1. Damage to the Frontal Aslant Tract Accounts for Visuo-Constructive Deficits in Alzheimer's Disease
- Author
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Marco Bozzali, Giulia Bechi Gabrielli, Giacomo Koch, Carlo Caltagirone, Camillo Marra, E Tuzzi, Giovanni Giulietti, Virginia Failoni, Mara Cercignani, Barbara Spanò, and Laura Serra
- Subjects
Male ,Alzheimer’s disease ,disconnection ,frontal aslant tract ,tractography ,visuo-spatial abilities ,Audiology ,Neuropsychological Tests ,Cohort Studies ,0302 clinical medicine ,Cognition ,Neural Pathways ,Supplementary motor area ,medicine.diagnostic_test ,General Neuroscience ,05 social sciences ,Brain ,General Medicine ,Alzheimer's disease ,SMA ,Magnetic Resonance Imaging ,Clinical Psychology ,Settore MED/26 - NEUROLOGIA ,medicine.anatomical_structure ,Diffusion Tensor Imaging ,R895 ,Psychiatry and Mental Health ,Visual Perception ,Female ,Tractography ,medicine.medical_specialty ,RC0523 ,Motor Activity ,050105 experimental psychology ,NO ,03 medical and health sciences ,Alzheimer Disease ,Fractional anisotropy ,medicine ,Humans ,0501 psychology and cognitive sciences ,Psychiatry ,Aged ,Alzheimer’s disease, disconnection, frontal aslant tract, tractography, visuo-spatial abilities, Aged, Brain, Diffusion Tensor Imaging, Cohort Studies, Motor Activity, Neural Pathways, Cognition, Visual Perception, Neuropsychological Tests, Magnetic Resonance Imaging ,business.industry ,Magnetic resonance imaging ,medicine.disease ,Geriatrics and Gerontology ,business ,030217 neurology & neurosurgery ,Diffusion MRI - 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.
- Published
- 2017