TY - JOUR T1 - Progressive Disintegration of Brain Networking from Normal Aging to Alzheimer Disease: Analysis of Independent Components of <sup>18</sup>F-FDG PET Data JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1132 LP - 1139 DO - 10.2967/jnumed.116.184309 VL - 58 IS - 7 AU - Marco Pagani AU - Alessandro Giuliani AU - Johanna Öberg AU - Fabrizio De Carli AU - Silvia Morbelli AU - Nicola Girtler AU - Dario Arnaldi AU - Jennifer Accardo AU - Matteo Bauckneht AU - Francesca Bongioanni AU - Andrea Chincarini AU - Gianmario Sambuceti AU - Cathrine Jonsson AU - Flavio Nobili Y1 - 2017/07/01 UR - http://jnm.snmjournals.org/content/58/7/1132.abstract N2 - Brain connectivity has been assessed in several neurodegenerative disorders investigating the mutual correlations between predetermined regions or nodes. Selective breakdown of brain networks during progression from normal aging to Alzheimer disease dementia (AD) has also been observed. Methods: We implemented independent-component analysis of 18F-FDG PET data in 5 groups of subjects with cognitive states ranging from normal aging to AD—including mild cognitive impairment (MCI) not converting or converting to AD—to disclose the spatial distribution of the independent components in each cognitive state and their accuracy in discriminating the groups. Results: We could identify spatially distinct independent components in each group, with generation of local circuits increasing proportionally to the severity of the disease. AD-specific independent components first appeared in the late-MCI stage and could discriminate converting MCI and AD from nonconverting MCI with an accuracy of 83.5%. Progressive disintegration of the intrinsic networks from normal aging to MCI to AD was inversely proportional to the conversion time. Conclusion: Independent-component analysis of 18F-FDG PET data showed a gradual disruption of functional brain connectivity with progression of cognitive decline in AD. This information might be useful as a prognostic aid for individual patients and as a surrogate biomarker in intervention trials. ER -