Effect of vestibular exercise and optokinetic stimulation using virtual reality in persistent postural-perceptual dizziness

To determine the effect of customized vestibular exercise (VE) and optokinetic stimulation (OS) using a virtual reality system in patients with persistent postural-perceptual dizziness (PPPD). Patients diagnosed with PPPD were randomly assigned to the VE group or VE with OS group. All participants received VE for 20 min using a virtual reality system with a head mount display once a week for 4 weeks. The patients in the VE with OS group additionally received OS for 9 min. We analysed the questionnaires, timed up-to-go (TUG) test, and posturography scores at baseline and after 4 weeks. A total of 28 patients (median age = 74.5, IQR 66–78, men = 12) completed the intervention. From baseline to 4 weeks, the dizziness handicap inventory, activities of daily living (ADL), visual vertigo analogue scale, and TUG improved in the VE group, but only ADL and TUG improved in the VE with OS group. Patients with severe visual vertigo improved more on their symptoms than patients with lesser visual vertigo (Pearson’s p = 0.716, p < 0.001). Our VE program can improve dizziness, quality of life, and gait function in PPPD; however, additional optokinetic stimuli should be applied for individuals with visual vertigo symptoms.

Subtypes of Persistent Postural-Perceptual Dizziness

Background: Persistent postural-perceptual dizziness (PPPD) is a persistent chronic vestibular syndrome exacerbated by upright posture/walking, active or passive motion, and exposure to moving or complex visual stimuli. PPPD has four precursors: phobic postural vertigo, space-motion discomfort, visual vertigo, and chronic subjective dizziness. These four diseases share clinical features that form the basis of the diagnostic criteria for PPPD. Semiological similarities do not necessarily mean that PPPD is a single entity. However, if PPPD is not a single disorder but just a composite of four precursors, it may be subdivided according to the characteristics of each precursor.Objective: To test whether PPPD is a single disorder, we attempted a subtyping of PPPD.Methods: One-hundred-eight untreated patients with PPPD were enrolled in the study, who filled out the Niigata PPPD Questionnaire (NPQ) that consists of 12 questions on exacerbating factors for PPPD. A factor analysis of the patients' answers to the NPQ and a subsequent cluster analysis of the patients with PPPD using factors revealed by the factor analysis were performed. To validate our cluster classification, cluster differences were assessed using analysis of variance. Multiple comparison analyses were performed on demographical data, precipitating diseases, the Dizziness Handicap Inventory, the Hospital Anxiety and Depression Scale, and several vestibular tests to characterize each cluster.Results: Factor analysis revealed three underlying factors among the exacerbating factors in the NPQ. Exacerbation by visual stimuli (visual factor) accounted for 47.4% of total variance in the questionnaire. Exacerbation by walking/active motion (active-motion factor) and by passive motion/standing (passive-motion/standing factor) accounted for 12.0 and 7.67% of variance, respectively. Cluster analysis revealed three clusters: the visual-dominant subtype (n = 49); the active motion-dominant subtype (n = 20); and the mixed subtype (n = 39). The patients in the active motion-dominant subtype were significantly older than those in the visual-dominant subtype. There were no significant differences among the subtypes in other demographical data or conventional vestibular tests.Conclusions: The most common main exacerbating factor of PPPD was the visual factor. PPPD may be categorized into three subtypes. Conventional vestibular tests failed to point the characteristics of each subtype.

Persistent postural perceptual dizziness is on a spectrum in the general population

ObjectiveTo examine the idea that symptoms of persistent postural perceptual dizziness (PPPD) are more common than previously assumed and lie on a spectrum in the general population, thus challenging current theories that PPPD is only a consequence of a vestibular insult.MethodsWe collected 2 common clinical questionnaires of PPPD (Visual Vertigo Analogue Scale [VVAS] and Situational Characteristics Questionnaire [SCQ]) in 4 cohorts: community research volunteers (n = 1941 for VVAS, n = 1,474 for SCQ); paid online participants (n = 190 for VVAS, n = 125 for SCQ); students (n = 204, VVAS only); and patients diagnosed with PPPD (n = 25).ResultsWe found that around 9%, 4%, and 11%, respectively, of the 3 nonclinical cohorts scored above the 25th percentile patient score on 1 PPPD measure (VVAS) and 49% and 54% scored above the 25th percentile patient score on the other measure (SCQ). Scores correlated negatively with age (counter to expectation). As expected, scores correlated with migraine in 2 populations, but this only explained a small part of the variance, suggesting that migraine is not the major factor underlying the spectrum of PPPD symptoms in the general population.ConclusionWe found high levels of PPPD symptoms in nonclinical populations, suggesting that PPPD is a spectrum that preexists in the population, rather than only being a consequence of vestibular insult. Atypical visuo-vestibular processing predisposes some individuals to visually induced dizziness, which is then exacerbated should vestibular insult (or more generalized insult) occur.

Visual Vertigo, Motion Sickness, and Disorientation in Vehicles

Environmental circumstances that result in ambiguity or conflict with the patterns of sensory stimulation may adversely affect the vestibular system. The effect of this conflict in sensory information may be dizziness, a sense of imbalance, nausea, and motion sickness sometimes even to seemingly minor daily head movement activities. In some, it is not only exposure to motion but also the observation of objects in motion around them such as in supermarket aisles or other places with visual commotion; this can lead to dizziness, nausea, or a feeling of motion sickness that is referred to as visual vertigo. All people with normal vestibular function can be made to experience motion sickness, although individual susceptibility varies widely and is at least partially heritable. Motorists learn to interpret sensory stimuli in the context of the car stabilized by its suspension and guided by steering. A type of motorist's disorientation occurs in some individuals who develop a heightened awareness of perceptions of motion in the automobile that makes them feel as though they may be rolling over on corners and as though they are veering on open highways or in streaming traffic. This article discusses the putative mechanisms, consequences and approach to managing patients with visual vertigo, motion sickness, and motorist's disorientation syndrome in the context of chronic dizziness and motion sensitivity.