ReHo differences in three different frequency bands (A,

Frequency-dependent changes in the regional amplitude and synchronization of resting-state functional MRI in stroke. Zhu J, Jin Y, Wang K, Zhou Y, Feng Y, Yu M, Jin X - PLoS ONE (2015) Bottom Line: 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. View Article: PubMed Central - PubMed Affiliation: Department of Acupuncture and Moxibustion, Zhejiang Hospital, Number 12, Lingyin Road, Xihu District, Hangzhou, China. 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. Show MeSH Major Brain/physiopathology* Brain Ischemia/physiopathology* Stroke/physiopathology* Minor Aged Aged, 80 and over Brain Mapping Female Humans Image Processing, Computer-Assisted Magnetic Resonance Imaging Male Middle Aged Related in: MedlinePlus	© Copyright Policy Related In: Results - Collection License Show All Figures getmorefigures.php?uid=PMC4401774&req=5 pone.0123850.g002: ReHo differences in three different frequency bands (A, typical band: 0.01–0.1 Hz; B, slow-5: 0.01–0.027 Hz; C, slow-4: 0.027–0.73 Hz) between stroke patients and healthy controls.Warm colors indicate regions showing higher ReHo in patients versus controls. Threshold for ReHo: p < 0.05 (corrected). Left in the figure shows the left side of the brain. Mentions: In the full frequency band of 0.01–0.1 Hz, a cluster including the left superior parietal lobule and precuneus was identified that showed significantly increased ReHo in the patients in compared with healthy controls (p < 0.05, corrected, Table 3, Fig 2A). In the slow-5 frequency-band (0.01–0.027 Hz), a larger cluster that exhibited decreased ReHo in the patients that was largely overlapped with the cluster detected in the full frequency-band (p < 0.05, corrected, Table 3, Fig 2B). As for the slow-4 frequency-band (0.027–0.073 Hz), although the same cluster was also detected showing increased ReHo in the patients, the spatial extent was reduced by approximately half relative to the extent in the full-frequency-band (p < 0.05, corrected, Table 3, Fig 2C).

Frequency-dependent changes in the regional amplitude and synchronization of resting-state functional MRI in stroke.

Zhu J, Jin Y, Wang K, Zhou Y, Feng Y, Yu M, Jin X - PLoS ONE (2015)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Department of Acupuncture and Moxibustion, Zhejiang Hospital, Number 12, Lingyin Road, Xihu District, Hangzhou, China.

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.

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Related in: MedlinePlus

ReHo differences in three different frequency bands (A, typical band: 0.01–0.1 Hz; B, slow-5: 0.01–0.027 Hz; C, slow-4: 0.027–0.73 Hz) between stroke patients and healthy controls.Warm colors indicate regions showing higher ReHo in patients versus controls. Threshold for ReHo: p < 0.05 (corrected). Left in the figure shows the left side of the brain.

Related In: Results - Collection

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pone.0123850.g002: ReHo differences in three different frequency bands (A, typical band: 0.01–0.1 Hz; B, slow-5: 0.01–0.027 Hz; C, slow-4: 0.027–0.73 Hz) between stroke patients and healthy controls.Warm colors indicate regions showing higher ReHo in patients versus controls. Threshold for ReHo: p < 0.05 (corrected). Left in the figure shows the left side of the brain.

Mentions: In the full frequency band of 0.01–0.1 Hz, a cluster including the left superior parietal lobule and precuneus was identified that showed significantly increased ReHo in the patients in compared with healthy controls (p < 0.05, corrected, Table 3, Fig 2A). In the slow-5 frequency-band (0.01–0.027 Hz), a larger cluster that exhibited decreased ReHo in the patients that was largely overlapped with the cluster detected in the full frequency-band (p < 0.05, corrected, Table 3, Fig 2B). As for the slow-4 frequency-band (0.027–0.073 Hz), although the same cluster was also detected showing increased ReHo in the patients, the spatial extent was reduced by approximately half relative to the extent in the full-frequency-band (p < 0.05, corrected, Table 3, Fig 2C).