The Clinical Key Features of Persistent Postural Perceptual Dizziness in the General Medicine Outpatient Setting: A Case Series Study of 33 Patients

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.

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.

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.

Treating Psychiatric Symptoms in Persistent Postural Perceptual Dizziness

Persistent postural perceptual dizziness (PPPD) is a functional neurological disorder characterized by troublesome feelings of dizziness and might be precipitated by vestibular events, postural changes, psychopathologies, and/or a person's perceptual experiences. The diagnosis is confirmed by assessing a patient's history. A variety of psychiatric symptoms are associated with PPPD; anxiety and depression are the most common. Psychotherapy and pharmacotherapy can be clinically helpful in reducing psychiatric symptoms and dizziness. Early intervention improves prognosis.

Comparison of Clinical Balance and Visual Dependence Tests in Patients With Chronic Dizziness With and Without Persistent Postural-Perceptual Dizziness: A Cross-Sectional Study

Background

The diagnosis of persistent postural-perceptual dizziness (PPPD) is primarily based on medical history taking. Research on the value of clinical balance and visual dependence tests in identifying PPPD is scarce.

Objectives

(1) to contrast clinical balance and visual dependence tests between PPPD patients, dizzy non-PPPD patients, and healthy persons; and (2) to evaluate whether these clinical tests can help to identify PPPD in patients with chronic dizziness.

Methods

Consecutive patients with chronic dizziness (38 PPPD and 21 non-PPPD) and 69 healthy persons underwent Static Balance tests, the Timed Up and Go test, the Tandem Gait test, and the Functional Gait Assessment (FGA). Visual dependence tests included the Visual Vertigo Analog Scale (VVAS), the Rod-and-Disc test (RDT), and postural sway while facing rotating dots. Groups were compared using ANOVA with post-hoc Tukey, or independent samples t-tests. The value of the clinical tests for PPPD identification was evaluated through logistic regression and Partial Least Squares Discriminant (PLS-DA) analyses.

Results

PPPD patients had significantly higher VVAS scores than dizzy non-PPPD patients (p = 0.006). Facing rotating dots, PPPD and dizzy non-PPPD patients had increased postural sway compared to healthy persons (PPPD vs. healthy: center of pressure (COP) velocity p < 0.001, and COP area p < 0.001; but non-PPPD vs. healthy: COP velocity p = 0.116 and COP area p = 0.207). PPPD patients had no significantly increased postural sway compared to dizzy non-PPPD patients. PPPD and dizzy non-PPPD patients also scored significantly worse on balance tests compared to healthy persons (PPPD vs. healthy: for all balance tests p < 0.001; non-PPPD vs. healthy: FGA p < 0.001, for all other tests p < 0.05). Differences were insignificant in balance scores between PPPD and dizzy non-PPPD patients, or in RDT scores between the three study groups. In patients with chronic dizziness, a higher VVAS score was most associated with PPPD [odds ratio 1.04; 95% CI (1.01; 1.07); p = 0.010]. The cross-validated (CV) PLS-DA model with all clinical tests included, had fair discriminative ability (CVerror = 47%).

Conclusion

PPPD patients were more visually dependent, but did not have worse postural balance compared to dizzy non-PPPD patients. Elevated VVAS scores characterized PPPD most in patients with chronic dizziness.

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.

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.