Distorted own-body representations in patients with dizziness and during caloric vestibular stimulation.
Christophe Lopez, Estelle Nakul, Nora Preuss, Maya Elzière, Fred W Mast
Journal of neurology October 1, 2018 DOI: 10.1007/s00415-018-8906-8 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort and experimental study Peer reviewed |
|---|---|
| Sample size | 120 |
| Population | 60 patients with dizziness and 60 healthy controls; healthy volunteers for the experimental study |
| Intervention | caloric vestibular stimulation (CVS) |
| Keywords | Bodily self-consciousness Body schema Depersonalization Derealization Out-of-body experience Vestibular disorder |
| Key findings | Vestibular disorders and artificial vestibular stimulation produce distortions in own-body representations, including perceived body size, sense of agency, body ownership, and disembodiment. |
Abstract
There is increasing evidence that vestibular disorders evoke deficits reaching far beyond imbalance, oscillopsia and spatial cognition. Yet, how vestibular disorders affect own-body representations, in particular the perceived body shape and size, has been overlooked. Here, we explored vestibular contributions to own-body representations using two approaches. Study 1 measured the occurrence and severity of distorted own-body representations in 60 patients with dizziness and 60 healthy controls using six items from the Cambridge Depersonalization Scale. 12% of the patients have experienced distorted own-body representations (their hands or feet felt larger or smaller), 37% reported abnormal sense of agency, 35% reported disownership for the body, and 22% reported disembodiment. These proportions were larger in patients than controls. Study 2 aimed at testing whether artificial stimulation of the vestibular apparatus produced comparable distortions of own-body representations in healthy volunteers. We compared the effects of right-warm/left-cold caloric vestibular stimulation (CVS), left-warm/right-cold CVS and sham CVS on internal models of the left and right hands using a pointing task. The perceived length of the dorsum of the hand was increased specifically during left-warm/right-cold CVS, and this effect was found for both hands. Our studies show a vestibular contribution to own-body representations and should help understand the complex symptomatology of patients with dizziness.