title: Frequency-dependent changes in the regional amplitude and synchronization of resting-state functional MRI in stroke.
abstract: Resting-state functional magnetic resonance imaging (R-fMRI) has been intensively used to assess alterations of inter-regional functional connectivity in patients with stroke, but the regional properties of brain activity in stroke have not yet been fully investigated. Additionally, no study has examined a frequency effect on such regional properties in stroke patients, although this effect has been shown to play important roles in both normal brain functioning and functional abnormalities. Here we utilized R-fMRI to measure the amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo), two major methods for characterizing the regional properties of R-fMRI, in three different frequency bands (slow-5: 0.01-0.027 Hz; slow-4: 0.027-0.73 Hz; and typical band: 0.01-0.1 Hz) in 19 stroke patients and 15 healthy controls. Both the ALFF and ReHo analyses revealed changes in brain activity in a number of brain regions, particularly the parietal cortex, in stroke patients compared with healthy controls. Remarkably, the regions with changed activity as detected by the slow-5 band data were more extensive, and this finding was true for both the ALFF and ReHo analyses. These results not only confirm previous studies showing abnormality in the parietal cortex in patients with stroke, but also suggest that R-fMRI studies of stroke should take frequency effects into account when measuring intrinsic brain activity.
authors.affiliation: Department of Acupuncture and Moxibustion, Zhejiang Hospital, Number 12, Lingyin Road, Xihu District, Hangzhou, China.
authors.forename: Jianfang
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Acupuncture and Moxibustion, Zhejiang Hospital, Number 12, Lingyin Road, Xihu District, Hangzhou, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Department of Acupuncture and Moxibustion, Zhejiang Hospital, Number 12, Lingyin Road, Xihu District, Hangzhou, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.affiliation: Department of Neurology, Zhejiang Hospital, Number 12, Lingyin Road, Xihu District, Hangzhou, China.
authors.forename: Yumiao
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Radiology, Zhejiang Hospital, Number 12, Lingyin Road, Xihu District, Hangzhou, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Department of Acupuncture and Moxibustion, Zhejiang Hospital, Number 12, Lingyin Road, Xihu District, Hangzhou, China.
authors.forename: Maihong
authors.initials: M
authors.lastname: Yu
authors.affiliation: Department of Acupuncture and Moxibustion, Zhejiang Hospital, Number 12, Lingyin Road, Xihu District, Hangzhou, China.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Jin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000503:physiopathology*; D002545:Brain Ischemia / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000503:physiopathology*