Progression of Corpus Callosum Atrophy in Early Stage of Alzheimer’s Disease

Abstract

Rationale and Objectives Magnetic resonance imaging (MRI) studies reveal that the atrophy of the corpus callosum (CC) is involved in early Alzheimer’s disease (AD). This study investigates when and how the callosal change occur in the early course of AD. Materials and Methods High-resolution structural MRI were obtained from 196 old people, subjects were characterized using the Clinical Dementia Rating (CDR), 98 healthy controls were nondemented (CDR 0), 70 patients had a clinical diagnosis of AD in very mild (CDR 0.5) and 28 patients in mild (CDR 1) dementia stage. A semi-automatic segmentation method was used to extract the CC on the midsagittal plane (MSP). We measured the total and regional areas of CC. Results Results indicate that the callosal atrophy occurs in the subjects when their CDR is 0.5. The area of genu and rostral body of CC of the healthy controls (CDR 0) is significantly different from that of the subjects with very mild dementia (CDR 0.5) (p< .05). The significant difference can also be found in the area of rostral and midbody of CC between the subjects with very mild dementia (CDR 0.5) and those with mild dementia (CDR 1) (p< .05). Conclusion The callosal atrophy can be detected in the subjects when their CDR is 0.5. The change of CC in the early stage of AD indicates an anterior-to-posterior atrophic process when the degree of dementia increases (CDR 0→0.5→1).

Corpus Callosum Atrophy and Cognitive Decline in Early Alzheimer's Disease: Longitudinal MRI Study

“…The CC on the midsagittal plane (MSP) was segmented using a previously described semi-automatic method [15]. The method consists of the following 3 steps:…”

“…Most previous studies [5,6,7,8,9,10,11,12,13,14,15] have focused on the investigation of CC atrophy using cross-sectional data, in which intersubject variance is inevitable. However, the analysis of longitudinal data can reduce the impact of intersubject variance by measuring changes within individuals relative to their own baselines, and this type of analysis can also control for differences associated with cross-sectional data.…”

“…Magnetic resonance imaging (MRI) has been widely used to assess CC atrophy in vivo, and most cross-sectional studies have documented that patients with AD exhibit CC atrophy [5,6,7,8,9,10,11,12,13,14,15]. Although not all reports are in agreement, patterns of atrophy in the anterior and posterior subregions of the CC, as well as in the total CC area, are the most consistent findings in AD patients [5,6,16,17,18].…”

Corpus callosum atrophy associated with the degree of cognitive decline in patients with Alzheimer's dementia or mild cognitive impairment: A meta-analysis of the region of interest structural imaging studies

“…However, the results from previous studies have been inconsistent. Some studies revealed a smaller CC size in patients with AD compared with healthy controls (Gootjes et al, 2006;Li et al, 2008;Wiltshire et al, 2005); some found a smaller anterior region of the CC (Thomann et al, 2006;Zhu et al, 2012); and others found a smaller posterior the CC (Hanyu et al, 1999;. There were also studies reporting no relationships between AD and total CC size (Kaufer et al, 1997;Thompson et al, 1998).…”

“…The CC atrophy and structural changes have been found by using the region of interest (ROI) analysis in patients with AD (Di Paola et al, 2010a;Frederiksen et al, 2011;Zhu et al, 2012Zhu et al, , 2014, and some of these studies have revealed that the decrease in the CC midsagittal crosssectional area was independently associated with the progression of AD. It was speculated that the decrease in the CC area might be due to the loss of callosal fibers (Aboitiz et al, 1992;Riise and Pakkenberg, 2011).…”