[Low-frequency fluctuation amplitude changes in resting-state brain functional magnetic resonance imaging and its correlation with clinical hearing levels in patients with unilateral hearing impairment].

Objective: To investigate low-frequency fluctuation amplitude changes in resting-state brain fMRI and its correlation with clinical hearing levels in patients with clinical hearing level in patients with unilateral hearing impairment. Methods: Forty-five patients with unilateral hearing impairment[12 males and 33 females, aged 36-67 (46.0±9.7) years], and 31 controls with normal hearing[9 males and 22 females, aged 36-67 (46.0±10.1) years], were retrospectively included. All subjects underwent blood oxygen level-dependent (BOLD) resting-state functional magnetic resonance imaging and high-resolution T1-weighted imaging. The patients were divided into the left-sided hearing impaired group(24 cases), and the right-sided hearing impaired group(21 cases). After data being preprocessed, differences in low frequency amplitude (ALFF) metrics between the evaluated patients and controls were calculated and analyzed, and the statistics were corrected for Gaussian random field (GFR). Results: Overall comparative analysis of patients with hearing impairment showed that one-way ANOVA among the three groups showed abnormal ALFF values only in the right anterior cuneiform lobe (GRF adjusted P=0.002). The ALFF value of the hearing impaired group was higher than that of the control group in one cluster (peak coordinates: X=9, Y=-72, Z=48, T=5.82), involving the left occipital gyrus, right anterior cuneiform lobe, left superior cuneiform lobe, left superior parietal gyrus, and left angular gyrus (GRF adjusted P=0.031). The ALFF value of the hearing impaired group was lower than that of the control group in three clusters (peak coordinates: X=57, Y=-48, Z=-24; T=-4.99; X=45, Y=-66, Z=0, T=-4.06; X=42, Y=-12, Z=36, T=-4.03), involving the right inferior temporal gyrus, the right middle temporal gyrus, and the right precentral gyrus (GRF adjusted P=0.009). Compared with the control group, the ALFF value of the left hearing impairment group was significantly higher than that of the control group in one cluster (peak coordinates: X=-12, Y=-75, Z=45, T=5.78), involving the left anterior cuneiform lobe, right anterior cuneiform lobe, left middle occipital gyrus, left superior parietal gyrus, left superior occipital gyrus, left cuneiform lobe, and right cuneiform lobe (P=0.023 after GRF correction). Compared with the control group, the right hearing impairment group had a significantly higher ALFF value in one cluster (peak coordinates: X=9, Y=-46, Z=22, T=6.06), involving the left middle occipital gyrus, right anterior cuneiform lobe, left cuneiform lobe, right cuneiform lobe, left superior occipital gyrus, and right superior occipital gyrus (GRF adjusted P=0.022); The brain area with reduced ALFF values is located in the right inferior temporal gyrus (GRF adjusted P=0.029). Spearman's two-tailed correlation analysis between ALFF values and pure tone average in the abnormal brain regions showed that ALFF values in the abnormal brain regions correlated to some extent with the pure tone average (PTA) only in the left-sided hearing impaired group(PTA=2 000 Hz, r=0.318,P=0.033;PTA=4 000 Hz,r=0.386,P=0.009). Conclusion: The abnormal neural activity within the brain are different in patients with left-sided and right-sided hearing impairment, and the severity of hearing impairment is related to the difference in functional integration of brain regions.

[Analysis of cerebral blood perfusion changes in patients with unilateral sudden sensorineural hearing loss based on three-dimensional pseudo-continuous arterial spin labeling].

Objective: To explore the changes of cerebral blood perfusion in patients with unilateral sudden sensorineural hearing loss (SSNHL) by using the three-dimensional pseudo-continuous arterial spin labeling (3D pCASL) technique. Methods: The clinical characteristics and ASL data of the 32 patients with unilateral SSNHL were retrospectively collected from November 2020 to June 2021 in Beijing Fuxing Hospital of Capital Medical University, among them, there were 7 males and 25 females, aged from 17 to 73 (44.9±14.4) years. According to the location of SSNHL, they were divided into the left SSNHL (L-SSNHL) group (18 cases) and the right SSNHL (R-SSNHL) group (14 cases). A total of 34 healthy volunteers, which including 14 males and 20 females, aged from 24 to 68 (46.2±14.4) years were enrolled from the local community. The parameter of cerebral blood flow (CBF) of each brain area was obtained using the CereFlow software. The Brainnetome Atlas software package based on MATLAB was used for visualization. The independent-samples t test was conducted to compare the difference of cerebral blood perfusion between the unilateral SSNHL group and healthy control (HC) group. Pearson correlation analysis was used to evaluate the correlation between changes in cerebral blood perfusion and clinical scale scores. Results: The CBF of left orbital gyrus part 5, left inferior temporal gyrus part 7, right orbital gyrus part 5, right inferior temporal gyrus part 1, right inferior temporal gyrus part 7, and right parahippocampal gyrus part 3 of the L-SSNHL group were higher than that in the HC group[(49.1±8.8) vs (31.6±10.9)ml·100g-1·min-1;(42.8±14.3) vs (27.1±13.6)ml·100g-1·min-1;(51.8±9.4) vs (27.2±11.2)ml·100g-1·min-1;(38.8±5.7) vs (28.0±9.2)ml·100g-1·min-1;(38.4±13.8) vs (23.6±10.3)ml·100g-1·min-1;(42.4±9.4) vs (30.1±12.6)ml·100g-1·min-1; all P<0.05]. The CBF of left superior frontal gyrus part 7 and left middle frontal gyrus part 3 of the L-SSNHL group were lower than that in the HC group[(48.2±7.9) vs (59.3±13.7)ml·100g-1·min-1;(46.4±10.3) vs (59.3±16.9)ml·100g-1·min-1;all P<0.05]. The CBF of left orbital gyrus part 5, right orbital gyrus part 5, right inferior temporal gyrus part 1, and right inferior temporal gyrus part 7 of the R-SSNHL group were higher than that in the HC group[(50.6±7.0) vs (31.6±10.9)ml·100g-1·min-1;(50.9±8.8) vs (27.2±11.2)ml·100 g-1·min-1;(38.0±7.2) vs (28.0±9.2)ml·100g-1·min-1;(35.7±8.5) vs (23.6±10.3)ml·100g-1·min-1;all P<0.05]; the CBF of right insular part 4 was lower than that in the HC group [(44.2±6.1) vs (54.4±11.3) ml·100 g-1·min-1, P=0.018]. In the L-SSNHL group, the CBF of left superior frontal gyrus part 7 and right orbital gyrus part 5 were negatively correlated with the VAS score(r=-0.83, -0.81, all P<0.05), and the CBF of right orbital gyrus part 5 was negatively correlated with the THI score(r=-0.75, P=0.013). There was no statistically significant correlation between the remaining differences in brain regions and clinical scale scores(all P>0.05). Conclusion: Changes in cerebral blood perfusion in multiple brain regions were found in patients with unilateral SSNHL by using the 3D pCASL technique.