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Basal Forebrain Atrophy Contributes to Allocentric Navigation Impairment in Alzheimer's Disease Patients.

Kerbler GM, Nedelska Z, Fripp J, Laczó J, Vyhnalek M, Lisý J, Hamlin AS, Rose S, Hort J, Coulson EJ - Front Aging Neurosci (2015)

Bottom Line: When considering the entire sample, we found that basal forebrain volume correlated with spatial accuracy in allocentric (cued) and mixed allo/egocentric navigation tasks but not the egocentric (uncued) task, demonstrating an important role of the basal forebrain in mediating cue-based spatial navigation capacity.Regression analysis revealed that, although hippocampal volume reflected navigation performance across the entire sample, basal forebrain volume contributed to mixed allo/egocentric navigation performance in the AD group, whereas hippocampal volume did not.This suggests that atrophy of the basal forebrain contributes to aspects of navigation impairment in AD that are independent of hippocampal atrophy.

View Article: PubMed Central - PubMed

Affiliation: Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland , Brisbane, QLD , Australia.

ABSTRACT
The basal forebrain degenerates in Alzheimer's disease (AD) and this process is believed to contribute to the cognitive decline observed in AD patients. Impairment in spatial navigation is an early feature of the disease but whether basal forebrain dysfunction in AD is responsible for the impaired navigation skills of AD patients is not known. Our objective was to investigate the relationship between basal forebrain volume and performance in real space as well as computer-based navigation paradigms in an elderly cohort comprising cognitively normal controls, subjects with amnestic mild cognitive impairment and those with AD. We also tested whether basal forebrain volume could predict the participants' ability to perform allocentric- vs. egocentric-based navigation tasks. The basal forebrain volume was calculated from 1.5 T magnetic resonance imaging (MRI) scans, and navigation skills were assessed using the human analog of the Morris water maze employing allocentric, egocentric, and mixed allo/egocentric real space as well as computerized tests. When considering the entire sample, we found that basal forebrain volume correlated with spatial accuracy in allocentric (cued) and mixed allo/egocentric navigation tasks but not the egocentric (uncued) task, demonstrating an important role of the basal forebrain in mediating cue-based spatial navigation capacity. Regression analysis revealed that, although hippocampal volume reflected navigation performance across the entire sample, basal forebrain volume contributed to mixed allo/egocentric navigation performance in the AD group, whereas hippocampal volume did not. This suggests that atrophy of the basal forebrain contributes to aspects of navigation impairment in AD that are independent of hippocampal atrophy.

No MeSH data available.


Related in: MedlinePlus

Anterior basal forebrain volume of AD subjects is significantly correlated (R = 0.82, p = 0.003) to distance error in the mixed allo/egocentric real space test. A linear fit line with 95% confidence interval is shown.
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Figure 5: Anterior basal forebrain volume of AD subjects is significantly correlated (R = 0.82, p = 0.003) to distance error in the mixed allo/egocentric real space test. A linear fit line with 95% confidence interval is shown.

Mentions: To test whether basal forebrain volumes were correlated to navigation dysfunction in clinical groups, we performed correlations of basal forebrain volumes and navigation task scores in individual groups. This analysis revealed no significant interactions of any basal forebrain volumetric measure with distance error in any of the real space or computer-based navigation tasks in the aMCI and NC groups. However, in the AD group, the anterior (Figure 5; R = 0.82, p = 0.003; Table 3) and whole (R = 0.68, p = 0.029) basal forebrain volumes significantly correlated with distance error in the mixed allo/egocentric real space task. In addition, posterior basal forebrain volume was significantly correlated to distance error in the mixed allo/egocentric virtual space task (R = 0.55, p = 0.040; Table 3).


Basal Forebrain Atrophy Contributes to Allocentric Navigation Impairment in Alzheimer's Disease Patients.

Kerbler GM, Nedelska Z, Fripp J, Laczó J, Vyhnalek M, Lisý J, Hamlin AS, Rose S, Hort J, Coulson EJ - Front Aging Neurosci (2015)

Anterior basal forebrain volume of AD subjects is significantly correlated (R = 0.82, p = 0.003) to distance error in the mixed allo/egocentric real space test. A linear fit line with 95% confidence interval is shown.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4585346&req=5

Figure 5: Anterior basal forebrain volume of AD subjects is significantly correlated (R = 0.82, p = 0.003) to distance error in the mixed allo/egocentric real space test. A linear fit line with 95% confidence interval is shown.
Mentions: To test whether basal forebrain volumes were correlated to navigation dysfunction in clinical groups, we performed correlations of basal forebrain volumes and navigation task scores in individual groups. This analysis revealed no significant interactions of any basal forebrain volumetric measure with distance error in any of the real space or computer-based navigation tasks in the aMCI and NC groups. However, in the AD group, the anterior (Figure 5; R = 0.82, p = 0.003; Table 3) and whole (R = 0.68, p = 0.029) basal forebrain volumes significantly correlated with distance error in the mixed allo/egocentric real space task. In addition, posterior basal forebrain volume was significantly correlated to distance error in the mixed allo/egocentric virtual space task (R = 0.55, p = 0.040; Table 3).

Bottom Line: When considering the entire sample, we found that basal forebrain volume correlated with spatial accuracy in allocentric (cued) and mixed allo/egocentric navigation tasks but not the egocentric (uncued) task, demonstrating an important role of the basal forebrain in mediating cue-based spatial navigation capacity.Regression analysis revealed that, although hippocampal volume reflected navigation performance across the entire sample, basal forebrain volume contributed to mixed allo/egocentric navigation performance in the AD group, whereas hippocampal volume did not.This suggests that atrophy of the basal forebrain contributes to aspects of navigation impairment in AD that are independent of hippocampal atrophy.

View Article: PubMed Central - PubMed

Affiliation: Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland , Brisbane, QLD , Australia.

ABSTRACT
The basal forebrain degenerates in Alzheimer's disease (AD) and this process is believed to contribute to the cognitive decline observed in AD patients. Impairment in spatial navigation is an early feature of the disease but whether basal forebrain dysfunction in AD is responsible for the impaired navigation skills of AD patients is not known. Our objective was to investigate the relationship between basal forebrain volume and performance in real space as well as computer-based navigation paradigms in an elderly cohort comprising cognitively normal controls, subjects with amnestic mild cognitive impairment and those with AD. We also tested whether basal forebrain volume could predict the participants' ability to perform allocentric- vs. egocentric-based navigation tasks. The basal forebrain volume was calculated from 1.5 T magnetic resonance imaging (MRI) scans, and navigation skills were assessed using the human analog of the Morris water maze employing allocentric, egocentric, and mixed allo/egocentric real space as well as computerized tests. When considering the entire sample, we found that basal forebrain volume correlated with spatial accuracy in allocentric (cued) and mixed allo/egocentric navigation tasks but not the egocentric (uncued) task, demonstrating an important role of the basal forebrain in mediating cue-based spatial navigation capacity. Regression analysis revealed that, although hippocampal volume reflected navigation performance across the entire sample, basal forebrain volume contributed to mixed allo/egocentric navigation performance in the AD group, whereas hippocampal volume did not. This suggests that atrophy of the basal forebrain contributes to aspects of navigation impairment in AD that are independent of hippocampal atrophy.

No MeSH data available.


Related in: MedlinePlus