Atrophy of the Corpus Callosum in Alzheimer's Disease Versus Healthy Aging

Abstract

Atrophy of the CC differentiates HE and ID from AD subjects and tracks the cognitive decline of this disease. In addition, optimally healthy subjects show an age-related decline in callosum size. The atrophy is specific to the CC, a cortical projection system, and does not occur in cerebellum or pons.

Disrupted white matter structural networks in healthy older adult APOE ε4 carriers – An international multicenter DTI study

“…In particular, in agreement with previous evidence, we found lower FA and higher radD values in ε4 carriers compared to non-carriers in the genu and splenium of corpus callosum (Persson et al, 2006, Smith et al, 2010, Ryan et al, 2011, Adluru et al, 2014, Tsao et al, 2014, Lee et al, 2016. This finding also agrees with prior MRI studies observing macroscopic WM lesions in both normal aging (Bartzokis, 2004, Filippini et al, 2009 and AD patients (Janowsky et al, 1996, Teipel et al, 2003 in the corpus callosum. Morphological differences in the corpus callosum may point to regional and cell-type specific neuronal neurodegeneration (Hampel et al, 1998); indeed, WM fibres of the splenium originate from the temporoparietal regions (Conturo et al, 1999), which are characteristically affected in the early stages of AD (Thompson et al, 2001, Ewers et al, 2011a).…”

Disrupted white matter structural networks in healthy older adult APOE ε4 carriers – An international multicenter DTI study

“…In particular, in agreement with previous evidence, we found lower FA and higher radD values in ε4 carriers compared to non-carriers in the genu and splenium of corpus callosum (Persson et al, 2006, Smith et al, 2010, Ryan et al, 2011, Adluru et al, 2014, Tsao et al, 2014, Lee et al, 2016. This finding also agrees with prior MRI studies observing macroscopic WM lesions in both normal aging (Bartzokis, 2004, Filippini et al, 2009 and AD patients (Janowsky et al, 1996, Teipel et al, 2003 in the corpus callosum. Morphological differences in the corpus callosum may point to regional and cell-type specific neuronal neurodegeneration (Hampel et al, 1998); indeed, WM fibres of the splenium originate from the temporoparietal regions (Conturo et al, 1999), which are characteristically affected in the early stages of AD (Thompson et al, 2001, Ewers et al, 2011a).…”

Corpus callosum shape changes in early Alzheimer’s disease: an MRI study using the OASIS brain database

“…As far as we are aware, changes in the CC shape, as measured by CIR, with age have not been reported previously. Our finding of CCA changes with age are consistent with the results of Janowsky et al (1996) who found that CCA showed a significant decline with age in healthy elderly subjects and in a group of “incipient dementia” subjects who were cognitively normal at the time of their MRI study but subsequently developed MCI as indicated by a CDR of 0.5 or greater on two successive 6-month follow-up visits. However, Janowsky et al did not find an age-related decline in CCA in a group of AD patients (ρ = −0.15; p < 0.354), while we found a significant negative correlation between age and CCA in both NC and AD patients.…”

Regionally specific atrophy of the corpus callosum in AD, MCI and cognitive complaints

“…Our findings are consistent with previous reports of regionally specific posterior callosal atrophy in mild AD [23,38]. Studies showing more pervasive callosal atrophy have typically involved AD patients with moderate or severe dementia [18,20,21,23,27,34,35]. For example, one study [23] found atrophy in all callosal subregions in their total AD sample; however, when just the mild AD subset from the AD group was analyzed, only the posterior mid-body, isthmus, and splenium showed significant reduction relative to controls.…”

Disrupted white matter structural networks in healthy older adult APOE ε4 carriers – An international multicenter DTI study

“…In particular, in agreement with previous evidence, we found lower FA and higher radD values in ε4 carriers compared to non-carriers in the genu and splenium of corpus callosum (Persson et al, 2006, Smith et al, 2010, Ryan et al, 2011, Adluru et al, 2014, Tsao et al, 2014, Lee et al, 2016. This finding also agrees with prior MRI studies observing macroscopic WM lesions in both normal aging (Bartzokis, 2004, Filippini et al, 2009 and AD patients (Janowsky et al, 1996, Teipel et al, 2003 in the corpus callosum. Morphological differences in the corpus callosum may point to regional and cell-type specific neuronal neurodegeneration (Hampel et al, 1998); indeed, WM fibres of the splenium originate from the temporoparietal regions (Conturo et al, 1999), which are characteristically affected in the early stages of AD (Thompson et al, 2001, Ewers et al, 2011a).…”

Corpus callosum shape changes in early Alzheimer’s disease: an MRI study using the OASIS brain database

“…As far as we are aware, changes in the CC shape, as measured by CIR, with age have not been reported previously. Our finding of CCA changes with age are consistent with the results of Janowsky et al (1996) who found that CCA showed a significant decline with age in healthy elderly subjects and in a group of “incipient dementia” subjects who were cognitively normal at the time of their MRI study but subsequently developed MCI as indicated by a CDR of 0.5 or greater on two successive 6-month follow-up visits. However, Janowsky et al did not find an age-related decline in CCA in a group of AD patients (ρ = −0.15; p < 0.354), while we found a significant negative correlation between age and CCA in both NC and AD patients.…”

Regionally specific atrophy of the corpus callosum in AD, MCI and cognitive complaints

“…Our findings are consistent with previous reports of regionally specific posterior callosal atrophy in mild AD [23,38]. Studies showing more pervasive callosal atrophy have typically involved AD patients with moderate or severe dementia [18,20,21,23,27,34,35]. For example, one study [23] found atrophy in all callosal subregions in their total AD sample; however, when just the mild AD subset from the AD group was analyzed, only the posterior mid-body, isthmus, and splenium showed significant reduction relative to controls.…”

Disrupted white matter structural networks in healthy older adult APOE ε4 carriers – An international multicenter DTI study

“…In particular, in agreement with previous evidence, we found lower FA and higher radD values in ε4 carriers compared to non-carriers in the genu and splenium of corpus callosum (Persson et al, 2006, Smith et al, 2010, Ryan et al, 2011, Adluru et al, 2014, Tsao et al, 2014, Lee et al, 2016. This finding also agrees with prior MRI studies observing macroscopic WM lesions in both normal aging (Bartzokis, 2004, Filippini et al, 2009 and AD patients (Janowsky et al, 1996, Teipel et al, 2003 in the corpus callosum. Morphological differences in the corpus callosum may point to regional and cell-type specific neuronal neurodegeneration (Hampel et al, 1998); indeed, WM fibres of the splenium originate from the temporoparietal regions (Conturo et al, 1999), which are characteristically affected in the early stages of AD (Thompson et al, 2001, Ewers et al, 2011a).…”

Corpus callosum shape changes in early Alzheimer’s disease: an MRI study using the OASIS brain database

“…As far as we are aware, changes in the CC shape, as measured by CIR, with age have not been reported previously. Our finding of CCA changes with age are consistent with the results of Janowsky et al (1996) who found that CCA showed a significant decline with age in healthy elderly subjects and in a group of “incipient dementia” subjects who were cognitively normal at the time of their MRI study but subsequently developed MCI as indicated by a CDR of 0.5 or greater on two successive 6-month follow-up visits. However, Janowsky et al did not find an age-related decline in CCA in a group of AD patients (ρ = −0.15; p < 0.354), while we found a significant negative correlation between age and CCA in both NC and AD patients.…”

Regionally specific atrophy of the corpus callosum in AD, MCI and cognitive complaints

“…Our findings are consistent with previous reports of regionally specific posterior callosal atrophy in mild AD [23,38]. Studies showing more pervasive callosal atrophy have typically involved AD patients with moderate or severe dementia [18,20,21,23,27,34,35]. For example, one study [23] found atrophy in all callosal subregions in their total AD sample; however, when just the mild AD subset from the AD group was analyzed, only the posterior mid-body, isthmus, and splenium showed significant reduction relative to controls.…”