Abstract：Objective: To investigate the cerebral metabolic changes in patients with obstructive sleep apnea hypopnea syndrome(OSAHS) by 1H magnetic resonance spectroscopy(1H-MRS), and to explore the value of 1H-MRS on OSAHS. Methods: 1H-MRS was performed in 26 patients with OSAHS and 12 control subjects. The patients were classified into two groups based on clinical manifestations and the results of polysomnography(PSG): mild OSAHS(10 patients) or moderate to severe OSAHS(16 patients). Cerebral metabolism was studied by assessing ratios of N-acetylaspartate(NAA) to choline(Cho) and to creatine(Cr) as well as Cho to Cr was calculated from the peak areas in normal-appearing regions of cerebral white matter or cortex selected. Results: In the patients with moderate to severe OSAHS, the NAA/Cho ratios for the white matter were significantly decreased and lower than that of the control subjects as well as mild OSAHS(P＜0.01). The ratios of NAA/Cr and Cho/Cr had no obvious changes(P＞0.05). However, no significant difference in the three metabolite ratios was found between patients with mild OSAHS and control subjects for cerebral white matter, as well as among three groups for cerebral cortex(P＞0.05). None of the subjects exhibited an obvious lactate signal in brain tissue. There was a negative correlation between the NAA/Cho ratios for the white matter and apnea hypopnea index(AHI)(r=-0.36, P＜0.01). Conclusion: 1H-MRS was sensitive to demonstrate the metabolic impairment in patients with moderate to severe OSAHS, and can provide valuable diagnostic and therapeutic information.
2008, Vol. 19 
