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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

ALFF 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.Cold colors indicate regions showing lower ALFF in patients versus the controls. Threshold for ALFF: p< 0.05 (corrected). Left in the figure shows the left side of the brain.
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pone.0123850.g001: ALFF 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.Cold colors indicate regions showing lower ALFF in patients versus the controls. Threshold for ALFF: p< 0.05 (corrected). Left in the figure shows the left side of the brain.

Mentions: In the full frequency band (0.01–0.1 Hz), 7 clusters were detected that showed decreased ALFF in the stroke patients compared with healthy controls, including the following: right middle temporal gyrus and middle occipital gyrus; right precuneus and superior parietal lobule; right inferior parietal lobule and angular gurus; left superior parietal lobule and precuneus; left inferior and superior parietal lobule; left middle and superior occipital gyrus; and left middle cingulate gyrus and precuneus (p < 0.05, corrected, Table 2, Fig 1A). The between-group differences in the slow-5 band (0.01–0.027 Hz) highly resembled the differences in the 0.01–0.1 Hz band but the voxels with decreased ALFF were spatially more extensive (p < 0.05, corrected, Table 2, Fig 1B).


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)

ALFF 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.Cold colors indicate regions showing lower ALFF in patients versus the controls. Threshold for ALFF: p< 0.05 (corrected). Left in the figure shows the left side of the brain.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401774&req=5

pone.0123850.g001: ALFF 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.Cold colors indicate regions showing lower ALFF in patients versus the controls. Threshold for ALFF: p< 0.05 (corrected). Left in the figure shows the left side of the brain.
Mentions: In the full frequency band (0.01–0.1 Hz), 7 clusters were detected that showed decreased ALFF in the stroke patients compared with healthy controls, including the following: right middle temporal gyrus and middle occipital gyrus; right precuneus and superior parietal lobule; right inferior parietal lobule and angular gurus; left superior parietal lobule and precuneus; left inferior and superior parietal lobule; left middle and superior occipital gyrus; and left middle cingulate gyrus and precuneus (p < 0.05, corrected, Table 2, Fig 1A). The between-group differences in the slow-5 band (0.01–0.027 Hz) highly resembled the differences in the 0.01–0.1 Hz band but the voxels with decreased ALFF were spatially more extensive (p < 0.05, corrected, Table 2, Fig 1B).

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
Related in: MedlinePlus