Ayton, Scott

Fazlollahi, Amir

Bourgeat, Pierrick

Raniga, Parnesh

Ng, Amanda

Lim, Yen Ying

Diouf, Ibrahima

Farquharson, Shawna

Fripp, Jurgen

Ames, David

Doecke, James D

Desmond, Patricia

Ordidge, Roger

Masters, Colin L

Rowe, Christopher C

Maruff, Paul

Villemagne, Victor L

Australian Imaging, Biomarkers and Lifestyle (AIBL) Research Group

Salvado, Olivier

Bush, Ashley I

2017-07-24

See Derry and Kent (doi:10.1093/awx167) for a scientific commentary on this article. The large variance in cognitive deterioration in subjects who test positive for amyloid-β by positron emission tomography indicates that convergent pathologies, such as iron accumulation, might combine with amyloid-β to accelerate Alzheimer’s disease progression. Here, we applied quantitative susceptibility mapping, a relatively new magnetic resonance imaging method sensitive to tissue iron, to assess the relationship between iron, amyloid-β load, and cognitive decline in 117 subjects who underwent baseline magnetic resonance imaging and amyloid-β positron emission tomography from the Australian Imaging, Biomarkers and Lifestyle study (AIBL). Cognitive function data were collected every 18 months for up to 6 years from 100 volunteers who were either cognitively normal (n = 64) or diagnosed with mild cognitive impairment (n = 17) or Alzheimer’s disease (n = 19). Among participants with amyloid pathology (n = 45), higher hippocampal quantitative susceptibility mapping levels predicted accelerated deterioration in composite cognition tests for episodic memory [β(standard error) = −0.169 (0.034), P = 9.2 × 10−7], executive function [β(standard error) = −0.139 (0.048), P = 0.004), and attention [β(standard error) = −0.074 (0.029), P = 0.012]. Deteriorating performance in a composite of language tests was predicted by higher quantitative susceptibility mapping levels in temporal lobe [β(standard error) = −0.104 (0.05), P = 0.036] and frontal lobe [β(standard error) = −0.154 (0.055), P = 0.006]. These findings indicate that brain iron might combine with amyloid-β to accelerate clinical progression and that quantitative susceptibility mapping could be used in combination with amyloid-β positron emission tomography to stratify individuals at risk of decline.

Brain 2017; 140(8): 2112-2119

Brain

0000-0002-2605-4766

0000-0003-3910-2453

0000-0001-8259-9069

https://ahro.austin.org.au/austinjspui/handle/1/16744

Quantitative Susceptibility Mapping

MRI

iron

Alzheimer’s

Cognitive decline

Cerebral quantitative susceptibility mapping predicts amyloid-β-related cognitive decline

Journal Article