阻塞性睡眠呼吸暂停低通气综合征的^1H—MRS初步研究

目的：探讨阻塞性睡眠呼吸暂停低通气综合征（OSAHS）的质子磁共振波谱（^1H—MRS）改变及其临床应用价值。方法：对26例OSAHS患者和12例健康志愿者（正常对照组）行^1H-MRS检查。根据临床表现和多导睡眠呼吸监测结果将患者分为轻度组10例和中重度组16例。分别测量脑皮质和白质代谢物氮-乙酰天门冬氨酸（NAA）、胆碱复合物（Cho）、肌酸及磷酸肌酸（Cr）波峰下面积，比较各组间NAA／Cho、NAA／Cr、Cho／Cr的差异，并观察有无乳酸（Lac）峰出现。结果：中重度组患者的脑白质NAA／Cho低于轻度组和正常对照组，差异有统计学意义（P〈0．01），NAA／Cr轻度降低，Cho／Cr轻度升高，但差异无统计学意义（P〉0．05）。轻度组与正常对照组的脑白质以及各组间脑皮质NAA／Cho、NAA／Cr、Cho／Cr的比较差异均无统计学意义（P〉0．05）。各组均未发现Lac峰。脑白质的NAA／Cho与睡眠呼吸暂停低通气指数（AHI）呈负相关（r=-0．36，P〈0．01）。结论：^1H-MRS能敏感显示OSAHS患者存在的脑代谢异常，为临床早期诊治提供客观的影像学依据。

Initial study of 1H-MR spectroscopy in obstructive sleep apnea hypopnea syndrome

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. Meth. ods： ^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 signifi- cantly 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： ^H-MRS was sensitive to demonstrate the metabolic impairment in patients with moderate to severe OSAHS, and can provide valuable diagnostic and therapeutic information.