Limits...
Unilateral vestibular loss impairs external space representation.

Borel L, Redon-Zouiteni C, Cauvin P, Dumitrescu M, Devèze A, Magnan J, Péruch P - PLoS ONE (2014)

Bottom Line: These individuals were also required to estimate their body pointing direction.Performance varied according to the time elapsed after neurotomy: deficits were stronger during the early stages, while gradual compensation occurred subsequently.These findings provide the first demonstration of the critical role of vestibular signals in the representation of external space and of body pointing direction in the early stages after unilateral vestibular loss.

View Article: PubMed Central - PubMed

Affiliation: Aix-Marseille Université, Marseille, France ; CNRS, UMR 7260 Laboratoire de Neurosciences Intégratives et Adaptatives, Marseille, France.

ABSTRACT
The vestibular system is responsible for a wide range of postural and oculomotor functions and maintains an internal, updated representation of the position and movement of the head in space. In this study, we assessed whether unilateral vestibular loss affects external space representation. Patients with Menière's disease and healthy participants were instructed to point to memorized targets in near (peripersonal) and far (extrapersonal) spaces in the absence or presence of a visual background. These individuals were also required to estimate their body pointing direction. Menière's disease patients were tested before unilateral vestibular neurotomy and during the recovery period (one week and one month after the operation), and healthy participants were tested at similar times. Unilateral vestibular loss impaired the representation of both the external space and the body pointing direction: in the dark, the configuration of perceived targets was shifted toward the lesioned side and compressed toward the contralesioned hemifield, with higher pointing error in the near space. Performance varied according to the time elapsed after neurotomy: deficits were stronger during the early stages, while gradual compensation occurred subsequently. These findings provide the first demonstration of the critical role of vestibular signals in the representation of external space and of body pointing direction in the early stages after unilateral vestibular loss.

Show MeSH

Related in: MedlinePlus

Effect of unilateral vestibular loss on the visual straight-ahead (SSA) as a function of session.Mean (±95% CI).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3921214&req=5

pone-0088576-g004: Effect of unilateral vestibular loss on the visual straight-ahead (SSA) as a function of session.Mean (±95% CI).

Mentions: The variations in SSA for each session are illustrated in Figure 4. The mean SSA significantly differed between the two groups (F1,24 = 36.63; p<0.001) as a function of the experimental session (F2,48 = 20.61; p<0.001). A significant interaction between Group and Session (F2,48 = 25.01; p<0.001) revealed that SSA was differentially affected over time in the two groups of participants. The patients showed a rightward deviation (D+7: 10.6±2.5°, p<0.001 and D+30: 2.6±2.4°, p<0.05), while the healthy participants exhibited no such deviation (session 2: −1.3±1.1° and session 3: −0.4±1.4°). In addition, the patient SSA significantly decreased between D+7 and D+30 (p<0.001). During the first session, the directions indicated for the healthy participants and patients were close to the sagittal fore-aft orientation and did not significantly differ between the two groups.


Unilateral vestibular loss impairs external space representation.

Borel L, Redon-Zouiteni C, Cauvin P, Dumitrescu M, Devèze A, Magnan J, Péruch P - PLoS ONE (2014)

Effect of unilateral vestibular loss on the visual straight-ahead (SSA) as a function of session.Mean (±95% CI).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3921214&req=5

pone-0088576-g004: Effect of unilateral vestibular loss on the visual straight-ahead (SSA) as a function of session.Mean (±95% CI).
Mentions: The variations in SSA for each session are illustrated in Figure 4. The mean SSA significantly differed between the two groups (F1,24 = 36.63; p<0.001) as a function of the experimental session (F2,48 = 20.61; p<0.001). A significant interaction between Group and Session (F2,48 = 25.01; p<0.001) revealed that SSA was differentially affected over time in the two groups of participants. The patients showed a rightward deviation (D+7: 10.6±2.5°, p<0.001 and D+30: 2.6±2.4°, p<0.05), while the healthy participants exhibited no such deviation (session 2: −1.3±1.1° and session 3: −0.4±1.4°). In addition, the patient SSA significantly decreased between D+7 and D+30 (p<0.001). During the first session, the directions indicated for the healthy participants and patients were close to the sagittal fore-aft orientation and did not significantly differ between the two groups.

Bottom Line: These individuals were also required to estimate their body pointing direction.Performance varied according to the time elapsed after neurotomy: deficits were stronger during the early stages, while gradual compensation occurred subsequently.These findings provide the first demonstration of the critical role of vestibular signals in the representation of external space and of body pointing direction in the early stages after unilateral vestibular loss.

View Article: PubMed Central - PubMed

Affiliation: Aix-Marseille Université, Marseille, France ; CNRS, UMR 7260 Laboratoire de Neurosciences Intégratives et Adaptatives, Marseille, France.

ABSTRACT
The vestibular system is responsible for a wide range of postural and oculomotor functions and maintains an internal, updated representation of the position and movement of the head in space. In this study, we assessed whether unilateral vestibular loss affects external space representation. Patients with Menière's disease and healthy participants were instructed to point to memorized targets in near (peripersonal) and far (extrapersonal) spaces in the absence or presence of a visual background. These individuals were also required to estimate their body pointing direction. Menière's disease patients were tested before unilateral vestibular neurotomy and during the recovery period (one week and one month after the operation), and healthy participants were tested at similar times. Unilateral vestibular loss impaired the representation of both the external space and the body pointing direction: in the dark, the configuration of perceived targets was shifted toward the lesioned side and compressed toward the contralesioned hemifield, with higher pointing error in the near space. Performance varied according to the time elapsed after neurotomy: deficits were stronger during the early stages, while gradual compensation occurred subsequently. These findings provide the first demonstration of the critical role of vestibular signals in the representation of external space and of body pointing direction in the early stages after unilateral vestibular loss.

Show MeSH
Related in: MedlinePlus