Application of amplitude of low frequency fluctuation to cognitive impaired patients with Parkinson's disease:a resting state fMRI study / 中华行为医学与脑科学杂志

ABSTRACT

Objective To investigate the changes of amplitude of low frequency fluctuation (ALFF) of the resting state fMRI in cognitively impaired Parkinson' s disease patients and discuss its underling neurophysiological mechanism.Methods Blood oxygen level-dependent low-frequency amplitude (ALFF) in resting-state functional magnetic resonance imaging were calculated in 16 healthy controls(HC) and 29 idiopathic Parkinson's disease patients (16 of which were patients with cognitive normal,PDCN and 13 with cognitive impairment,PDCI).The brain regions showing increased and decreased ALFF in patients were demonstrated by comparing normal subjects with 2-sample t-test with threshold of P＜ 0.05 and the analysis of the relationship between the different regions of the brain activity and cognitive function tests scores were also analyzed.Results Compared with PDCN,the PDCI patients showed decreased activity in the caudate nucleus (-3,9,12),occipital lobe (0,-78,-15) and medial temporal lobe (42,9,-27) and increased activity in the superior frontal gyrus (9,63,24).PDCI patients showed increased activity mainly in the precuneus and inferior parietal lobules compared with controls.Additionally,the regions with ALFF changes had significant correlations with the cognitive performance of patients as measured by Montreal cognitive test(Beijing Version) and neuropsychological tests (including memory,attention,visuospatial functions and executive function).Conclusion The results demonstrate that there is a specific pattern of intrinsic activity in PDCI providing insights into neurophysiological mechanisms of the Parkinson's disease dementia.