Time to consider the role of rationalisation in health psychology

OBJECTIVE

The objective of this study was to determine the interaction between psychological factors, belief systems, and engagement around public health initiatives.

STUDY DESIGN

We conducted a longitudinal observational study, utilising convenience sampling to examine illness-related perception in the immediate and medium-term stages of the first wave of the SARS-CoV-2 pandemic in the UK.

METHODS

Weekly questionnaires assessed our primary measure, illness-related perception, using The Health Anxiety Inventory. Other psychological measures included apathy, loneliness, depersonalisation, state anxiety, trait anxiety as well as personality traits. Multiple regressions were performed to determine which psychological factors predicted the variance of health anxiety every week using the enter method.

RESULTS

A combination of psychological variables that varied over time and were modulated by external events predicted the evolution of illness-related perception and associated aversion to perceived threat.

CONCLUSION

Our findings highlight how in the face of a public health crisis, psychological factors play a determining role in the synthesis of beliefs as well as guiding human behaviour.

Neuroimaging in Functional Neurological Disorder: State of the Field and Research Agenda

Functional neurological disorder (FND) was of great interest to early clinical neuroscience leaders. During the 20th century, neurology and psychiatry grew apart - leaving FND a borderland condition. Fortunately, a renaissance has occurred in the last two decades, fostered by increased recognition that FND is prevalent and diagnosed using "rule-in" examination signs. The parallel use of scientific tools to bridge brain structure - function relationships has helped refine an integrated biopsychosocial framework through which to conceptualize FND. In particular, a growing number of quality neuroimaging studies using a variety of methodologies have shed light on the emerging pathophysiology of FND. This renewed scientific interest has occurred in parallel with enhanced interdisciplinary collaborations, as illustrated by new care models combining psychological and physical therapies and the creation of a new multidisciplinary FND society supporting knowledge dissemination in the field. Within this context, this article summarizes the output of the first International FND Neuroimaging Workgroup meeting, held virtually, on June 17th, 2020 to appraise the state of neuroimaging research in the field and to catalyze large-scale collaborations. We first briefly summarize neural circuit models of FND, and then detail the research approaches used to date in FND within core content areas: cohort characterization; control group considerations; task-based functional neuroimaging; resting-state networks; structural neuroimaging; biomarkers of symptom severity and risk of illness; and predictors of treatment response and prognosis. Lastly, we outline a neuroimaging-focused research agenda to elucidate the pathophysiology of FND and aid the development of novel biologically and psychologically-informed treatments.

Exploratory Factor Analysis of the Vestibular Activities Avoidance Instrument

Importance

Fear avoidance is a behavioral response to dizziness that can lead to chronic symptoms and maladaptation of the vestibular system, but there is no valid and reliable clinical measure of fear avoidance for persons with dizziness. Although the Vestibular Activities Avoidance Instrument (VAAI) was developed to identify fear avoidance beliefs in persons with dizziness, it was considered too long for clinical use.

Objective

To continue development of the VAAI for clinical use by reducing its length and by assessing the internal consistency and construct validity through associations with measures of disability, quality of life, and psychological well-being.

Design, Setting, and Participants

This prospective cohort study conducted from February 2018 to December 2019 at a tertiary care balance disorders clinic and in outpatient physical therapy clinics in the United States included 404 adults with dizziness.

Main Outcomes and Measures

Participants completed the 81-item VAAI, the Vestibular Activities and Participation (VAP) measure, the 12-Item Short Form Health Survey (SF-12), and the Hospital Anxiety and Depression Scale (HADS) at baseline. Exploratory factor analysis of the VAAI was conducted to reduce the number of items. Internal consistency of the reduced VAAI was determined by calculating the Cronbach α. Convergent validity was assessed by examining the associations between the reduced VAAI and the VAP, the SF-12, and the HADS using Spearman correlation coefficients.

Results

Data from 404 adults (mean [SD] age, 54.0 [17.0] years; 64.6% women) were included in the analyses. The exploratory factor analysis indicated that 2 factors explained the underlying constructs of the 81-Item VAAI. The first factor was retained and measured the construct of fear avoidance. The VAAI was reduced to 9 items (VAAI-9). The VAAI-9 showed excellent internal consistency (Cronbach α = 0.92) and was positively associated with the VAP (ρ = 0.81) and the HADS anxiety (ρ = 0.47) and depression (ρ = 0.64) subscales, and negatively associated with physical (ρ = -0.76) and mental (ρ = -0.47) health-related quality of life.

Conclusions and Relevance

These findings indicate that the VAAI-9 is a short, internally consistent, valid measure of fear avoidance and is associated with quality of life, activity limitations and participation restrictions, and psychological well-being. The next steps in the development of the VAAI-9 will include validation in an external sample, assessment of test-retest validity, and prospective investigations of its association with future disability.

Assessment of Potential Risk Factors for the Development of Persistent Postural-Perceptual Dizziness: A Case-Control Pilot Study

Objectives: (1) To assess whether neuroticism, state anxiety, and body vigilance are higher in patients with persistent postural-perceptual dizziness (PPPD) compared to a recovered vestibular patient group and a non-dizzy patient group; (2) To gather pilot data on illness perceptions of patients with PPPD. Materials and Methods: 15 cases with PPPD and two control groups: (1) recovered vestibular patients (n = 12) and (2) non-dizzy patients (no previous vestibular insult, n = 12). Main outcome measures: Scores from the Big Five Inventory (BFI) of personality traits, Generalized Anxiety Disorder - 7 (GAD-7) scale, Body Vigilance Scale (BVS), Dizziness Handicap Inventory (DHI), modified Vertigo Symptom Scale (VSS) and Brief Illness Perception Questionnaire (BIPQ). Results: Compared to non-dizzy patients, PPPD cases had higher neuroticism (p = 0.02), higher introversion (p = 0.008), lower conscientiousness (p = 0.03) and higher anxiety (p = 0.02). There were no differences between PPPD cases and recovered vestibular patients in BFI and GAD-7. PPPD cases had higher body vigilance to dizziness than both control groups and their illness perceptions indicated higher levels of threat than recovered vestibular patients. Conclusion: PPPD patients showed statistically significant differences to non-dizzy patients, but not recovered vestibular controls in areas such as neuroticism and anxiety. Body vigilance was increased in PPPD patients when compared with both recovered vestibular and non-dizzy patient groups. PPPD patients also exhibited elements of negative illness perception suggesting that this may be the key element driving the development of PPPD. Large scale studies focusing on this area in the early stages following vestibular insult are needed.

A Comparison of Dizziness Handicap Inventory Scores by Categories of Vestibular Diagnoses

OBJECTIVE

The Dizziness Handicap Inventory (DHI) is a 25-item self-report quantifying dizziness-related physical and emotional symptoms and restrictions in daily activities. DHI scores do not correlate with severity of structural vestibular deficits; thus, high DHI scores may reflect other causes of morbidity. This study investigated the relationship between total DHI scores and the presence of structural, functional, and psychiatric disorders in tertiary neurotology patients.

STUDY DESIGN

Retrospective.

SETTING

Tertiary center.

PATIENTS

Eighty-five patients who underwent multidisciplinary neurotologic evaluations.

INTERVENTION

Diagnostic.

MAIN OUTCOME MEASURE(S)

Active illnesses identified by a multidisciplinary neurotology team were abstracted from medical records, cataloged as structural, functional, or psychiatric disorders, and used to group patients into diagnostic categories: structural (structural disorders only), functional (functional disorders with/without structural disorders), and psychiatric (psychiatric disorders with/without other conditions). DHI scores were compared across diagnostic categories. Sensitivities and specificities of DHI scores for identifying structural versus functional or psychiatric disorders were calculated.

RESULTS

Mean DHI scores differed significantly by diagnostic category (structural 35 ± 18, functional 64 ± 15, and psychiatric 65 ± 19), before and after adjusting for age and sex (p < 0.001, Hedges' g>1.62 for structural versus functional and psychiatric categories). DHI≤30 (mild handicap) had specificity = 0.98 for structural disorders alone, whereas DHI>60 (severe handicap) had specificity = 0.88 for functional or psychiatric disorders.

CONCLUSIONS

In this tertiary cohort, categories of illnesses had large effects on total DHI scores. Patients with scores ≤30 were likely to have structural disorders alone, whereas those with scores >60 were likely to have functional or psychiatric disorders, with or without coexisting structural conditions.

Hemodynamic orthostatic dizziness/vertigo: Diagnostic criteria

This paper presents the diagnostic criteria for hemodynamic orthostatic dizziness/vertigo to be included in the International Classification of Vestibular Disorders (ICVD). The aim of defining diagnostic criteria of hemodynamic orthostatic dizziness/vertigo is to help clinicians to understand the terminology related to orthostatic dizziness/vertigo and to distinguish orthostatic dizziness/vertigo due to global brain hypoperfusion from that caused by other etiologies. Diagnosis of hemodynamic orthostatic dizziness/vertigo requires: A) five or more episodes of dizziness, unsteadiness or vertigo triggered by arising or present during upright position, which subsides by sitting or lying down; B) orthostatic hypotension, postural tachycardia syndrome or syncope documented on standing or during head-up tilt test; and C) not better accounted for by another disease or disorder. Probable hemodynamic orthostatic dizziness/vertigo is defined as follows: A) five or more episodes of dizziness, unsteadiness or vertigo triggered by arising or present during upright position, which subsides by sitting or lying down; B) at least one of the following accompanying symptoms: generalized weakness/tiredness, difficulty in thinking/concentrating, blurred vision, and tachycardia/palpitations; and C) not better accounted for by another disease or disorder. These diagnostic criteria have been derived by expert consensus from an extensive review of 90 years of research on hemodynamic orthostatic dizziness/vertigo, postural hypotension or tachycardia, and autonomic dizziness. Measurements of orthostatic blood pressure and heart rate are important for the screening and documentation of orthostatic hypotension or postural tachycardia syndrome to establish the diagnosis of hemodynamic orthostatic dizziness/vertigo.

Associations of depressive symptoms with outcomes in patients implanted with left ventricular assist devices

OBJECTIVE

We examined characteristics of depressive symptoms in patients who received left ventricular assist devices (LVAD) to assess their effects on negative outcomes post-implantation.

METHODS

We retrospectively identified 203 adults with pre-operative PHQ-9 scores who underwent LVAD placement as bridge to transplant (BTT) or destination therapy (DT). We analyzed effects of PHQ-9 total, somatic, and cognitive/affective scores and proportion of patients with clinical depression on all-cause mortality, rehospitalization, major bleeding, and neurologic events post-implantation, controlling for demographics and other medical comorbidities.

RESULTS

Mean total PHQ-9 scores did not differ between 81 BTT and 122 DT patients (BTT 6.4 vs. DT 7.5, p = 0.12). A higher proportion of DT patients had clinical depression (BTT 22% vs. DT 39%, p = 0.015). Somatic symptoms accounted for three-quarters of total scores in both groups. PHQ-9 domains were not associated with negative outcomes post-implantation.

CONCLUSION

Depression severity did not differ based on implant strategy, but more DT patients had clinical depression. Somatic symptoms were the biggest contributor to depressive symptoms. Pre-implantation PHQ-9 scores were not associated with outcomes, possibly because depression was mild in both groups. Additional work is needed in LVAD patients to better characterize depressive symptoms and their unique effects on clinical course and well-being.

Probabilistic Template of the Lateral Parabrachial Nucleus, Medial Parabrachial Nucleus, Vestibular Nuclei Complex, and Medullary Viscero-Sensory-Motor Nuclei Complex in Living Humans From 7 Tesla MRI

The lateral parabrachial nucleus, medial parabrachial nucleus, vestibular nuclei complex, and medullary viscero-sensory-motor (VSM) nuclei complex (the latter including among others the solitary nucleus, vagus nerve nucleus, and hypoglossal nucleus) are anatomically and functionally connected brainstem gray matter structures that convey signals across multiple modalities between the brain and the spinal cord to regulate vital bodily functions. It is remarkably difficult to precisely extrapolate the location of these nuclei from ex vivo atlases to conventional 3 Tesla in vivo images; thus, a probabilistic brainstem template in stereotaxic neuroimaging space in living humans is needed. We delineated these nuclei using single-subject high contrast 1.1 mm isotropic resolution 7 Tesla MRI images. After precise coregistration of nuclei labels to stereotaxic space, we generated a probabilistic template of their anatomical locations. Finally, we validated the nuclei labels in the template by assessing their inter-rater agreement, consistency across subjects and volumes. We also performed a preliminary comparison of their location and microstructural properties to histologic sections of a postmortem human brainstem specimen. In future, the resulting probabilistic template of these brainstem nuclei in stereotaxic space may assist researchers and clinicians in evaluating autonomic, vestibular and VSM nuclei structure, function and connectivity in living humans using conventional 3 Tesla MRI scanners.

Reduced betweenness centrality of a sensory-motor vestibular network in subclinical agoraphobia

Agoraphobic patients feel dizzy in crowded open spaces and respond to this symptom with excessive fear and avoidance. These clinical features show great similitude with the newly defined syndrome of persistent postural perceptual dizziness (PPPD). Patients with PPPD show decreased activity and connectivity in regions of the vestibular cortex. Due to the great overlap between these two conditions, we hypothesized that individuals with sub-clinical agoraphobia would show reduction in the connectivity features of these regions. We selected a group of healthy individuals from the Human Connectome Project that self-reported agoraphobia episodes, and compared it with a control group. We accurately matched the two groups for psychological measures and personality traits in order to study the neural correlates of vestibular symptoms independently of possible psychiatric vulnerabilities. We found that the agoraphobia group showed reduced betweenness centrality of a network encompassing key regions of the vestibular cortex. Dysfunctions of the vestibular cortex may explain the dizziness symptom for a disorder previously labelled as psychogenic.

Persistent Postural-Perceptual Dizziness

Persistent postural-perceptual dizziness (PPPD) was defined for the International Classification of Vestibular Disorders in 2017. It is a chronic vestibular disorder that manifests with waxing and waning symptoms of dizziness, unsteadiness, or nonspinning vertigo that last for 3 months or more and are exacerbated by upright posture, active or passive motion of self, and exposure to environments with complex or moving visual stimuli. Triggers of PPPD include a wide variety of conditions that may cause vestibular symptoms or disrupt balance functioning, including neuro-otologic and other medical conditions and psychological distress. The diagnosis is made by identifying key symptoms in patients' histories and conducting physical examinations and diagnostic testing of sufficient detail to establish PPPD as opposed to other illnesses. Ongoing research is providing insights into the pathophysiological mechanisms underlying PPPD and support for multimodality treatment plans incorporating specially adapted vestibular rehabilitation, serotonergic medications, and cognitive-behavior therapy.

Lower Functional Connectivity in Vestibular-Limbic Networks in Individuals With Subclinical Agoraphobia

Background: Agoraphobia was described in 1871 as a condition of fear-related alterations in spatial orientation and locomotor control triggered by places or situations that might cause a patient to panic and feel trapped. In contemporary nosology, however, this original concept of agoraphobia was split into two diagnostic entities, i.e., the modern anxiety disorder of agoraphobia, consisting solely of phobic/avoidant symptoms in public spaces, and the recently defined vestibular disorder of persistent postural perceptual dizziness (PPPD), characterized by dizziness, and unsteadiness exacerbated by visual motion stimuli. Previous neuroimaging studies found altered brain activity and connectivity in visual-vestibular networks of patients with PPPD vs. healthy controls. Neuroticism and introversion, which pre-dispose to both agoraphobia and PPPD, influenced brain responses to vestibular and visual motion stimuli in patients with PPPD. Similar neuroimaging studies have not been undertaken in patients with agoraphobia in its current definition. Given their shared history and pre-disposing factors, we sought to test the hypotheses that individuals with agoraphobic symptoms have alterations in visual-vestibular networks similar to those of patients with PPPD, and that these alterations are influenced by neuroticism and introversion. Methods: Drawing from the Human Connectome Project (HCP) database, we matched 52 participants with sub-clinical agoraphobia and 52 control subjects without agoraphobic symptoms on 19 demographic and psychological/psychiatric variables. We then employed a graph-theoretical framework to compare resting-state functional magnetic resonance images between groups and evaluated the interactive effects of neuroticism and introversion on the brain signatures of agoraphobia. Results: Individuals with subclinical agoraphobia had lower global clustering, efficiency and transitivity relative to controls. They also had lower connectivity metrics in two brain networks, one positioned to process incoming visual space-motion information, assess threat, and initiate/inhibit behavioral responses (visuospatial-emotional network) and one positioned to control and monitor locomotion (vestibular-navigational network). Introversion interacted with agoraphobic symptoms to lower the connectivity of the visuospatial-emotional network. This contrasted with previous findings describing neuroticism-associated higher connectivity in a narrower visual-spatial-frontal network in patients with PPPD. Conclusion: Functional connectivity was lower in two brain networks in subclinical agoraphobia as compared to healthy controls. These networks integrate visual vestibular and emotional response to guide movement in space.

Psychiatric Considerations in the Management of Dizzy Patients

Research over the last 4 decades has revealed a great deal of information about psychiatric and functional causes, consequences, and comorbidity of vestibular syndromes. Primary care clinicians, neurologists, and otologists who are willing to set aside the 20th century notion of "psychogenic dizziness" and incorporate 21st century concepts about 5 behavioral entities into their practices will be rewarded for their efforts with a marked improvement in diagnostic acumen and therapeutic effectiveness. Panic attacks may cause or contribute to acute or episodic vestibular symptoms. Generalized anxiety and depression do the same for chronic vestibular symptoms. Fear of falling causes considerable functional impairment, particularly in the elderly. Persistent postural-perceptual dizziness, a newly defined functional vestibular disorder that was 145 years in the making, is the most common cause of chronic dizziness in neurotologic practice. These 5 disorders are the primary diagnoses in 8-10% of patients who consult neurologists or otologists for vestibular symptoms and may be present in up to 50% of patients with structural vestibular disorders. They affect the clinical course of other illnesses and outcomes of medical and surgical interventions. Fortunately, when recognized properly, they are among the most treatment responsive of all conditions that cause vestibular symptoms.

Validation of a Teaching Effectiveness Assessment in Psychiatry Continuing Medical Education

OBJECTIVE

Little is known about factors associated with effective continuing medical education (CME) in psychiatry. The authors aimed to validate a method to assess psychiatry CME teaching effectiveness and to determine associations between teaching effectiveness scores and characteristics of presentations, presenters, and participants.

METHODS

This cross-sectional study was conducted at the Mayo Clinic Psychiatry Clinical Reviews and Psychiatry in Medical Settings. Presentations were evaluated using an eight-item CME teaching effectiveness instrument, its content based on previously published instruments. Factor analysis, internal consistency and interrater reliabilities, and temporal stability reliability were calculated. Associations were determined between teaching effectiveness scores and characteristics of presentations, presenters, and participants.

RESULTS

In total, 364 participants returned 246 completed surveys (response rate, 67.6%). Factor analysis revealed a unidimensional model of psychiatry CME teaching effectiveness. Cronbach α for the instrument was excellent at 0.94. Item mean score (SD) ranged from 4.33 (0.92) to 4.71 (0.59) on a 5-point scale. Overall interrater reliability was 0.84 (95% CI, 0.75-0.91), and temporal stability was 0.89 (95% CI, 0.77-0.97). No associations were found between teaching effectiveness scores and characteristics of presentations, presenters, and participants.

CONCLUSIONS

This study provides a new, validated measure of CME teaching effectiveness that could be used to improve psychiatry CME. In contrast to prior research in other medical specialties, CME teaching effectiveness scores were not associated with use of case-based or interactive presentations. This outcome suggests the need for distinctive considerations regarding psychiatry CME; a singular approach to CME teaching may not apply to all medical specialties.

Altered brain function in persistent postural perceptual dizziness: A study on resting state functional connectivity

This study used resting state functional magnetic resonance imaging (rsfMRI) to investigate whole brain networks in patients with persistent postural perceptual dizziness (PPPD). We compared rsfMRI data from 38 patients with PPPD and 38 healthy controls using whole brain and region of interest analyses. We examined correlations among connectivity and clinical variables and tested the ability of a machine learning algorithm to classify subjects using rsfMRI results. Patients with PPPD showed: (a) increased connectivity of subcallosal cortex with left superior lateral occipital cortex and left middle frontal gyrus, (b) decreased connectivity of left hippocampus with bilateral central opercular cortices, left posterior opercular cortex, right insular cortex and cerebellum, and (c) decreased connectivity between right nucleus accumbens and anterior left temporal fusiform cortex. After controlling for anxiety and depression as covariates, patients with PPPD still showed decreased connectivity between left hippocampus and right inferior frontal gyrus, bilateral temporal lobes, bilateral insular cortices, bilateral central opercular cortex, left parietal opercular cortex, bilateral occipital lobes and cerebellum (bilateral lobules VI and V, and left I-IV). Dizziness handicap, anxiety, and depression correlated with connectivity in clinically meaningful brain regions. The machine learning algorithm correctly classified patients and controls with a sensitivity of 78.4%, specificity of 76.9%, and area under the curve = 0.88 using 11 connectivity parameters. Patients with PPPD showed reduced connectivity among the areas involved in multisensory vestibular processing and spatial cognition, but increased connectivity in networks linking visual and emotional processing. Connectivity patterns may become an imaging biomarker of PPPD.

Brain responses to virtual reality visual motion stimulation are affected by neurotic personality traits in patients with persistent postural-perceptual dizziness

OBJECTIVE

Persistent postural perceptual dizziness (PPPD) is a common vestibular disorder of persistent dizziness and unsteadiness, exacerbated by upright posture, self-motion, and exposure to complex or moving visual stimuli. Previous functional magnetic resonance imaging (fMRI) studies found dysfunctional activity in the visual-vestibular cortices in patients with PPPD. Clinical studies showed that the anxiety-related personality traits of neuroticism and introversion may predispose individuals to PPPD. However, the effects of these traits on brain function in patients with PPPD versus healthy controls (HCs) have not been studied.

METHODS

To investigate potential differential effects of neuroticism and introversion on functioning of their visuo-vestibular networks, 15 patients with PPPD and 15 HCs matched for demographics and motion sickness susceptibility underwent fMRI during virtual reality simulation of a rollercoaster ride in vertical and horizontal directions.

RESULTS

Neuroticism positively correlated with activity in the inferior frontal gyrus (IFg), and enhanced connectivity between the IFg and occipital regions in patients with PPPD relative to HCs during vertical versus horizontal motion comparison.

CONCLUSIONS

In patients with PPPD, neuroticism increased the activity and connectivity of neural networks that mediate attention to visual motion cues during vertical motion. This mechanism may mediate visual control of balance in neurotic patients with PPPD.

Persistent postural-perceptual dizziness (PPPD): a common, characteristic and treatable cause of chronic dizziness

Persistent postural-perceptual dizziness (PPPD) is a newly defined diagnostic syndrome that unifies key features of chronic subjective dizziness, phobic postural vertigo and related disorders. It describes a common chronic dysfunction of the vestibular system and brain that produces persistent dizziness, non-spinning vertigo and/or unsteadiness. The disorder constitutes a long-term maladaptation to a neuro-otological, medical or psychological event that triggered vestibular symptoms, and is usefully considered within the spectrum of other functional neurological disorders. While diagnostic tests and conventional imaging usually remain negative, patients with PPPD present in a characteristic way that maps on to positive diagnostic criteria. Patients often develop secondary functional gait disorder, anxiety, avoidance behaviour and severe disability. Once recognised, PPPD can be managed with effective communication and tailored treatment strategies, including specialised physical therapy (vestibular rehabilitation), serotonergic medications and cognitive-behavioural therapy.

Altered Insular and Occipital Responses to Simulated Vertical Self-Motion in Patients with Persistent Postural-Perceptual Dizziness

BACKGROUND

Persistent postural-perceptual dizziness (PPPD) is a common functional vestibular disorder characterized by persistent symptoms of non-vertiginous dizziness and unsteadiness that are exacerbated by upright posture, self-motion, and exposure to complex or moving visual stimuli. Recent physiologic and neuroimaging data suggest that greater reliance on visual cues for postural control (as opposed to vestibular cues-a phenomenon termed visual dependence) and dysfunction in central visuo-vestibular networks may be important pathophysiologic mechanisms underlying PPPD. Dysfunctions are thought to involve insular regions that encode recognition of the visual effects of motion in the gravitational field.

METHODS

We tested for altered activity in vestibular and visual cortices during self-motion simulation obtained via a visual virtual-reality rollercoaster stimulation using functional magnetic resonance imaging in 15 patients with PPPD and 15 healthy controls (HCs). We compared between groups differences in brain responses to simulated displacements in vertical vs horizontal directions and correlated the difference in directional responses with dizziness handicap in patients with PPPD.

RESULTS

HCs showed increased activity in the anterior bank of the central insular sulcus during vertical relative to horizontal motion, which was not seen in patients with PPPD. However, for the same comparison, dizziness handicap correlated positively with activity in the visual cortex (V1, V2, and V3) in patients with PPPD.

CONCLUSION

We provide novel insight into the pathophysiologic mechanisms underlying PPPD, including functional alterations in brain processes that affect balance control and reweighting of space-motion inputs to favor visual cues. For patients with PPPD, difficulties using visual data to discern the effects of gravity on self-motion may adversely affect balance control, particularly for individuals who simultaneously rely too heavily on visual stimuli. In addition, increased activity in the visual cortex, which correlated with severity of dizziness handicap, may be a neural correlate of visual dependence.

Diagnostic criteria for persistent postural-perceptual dizziness (PPPD): Consensus document of the committee for the Classification of Vestibular Disorders of the Bárány Society

This paper presents diagnostic criteria for persistent postural-perceptual dizziness (PPPD) to be included in the International Classification of Vestibular Disorders (ICVD). The term PPPD is new, but the disorder is not. Its diagnostic criteria were derived by expert consensus from an exhaustive review of 30 years of research on phobic postural vertigo, space-motion discomfort, visual vertigo, and chronic subjective dizziness. PPPD manifests with one or more symptoms of dizziness, unsteadiness, or non-spinning vertigo that are present on most days for three months or more and are exacerbated by upright posture, active or passive movement, and exposure to moving or complex visual stimuli. PPPD may be precipitated by conditions that disrupt balance or cause vertigo, unsteadiness, or dizziness, including peripheral or central vestibular disorders, other medical illnesses, or psychological distress. PPPD may be present alone or co-exist with other conditions. Possible subtypes await future identification and validation. The pathophysiologic processes underlying PPPD are not fully known. Emerging research suggests that it may arise from functional changes in postural control mechanisms, multi-sensory information processing, or cortical integration of spatial orientation and threat assessment. Thus, PPPD is classified as a chronic functional vestibular disorder. It is not a structural or psychiatric condition.

Neuroticism modulates brain visuo-vestibular and anxiety systems during a virtual rollercoaster task

Different lines of research suggest that anxiety‐related personality traits may influence the visual and vestibular control of balance, although the brain mechanisms underlying this effect remain unclear. To our knowledge, this is the first functional magnetic resonance imaging (fMRI) study that investigates how individual differences in neuroticism and introversion, two key personality traits linked to anxiety, modulate brain regional responses and functional connectivity patterns during a fMRI task simulating self‐motion. Twenty‐four healthy individuals with variable levels of neuroticism and introversion underwent fMRI while performing a virtual reality rollercoaster task that included two main types of trials: (1) trials simulating downward or upward self‐motion (vertical motion), and (2) trials simulating self‐motion in horizontal planes (horizontal motion). Regional brain activity and functional connectivity patterns when comparing vertical versus horizontal motion trials were correlated with personality traits of the Five Factor Model (i.e., neuroticism, extraversion‐introversion, openness, agreeableness, and conscientiousness). When comparing vertical to horizontal motion trials, we found a positive correlation between neuroticism scores and regional activity in the left parieto‐insular vestibular cortex (PIVC). For the same contrast, increased functional connectivity between the left PIVC and right amygdala was also detected as a function of higher neuroticism scores. Together, these findings provide new evidence that individual differences in personality traits linked to anxiety are significantly associated with changes in the activity and functional connectivity patterns within visuo‐vestibular and anxiety‐related systems during simulated vertical self‐motion. Hum Brain Mapp 38:715–726, 2017. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Retrospective review and telephone follow-up to evaluate a physical therapy protocol for treating persistent postural-perceptual dizziness: A pilot study

BACKGROUND

Persistent postural-perceptual dizziness (PPPD) (formerly chronic subjective dizziness) may be treated using the habituation form of vestibular and balance rehabilitation therapy (VBRT), but therapeutic outcomes have not been formally investigated.

OBJECTIVE

This pilot study gathered the first data on the efficacy of VBRT for individuals with well-characterized PPPD alone or PPPD plus neurotologic comorbidities (vestibular migraine or compensated vestibular deficits).

METHODS

Twenty-six participants were surveyed by telephone an average of 27.5 months after receiving education about PPPD and instructions for home-based VBRT programs. Participants were queried about exercise compliance, perceived benefits of therapy, degree of visual or motion sensitivity remaining, disability level, and other interventions.

RESULTS

Twenty-two of 26 participants found physical therapy consultation helpful. Fourteen found VBRT exercises beneficial, including 8 of 12 who had PPPD alone and 6 of 14 who had PPPD with co-morbidities. Of the 14 participants who found VBRT helpful, 7 obtained relief of sensitivity to head/body motion, 5 relief of sensitivity to visual stimuli, and 4 complete remission. Comparable numbers for the 12 participants who found VBRT not helpful were 1 (head/body motion), 3 (visual stimuli), and 0 (remission).

CONCLUSIONS

This pilot study offers the first data supporting the habituation form of VBRT for treatment of PPPD.

Functional (psychogenic) dizziness

Functional and psychiatric disorders that cause vestibular symptoms (i.e., vertigo, unsteadiness, and dizziness) are common. In fact, they are more common than many well-known structural vestibular disorders. Neurologists and otologists are more likely to encounter patients with vestibular symptoms due to persistent postural-perceptual dizziness or panic disorder than Ménière's disease or bilateral vestibular loss. Successful approaches to identifying functional and psychiatric causes of vestibular symptoms can be incorporated into existing practices without much difficulty. The greatest challenge is to set aside dichotomous thinking that strongly emphasizes investigations of structural diseases in favor of a three-pronged approach that assesses structural, functional, and psychiatric disorders simultaneously. The pathophysiologic mechanisms underlying functional and psychiatric causes of vestibular symptoms are better understood than many clinicians realize. Research methods such as advanced posturographic analysis and functional brain imaging will push this knowledge further in the next few years. Treatment plans that include patient education, vestibular rehabilitation, cognitive and behavioral therapies, and medications substantially reduce morbidity and offer the potential for sustained remission when applied systematically. Diagnostic and therapeutic approaches are necessarily multidisciplinary in nature, but they are well within the purview of collaborative care teams or networks of clinicians coordinated with the neurologists and otologists whom patients consult first.

Functional and psychiatric vestibular disorders

Behavioral factors have long been recognized as affecting spatial orientation and balance function. Neuroanatomic and neurophysiologic studies conducted worldwide over the last 30 years have substantially advanced our knowledge about the inherently strong connectivity among threat/anxiety, vestibular, visual, and somatosensory systems in the brain. Clinical investigations have shed greater light on the nature of functional and psychiatric disorders that manifest or magnify vestibular morbidity. Concepts of these syndromes have changed over 150 years. Even their nomenclature has had different meanings in different eras. This chapter will review functional and psychiatric vestibular disorders. Terminology will follow the International Classification of Diseases, 11th edition, beta draft and the International Classification of Vestibular Disorders. Anxiety plays a central role in behavioral vestibular morbidity. Anxiety, traumatic stress, obsessive, and depressive disorders may be primary causes of episodic and chronic vestibular symptoms or secondary complications of other vestibular disorders. These psychiatric illnesses affect 30-50% of patients who consult neurologists or otologists for vestibular symptoms. Coexisting psychiatric disorders adversely affect treatment for patients with structural vestibular diseases, especially when unrecognized. Persistent postural-perceptual dizziness is the leading cause of long-term vestibular disability. Fortunately, pharmacologic, psychotherapeutic, and rehabilitative treatments of these illnesses have improved in recent years.