Damage to the frontal aslant tract accounts for visuo-constructive deficits in Alzheimer's disease

Serra, Laura, Gabrielli, Giulia Bechi, Tuzzi, Elisa, Spanò, Barbara, Giulietti, Giovanni, Failoni, Virginia, Marra, Camillo, Caltagirone, Carlo, Koch, Giacomo, Cercignani, Mara and Bozzali, Marco (2017) Damage to the frontal aslant tract accounts for visuo-constructive deficits in Alzheimer's disease. Journal of Alzheimer's Disease, 60 (3). pp. 1015-1024. ISSN 1875-8908

[img] PDF - Accepted Version
Download (674kB)

Abstract

The frontal aslant tract (FAT) has been described as a bundle connecting the Broca's area to the supplementary motor area (SMA) and the pre-SMA in both hemispheres. The functional properties of this tract and its role in degenerative dementia, such as Alzheimer's disease (AD), still need to be fully clarified. The aim of this study was to explore the microstructural integrity of the FAT in patients with AD and its potential relationship with cognitive functioning. Twenty-three patients with AD and 25 healthy subjects (HS) were enrolled. All subjects underwent cognitive and MRI examination. MRI, including diffusion sequences, was used for probabilistic tractography analysis. We reconstructed individual FATs bilaterally and assessed their microstructural integrity using fractional anisotropy (FA), computed as both mean tract value and voxel-wise using SPM-8. Mean FA values were then used to test for correlations with cognitive measures. Mean tract FA and voxel-wise analyses revealed that patients with AD, compared to HS, had decreased FA in the FAT bilaterally. In addition, positive associations were found between FA in the FATs and patients' performance at tests for constructional praxis and visuospatial logical reasoning. The present results reveal a bilateral damage of FAT in AD patients. The association between FATs' microscopic abnormalities and constructive abilities fits well with the knowledge of a functional involvement of SMA and pre-SMA in movement sequences when executing constructive praxis tasks. The FAT is an associative bundle critically involved in the network sub-serving constructional praxis in patients with AD.

Item Type: Article
Keywords: Alzheimer’s disease, disconnection, frontal aslant tract, tractography, visuo-spatial abilities
Schools and Departments: Brighton and Sussex Medical School > Neuroscience
Subjects: R Medicine > R Medicine (General) > R895 Medical physics. Medical radiology. Nuclear medicine
R Medicine > RC Internal medicine > RC0321 Neurosciences. Biological psychiatry. Neuropsychiatry > RC0438 Psychiatry > RC0512 Psychopathology > RC0513 Psychoses > RC0521 Dementia > RC0522 Presenile dementia > RC0523 Alzheimer's disease
Depositing User: Patricia Butler
Date Deposited: 20 Dec 2017 13:12
Last Modified: 15 Jan 2018 11:09
URI: http://sro.sussex.ac.uk/id/eprint/72347

View download statistics for this item

📧 Request an update