A Resting-State Functional Magnetic Resonance Imaging Study In Patients With Obstructive Sleep Apnea-Hypopnea Syndrome Based On The Data-Driven Methods

Part 1Regional homogeneity changes in patients with obstructive sleep apnea-hypopnea syndrome:resting-state functional MRI studyObjective To investigate the change of regional homogeneity (ReHo) in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) using resting-state functional magnetic resonance imaging(rsfMRI).Methods Resting-state fMRI data were collected from 27 patients with OSAHS and 22 normal controls. Patients were enrolled from the Sleep Laboratory of the Otolaryngology-Head and Neck Surgery Department of Zhongda Hospital, Southeast University, Nanjing from November 2014 to January 2016 The data were analyzed with the ReHo method and compared between OSAHS and controls.Results The ReHo showed a significant increase in the left cerebellum (t=4.8141, P<0.000), bilateral brainstem (t=5.0520, P< 0.000), right parahippocampal gyrus/fusiform gyrus/ temporal lobe (t=6.4241, P<0.000) and left parahippocampal gyrus/fusiform gyrus/temporal lobe (t=6.2399, P<0.000) and a decrease in the right parietal lobe (t=-6.0863, P<0.000) and bilateral precuneus/posterior cingulate cortex (t=-6.6964, P<0.000) in patients with OSAHS. Furthermore, the average ReHo values of right parietal lobe (r=-0.430, P=0.025) was negatively correlated with the apnea-hypopnea index; the average ReHo values of the left cerebellum (r=0.402, P=0.038), left parahippocampal gyrus/fusiform gyrus/temporal lobe (r=0.402, P=0.038) were positively correlated with the LMT scores; the average ReHo values of the left cerebellum (r=0.392, P=0.043), left parahippocampal gyrus/fusiform gyrus/ temporal lobe (r=0.392, P=0.043) were positively correlated with the LMT-delayed recall scores; the average ReHo values of right parietal lobe (r=0.515, P=0.006) was positively correlated with the TMT-A scores; the average ReHo values of bilateral precuneus/posterior cingulate cortex (r=0.405, P=0.036) was positively correlated with the TMT-B scores.Conclusion The current findings indicate that significant changes of ReHo in the global brain regions have been detected in OSAHS patients and the compensatory change of brain function occur. Abnormal ReHo values in the the left cerebellum, left parahippocampal gyrus /fusiform gyrus/temporal lobe, right parietal lobe, bilateral precuneus/posterior cingulate cortex could serve as potential biomarkers for assessment of neuronal damage and further provides insights into the biological mechanism of the disease.Part 2Amplitude of low-frequency fluctuation changes in patients with obstructive sleep apnea-hypopnea syndrome:resting-state functional MRI studyObjective To investigate the change of low-frequency fluctuation (ALFF) in patients with OSAHS using rsfMRI.Methods Resting-state fMRI data were collected from 27 patients with OSAHS and 22 normal controls. Patients were enrolled from the Sleep Laboratory of the Otolaryngology-Head and Neck Surgery Department of Zhongda Hospital, Southeast University, Nanjing from November 2014 to January 2016 The data were analyzed with the ALFF method and compared between OSAHS and controls.Results The ALFF showed a significant increase in the left insular (t=2.3752, P< 0.022), and a decrease in the bilateral posterior cingulate cortex/precuneus (t=-4.4243, P< 0.000), bilateral parietal lobe (t=-3.7281, P<0.001), and left basal ganglia (t=-3.8699, P<0.001) in patients with OSAHS. Furthermore, the average ALFF values of left insular (r=-0.422, P=0.028) and left basal ganglia (r=-0.422, P=0.028) was negatively correlated with the apnea-hypopnea index; Meanwhile, the average ALFF values of left insular (r=-0.422, P=0.028) and left basal gangliar (r=-0.422, P=0.028) was negatively correlated with the ESS score. Finally, the average ReHo values of all the brain regions talked above were uncorrelated with the MMSE, CFT, CFT-delayed recall, LMT, LMT-delayed recall, TMT-A and TMT-B scores.Conclusion The current findings indicate that significant changes of ALFF in the global brain regions have been detected in OSAHS patients and the compensatory change of brain function occur.