient ([Formula: see text]), decreased global efficiency ([Formula: see text]), and increased small-worldness (σ) when compared with healthy dogs. The nodal parameters that differed between the anxious dogs and healthy dogs were mainly located in the posterior part of the brain, including the occipital lobe, posterior cingulate gyrus, hippocampus, mesencephalon, and cerebellum. Furthermore, the nodal degree ([Formula: see text]) of the left cerebellum was significantly negatively correlated with "excitability" in the C-BARQ of anxious dogs. These findings could contribute to the understanding of a disrupted brain structural connectome underlying the pathological mechanisms of anxiety-related disorders in dogs.

Common neural correlates of vestibular stimulation and fear learning: an fMRI meta-analysis

BACKGROUND

A bidirectional functional link between vestibular and fear-related disorders has been previously suggested.

OBJECTIVE

To test a potential overlap of vestibular and fear systems with regard to their brain imaging representation maps.

METHODS

By use of voxel-based mapping permutation of subject images, we conducted a meta-analysis of earlier functional magnetic resonance imaging (fMRI) studies applying vestibular stimulation and fear conditioning in healthy volunteers.

RESULTS

Common clusters of concordance of vestibular stimulation and fear conditioning were found in the bilateral anterior insula cortex, ventrolateral prefrontal cortex and the right temporal pole, bilaterally in the adjacent ventrolateral prefrontal cortex, cingulate gyrus, secondary somatosensory cortex, superior temporal and intraparietal lobe, supplementary motor area and premotor cortex, as well as subcortical areas, such as the bilateral thalamus, mesencephalic brainstem including the collicular complex, pons, cerebellar vermis and bilateral cerebellar hemispheres. Peak areas of high concordance for activations during vestibular stimulation but deactivations during fear conditioning were centered on the posterior insula and S2.

CONCLUSIONS

The structural overlap of both networks allows the following functional interpretations: first, the amygdala, superior colliculi, and antero-medial thalamus might represent a release of preprogramed sensorimotor patterns of approach or avoidance. Second, the activation (vestibular system) and deactivation (fear system) of the bilateral posterior insula is compatible with the view that downregulation of the fear network by acute vestibular disorders or unfamiliar vestibular stimulation makes unpleasant perceived body accelerations less distressing. This also fits the clinical observation that patients with bilateral vestibular loss suffer from less vertigo-related anxiety.