Here, we aimed to investigate the possible subtypes of PPPD, based on the exacerbating factors assessed by the symptom scale for PPPD, the Niigata PPPD Questionnaire (NPQ) ( 8), using factor and cluster analysis. To test whether PPPD is a single disorder, we attempted a subtyping of PPPD. 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 such as the postural- or visual-provocation dominant subtypes. Semiological similarities do not necessarily indicate that PPPD is a single entity. Exacerbation by upright posture, active or passive motion, complex visual pattern, and motion of self or objects in the environment have been emphasized in PPV, SMD, VV, and CSD, respectively ( 1). These four diseases share clinical features that form the basis of the diagnostic criteria of PPPD ( 1). PPPD has four precursors: phobic postural vertigo (PPV), space-motion discomfort (SMD), visual vertigo (VV), and chronic subjective dizziness (CSD) ( 3– 7). Nonetheless, it is not a disorder of the vestibular periphery rather, it is considered a functional disorder caused by shifts in the functioning of spatial orientation systems to favor visual or somatosensory/proprioceptive stimuli over vestibular inputs ( 2).

PPPD presents with chronic vestibular symptoms. The core vestibular symptoms of PPPD are dizziness, unsteadiness, and/or non-spinning vertigo that are exacerbated by an upright posture (standing or walking), active or passive motion, and exposure to moving visual stimuli or complex visual patterns ( 1). Persistent postural-perceptual dizziness (PPPD), which has been included in the 11th revision of the International Classification of Diseases, is a persistent chronic vestibular syndrome typically preceded by acute vestibular disorders ( 1). Conventional vestibular tests failed to point the characteristics of each subtype. PPPD may be categorized into three subtypes. There were no significant differences among the subtypes in other demographical data or conventional vestibular tests.Ĭonclusions: The most common main exacerbating factor of PPPD was the visual factor. The patients in the active motion-dominant subtype were significantly older than those in the visual-dominant subtype. Cluster analysis revealed three clusters: the visual-dominant subtype ( n = 49) the active motion-dominant subtype ( n = 20) and the mixed subtype ( n = 39). 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. Exacerbation by visual stimuli (visual factor) accounted for 47.4% of total variance in the questionnaire. Results: Factor analysis revealed three underlying factors among the exacerbating factors in the NPQ. 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. To validate our cluster classification, cluster differences were assessed using analysis of variance. 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. 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. Objective: To test whether PPPD is a single disorder, we attempted a subtyping of PPPD. 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. Semiological similarities do not necessarily mean that PPPD is a single entity. These four diseases share clinical features that form the basis of the diagnostic criteria for PPPD. PPPD has four precursors: phobic postural vertigo, space-motion discomfort, visual vertigo, and chronic subjective dizziness. Department of Otolaryngology Head and Neck Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japanīackground: 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.Chihiro Yagi *, Yuka Morita, Meiko Kitazawa, Tatsuya Yamagishi, Shinsuke Ohshima, Shuji Izumi, Kuniyuki Takahashi and Arata Horii

Dizziness handicap inventory online