Impaired tilt perception in XXXX : a central vestibular integration failure.

@entity1 @entity6461 @entity73 @entity191 @entity347
INTRODUCTION: Impaired balance control is a hallmark symptom in @entity191 ( @entity191 ). Altered sensory-motor integration contributes to the deficiency. We aimed to determine whether impaired vestibular signal processing added to the disorder. We exposed @entity1 (N = 11; 68  6y) and age-matched healthy subjects (hS: N = 19; 65  11y) on a motion platform in complete darkness to two consecutive forward tilt movements (12 series; N = 24; overall 288 trials) and asked them to indicate which tilt was perceived larger. By combing tilt movements with translations we manipulated vestibular sensory input in order to investigate whether putative impairment resulted from a @entity347 (semicircular canals in 'single- @entity6461 -cue-condition', otoliths in 'single-OT-cue-condition') themselves or to a sensory integration failure ('multi-cue-condition'). RESULTS: Tilt discrimination in the multi-cue-condition was inferior in @entity1 compared to hS (p = 0.02). No significant differences between the two groups were found for both single-cue-conditions. Comparison of multi-cue-condition with a prediction resulting from the combination of both single-cue-conditions by optimal observer theory revealed that @entity1 (p = 0.04), in contrast to hS, failed to efficiently combine @entity6461 and OT information to improve tilt perception. CONCLUSION: We found that @entity191 @entity1 distinguished forward tilts less precise than hS, suggesting @entity73 . Tilt discrimination in @entity1 , moreover, did not improve as much as in hS in conditions where both @entity6461 and OT information was available compared to conditions where only @entity6461 or OT cues were activated. The latter provides evidence that tilt misperception in @entity191 most likely results from an integration failure of vestibular signals.
