TY - JOUR
T1 - Callosal atrophy in mild cognitive impairment and Alzheimer's disease
T2 - Different effects in different stages
AU - Di Paola, Margherita
AU - Luders, Eileen
AU - Di Iulio, Fulvia
AU - Cherubini, Andrea
AU - Passafiume, Domenico
AU - Thompson, Paul M.
AU - Caltagirone, Carlo
AU - Toga, Arthur W.
AU - Spalletta, Gianfranco
PY - 2010/1/1
Y1 - 2010/1/1
N2 - Alzheimer's Disease (AD) is a neurodegenerative disorder that mainly affects grey matter (GM). Nevertheless, a number of investigations have documented white matter (WM) pathology associated with AD. The corpus callosum (CC) is the largest WM fiber bundle in the human brain. It has been shown to be susceptible to atrophy in AD mainly as a correlate of Wallerian degeneration of commissural nerve fibers of the neocortex. The aim of this study was to investigate which callosal regions are affected and whether callosal degeneration is associated with the stage of the disease. For this purpose, we analyzed high-resolution MRI data of patients with amnesic mild cognitive impairment (MCI) (n = 20), mild AD (n = 20), severe AD (n = 10), and of healthy controls (n = 20). Callosal morphology was investigated applying two different structural techniques: mesh-based geometrical modeling methods and whole-brain voxel-based analyses. Our findings indicate significant reductions in severe AD patients compared to healthy controls in anterior (genu and anterior body) and posterior (splenium) sections. In contrast, differences between healthy controls and mild AD patients or amnesic MCI patients were less pronounced and did not survive corrections for multiple comparisons. When correlating anterior and posterior WM density of the CC with GM density of the cortex in the severe AD group, we detected significant positive relationships between posterior sections of the CC and the cortex. We conclude that callosal atrophy is present predominantly in the latest stage of AD, where two mechanisms might contribute to WM alterations in severe AD: the Wallerian degeneration in posterior subregions and the myelin breakdown process in anterior subregions.
AB - Alzheimer's Disease (AD) is a neurodegenerative disorder that mainly affects grey matter (GM). Nevertheless, a number of investigations have documented white matter (WM) pathology associated with AD. The corpus callosum (CC) is the largest WM fiber bundle in the human brain. It has been shown to be susceptible to atrophy in AD mainly as a correlate of Wallerian degeneration of commissural nerve fibers of the neocortex. The aim of this study was to investigate which callosal regions are affected and whether callosal degeneration is associated with the stage of the disease. For this purpose, we analyzed high-resolution MRI data of patients with amnesic mild cognitive impairment (MCI) (n = 20), mild AD (n = 20), severe AD (n = 10), and of healthy controls (n = 20). Callosal morphology was investigated applying two different structural techniques: mesh-based geometrical modeling methods and whole-brain voxel-based analyses. Our findings indicate significant reductions in severe AD patients compared to healthy controls in anterior (genu and anterior body) and posterior (splenium) sections. In contrast, differences between healthy controls and mild AD patients or amnesic MCI patients were less pronounced and did not survive corrections for multiple comparisons. When correlating anterior and posterior WM density of the CC with GM density of the cortex in the severe AD group, we detected significant positive relationships between posterior sections of the CC and the cortex. We conclude that callosal atrophy is present predominantly in the latest stage of AD, where two mechanisms might contribute to WM alterations in severe AD: the Wallerian degeneration in posterior subregions and the myelin breakdown process in anterior subregions.
KW - Amnesic MCI
KW - Corpus callosum
KW - Mild AD
KW - Region-of-interest
KW - Severe AD
KW - Voxel-based morphometry
UR - http://www.scopus.com/inward/record.url?scp=70349970009&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=70349970009&partnerID=8YFLogxK
U2 - 10.1016/j.neuroimage.2009.07.050
DO - 10.1016/j.neuroimage.2009.07.050
M3 - Article
C2 - 19643188
AN - SCOPUS:70349970009
VL - 49
SP - 141
EP - 149
JO - NeuroImage
JF - NeuroImage
SN - 1053-8119
IS - 1
ER -