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

Abstract

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.