Reduced vestibular perception thresholds in persistent postural-perceptual dizziness- a cross-sectional study.

Area of Science:

• Neuroscience
• Vestibular System Disorders
• Functional Neurological Disorders

Background:

• Persistent postural-perceptual dizziness (PPPD) is a common functional vestibular disorder.
• Pathophysiology may involve multisensory mismatch influenced by psychological factors and increased central excitability.
• Hypothesis: Decreased motion perception thresholds indicate abnormal vestibular responsiveness in PPPD.

Purpose of the Study:

• Investigate vestibular perception and vestibular-ocular reflex thresholds in PPPD patients.
• Gain insights into the processing and adaptation to vestibular provocation.
• Explore the relationship between vestibular sensitivity, psychological comorbidities, and disease duration.

Main Methods:

• Cross-sectional study comparing 26 female PPPD patients and 33 age-matched healthy female controls (HC).
• Utilized a motorized rotary chair with controlled visual and acoustic shielding.
• Assessed motion perception thresholds, vestibular-ocular reflex thresholds, and vegetative responses; psychological comorbidities and dizziness scores were also evaluated.

Main Results:

• PPPD patients demonstrated significantly reduced vestibulo-perceptual thresholds (10.9°/s) compared to HC (29.5°/s).
• Increased motion sensitivity and vegetative responses were observed in PPPD patients during and after rotation.
• Higher vestibular sensitivity correlated with longer disease duration; no significant differences in nystagmus parameters were found.

Conclusions:

• PPPD patients exhibit decreased vestibulo-perceptual thresholds and increased vegetative responses, linked to disease duration.
• Findings suggest that heightened vestibular excitability may sustain PPPD, causing motion intolerance and dizziness.
• These results offer insights into the mechanisms underlying functional vestibular disorders.