Affiliations: [a] The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA | [b] Department of Psychiatry, New York University School of Medicine, New York, NY, USA
Correspondence:
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Correspondence to: Babak A. Ardekani, Ph.D., Center for Advanced Brain Imaging, Nathan Kline Institute, 140 Old Orangeburg Rd, Orangeburg, NY 10962, USA. Tel.: +845 398 5490; Fax: +1 845 398 5472; E-mail: ardekani@nki.rfmh.org.
Abstract: Background:Alzheimer’s disease (AD) has been shown to be associated with shrinkage of the corpus callosum mid-sagittal cross-sectional area (CCA). Objective:To study temporal rates of corpus callosum atrophy not previously reported for early AD. Methods:We used longitudinal MRI scans to study the rates of change of CCA and circularity (CIR), a measure of its shape, in normal controls (NC, n = 75), patients with very mild AD (AD-VM, n = 51), and mild AD (AD-M, n = 21). Results:There were significant reduction rates in CCA and CIR in all three groups. While CCA reduction rates were not statistically different between groups, the CIR declined faster in AD-VM (p < 0.03) and AD-M (p < 0.0001) relative to NC, and in AD-M relative to AD-VM (p < 0.0004). Conclusion:CIR declines at an accelerated rate with AD severity. Its rate of change is more closely associated with AD progression than CCA or any of its sub-regions. CIR may be a useful group biomarker for objective assessment of treatments that aim to slow AD progression.
Keywords: Alzheimer's disease, brain, circularity, corpus callosum, magnetic resonance imaging, shape analysis
