ABSTRACT
Objective:To explore the characteristics of local brain neural activity in post stroke aphasia (PSA) patients in different frequency bands and the relationship between Western Aphasia Battery (WAB) scores and specific frequency bands. Methods:From March, 2015 to May, 2018, 15 PSA patients, and 15 healthy adults as controls matched for age, gender and education were recruited. They were assessed with WAB and scaned with resting-state functional magnetic resonance imaging. The amplitude of low-frequency fluctuation (ALFF) and fractional amplitude of low-frequency fluctuation (fALFF) on the frequency bands of 0.01-0.08 Hz, 0.027-0.073 Hz, and 0.01-0.027 Hz were calculated. The ALFF and fALFF in different frequency bands were extracted and the correlation with the WAB scores in the patients were analyzed. Results:On 0.01-0.08 Hz, ALFF increased in the right precentral gyrus in the patients. On 0.027-0.073 Hz, ALFF increased values in the right precentral gyrus, and fALFF decreased in the right cerebellar Crus2 region; fALFF in the right cerebellar Crus2 region negatively correlated with the scores of information content (r = -0.576, P = 0.025), auditory comprehension (r = -0.658, P = 0.008), repetition (r = -0.616, P = 0.014) and aphasia quotient (r = -0.611, P = 0.016) of WAB. On 0.01-0.027 Hz, the fALFF decreased in the left inferior parietal limbic gyrus, and positively correlated with the scores of information content (r = 0.538, P = 0.039) and aphasia quotient (r = 0.526, P = 0.044). Conclusion:Resting-state fALFF abnormalities in PSA patients are frequency-dependent, which associate with some frequency-specific neurofunctional alterations.
ABSTRACT
Objective:To study the effect of right brain language network in post-stroke aphasia (PSA) patients with left hemisphere injury. Methods:From December, 2018 to June, 2019, twelve PSA patients with left hemisphere injury, and twelve matched healthy controls were recruited to accept rest-state functional magnetic resonance imaging (f-MRI) scan, and analyzed the characteristics of right brain function network with Dual Stream model. Results:There were two patients lost. Compared with the controls, for dorsolateral lingual pathway, the functional connections increased from superior marginal gyrus to middle frontal gyrus and inferior frontal gyrus of trigone in the patients, while those decreased from posterior central gyrus to inferior frontal gyrus of insula. For ventral lingual pathway, the functional connection increased from angular gyrus to orbital inferior frontal gyrus. For ventral and dorsolateral double-pathway, the functional connections increased from temporal lobe to lenticular pallidum and angular gyrus, from caudate nucleus to inferior frontal gyrus of insula, from lenticular putamen nucleus to middle frontal gyrus and trigonometry, while it decreased from superior marginal gyrus and temporal lobe to inferior frontal gyrus of insula. There was a negative correlation between the functional connection from inferior frontal gyrus to lenticular putamen and repeating (r = -0.720, P < 0.05), between the functional connection from inferior frontal gyrus to the caudate nucleus to speaking and repeating (r < -0.696, P < 0.05). In terms of network index, there were significant differences between the patients and the controls in both local and global indexes for language key brain area in right brain (|t| > 2.143, P < 0.05). Conclusion:The functional network has reorganized in right hemisphere of PSA patients. However, the increase of connection between language critical cortex and subcortical nuclei may play a role in improvement of language function.