From the Research
Pathophysiology of Persistent Postural Perceptual Dizziness (PPPD)
- The pathophysiology of PPPD is not fully understood, but it is thought to involve functional changes in postural control mechanisms, multi-sensory information processing, or cortical integration of spatial orientation and threat assessment 1.
- Neuroimaging studies suggest that PPPD is associated with decreased local activity and functional connectivity in multimodal vestibular cortical areas, potentially related to structural abnormalities such as reductions in cortical folding and grey-matter volume 2.
- There is also evidence of increased connectivity between the prefrontal cortex, primary visual and motor regions, and emotional networks, which may contribute to the development of PPPD 2.
- Additionally, PPPD may involve disrupted spatial cognition processes, including allocentric spatial navigation and high-demand visuospatial cognitive tasks that involve executive functions and planning 3.
Etiology of Persistent Postural Perceptual Dizziness (PPPD)
- PPPD may be precipitated by conditions that disrupt balance or cause vertigo, unsteadiness, or dizziness, including peripheral or central vestibular disorders, other medical illnesses, or psychological distress 1.
- The disorder is thought to arise from a maladaptive state to a variety of insults, including vestibular dysfunction, and is not a structural or psychiatric condition 4.
- PPPD is mostly precipitated by acute or episodic vestibular diseases, but its symptoms cannot be accounted for by its precipitants 5.
- The exact causes of PPPD are still unknown, but it is believed to involve a complex interplay between vestibular, visual, and emotional systems 2, 3, 5.
Key Features of Persistent Postural Perceptual Dizziness (PPPD)
- The core vestibular symptoms of PPPD 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 1, 5.
- PPPD is characterized by somatosensory- and visually-dependent spatial orientation, and may be detected using the head roll-tilt subjective visual vertical test and gaze stability test after exposure to moving visual stimuli 5.
- The disorder is often observed in individuals around 50 years of age, with a female predominance, and may coexist with other structural diseases 5.