Neural Correlates In Mild Alzheimer's Disease

All neuroimaging procedures were performed on a research-dedicated GE 3.0 Tesla whole-body Excite scanner with 8-channel phase-array head coil. Resting-state functional magnetic resonance imaging (fMRI) of the medial temporal lobe (MTL) was performed. The functional HCI was derived from the MTL network using a data driven approach corresponding voxel time courses from the fMR images were processed to extract low frequency fluctuations. Functional connectivity was quantified by calculating the cross-correlation of each voxel time course in the hippocampus to all voxel time courses of the whole brain and the mean of absolute cross-correlation coefficients between a hippocampus voxel to the whole-brain voxels. HCI was then calculated as the average of all hippocampus cross-correlation coefficients. Change from baseline (CFB) was calculated using the CBF-Perfusion Processing Method. A positive change from baseline for HCI indicates improved function.

The ADAS-cog is a 13-item performance-based test that examines selected aspects of cognition including memory, orientation, attention, reasoning, language, and praxis. Total score ranges from 0 to 70 with higher scores indicating greater cognitive impairment. A decrease from baseline indicates improved cognitive function. The ADAS-cog was administered by a trained individual unaware of adverse events reported during this trial.

MMSE was a 11-item scale to measure cognitive status where a higher score indicated better cognitive state. The score ranged from 0 to 30, with a higher score indicating better function. A positive change score indicated improvement from baseline. The mean change was analyzed by Wilcoxon's signed rank test.

IADL Scale measures 7 areas of more complex activities required for optimal independent functioning, as reported by the caregiver. The scoring indicates whether the participant was completely independent (3), requires assistance (2), or is dependent (1) for the performance of each activity. A summary score ranges from 7 (high function, independent) to 21 (low function, dependent). The mean change was analyzed by Wilcoxon's signed rank test. A decrease from Baseline to Week 12 indicates improved function.

NPI was a 12-item caregiver-based assessment of behavioral disturbances commonly occurring in participants with AD. NPI includes 12 sections which are Delusions, Hallucinations, Agitation, Depression, Anxiety, Euphoria, Apathy, Disinhibition, Irritability, Aberrant motor behavior, Night-time behaviors and Appetite and eating disorders. The score of each section ranges from 0 to 12, and higher score means higher severity and frequency of the neuropsychiatric disturbances. The mean change was analyzed by Wilcoxon's signed rank test.