Predictors of persistent postural-perceptual dizziness (PPPD) and similar forms of chronic dizziness precipitated by peripheral vestibular disorders: a systematic review

The literature on predictors of persistent postural-perceptual dizziness (PPPD) following peripheral vestibular insults has not been systematically reviewed.We systematically reviewed studies on predictors of PPPD and its four predecessors (phobic postural vertigo, space-motion discomfort, chronic subjective dizziness and visual vertigo). Investigations focused on new onset chronic dizziness following peripheral vestibular insults, with a minimum follow-up of 3 months. Precipitating events, promoting factors, initial symptoms, physical and psychological comorbidities and results of vestibular testing and neuroimaging were extracted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.We identified 13 studies examining predictors of PPPD or PPPD-like chronic dizziness. Anxiety following vestibular injury, dependent personality traits, autonomic arousal and increased body vigilance following precipitating events and visual dependence, but not the severity of initial or subsequent structural vestibular deficits or compensation status, were the most important predictors of chronic dizziness. Disease-related abnormalities of the otolithic organs and semi-circular canals and age-related brain changes seem to be important only in a minority of patients. Data on pre-existing anxiety were mixed.After acute vestibular events, psychological and behavioural responses and brain maladaptation are the most likely predictors of PPPD, rather than the severity of changes on vestibular testing. Age-related brain changes appear to have a smaller role and require further study. Premorbid psychiatric comorbidities, other than dependent personality traits, are not relevant for the development of PPPD.