Functional dizziness: from phobic postural vertigo and chronic subjective dizziness to persistent postural-perceptual dizziness

Persistent postural-perceptual dizziness: A functional neuro-otologic disorder

Persistent postural-perceptual dizziness (PPPD) is a functional neuro-otologic disorder that is the most frequent cause of chronic vestibular syndrome. The core vestibular symptoms include dizziness, unsteadiness, and non-spinning vertigo, which are exacerbated by an upright posture or walking, active or passive motion, and exposure to moving or complex visual stimuli. PPPD is mostly precipitated by acute or episodic vestibular diseases; however, its symptoms cannot be accounted for by its precipitants. PPPD is not a diagnosis of exclusion, but may coexist with other structural diseases. Thus, when diagnosing PPPD, the patient's symptoms must be explained by PPPD alone or by PPPD in combination with a structural illness. PPPD is most frequently observed at approximately 50 years of age, with a female predominance. Conventional vestibular tests do not reveal any specific signs of PPPD. However, the head roll-tilt subjective visual vertical test and gaze stability test after exposure to moving visual stimuli may detect the characteristic features of PPPD, that is, somatosensory- and visually-dependent spatial orientation, respectively. Therefore, these tests could be used as diagnostic tools for PPPD. Regarding the pathophysiology of PPPD, neuroimaging studies suggest shifts in interactions among visuo-vestibular, sensorimotor, and emotional networks, where visual inputs dominate over vestibular inputs. Postural control also shifts, leading to the stiffening of the lower body. To treat PPPD, selective serotonin reuptake inhibitors/serotonin noradrenaline reuptake inhibitors, vestibular rehabilitation, and cognitive behavioral therapy are used alone or in combination.

Additional cognitive behavior therapy for persistent postural-perceptual dizziness: a meta-analysis

OBJECTIVE

To investigate whether additional Cognitive Behavior Therapy (CBT) combined with conventional therapy improves outcomes for patients with Persistent Postural-Perceptual Dizziness (PPPD) compared with conventional therapy alone.

METHODS

Two reviewers independently searched PubMed, Embase, Web of Science, Cochrane Library, and ClinicalTrials.gov for relevant Randomized Controlled Trials (RCTs) examining CBT for PPPD which were conducted and published in English from January 2002 to November 2022. RCTs reporting any indicators for assessing corresponding symptoms of PPPD were included, such as Dizziness Handicap Inventory (DHI), Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), Hospital Anxiety and Depression Scale (HADS), and Patient Health Questionnaire-9 (PHQ-9). Two independent reviewers conducted extraction of relevant information and evaluation of risk of bias. The Cochrane Collaboration risk of bias tool version 1.0 was used to evaluate risks and assess the quality of the included studies, and Cochrane Review Manager 5.3 software (RevMan 5.3) was used to perform meta-analyses.

RESULTS

The results of six RCTs indicated that combining additional CBT with conventional therapy significantly improved outcomes for PPPD patients compared with conventional therapy alone, especially in DHI-Total scores (Mean Difference [MD = -8.17], 95% Confidence Interval [95% CI: -10.26, -6.09], p < 0.00001), HAMA scores (MD = -2.76, 95% CI: [-3.57, -1.94], p < 0.00001), GAD-7 scores (MD = -2.50, 95% CI [-3.29, -1.70], p < 0.00001), and PHQ-9 scores (MD = -2.29, 95% CI [-3.04, -1.55], p < 0.00001). Subgroup analysis revealed a significant benefit of additional CBT compared with conventional therapies alone, including Vestibular Rehabilitation Therapy (VRT) (MD = -8.70, 95% CI: [-12.17, -5.22], p < 0.00001), Selective Serotonin Reuptake Inhibitor (SSRI) (with controlled SSRI: MD = -10.70, 95% CI: [-14.97, -6.43], p < 0.00001), and VRT combined with SSRI (MD = -6.08, 95% CI [-9.49, -2.67], p = 0.0005) in DHI-Total scores.

CONCLUSION

Additional CBT combined with conventional therapy may provide additional improvement for patients with PPPD compared with conventional therapy alone. However, more RCTs are needed to support and guide the application of CBT in treating PPPD.

LEVEL OF EVIDENCE

I; Systematic review of RCTs.

Clinical characteristics of persistent postural-perceptual dizziness and its visual subtype in Korean patients: A multicenter cross-sectional study

OBJECTIVES

Persistent postural-perceptual dizziness (PPPD) is a chronic functional vestibular disorder for which the Bárány Society has established diagnostic criteria. This nationwide multicenter study aims to investigate the clinical features of individuals with definite PPPD and clinical variant PPPD who do not fully meet the diagnostic criteria, with a particular focus on visual exaggeration.

METHODS

Between September 2020 and September 2021, a total of 76 individuals with definite PPPD and 109 individuals with clinical variant PPPD who did not meet all three exacerbating factors outlined in Criterion B were recruited from 18 medical centers in South Korea. The study gathered information on demographic factors, clinical manifestations, balance scales, and personality assessments.

RESULTS

Comparative analysis between groups with definite PPPD and clinical variant with visual exacerbation revealed no significant differences in sociodemographic characteristics, clinical course, dizziness impact, and specific precipitants. Only disease duration was significantly longer in definite PPPD compared with variant with visual exacerbation. However, the variant without visual exacerbation displayed significantly reduced rates of panic disorder, diminished space-motion discomfort, lesser impact of dizziness, and decreased prevalence of depression when compared with the definitive PPPD.

CONCLUSION

This is the first comprehensive nationwide study examining clinical features of both definite PPPD patients and its clinical variants, considering visual exacerbating factors. Differences in dizziness and personality traits emerged between definite PPPD and its potential variant without visual issues. Our results highlight the possibility of a distinct clinical variant of PPPD influenced by visual dependency.

Analysis of postural stability using foam posturography in patients with persistent postural-perceptual dizziness

BACKGROUND/OBJECTIVE

Persistent postural-perceptual dizziness (PPPD) is worsened in a standing posture, or by body movement, or visual stimulation. We aimed to evaluate postural stability in PPPD patients using foam posturography and to investigate the dependence on visual and somatosensory input in the standing posture.

METHODS

Foam posturography was performed on 53 PPPD patients, and data from the PPPD patients were compared with the data from an age- and sex-matched healthy controls. The PPPD patients were divided into four groups based on the findings of vestibular function tests and the effect of vestibular function on posturographic data was examined.

RESULTS

Romberg's ratios were significantly higher in PPPD patients than in controls. The median Romberg's ratios in PPPD patients with normal vestibular function were also higher than those in controls. However, foam ratio was significantly lower in PPPD patients than in controls. The median foam ratios in PPPD patients with vestibular dysfunction were also lower than those in controls.

CONCLUSIONS

In a standing posture, PPPD patients may be more dependent on visual input and less dependent on somatosensory input than healthy subjects. Higher dependence on visual and lower dependence on somatosensory input in PPPD may be a feature unaffected by vestibular function.

Sense of direction in vestibular disorders

BACKGROUND

Our sense of direction (SOD) ability relies on the sensory integration of both visual information and self-motion cues from the proprioceptive and vestibular systems. Here, we assess how dysfunction of the vestibular system impacts perceived SOD in varying vestibular disorders, and secondly, we explore the effects of dizziness, migraine and psychological symptoms on SOD ability in patient and control groups.

METHODS

87 patients with vestibular disorder and 69 control subjects were assessed with validated symptom and SOD questionnaires (Santa Barbara Sense of Direction scale and the Object Perspective test).

RESULTS

While patients with vestibular disorders performed significantly worse than controls at the group level, only central and functional disorders (vestibular migraine and persistent postural perceptual dizziness), not peripheral disorders (benign-paroxysmal positional vertigo, bilateral vestibular failure and Meniere's disease) showed significant differences compared to controls on the level of individual vestibular groups. Additionally, orientational abilities associated strongly with spatial anxiety and showed clear separation from general dizziness and psychological factors in both patient and control groups.

CONCLUSIONS

SOD appears to be less affected by peripheral vestibular dysfunction than by functional and/or central diagnoses, indicating that higher level disruptions to central vestibular processing networks may impact SOD more than reductions in sensory peripheral inputs. Additionally, spatial anxiety is highly associated with orientational abilities in both patients and control subjects.

Functional Dizziness as a Spatial Cognitive Dysfunction

(1) Background: Persistent postural-perceptual dizziness (PPPD) is a common chronic dizziness disorder with an unclear pathophysiology. It is hypothesized that PPPD may involve disrupted spatial cognition processes as a core feature. (2) Methods: A cohort of 19 PPPD patients underwent psycho-cognitive testing, including assessments for anxiety, depression, memory, attention, planning, and executive functions, with an emphasis on spatial navigation via a virtual Morris water maze. These patients were compared with 12 healthy controls and 20 individuals with other vestibular disorders but without PPPD. Vestibular function was evaluated using video head impulse testing and vestibular evoked myogenic potentials, while brain magnetic resonance imaging was used to exclude confounding pathology. (3) Results: PPPD patients demonstrated unique impairments in allocentric spatial navigation (as evidenced by the virtual Morris water maze) and in other high-demand visuospatial cognitive tasks that involve executive functions and planning, such as the Towers of London and Trail Making B tests. A factor analysis highlighted spatial navigation and advanced visuospatial functions as being central to PPPD, with a strong correlation to symptom severity. (4) Conclusions: PPPD may broadly impair higher cognitive functions, especially in spatial cognition. We discuss a disruption in the creation of enriched cognitive spatial maps as a possible pathophysiology for PPPD.

Similarities between explaining dizziness and explaining pain? Exploring common patient experiences, theoretical models, treatment approaches and potential therapeutic narratives for persistent dizziness or pain

Pain and dizziness are common experiences throughout the lifespan. However, nearly a quarter of those with acute pain or dizziness experience persistence, which is associated with disability, social isolation, psychological distress, decreased independence, and poorer quality of life. Thus, persistent pain or dizziness impacts peoples' lives in similarly negative ways. Conceptual models of pain and dizziness also have many similarities. Many of these models are more expansive than explaining mere symptoms; rather they describe pain or dizziness as holistic experiences that are influenced by biopsychosocial and contextual factors. These experiences also appear to be associated with multi-modal bodily responses related to evaluation of safety, threat detection and anticipation, as influenced by expectations, and predictions anticipation, not simply a reflection of tissue injury or pathology. Conceptual models also characterize the body as adaptable and therefore capable of recovery. These concepts may provide useful therapeutic narratives to facilitate understanding, dethreaten the experience, and provide hope for patients. In addition, therapeutic alliance, promoting an active movement-based approach, building self-efficacy, and condition-specific approaches can help optimize outcomes. In conclusion, there are significant overlaps in the patient experience, theoretical models and potential therapeutic narratives that guide care for people suffering with persistent pain or dizziness.

Persistent Postural-Perceptual Dizziness: Review and Update on Key Mechanisms of the Most Common Functional Neuro-otologic Disorder

Persistent postural-perceptual dizziness (PPPD) is a functional neuro-otologic (vestibular) disorder manifesting dizziness, unsteadiness, or nonspinning vertigo lasting 3 months or more and exacerbated by upright posture, active or passive motion, and complex visual stimuli. PPPD is the most common cause of chronic vestibular symptoms. Early pathophysiologic models of PPPD emphasized the adverse effects of anxiety on postural control and spatial orientation. More recent concepts added predictive processing of sensory inputs and alterations in motion perception. Herein, a third-generation model incorporates prioritization of postural stability over fluid locomotion to explain symptoms, physiologic and neuroimaging data, and effects of current treatments.

Developing a Curriculum for Functional Neurological Disorder in Neurology Training: Questions and Answers

Functional neurologic disorder (FND) is a common condition for which neurology residents often receive little to no formal teaching. Using a question-and-answer format, this article puts forward a case for why an FND curriculum is needed and aims to provide guidance on possible curricular content including medical knowledge, clinical skills, communication, and team-based collaboration. The authors also discuss methods for teaching and evaluating this knowledge and associated clinical skills, linking this to current Accreditation Council for Graduate Medical Education neurology milestones. Finally, the authors consider how to better engage and energize neurology trainees around this underserved yet challenging patient population.

Improvement of vertigo symptoms after 2 months of Vertigoheel treatment: a case series in patients with bilateral vestibulopathy and functional dizziness

Background

Dizziness is a common leading symptom in bilateral vestibulopathy (BVP) and functional dizziness (FD), with significant negative effects on functional ability and quality of life. Vertigoheel is a widely used non-prescription drug for the treatment of vertigo. In order to generate systematic data for Vertigoheel in BVP and FD, we conducted a non-interventional study assessing vertigo symptoms.

Methods

This study was conducted as an open-label, prospective, monocentric, non-interventional case series (ClinicalTrials.gov identifier NCT05897853). Patients with BVP and FD received Vertigoheel according to market approval for an observational period of 2 months. Change from baseline after 2 months was assessed for the following endpoints: Dizziness Handicap Inventory (DHI) as the primary endpoint, quality of life (QoL) by EQ-5D-5L, and body sway by static posturography. Patients with FD were additionally assessed for depression and anxiety by PHQ-9 and GAD-7 questionnaires. Patients with BVP were assessed for vestibular function by video head impulse testing and caloric testing. Adverse events and other safety-related observations were evaluated.

Results

Of 41 patients with FD and 13 with BVP, two with FD and none with BVP dropped out before the follow-up visit. Both patient groups showed significantly improved disability caused by dizziness after 2 months: In BVP, the DHI decreased on average by 13.2 points from 45.4 to 32.2 (p < 0.001). In FD, the DHI decreased on average by 12.0 points from 46.5 to 34.5 (p < 0.001). In patients with FD, significant improvements were also observed for the secondary endpoints QoL, anxiety, and depression. No significant change was observed for posturography readouts. In patients with BVP, there were no statistically significant improvements for the secondary endpoints QoL, posturography, or vestibular function within the observation period. The study found no evidence of a safety risk.

Conclusion

The study provides evidence for Vertigoheel's clinical safety and limited evidence - because of the non-interventional design - for its effectiveness in BVP and FD that are considered disease entities with high medical need for new treatment options. The results may serve as the basis for randomized placebo-controlled trials.

Recurrence quantification analysis of postural sway in patients with persistent postural perceptual dizziness

Background

Persistent postural perceptual dizziness (PPPD) is a common cause of chronic dizziness and imbalance. Emerging evidence suggests that changes in quantitative measures of postural control may help identify individuals with PPPD, however, traditional linear metrics of sway have yielded inconsistent results. Methodologies to examine the temporal structure of sway, including recurrent quantification analysis (RQA), have identified unique changes in dynamic structure of postural control in other patient populations. This study aimed to determine if adults with PPPD exhibit changes in the dynamic structure of sway and whether this change is modulated on the basis of available sensory cues.

Methods

Twelve adults diagnosed with PPPD and twelve age-matched controls, completed a standard battery of quiet stance balance tasks that involved the manipulation of visual and/or proprioceptive feedback. For each group, the regularity and complexity of the CoP signal was assessed using RQA and the magnitude and variability of the CoP signal was quantified using traditional linear measures.

Results

An overall effect of participant group (i.e., healthy controls vs. PPPD) was seen for non-linear measures of temporal complexity quantified using RQA. Changes in determinism (i.e., regularity) were also modulated on the basis of availability of sensory cues in patients with PPPD. No between-group difference was identified for linear measures assessing amount and variability of sway.

Conclusions

Participants with PPPD on average exhibited sway that was similar in magnitude to, but significantly more repeatable and less complex than, healthy controls. These data show that non-linear measures provide unique information regarding the effect of PPPD on postural control, and as a result, may serve as potential rehabilitation outcome measures.

[Functional neurological disorders: A clinical anthology]

Functional neurological disorders have a broad phenotypic spectrum and include different clinical syndromes, which are sometimes associated to each other or appear consecutively over the course of the disease. This clinical anthology provides details on the specific and sensitive positive signs that are to be sought in the context of a suspected functional neurological disorder. Beside these positive elements leading to the diagnosis of functional neurological disorder, we should keep in mind the possibility of an associated organic disorder as the combination of both organic and functional disorders is a relatively frequent situation in clinical practice. Here we describe the clinical characteristics of different functional neurological syndromes: motor deficits, abnormal hyperkinetic and hypokinetic movements, voice or speech disorders, sensory disorders, and functional dissociative seizures. The clinical examination and the identification of positive signs play a critical role in the diagnosis of functional neurological disorder. Knowledge of the specific signs associated with each phenotype render possible to make an early diagnosis. For that matter, it contributes to the improvement of patient care management. It allows to a better engagement in an appropriate care pathway, which influence their prognosis. Highlighting and discussing positive signs with patients can also be an interesting step in the process of explaining the disease and its management.

The Effects of Vibro-Tactile Biofeedback Balance Training on Balance Control and Dizziness in Patients with Persistent Postural-Perceptual Dizziness (PPPD)

BACKGROUND

Patients with persistent postural-perceptual dizziness (PPPD) frequently report having problems with balance control. Artificial systems providing vibro-tactile feedback (VTfb) of trunk sway to the patient could aid recalibration of "falsely" programmed natural sensory signal gains underlying unstable balance control and dizziness. Thus, the question we examine, retrospectively, is whether such artificial systems improve balance control in PPPD patients and simultaneously reduce the effects of dizziness on their living circumstances. Therefore, we assessed in PPPD patients the effects of VTfb of trunk sway on balance control during stance and gait tests, and on their perceived dizziness.

METHODS

Balance control was assessed in 23 PPPD patients (11 of primary PPPD origin) using peak-to-peak amplitudes of trunk sway measured in the pitch and roll planes with a gyroscope system (SwayStar™) during 14 stance and gait tests. The tests included standing eyes closed on foam, walking tandem steps, and walking over low barriers. The measures of trunk sway were combined into a Balance Control Index (BCI) and used to determine whether the patient had a quantified balance deficit (QBD) or dizziness only (DO). The Dizziness Handicap Inventory (DHI) was used to assess perceived dizziness. The subjects first underwent a standard balance assessment from which the VTfb thresholds in eight directions, separated by 45 deg, were calculated for each assessment test based on the 90% range of the trunk sway angles in the pitch and roll directions for the test. A headband-mounted VTfb system, connected to the SwayStar™, was active in one of the eight directions when the threshold for that direction was exceeded. The subjects trained for 11 of the 14 balance tests with VTfb twice per week for 30 min over a total of 2 consecutive weeks. The BCI and DHI were reassessed each week and the thresholds were reset after the first week of training.

RESULTS

On average, the patients showed an improved balance control in the BCI values after 2 weeks of VTfb training (24% p = 0.0001). The improvement was greater for the QBD patients than for the DO patients (26 vs. 21%), and greater for the gait tests than the stance tests. After 2 weeks, the mean BCI values of the DO patients, but not the QBD patients, were significantly less (p = 0.0008) than the upper 95% limit of normal age-matched reference values. A subjective benefit in balance control was spontaneously reported by 11 patients. Lower (36%), but less significant DHI values were also achieved after VTfb training (p = 0.006). The DHI changes were identical for the QBD and DO patients and approximately equal to the minimum clinical important difference.

CONCLUSIONS

These initial results show, as far as we are aware for the first time, that providing VTfb of trunk sway to PPPD subjects yields a significant improvement in balance control, but a far less significant change in DHI-assessed dizziness. The intervention benefitted the gait trials more than the stance trials and benefited the QBD group of PPPD patients more than the DO group. This study increases our understanding of the pathophysiologic processes underlying PPPD and provides a basis for future interventions.

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.

Somatic symptom distress and gender moderate the effect of integrative group psychotherapy for functional vertigo on vertigo handicap: A moderation analysis of a randomised controlled trial

OBJECTIVE

Psychotherapeutic treatments for functional vertigo have shown promising results in recent years but it is still to be determined for whom these treatments work best. The aim of this study was to run a moderation analysis to identify which baseline factors may moderate the success of integrative psychotherapeutic group treatment (IPGT) as compared to a self-help group (SHG) active control.

METHODS

Data from 159 patients included in a 16-week randomised controlled trial were analysed. The outcome was vertigo-related handicap at post-treatment and gender, age, baseline somatisation, depression and anxiety were taken as putative moderators.

RESULTS

We found that baseline somatic symptoms (i.e. PHQ-15 score, p = 0.04, ∆R2 = 0.02) and gender (p = 0.04, ∆R2 = 0.02) significantly moderated the effect of treatment type on post-treatment vertigo handicap. Patients with higher PHQ-15 scores at baseline and women reduced their vertigo handicap more in IPGT as compared to in the control condition.

CONCLUSION

A possible explanation for this result is that somatic symptom distress is the central aetiopathogenetic factor of functional vertigo, while depressiveness and anxiety are rather epiphenomena in the sense of comorbidity. Although the results are not entirely consistent, according to some studies, female gender seems to be a favourable predictor of better therapy outcome. Given the high impairment and healthcare costs in those with vertigo/dizziness and psychiatric comorbidity, it is important to effectively treat these patients as early as possible. This study provides a prescriptive tool for practitioners, allowing for more patient-tailored treatment decisions.

Implementation outcomes of a sensory integration therapy program with computerized dynamic posturography in patients with balance and sensory dysfunction

Objective

We describe the first-year implementation experience of an Instrumented Sensory Integration Therapy Program in Audiological & Balance Center patients.

Design

This is a retrospective descriptive study. Participants included Seventy-three adults with diagnoses of acute, episodic, or chronic vestibular syndromes. They were classified into the following two groups: group 1 included 46 individuals treated with ISIT plus VRT, and group 2 included 27 individuals treated only with ISIT.

Results

The Sensory Organization Test (SOT) for both groups showed a statistical significance for all three sensory inputs; visual systems (G1: p = 0.0003; G2: p = 0.0337), vestibular system (G1: p < 0.0001; G2: p = 0.0003), and balance as demonstrated by compound balance score (G1: p < 0.0001; G2: p = 0.0035), and balance percentage deficit (G1: p < 0.0001; G2: p = 0.0078).

Conclusions

The severity and complexity of functional neurological disorders in the context of vestibular syndromes seem to require between 10 and 20 therapy sessions, and combined ISIT plus VRT appears to be more effective than ISIT as a monotherapy.

Using interpretative phenomenological analysis to probe the lived experiences of persistent postural-perceptual dizziness (PPPD)

BACKGROUND

Persistent Postural-Perceptual Dizziness (PPPD) is a chronic neuro-vestibular condition characterised by subjective dizziness, non-spinning vertigo, and postural imbalance. Symptoms are typically induced by situations of visuo-vestibular conflict and intense visual-motion.

OBJECTIVE

Little research has focused on the lived experiences of people with PPPD. Therefore, our objective was to present an in-depth exploration of patient experiences and sense-making, and the effect of PPPD on psycho-social functioning.

METHODS

We conducted semi-structured interviews with 6 people with PPPD, who were recruited from an Audiovestibular department in Wales. We present a case-by-case Interpretive Phenomenological Analysis (IPA) for each participant and present common themes.

RESULTS

Our analysis revealed a range of superordinate and subordinate themes, individualised to each participant, but broadly described under the following headings: dismissal and non-belief, identity loss, dissociative experiences, poor psychological well-being and processes of sense-making.

CONCLUSION

The qualitative experiences documented in this study will help clinicians and researchers to better understand the lived experiences of PPPD, how PPPD patients make sense of their symptoms, and the psycho-social impacts of the condition.

Neurofunctional differences and similarities between persistent postural-perceptual dizziness and anxiety disorder

INTRODUCTION

Persistent postural-perceptual dizziness (PPPD) (ICD-11) and anxiety disorders (ANX) share behavioural symptoms like anxiety, avoidance, social withdrawal, hyperarousal, or palpitation as well as neurological symptoms like vertigo, stance and gait disorders. Furthermore, previous studies have shown a bidirectional link between vestibulo-spatial and anxiety neural networks. So far, there have been no neuroimaging-studies comparing these groups.

OBJECTIVES

The aim of this explorative study was to investigate differences and similarities of neural correlates between these two patient groups and to compare their findings with a healthy control group.

METHODS

63 participants, divided in two patient groups (ANX = 20 and PPPD = 14) and two sex and age matched healthy control groups (HC-A = 16, HC-P = 13) were included. Anxiety and dizziness related pictures were shown during fMRI-measurements in a block-design in order to induce emotional responses. All subjects filled in questionnaires regarding vertigo (VSS, VHQ), anxiety (STAI), depression (BDI-II), alexithymia (TAS), and illness-perception (IPQ). After modelling the BOLD response with a standard canonical HRF, voxel-wise t-tests between conditions (emotional-negative vs neutral stimuli) were used to generate statistical contrast maps and identify relevant brain areas (pFDR < 0.05, cluster size >30 voxels). ROI-analyses were performed for amygdala, cingulate gyrus, hippocampus, inferior frontal gyrus, insula, supramarginal gyrus and thalamus (p ≤ 0.05).

RESULTS

Patient groups differed from both HC groups regarding anxiety, dizziness, depression and alexithymia scores; ratings of the PPPD group and the ANX group did differ significantly only in the VSS subscale 'vertigo and related symptoms' (VSS-VER). The PPPD group showed increased neural responses in the vestibulo-spatial network, especially in the supramarginal gyrus (SMG), and superior temporal gyrus (STG), compared to ANX and HC-P group. The PPPD group showed increased neural responses compared to the HC-P group in the anxiety network including amygdala, insula, lentiform gyrus, hippocampus, inferior frontal gyrus (IFG) and brainstem. Neuronal responses were enhanced in visual structures, e.g. fusiform gyrus, middle occipital gyrus, and in the medial orbitofrontal cortex (mOFC) in healthy controls compared to patients with ANX and PPPD, and in the ANX group compared to the PPPD group.

CONCLUSIONS

These findings indicate that neuronal responses to emotional information in the PPPD and the ANX group are comparable in anxiety networks but not in vestibulo-spatial networks. Patients with PPPD revealed a stronger neuronal response especially in SMG and STG compared to the ANX and the HC group. These results might suggest higher sensitivity and poorer adaptation processes in the PPPD group to anxiety and dizziness related pictures. Stronger activation in visual processing areas in HC subjects might be due to less emotional and more visual processing strategies.

Beyond Vertigo- Perceptual Postural Phobic Dizziness (PPPD): Our experience

Notwithstanding current understanding of vertigo, there are various clinical scenarios which are intriguing for clinicians, where patients have been too symptomatic but the presentation does not fit into any diagnosis. We stumbled upon a new entity during literature search known as Persistent Postural Perceptual Dizziness (PPPD). It fills the lacuna where we are often left wanting for diagnosis in the existing pool of knowledge. This case series has been prepared keeping in view the lack of data regarding PPPD in Indian population. For better understanding we present the illustration of our patients in this case series. We presented the details of three patients who were diagnosed as PPPD and managed effectively and followed up for one year. The nomenclature portrays the core concept of dizziness. The diagnostic criteria clearly define PPPD. It should not be used as escape or exclusion diagnosis. Our case series highlights various presentation of, not so uncommon, PPPD in Indian population. The case series has been brought out to address the deficiency of knowledge in dealing with intriguing vertigo. Careful thorough history is important to reach a diagnosis and avoids unwarranted vestibular sedatives. It highlights that proper counselling and vestibular rehabilitation can help the patients overcome their chronic disability.

Central sensorimotor integration assessment reveals deficits in standing balance control in people with chronic mild traumatic brain injury

Imbalance is common following mild Traumatic Brain Injury (mTBI) and can persist months after the initial injury. To determine if mTBI subjects with chronic imbalance differed from healthy age- and sex-matched controls (HCs) we used both the Central SensoriMotor Integration (CSMI) test, which evaluates sensory integration, time delay, and motor activation properties and the standard Sensory Organization Test (SOT). Four CSMI conditions evoked center-of-mass sway in response to: surface tilts with eyes closed (SS/EC), surface tilts with eyes open viewing a fixed visual surround (SS/EO), visual surround tilts with eyes open standing on a fixed surface (VS/EO), and combined surface and visual tilts with eyes open (SS+VS/EO). The mTBI participants relied significantly more on visual cues during the VS/EO condition compared to HCs but had similar reliance on combinations of vestibular, visual, and proprioceptive cues for balance during SS/EC, SS/EO, and SS+VS/EO conditions. The mTBI participants had significantly longer time delays across all conditions and significantly decreased motor activation relative to HCs across conditions that included surface-tilt stimuli with a sizeable subgroup having a prominent increase in time delay coupled with reduced motor activation while demonstrating no vestibular sensory weighting deficits. Decreased motor activation compensates for increased time delay to maintain stability of the balance system but has the adverse consequence that sensitivity to both internal (e.g., sensory noise) and external disturbances is increased. Consistent with this increased sensitivity, SOT results for mTBI subjects showed increased sway across all SOT conditions relative to HCs with about 45% of mTBI subjects classified as having an “Aphysiologic” pattern based on published criteria. Thus, CSMI results provided a plausible physiological explanation for the aphysiologic SOT pattern. Overall results suggest that rehabilitation that focuses solely on sensory systems may be incomplete and may benefit from therapy aimed at enhancing rapid and vigorous responses to balance perturbations.

Determinants of functioning and health-related quality of life after vestibular stroke

Background

Stroke accounts for 5–10% of all presentations with acute vertigo and dizziness. The objective of the current study was to examine determinants of long-term functioning and health-related quality of life (HRQoL) in a patient cohort with vestibular stroke.

Methods

Thirty-six patients (mean age: 66.1 years, 39% female) with an MRI-proven vestibular stroke were followed prospectively (mean time: 30.2 months) in the context of the EMVERT (EMergency VERTigo) cohort study at the Ludwig-Maximilians Universität, Munich. The following scores were obtained once in the acute stage (<24 h of symptom onset) and once during long-term follow-up (preferably >1 year after stroke): European Quality of Life Scale-five dimensions-five levels questionnaire (EQ-5D-5L) and Visual Analog Scale (EQ-VAS) for HRQoL, Dizziness Handicap Inventory (DHI) for symptom severity, and modified Rankin Scale (mRS) for general functioning and disability. Anxiety state and trait were evaluated by STAI-S/STAI-T, and depression was evaluated by the Patient Health Questionnaire-9 (PHQ-9). Voxel-based lesion mapping was applied in normalized MRIs to analyze stroke volume and localization. Multiple linear regression models were calculated to determine predictors of functional outcome (DHI, EQ-VAS at follow-up).

Results

Mean DHI scores improved significantly from 45.0 in the acute stage to 18.1 at follow-up (p < 0.001), and mean mRS improved from 2.1 to 1.1 (p < 0.001). Mean HRQoL (EQ-5D-5L index/EQ-VAS) changed from 0.69/58.8 to 0.83/65.2 (p = 0.01/p = 0.11). Multiple linear regression models identified higher scores of STAI-T and DHI at the time of acute vestibular stroke and larger stroke volume as significant predictors for higher DHI at follow-up assessment. The effect of STAI-T was additionally enhanced in women. There was a significant effect of patient age on EQ-VAS, but not DHI during follow-up.

Conclusion

The average functional outcome of strokes with the chief complaint of vertigo and dizziness is favorable. The most relevant predictors for individual outcomes are the personal anxiety trait (especially in combination with the female sex), the initial symptom intensity, and lesion volume. These factors should be considered for therapeutic decisions both in the acute stage of stroke and during subsequent rehabilitation.

Vestibular syndromes after COVID-19 vaccination: a prospective cohort study

Background and purpose

Dizziness and vertigo are common symptoms after COVID‐19‐vaccination. We aimed to prospectively evaluate objective central or peripheral vestibular function in patients with dizziness, vertigo, and postural symptoms that started or worsened after COVID‐19‐vaccination.

Methods

Of 4137 patients who presented between January 2021 and April 2022 at the German Center for Vertigo and Balance Disorders, Ludwig Maximilian University of Munich, we identified 72 patients (mean age = 47 years) with enduring vestibular symptoms following COVID‐19 vaccination. All underwent medical history‐taking, and neurological and neuro‐otological workup with bithermal caloric test, video head‐impulse test, orthoptics, and audiometry. Diagnoses were based on international criteria. The distribution of diagnoses was compared to a cohort of 39,964 patients seen before the COVID‐19 pandemic.

Results

Symptom onset was within the first 4 weeks postvaccination. The most prevalent diagnoses were somatoform vestibular disorders (34.7%), vestibular migraine (19.4%), and overlap syndromes of both (18.1%). These disorders were significantly overrepresented compared to the prepandemic control cohort. Thirty‐six percent of patients with somatoform complaints reported a positive history of depressive or anxiety disorders. Nine patients presented with benign paroxysmal positional vertigo, three with acute unilateral vestibulopathy, and seven with different entities (vestibular paroxysmia, Ménière disease, polyneuropathy, ocular muscular paresis). Causally related central vestibular deficits were lacking. Novel peripheral vestibular deficits were found in four patients.

Conclusions

Newly induced persistent vestibular deficits following COVID‐19 vaccination were rare. The predominant causes of prolonged vestibular complaints were somatoform vestibular disorders and vestibular migraine, possibly triggered or aggravated by stress‐related circumstances due to the COVID‐19 pandemic or vaccination. An increase of other central or peripheral vestibular syndromes after COVID‐19 vaccination was not observed.

Self-motion perception without sensory motion

Various studies have demonstrated a role for cognition on self-motion perception. Those studies all concerned modulations of the perception of a physical or visual motion stimulus. In our study, however, we investigated whether cognitive cues could elicit a percept of oscillatory self-motion in the absence of sensory motion. If so, we could use this percept to investigate if the resulting mismatch between estimated self-motion and a lack of corresponding sensory signals is motion sickening. To that end, we seated blindfolded participants on a swing that remained motionless during two conditions, apart from a deliberate perturbation at the start of each condition. The conditions only differed regarding instructions, a secondary task and a demonstration, which suggested either a quick halt (“Distraction”) or continuing oscillations of the swing (“Focus”). Participants reported that the swing oscillated with larger peak-to-peak displacements and for a longer period of time in the Focus condition. That increase was not reflected in the reported motion sickness scores, which did not differ between the two conditions. As the reported motion was rather small, the lack of an effect on the motion sickness response can be explained by assuming a subthreshold neural conflict. Our results support the existence of internal models relevant to sensorimotor processing and the potential of cognitive (behavioral) therapies to alleviate undesirable perceptual issues to some extent. We conclude that oscillatory self-motion can be perceived in the absence of related sensory stimulation, which advocates for the acknowledgement of cognitive cues in studies on self-motion perception.

Central vestibular dysfunction: don't forget vestibular rehabilitation

INTRODUCTION

Vestibular rehabilitation (VR) is now a subject of active studies and has been shown to be effective for multiple vestibular disorders, peripheral or central. VR is a physical therapy that helps train the central nervous system to compensate for vestibular dysfunction. There is moderate to strong evidence that VR is safe and effective for the management of peripheral vestibular dysfunction. Nonetheless, the studies on how VR works on central vestibular dysfunction remains scanty.

AREAS COVERED

This article addressed the rehabilitation strategies and possible mechanisms, including how central vestibular function might improve upon rehabilitation. In addition, it provides some examples concerning the effect of VR on central vestibular dysfunction.

EXPERT OPINION

VR works on the vestibular system through repetition of specific physical exercises that activate central neuroplastic mechanisms to achieve adaptive compensation of the impaired functions. VR has become a mainstay in the management of patients with dizziness and balance dysfunction. Individualized VR programs are a safe and effective treatment option for a large percentage of patients with central vestibular disease reporting imbalance and dizziness. Exploration of various treatment strategies and possible mechanisms will help develop the best and personalized VR treatment for patients with central vestibular dysfunction.

Disruptive Dizziness Among Post-9/11 Veterans With Deployment-Related Traumatic Brain Injury

OBJECTIVE

To identify disruption due to dizziness symptoms following deployment-related traumatic brain injury (TBI) and factors associated with receiving diagnoses for these symptoms.

SETTING

Administrative medical record data from the Department of Veterans Affairs (VA).

PARTICIPANTS

Post-9/11 veterans with at least 3 years of VA care who reported at least occasional disruption due to dizziness symptoms on the comprehensive TBI evaluation.

DESIGN

A cross-sectional, retrospective, observational study.

MAIN MEASURES

International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes of dizziness, vestibular dysfunction, and other postconcussive conditions; neurobehavioral Symptom Inventory.

RESULTS

Increased access to or utilization of specialty care at the VA was significant predictors of dizziness and/or vestibular dysfunction diagnoses in the fully adjusted model. Veterans who identified as Black non-Hispanic and those with substance use disorder diagnoses or care were substantially less likely to receive dizziness and vestibular dysfunction diagnoses.

CONCLUSIONS

Access to specialty care was the single best predictor of dizziness and vestibular dysfunction diagnoses, underscoring the importance of facilitating referrals to and utilization of specialized, comprehensive clinical facilities or experts for veterans who report disruptive dizziness following deployment-related TBI. There is a clear need for an evidence-based pathway to address disruptive symptoms of dizziness, given the substantial variation in audiovestibular tests utilized by US providers by region and clinical specialty. Further, the dearth of diagnoses among Black veterans and those in more rural areas underscores the potential for enhanced cultural competency among providers, telemedicine, and patient education to bridge existing gaps in the care of dizziness.

Altered Neuromagnetic Activity in Persistent Postural-Perceptual Dizziness: A Multifrequency Magnetoencephalography Study

Objective

The aim of our study was to investigate abnormal changes in brain activity in patients with persistent postural-perceptual dizziness (PPPD) using magnetoencephalography (MEG).

Methods

Magnetoencephalography recordings from 18 PPPD patients and 18 healthy controls were analyzed to determine the source of brain activity in seven frequency ranges using accumulated source imaging (ASI).

Results

Our study showed that significant changes in the patterns of localization in the temporal-parietal junction (TPJ) were observed at 1–4, 4–8, and 12–30 Hz in PPPD patients compared with healthy controls, and changes in the frontal cortex were found at 1–4, 80–250, and 250–500 Hz in PPPD patients compared with controls. The neuromagnetic activity in TPJ was observed increased significantly in 1–4 and 4–8 Hz, while the neuromagnetic activity in frontal cortex was found increased significantly in 1–4 Hz. In addition, the localized source strength in TPJ in 1–4 Hz was positively correlated with DHI score (r = 0.7085, p < 0.05), while the localized source strength in frontal cortex in 1–4 Hz was positively correlated with HAMA score (r = 0.5542, p < 0.05).

Conclusion

Our results demonstrated that alterations in the TPJ and frontal cortex may play a critical role in the pathophysiological mechanism of PPPD. The neuromagnetic activity in TPJ may be related to dizziness symptom of PPPD patients, while the neuromagnetic activity in frontal lobe may be related to emotional symptoms of PPPD patients. In addition, frequency-dependent changes in neuromagnetic activity, especially neuromagnetic activity in low frequency bands, were involved in the pathophysiology of PPPD.

Persistent Postural-Perceptual Dizziness Interventions—An Embodied Insight on the Use Virtual Reality for Technologists

Persistent and inconsistent unsteadiness with nonvertiginous dizziness (persistent postural-perceptual dizziness (PPPD)) could negatively impact quality of life. This study highlights that the use of virtual reality (VR) systems offers bimodal benefits to PPPD, such as understanding symptoms and providing a basis for treatment. The aim is to develop an understanding of PPPD and its interventions, including current trends of VR involvement to extrapolate and re-evaluate VR design strategies. Therefore, recent virtual-reality-based research work that progressed in understanding PPPD is identified, collected, and analysed. This study proposes a novel approach to the understanding of PPPD, specifically for VR technologists, and examines the principles of effectively aligning VR development for PPPD interventions.

Neuroimaging Systematic Review in Persistent Postural-Perceptual Dizziness: The Elaborate Alterations in the Delicate Network to Remain Balanced

OBJECTIVES

Persistent postural-perceptual dizziness (PPPD) is a chronic functional vestibular disorder that may have normal physical examination, clinical laboratory testing and vestibular evaluation. However, advances in neuroimaging have provided new insights in brain functional connectivity and structure in patients with PPPD. This systematic review was aimed at identifying significant structural or alterations in functional connectivity in patients with PPPD.

DATABASES REVIEWED

Science Direct, Pubmed, Embase via Ovid databases, and Cochrane library.

METHODS

This review following the guidelines of PRISMA, systematically and independently examined papers published up to March 2021 which fulfilled the predetermined criteria. PROSPERO Registration (CRD42020222334).

RESULTS

A total of 15 studies were included (MRI = 4, SPECT = 1, resting state fMRI = 4, task-based fMRI = 5, task-based fMRI + MRI = 1). Significant changes in the gray matter volume, cortical folding, blood flow, and connectivity were seen at different brain regions involved in vestibular, visual, emotion, and motor processing.

CONCLUSION

There is a multisensory dimension to the impairment resulting in chronic compensatory changes in PPPD that is evident by the significant alterations in multiple networks involved in maintaining balance. These changes observed offer some explanation for the symptoms that a PPPD patient may experience.Systematic Review Registration: This study is registered with PROSPERO (CRD42020222334).

Visual stress responses to static images are associated with symptoms of Persistent Postural Perceptual Dizziness (PPPD)

BACKGROUND

Images that deviate from natural scene statistics in terms of spatial frequency and orientation content can produce visual stress (also known as visual discomfort), especially for migraine sufferers. These images appear to over-activate the visual cortex.

OBJECTIVE

To connect the literature on visual discomfort with a common chronic condition presenting in neuro-otology clinics known as persistent postural perceptual dizziness (PPPD). Patients experience dizziness when walking through highly cluttered environments or when watching moving stimuli. This is thought to arise from maladaptive interaction between vestibular and visual signals for balance.

METHODS

We measured visual discomfort to stationary images in patients with PPPD (N = 30) and symptoms of PPPD in a large general population cohort (N = 1858) using the Visual Vertigo Analogue Scale (VVAS) and the Situational Characteristics Questionnaire (SCQ).

RESULTS

We found that patients with PPPD, and individuals in the general population with more PPPD symptoms, report heightened visual discomfort to stationary images that deviate from natural spectra (patient comparison, F (1, 1865) = 29, p < 0.001; general population correlations, VVAS, rs (1387) = 0.46, p < 0.001; SCQ, rs (1387) = 0.39, p < 0.001). These findings were not explained by co-morbid migraine. Indeed, PPPD symptoms showed a significantly stronger relationship with visual discomfort than did migraine (VVAS, zH = 8.81, p < 0.001; SCQ, zH = 6.29, p < 0.001).

CONCLUSIONS

We speculate that atypical visual processing -perhaps due to a visual cortex more prone to over-activation -may predispose individuals to PPPD, possibly helping to explain why some patients with vestibular conditions develop PPPD and some do not.

Potential risk factors of persistent postural-perceptual dizziness: a pilot study

BACKGROUND

Persistent postural-perceptual dizziness (PPPD) unifies the main characteristics of chronic subjective dizziness, visual vertigo and related diseases, which is a common chronic disease in neurology. At present, the pathology of PPPD is not fully understood.

OBJECTIVE

In this single-center retrospective case series review, we aim to investigate the potential risk factors of PPPD.

METHODS

Eighty inpatients diagnosed with PPPD were recruited with 81 apparently healthy controls. Patient-specific clinico-radiological data were collected from both groups. Conditions of hypertension, diabetes, smoking, and drinking were derived from medical history. Blood test results were recorded including total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fibrinogen, vitamin B12, folic acid, total cholesterol, triglyceride, and folate level. The subjects were examined by carotid artery CTA and cranial MRI, and the imaging findings of carotid atherosclerosis (CAS), white matter hyperintensities (WMHs) and lacunar infarction (LI) were recorded. Binary logistic regression analysis was used to investigate the difference between the case and control groups. Significance was defined as p value less than 0.05.

RESULTS

The prevalence rate of hypertension in the case group was significantly higher than that in the control group, and the detection rates of CAS, WMHs, and LI in the case group were significantly higher than those in the control group (p < 0.05 for all).

CONCLUSION

Hypertension, CAS, WMHs, and LI are associated with PPPD, which may be potential risk factors for its development.

Web-based vestibular rehabilitation in persistent postural-perceptual dizziness

OBJECTIVES

The aims of the study were to investigate the feasibility and preliminary outcome of a Norwegian web-based self-help application for vestibular rehabilitation (VR) among patients with high symptom burden of chronic dizziness fulfilling the criteria for persistent postural-perceptual dizziness (PPPD).

MATERIALS AND METHODS

The web application consists of six weekly online sessions, with written information and video presentations. It is self-instructive and freely available on NHI.no (https://nhi.no/for-helsepersonell/vestibular-rehabilitering/). Ten consecutive patients referred to a neurologic outpatient clinic for chronic dizziness were included. They signed informed consent forms and were examined at inclusion and after three months. State of health and symptom burden were recorded using Vertigo symptom score (VSS), Niigata symptom score (NPQ), Patient Health Questionnaire (PHQ-9) and health-related quality of life score (EQ5D-5L). Experiences with the program were measured using a semi-structured interview at the end of the study.

RESULTS

Nine out of ten patients completed the program. The findings suggest that the web application was easy to use, instructive and educatable. Challenges were the load of exercises, motivation to continue training during relapses and performing the body rolling on the floor. Participants had high symptom burden (VSS mean 32.9) and long duration of symptoms in years (mean 11.5). The participants improved on average 6.9 points on the VSS score.

CONCLUSIONS

This web application for chronic dizziness appears to be feasible and may reduce symptoms in patients who have struggled with serious and long-lasting dizziness.

Receiving Long-Term Disability or Pursuing a Legal Claim May Prevent Recovery From Chronic Dizziness

OBJECTIVES/HYPOTHESIS

Chronic dizziness (CD) and imbalance have multiple etiologies. CD is strongly linked with psychiatric and psychological comorbidities, thus an interdisciplinary approach, including psychopharmacological interventions, is recommended. Despite the use of this comprehensive treatment approach, the recovery of individuals with CD that pursue long-term disability (LTD) insurance or legal claims (LC) appears hampered. As such, we aimed to compare symptom recovery from CD in an interdisciplinary setting between patients receiving LTD/LC versus those who were not, and to explore the factors that may contribute to changes in symptom severity.

STUDY DESIGN

Retrospective cohort study.

METHODS

Dizziness-related diagnoses were extracted from the charts of 195 adults in an outpatient interdisciplinary neurotology clinic in Toronto, Canada. Patients with baseline Dizziness Handicap Inventory (DHI) and Dizziness Catastrophizing Scale (DCS) assessments between August 2012 and July 2018 and a mean follow-up visit within approximately 10 months were included. The study participants were categorized as "LTD/LC+" (n = 92) or "LTD/LC-" (n = 103), referring to either receiving or pursuing LTD/LC or not, respectively.

RESULTS

There were differences in the mean percentage changes in DHI (t[187] = 3.02, P = .003) and DCS (t[179] = 2.63, P = .009) scores between LTD/LC+ and LTD/LC- patients. LTD/LC+ patients showed 8.0% and 7.6% mean increases in DHI and DCS scores, respectively, whereas LTD/LC- patients showed 21.5% and 25.9% reductions in DHI and DCS scores, respectively, controlling for age, sex, and baseline illness severity.

CONCLUSIONS

Patients receiving or pursuing LTD insurance or a legal claim did not improve from CD and dizziness catastrophizing compared to those who were not. Future studies are required to test these findings prospectively and to determine the factors that may contribute to symptom recovery, including the anxiety-aggravating effects of the LTD/LC process and the deleterious consequences of developing a sick-role while afflicted with a chronic illness.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

Brain Correlates of Persistent Postural-Perceptual Dizziness: A Review of Neuroimaging Studies

Persistent postural-perceptual dizziness (PPPD), defined in 2017, is a vestibular disorder characterized by chronic dizziness that is exacerbated by upright posture and exposure to complex visual stimuli. This review focused on recent neuroimaging studies that explored the pathophysiological mechanisms underlying PPPD and three conditions that predated it. The emerging picture is that local activity and functional connectivity in multimodal vestibular cortical areas are decreased in PPPD, which is potentially related to structural abnormalities (e.g., reductions in cortical folding and grey-matter volume). Additionally, connectivity between the prefrontal cortex, which regulates attentional and emotional responses, and primary visual and motor regions appears to be increased in PPPD. These results complement physiological and psychological data identifying hypervigilant postural control and visual dependence in patients with PPPD, supporting the hypothesis that PPPD arises from shifts in interactions among visuo-vestibular, sensorimotor, and emotional networks that overweigh visual over vestibular inputs and increase the effects of anxiety-related mechanisms on locomotor control and spatial orientation.

Vestibular-Evoked Cerebral Potentials

The human vestibular cortex has mostly been approached using functional magnetic resonance imaging and positron emission tomography combined with artificial stimulation of the vestibular receptors or nerve. Few studies have used electroencephalography and benefited from its high temporal resolution to describe the spatiotemporal dynamics of vestibular information processing from the first milliseconds following vestibular stimulation. Evoked potentials (EPs) are largely used to describe neural processing of other sensory signals, but they remain poorly developed and standardized in vestibular neuroscience and neuro-otology. Yet, vestibular EPs of brainstem, cerebellar, and cortical origin have been reported as early as the 1960s. This review article summarizes and compares results from studies that have used a large range of vestibular stimulation, including natural vestibular stimulation on rotating chairs and motion platforms, as well as artificial vestibular stimulation (e.g., sounds, impulsive acceleration stimulation, galvanic stimulation). These studies identified vestibular EPs with short latency (<20 ms), middle latency (from 20 to 50 ms), and late latency (>50 ms). Analysis of the generators (source analysis) of these responses offers new insights into the neuroimaging of the vestibular system. Generators were consistently found in the parieto-insular and temporo-parietal junction-the core of the vestibular cortex-as well as in the prefrontal and frontal areas, superior parietal, and temporal areas. We discuss the relevance of vestibular EPs for basic research and clinical neuroscience and highlight their limitations.

Persistent Postural-Perceptual Dizziness in Children and Adolescents

OBJECTIVE

Persistent postural-perceptual dizziness (PPPD) is a recently defined diagnostic syndrome characterized by chronic symptoms of dizziness, unsteadiness, and/or non-spinning vertigo. Although PPPD has been studied in adults, reports in the pediatric population are few. The goal of this study was to describe the presentation and treatment of PPPD in a group of pediatric patients.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

PATIENTS

≤21 years old, who met Bárány Society consensus criteria for a diagnosis of PPPD and were followed for ≥6 months or until symptom resolution.

MAIN OUTCOME MEASURESS

Patient demographics, comorbidities, symptom chronicity, and response to treatment(s).

RESULTS

Of the 53 patients identified, 44 (83.0%) were women. Mean age at the time of initial evaluation was 14.6 years old. Common diagnoses in addition to PPPD included benign paroxysmal positional vertigo (64.2%), vestibular migraine (56.6%), and anxiety (28.3%). A high proportion of patients (43.4%) reported initially missing school or work due to their symptoms. Eighteen patients (34.0%) reported symptom resolution ranging from 2 to 48 months after diagnosis (median 9 mo). Of these patients, 15 of 18 attended physical therapy (PT), 11 of 18 attended cognitive behavioral therapy (CBT) and/or biofeedback therapy, and 10 of 18 took selective serotonin reuptake inhibitor (SSRI) medications, and 7 of 18 (40%) did a combination of all three therapies.

CONCLUSION

PPPD can impact patients at a young age, and prolonged symptoms present a significant burden to children and adolescents, many of whom are unable to attend school. Treatments such as PT, CBT, and SSRI medication may be effective.

Using Base-ml to Learn Classification of Common Vestibular Disorders on DizzyReg Registry Data

Background: Multivariable analyses (MVA) and machine learning (ML) applied on large datasets may have a high potential to provide clinical decision support in neuro-otology and reveal further avenues for vestibular research. To this end, we build base-ml, a comprehensive MVA/ML software tool, and applied it to three increasingly difficult clinical objectives in differentiation of common vestibular disorders, using data from a large prospective clinical patient registry (DizzyReg).

Methods: Base-ml features a full MVA/ML pipeline for classification of multimodal patient data, comprising tools for data loading and pre-processing; a stringent scheme for nested and stratified cross-validation including hyper-parameter optimization; a set of 11 classifiers, ranging from commonly used algorithms like logistic regression and random forests, to artificial neural network models, including a graph-based deep learning model which we recently proposed; a multi-faceted evaluation of classification metrics; tools from the domain of “Explainable AI” that illustrate the input distribution and a statistical analysis of the most important features identified by multiple classifiers.

Results: In the first clinical task, classification of the bilateral vestibular failure (N = 66) vs. functional dizziness (N = 346) was possible with a classification accuracy ranging up to 92.5% (Random Forest). In the second task, primary functional dizziness (N = 151) vs. secondary functional dizziness (following an organic vestibular syndrome) (N = 204), was classifiable with an accuracy ranging from 56.5 to 64.2% (k-nearest neighbors/logistic regression). The third task compared four episodic disorders, benign paroxysmal positional vertigo (N = 134), vestibular paroxysmia (N = 49), Menière disease (N = 142) and vestibular migraine (N = 215). Classification accuracy ranged between 25.9 and 50.4% (Naïve Bayes/Support Vector Machine). Recent (graph-) deep learning models classified well in all three tasks, but not significantly better than more traditional ML methods. Classifiers reliably identified clinically relevant features as most important toward classification.

Conclusion: The three clinical tasks yielded classification results that correlate with the clinical intuition regarding the difficulty of diagnosis. It is favorable to apply an array of MVA/ML algorithms rather than a single one, to avoid under-estimation of classification accuracy. Base-ml provides a systematic benchmarking of classifiers, with a standardized output of MVA/ML performance on clinical tasks. To alleviate re-implementation efforts, we provide base-ml as an open-source tool for the community.

Cerebral Responses to Stationary Emotional Stimuli Measured by fMRI in Women with Persistent Postural-Perceptual Dizziness

Introduction  Persistent postural-perceptual dizziness (PPPD) is a functional vestibular disorder characterized by chronic dizziness, unsteadiness, and hypersensitivity to motion. Preexisting anxiety disorders and neurotic personality traits confer vulnerability to PPPD. High anxiety during acute vertigo or dizziness incites it. A functional magnetic resonance imaging (fMRI) study of chronic subjective dizziness found unexpectedly hypoactive responses to vestibular stimulation in cortical regions that integrate threat assessment and spatial perception.

Objective  This fMRI study used non-moving, but emotionally charged visual stimuli to investigate the brain's activity of PPPD patients and control subjects.

Methods  The participants included 16 women with PPPD and 16 age-matched women who recovered completely from acute episodes of vertigo or dizziness capable of triggering PPPD. Brain responses to positive, neutral, and negative figures from the International Affective Picture System were measured with fMRI and compared between the groups. Dizziness handicap, anxiety, and depression were assessed with validated questionnaires.

Results  Between group analyses: Participants with PPPD showed reduced activity in anterior cingulate cortex and increased activity in left angular gyrus in response to negative versus positive stimuli, which was not observed in recovered individuals. Within group analyses: Participants with PPPD had increased activity in visuospatial areas (parahippocampal gyrus, intraparietal sulcus) in negative versus positive and negative versus neutral contrasts, whereas recovered individuals had increased activity in anxiety regions (amygdala, orbitofrontal cortex).

Conclusion  Patients with PPPD may be more attuned to spatial elements than to the content of emotionally charged visual stimuli.

Vestibular Physical Therapy and Fall Risk Assessment

Vestibular physical therapy (VPT) is a specialized form of evidence-based therapy designed to alleviate primary (vertigo, dizziness, imbalance, gait instability, falls) and secondary (deconditioning, cervical muscle tension, anxiety, poor quality of life, fear of falling/fear avoidance behavior) symptoms related to vestibular disorders. This article provides an overview of VPT, highlighting various exercise modalities used to treat a variety of vestibular disorders. Patient safety and fall prevention are paramount; therefore, fall risk assessment and treatment are also addressed.

Vertigo in Patients with Degenerative Cervical Myelopathy

(1) Background: Cervical vertigo (CV) represents a controversial entity, with a prevalence ranging from reported high frequency to negation of CV existence. (2) Objectives: To assess the prevalence and cause of vertigo in patients with a manifest form of severe cervical spondylosis-degenerative cervical myelopathy (DCM) with special focus on CV. (3) Methods: The study included 38 DCM patients. The presence and character of vertigo were explored with a dedicated questionnaire. The cervical torsion test was used to verify the role of neck proprioceptors, and ultrasound examinations of vertebral arteries to assess the role of arteriosclerotic stenotic changes as hypothetical mechanisms of CV. All patients with vertigo underwent a detailed diagnostic work-up to investigate the cause of vertigo. (4) Results: Symptoms of vertigo were described by 18 patients (47%). Causes of vertigo included: orthostatic dizziness in eight (22%), hypertension in five (14%), benign paroxysmal positional vertigo in four (11%) and psychogenic dizziness in one patient (3%). No patient responded positively to the cervical torsion test or showed significant stenosis of vertebral arteries. (5) Conclusions: Despite the high prevalence of vertigo in patients with DCM, the aetiology in all cases could be attributed to causes outside cervical spine and related nerve structures, thus confirming the assumption that CV is over-diagnosed.

A Randomized Controlled Trial Evaluating Integrative Psychotherapeutic Group Treatment Compared to Self-Help Groups in Functional Vertigo/Dizziness

We tested the efficacy of an integrative psychotherapeutic group treatment (IPGT) in reducing vertigo/dizziness-related impairment along with depression, anxiety, and somatization by conducting a randomized controlled superiority trial comparing IPGT to self-help groups moderated by a clinical psychologist (SHG). Adult patients with functional vertigo and dizziness symptoms were randomly allocated to either the IPGT or SHG as active control group. Outcomes were assessed at baseline (t0), after treatment lasting 16 weeks (t1), and 12 months after treatment (t2). A total of 81 patients were assigned to IPGT and 78 patients were assigned to SHG. Vertigo-related impairment was reduced in both conditions (IPGT: t0–t1: d = 1.10, t0–t2: d = 1.06; SHG: t0–t1: d = 0.86, t0–t2: d = 1.29), showing the efficiency of both IPGT and SHG. Clinically relevant improvements were also obtained for depression in both groups. Linear mixed model analyses revealed no differences between groups for all outcomes (effect of group for the primary outcome: b = −1.15, SE = 2.13, t = −0.54, p = 0.59). Attrition rates were higher in SHG (52.6%) than in IPGT (28.4%). Both conditions improved primary and secondary outcomes while IPGT was better accepted by patients than SHG. Trial registration: ClinicalTrials.gov, Identifier: NCT02320851.

A Set of Eight Key Questions Helps to Classify Common Vestibular Disorders-Results From the DizzyReg Patient Registry

Precise history taking is the key to develop a first assumption on the diagnosis of vestibular disorders. Particularly in the primary care setting, algorithms are needed, which are based on a small number of questions and variables only to guide appropriate diagnostic decisions. The aim of this study is to identify a set of such key variables that can be used for preliminary classification of the most common vestibular disorders. A four-step approach was implemented to achieve this aim: (1) we conducted an online expert survey to collect variables that are meaningful for medical history taking, (2) we used qualitative content analysis to structure these variables, (3) we identified matching variables of the patient registry of the German Center for Vertigo and Balance Disorders, and (4) we used classification trees to build a classification model based on these identified variables and to analyze if and how these variables contribute to the classification of common vestibular disorders. We included a total of 1,066 patients with seven common vestibular disorders (mean age of 51.1 years, SD = 15.3, 56% female). Functional dizziness was the most frequent diagnosis (32.5%), followed by vestibular migraine (20.2%) and Menière's disease (13.3%). Using classification trees, we identified eight key variables which can differentiate the seven vestibular disorders with an accuracy of almost 50%. The key questions comprised attack duration, rotational vertigo, hearing problems, turning in bed as a trigger, doing sport or heavy household chores as a trigger, age, having problems with walking in the dark, and vomiting. The presented algorithm showed a high-face validity and can be helpful for taking initial medical history in patients with vertigo and dizziness. Further research is required to evaluate if the identified algorithm can be applied in the primary care setting and to evaluate its external validity.

Migraine Features in Patients with Persistent Postural-Perceptual Dizziness

OBJECTIVES

To evaluate the presence of migraine features in patients with persistent postural-perceptual dizziness (PPPD).

METHODS

In a retrospective survey study, consecutive patients presenting to a tertiary care neurotology clinic during an 18-month period were given questionnaires about headache and dizziness symptoms. The survey responses plus history and examination of the patient were used to diagnose patients with PPPD. The prevalence of migraine headache, vestibular migraine (VM), and migraine characteristics was evaluated.

RESULTS

In total, 36 subjects with PPPD were included in the study. The mean age of the subjects was 56 ± 16 years with a female (72%) predominance. A total of 19 (53%) patients met the International Classification of Headache Disorders criteria for migraine headache, and 6 of those (17%) met the criteria for definite VM. Of the patients who did not meet full migraine headache criteria, 6 (17%) patients met 4 of 5 criteria, and 5 (14%) patients met 3 of 5 criteria. There was no significant difference between PPPD patients who fulfilled full migraine headache criteria and those who did not in sensitivity to light, sound, smells, weather changes, feelings of mental fog/confusion, and sinus pain/facial pressure.

CONCLUSIONS

This study demonstrates that a majority of patients with PPPD fulfill the criteria for migraine headache. A large proportion of PPPD patients who do not meet the full criteria for migraine headache still meet a majority of the migraine headache criteria. This suggests an association between the 2 conditions. PPPD may be a part of the spectrum of otologic migraine, where migraine manifests as otologic symptoms.

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.

[Clinical diagnosis and treatment of chronic dizziness]

Chronic dizziness is defined as a complex of symptoms lasting months or years, including oscillopsia, nystagmus, and postural instability. Diagnostic search includes peripheral vestibulopathy - chronic unilateral vestibulopathy resulting from vestibular neuronitis, schwannoma of the 8th pair of cranial nerves, medical or surgical ablation of the labyrinth, and bilateral vestibulopathy; central vestibulopathy - syndromes accompanied by central vertical nystagmus, small vessel disease in patients with chronic cerebral ischemia; general somatic diseases, peripheral polyneuropathy, side-effects of medications as well as persistent postural-perceptual dizziness. Often, when collecting an anamnesis, it is not possible to identify specific features of dizziness and instability, therefore, clinical and instrumental examination of the patient is of particular importance. In the otoneurological examination, the greatest attention is paid to static/coordination tests, oculomotor tests aimed at identifying signs of damage to the vestibulo-ocular reflex. The principles of treatment depend on the diagnosed cause of dizziness and instability and can, to varying degrees, combine pharmacotherapy, vestibular rehabilitation and psychotherapy, as well as correction of therapy for the underlying disease that caused vestibulopathy.

'Excess anxiety' and 'less anxiety': both depend on vestibular function

PURPOSE OF REVIEW

To present evidence of a functional interrelation between the vestibular and the anxiety systems based on a complex reciprocally organized network. The review focuses on the differential effects of various vestibular disorders, on psychiatric comorbidity, and on anxiety related to vertigo.

RECENT FINDINGS

Episodic vertigo syndromes such as vestibular migraine, vestibular paroxysmia, and Menière's disease are associated with a significant increase of psychiatric comorbidity, in particular anxiety/phobic disorders and depression. Chronic unilateral and bilateral vestibulopathy (BVP) do not exhibit a higher than normal psychiatric comorbidity. Anxiety related to the vertigo symptoms is also increased in episodic structural vestibular disorders but not in patients with chronic unilateral or bilateral loss of vestibular function. The lack of vertigo-related anxiety in BVP is a novel finding. Several studies have revealed special features related to anxiety in patients suffering from BVP: despite objectively impaired postural balance with frequent falls, they usually do not complain about fear of falling; they do not report an increased susceptibility to fear of heights; they do not have an increased psychiatric comorbidity; and they do not report increased anxiety related to the perceived vertigo. Subtle or moderate vestibular stimulation (by galvanic currents or use of a swing) may have beneficial effects on stress or mood state in healthy adults, and promote sleep in humans and rodents. The intimate structural and functional linkage of the vestibular and anxiety systems includes numerous nuclei, provincial and connector hubs, the thalamocortical network, and the cerebellum with many neural transmitter systems.

SUMMARY

The different involvement of emotional processes and anxiety - to the extent of 'excess anxiety' or 'less anxiety' - in structural vestibular disorders may be due to the specific dysfunction and whether the system activity is excited or diminished. Both psychiatric comorbidity and vertigo-related anxiety are maximal with excitation and minimal with loss of peripheral vestibular function.