Thomas Michael Meindl MD, Presenter: Nothing to Disclose

Christine Maria Born MD, Abstract Co-Author: Nothing to Disclose

Arun Bokde MD, Abstract Co-Author: Nothing to Disclose

Stefan Teipel MD, Abstract Co-Author: Nothing to Disclose

Maximilian F. Reiser MD, Abstract Co-Author: Nothing to Disclose

The aim of this study was to detect cortical connectivity patterns in the absence of external input (resting-state) in healthy young and elderly subjects and to compare them to patterns in mild cognitive impaired (MCI) subjects and patients with Alzheimers disease (AD).

The study population consisted of 40 subjects: 10 healthy young (mean age, 24.0 years), 10 healthy elderly (mean age, 67.6 years), 10 MCI (mean age, 69.7 years), 10 AD (mean age, 67.4 years). Grouping of subjects was done by neuropsychological and genetic testing. Functional imaging was done by means of an echoplanar gradient-echo sequence at 3.0T. For anatomical reference, a sagittal high-resolution MPRAGE sequence was acquired. Data preprocessing and statistical analysis was done by BrainVoyager QX 1.7.4.. Preprocessing of functional data consisted of spatial smoothing, 3D motion correction and slice-scan-time correction. Afterwards, single-subject independent component analysis (ICA) and self-organizing group-level ICA were applied.

In healthy young subjects connections between the anterior and posterior cingulate gyrus (ACC and PCC) and the inferior parietal gyrus bilaterally were found. In healthy elderly, activation of the ACC decreased but connectivity patterns persisted. In MCI, activated clusters were found precuneally and in the PCC, however no connection to the pariatel lobe or ACC. In AD patients no PCC activation was found but smaller clusters in the cuneal and precuneal region.

Resting-state fMRI was able to identify different networks in different age groups and cognitive states. This method may function as useful approach for further understanding the pathophysiological changes associated with dementia.

Resting state fMRI identifies neural networks at different ages and cognitive states.

Meindl, T, Born, C, Bokde, A, Teipel, S, Reiser, M, Resting-state Networks in Healthy, Cognitive Impaired and Demented Subjects.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5010491.html