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Beyond Dizziness: Virtual Navigation, Spatial Anxiety and Hippocampal Volume in Bilateral Vestibulopathy.

Kremmyda O, Hüfner K, Flanagin VL, Hamilton DA, Linn J, Strupp M, Jahn K, Brandt T - Front Hum Neurosci (2016)

Bottom Line: In clinical practice, most patients do not have a complete loss of function but rather an asymmetrical residual functioning of the vestibular system.In the patients, the questionnaire showed a higher spatial anxiety and the Morris Water Maze Task a delayed spatial learning performance.Our current findings demonstrate that even partial bilateral vestibular loss leads to anatomical and functional changes in the hippocampal formation and objective and subjective behavioral deficits.

View Article: PubMed Central - PubMed

Affiliation: German Center for Vertigo and Balance DisordersMunich, Germany; Department of Neurology, Ludwig-Maximilians UniversityMunich, Germany.

ABSTRACT
Bilateral vestibulopathy (BVP) is defined as the impairment or loss of function of either the labyrinths or the eighth nerves. Patients with total BVP due to bilateral vestibular nerve section exhibit difficulties in spatial memory and navigation and show a loss of hippocampal volume. In clinical practice, most patients do not have a complete loss of function but rather an asymmetrical residual functioning of the vestibular system. The purpose of the current study was to investigate navigational ability and hippocampal atrophy in BVP patients with residual vestibular function. Fifteen patients with BVP and a group of age- and gender- matched healthy controls were examined. Self-reported questionnaires on spatial anxiety and wayfinding were used to assess the applied strategy of wayfinding and quality of life. Spatial memory and navigation were tested directly using a virtual Morris Water Maze Task. The hippocampal volume of these two groups was evaluated by voxel-based morphometry. In the patients, the questionnaire showed a higher spatial anxiety and the Morris Water Maze Task a delayed spatial learning performance. MRI revealed a significant decrease in the gray matter mid-hippocampal volume (Left: p = 0.006, Z = 4.58, Right: p < 0.001, Z = 3.63) and posterior parahippocampal volume (Right: p = 0.005, Z = 4.65, Left: p < 0.001, Z = 3.87) compared to those of healthy controls. In addition, a decrease in hippocampal formation volume correlated with a more dominant route-finding strategy. Our current findings demonstrate that even partial bilateral vestibular loss leads to anatomical and functional changes in the hippocampal formation and objective and subjective behavioral deficits.

No MeSH data available.


Related in: MedlinePlus

(A) Example of a visual cue as seen from the subject's perspective, while navigating in the platform. (B) Floor plan of the virtual room, indicating the position of the cues and the platform (black square).
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Figure 1: (A) Example of a visual cue as seen from the subject's perspective, while navigating in the platform. (B) Floor plan of the virtual room, indicating the position of the cues and the platform (black square).

Mentions: In brief, the basic features of the environment consisted of a circular pool located in the center of a room with a square floor plan (Figure 1). Four conspicuous cues of equal size were placed around the distal walls. The cues were positioned so that one cue was on each of the four distal room walls, and the platform could not be encountered by simply moving toward a single cue from any release point. The platform was positioned in the center of one quadrant (N/E) and occupied 2% of the pool area. A first-person view of the virtual environment was displayed. The observer's position was always slightly above the surface of the water, and forward movement was controlled by the UP (:) arrow key on the keyboard. Rotation was controlled by the LEFT (/) and RIGHT (?) arrow keys. Backward navigation or up-down movement within the pool was not possible. A full 360° rotation in the absence of forward movement required 2.5 s to complete, and the direct path from a release point to the opposite side of the pool tool 4 s.


Beyond Dizziness: Virtual Navigation, Spatial Anxiety and Hippocampal Volume in Bilateral Vestibulopathy.

Kremmyda O, Hüfner K, Flanagin VL, Hamilton DA, Linn J, Strupp M, Jahn K, Brandt T - Front Hum Neurosci (2016)

(A) Example of a visual cue as seen from the subject's perspective, while navigating in the platform. (B) Floor plan of the virtual room, indicating the position of the cues and the platform (black square).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4814552&req=5

Figure 1: (A) Example of a visual cue as seen from the subject's perspective, while navigating in the platform. (B) Floor plan of the virtual room, indicating the position of the cues and the platform (black square).
Mentions: In brief, the basic features of the environment consisted of a circular pool located in the center of a room with a square floor plan (Figure 1). Four conspicuous cues of equal size were placed around the distal walls. The cues were positioned so that one cue was on each of the four distal room walls, and the platform could not be encountered by simply moving toward a single cue from any release point. The platform was positioned in the center of one quadrant (N/E) and occupied 2% of the pool area. A first-person view of the virtual environment was displayed. The observer's position was always slightly above the surface of the water, and forward movement was controlled by the UP (:) arrow key on the keyboard. Rotation was controlled by the LEFT (/) and RIGHT (?) arrow keys. Backward navigation or up-down movement within the pool was not possible. A full 360° rotation in the absence of forward movement required 2.5 s to complete, and the direct path from a release point to the opposite side of the pool tool 4 s.

Bottom Line: In clinical practice, most patients do not have a complete loss of function but rather an asymmetrical residual functioning of the vestibular system.In the patients, the questionnaire showed a higher spatial anxiety and the Morris Water Maze Task a delayed spatial learning performance.Our current findings demonstrate that even partial bilateral vestibular loss leads to anatomical and functional changes in the hippocampal formation and objective and subjective behavioral deficits.

View Article: PubMed Central - PubMed

Affiliation: German Center for Vertigo and Balance DisordersMunich, Germany; Department of Neurology, Ludwig-Maximilians UniversityMunich, Germany.

ABSTRACT
Bilateral vestibulopathy (BVP) is defined as the impairment or loss of function of either the labyrinths or the eighth nerves. Patients with total BVP due to bilateral vestibular nerve section exhibit difficulties in spatial memory and navigation and show a loss of hippocampal volume. In clinical practice, most patients do not have a complete loss of function but rather an asymmetrical residual functioning of the vestibular system. The purpose of the current study was to investigate navigational ability and hippocampal atrophy in BVP patients with residual vestibular function. Fifteen patients with BVP and a group of age- and gender- matched healthy controls were examined. Self-reported questionnaires on spatial anxiety and wayfinding were used to assess the applied strategy of wayfinding and quality of life. Spatial memory and navigation were tested directly using a virtual Morris Water Maze Task. The hippocampal volume of these two groups was evaluated by voxel-based morphometry. In the patients, the questionnaire showed a higher spatial anxiety and the Morris Water Maze Task a delayed spatial learning performance. MRI revealed a significant decrease in the gray matter mid-hippocampal volume (Left: p = 0.006, Z = 4.58, Right: p < 0.001, Z = 3.63) and posterior parahippocampal volume (Right: p = 0.005, Z = 4.65, Left: p < 0.001, Z = 3.87) compared to those of healthy controls. In addition, a decrease in hippocampal formation volume correlated with a more dominant route-finding strategy. Our current findings demonstrate that even partial bilateral vestibular loss leads to anatomical and functional changes in the hippocampal formation and objective and subjective behavioral deficits.

No MeSH data available.


Related in: MedlinePlus