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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

Areas of higher GM volume in healthy controls compared to BVP patients. (A) Clusters of GM differences between the two groups are shown on sagittal and coronal planes through the maximum cluster in the right hemisphere at 28 −22 −9 at p < 0.001 uncorr. and (B) left hemisphere at −28 −25 −17 p < 0.05 FWE corr. Clusters and significance values are from an ROI analysis of the HC and PHC bilaterally and are projected onto a mean image of the included subjects. Color bars indicate the range of t-values. The threshold for statistical significance was 3.69.
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Figure 4: Areas of higher GM volume in healthy controls compared to BVP patients. (A) Clusters of GM differences between the two groups are shown on sagittal and coronal planes through the maximum cluster in the right hemisphere at 28 −22 −9 at p < 0.001 uncorr. and (B) left hemisphere at −28 −25 −17 p < 0.05 FWE corr. Clusters and significance values are from an ROI analysis of the HC and PHC bilaterally and are projected onto a mean image of the included subjects. Color bars indicate the range of t-values. The threshold for statistical significance was 3.69.

Mentions: Gray matter brain volumes of BVP patients were compared to those of matched controls using voxel-based morphometry (Wright et al., 1995; Ashburner and Friston, 1997; Critchley et al., 2003). Whole brain analysis did not reveal any areas of gray matter change (p > 0.05, FWE corr.) for both contrasts (BVP > CON and CON>BVP). A ROI analysis of the HC and PHC detected no gray matter changes for the contrast BVP > CON (p > 0.05 FWE corr. or 0.001 uncorr.). For the contrast CON > BVP loss of gray matter was found in the HC and PHC bilaterally (Table 3, Figure 4). This included the mid-hippocampus bilaterally with a maximum at y = −22 right and at y = −25 left, reaching into the posterior HC on the left side, as well as the posterior PHC bilaterally (y = −37). No differences were observed in the caudate nucleus between the two groups.


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)

Areas of higher GM volume in healthy controls compared to BVP patients. (A) Clusters of GM differences between the two groups are shown on sagittal and coronal planes through the maximum cluster in the right hemisphere at 28 −22 −9 at p < 0.001 uncorr. and (B) left hemisphere at −28 −25 −17 p < 0.05 FWE corr. Clusters and significance values are from an ROI analysis of the HC and PHC bilaterally and are projected onto a mean image of the included subjects. Color bars indicate the range of t-values. The threshold for statistical significance was 3.69.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 4: Areas of higher GM volume in healthy controls compared to BVP patients. (A) Clusters of GM differences between the two groups are shown on sagittal and coronal planes through the maximum cluster in the right hemisphere at 28 −22 −9 at p < 0.001 uncorr. and (B) left hemisphere at −28 −25 −17 p < 0.05 FWE corr. Clusters and significance values are from an ROI analysis of the HC and PHC bilaterally and are projected onto a mean image of the included subjects. Color bars indicate the range of t-values. The threshold for statistical significance was 3.69.
Mentions: Gray matter brain volumes of BVP patients were compared to those of matched controls using voxel-based morphometry (Wright et al., 1995; Ashburner and Friston, 1997; Critchley et al., 2003). Whole brain analysis did not reveal any areas of gray matter change (p > 0.05, FWE corr.) for both contrasts (BVP > CON and CON>BVP). A ROI analysis of the HC and PHC detected no gray matter changes for the contrast BVP > CON (p > 0.05 FWE corr. or 0.001 uncorr.). For the contrast CON > BVP loss of gray matter was found in the HC and PHC bilaterally (Table 3, Figure 4). This included the mid-hippocampus bilaterally with a maximum at y = −22 right and at y = −25 left, reaching into the posterior HC on the left side, as well as the posterior PHC bilaterally (y = −37). No differences were observed in the caudate nucleus between the two groups.

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