轻度认知功能损害及阿尔茨海默病氢质子磁共振波谱研究

摘要

目的 探讨前额叶、海马和扣带回后部氢质子磁共振波谱(1H-MRS)在轻度认知功能损害(MCI)和阿尔茨海默病(AD)早期诊断中的作用. 方法 运用氢质子磁共振波谱(1H-MRS)技术检测30例AD患者(AD组),30例MCI患者(MCI组)及30名健康老年人(正常对照组)大脑前额叶、海马和扣带回后部的各种代谢物水平.对N-乙酰天门冬氨酸(NAA)、胆碱复合物(Cho)、肌酸复合物(Cr)和肌醇(mI)波谱数据进行分析统计. 结果 在海马区和扣带回后部AD组和MCI组与正常对照组相比,NAA/mI降低,mI/Cr升高(均P＜0.05)；在前额叶AD组和MCI组与正常对照组相比NAA/mI降低(均P＜0.05).在这三个脑区,AD组的NAA/mI均显著低于MCI组(P＜0.05).在正常、MCI和AD三组中随病情进展,海马和扣带回后部NAA/mI呈递减趋势,mI/Cr呈递增趋势(均P＜0.05).AD组与正常对照组的NAA/mI差值海马部显著大于扣带回后部和前额叶；MCI组与正常对照组的NAA/mI差值海马部显著小于扣带回后部和前额叶. 结论 MRS对于诊断MCI和AD有重要的意义,不同脑区NAA/mI比值是关键的诊断指标.%Objective To evaluate the role of ' H-MRS changes in the hippocampus and the posterior cingulated gyms in the diagnosis of mild cognitive impairment( MCI) and early Alzheimer' s disease( AD) . Methods H-MRS was performed to examine the levels of N-acetyl aspartic acid(NAA) ,choline(Cho) ,creatine( Cr) ,myoinositol( ml) in the frontal lobe,the posterior cingulated gyrus and the hippocampus in 30 cases of AD, 30 cases of MCI, and 30 cases of age-matched healthy controls. Results Compared with normal group, NAA/ml was significantly decreased and ml/Cr was significantly enhanced in hippocampus and posterior cingulated gyrus in AD and MCI groups( P < 0.05). In frontal lobe,NAA/ml was significantly decreased compared with normal group. In these three brain areas, NAA/ml in AD group was significantly lower than in MCI group(P <0.05). With the disease developing from the normal,MCI to AD,mI/Cr gradually increased and NAA/ml gradually decreased(P <0.05). The difference of NAA/ml between AD patients and controls was significantly larger in the hippocampus than those in the posterior cingulated gyrus and the frontal lobe,while the difference of NAA/ml between MCI patients and controls was significantly smaller in the hippocampus than those in the posterior cingulated gyrus and the frontal lobe. Conclusion MRS is a very good method in the diagnosis of MCI and AD. NAA/ml ratio in different brain regions is an important index for detecting AD and MCI.