Abstract:

Objective To retrospectively analyze and investigate the conversion of cognitive function and characteristics of hydrogen proton magnetic resonance spectroscopy (¹H-MRS) in patients with mild cognitive impairment (MCI).  Methods  Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were used to assess the cognitive function of 75 MCI patients and 17 normal controls who were matched in sex, age and education with MCI patients. ¹H-MRS was performed in the left hippocampus and left frontal lobe with 3.0T MRI respectively to evaluate related metabolites in the brain, including N-acetyl-aspartate (NAA), choline (Cho), creatine (Cr), myo-inositol (mI) and glutamate complex (Glx).  Results  Compared with normal control group, the Glx/Cr ratio of left hippocampus and left frontal lobe in MCI group were significantly lower (P = 0.030, 0.030). By the end of follow-up, 7 of 75 subjects (9.33%) in MCI group had converted to Alzheimer's disease (MCI-AD subgroup), 55 cases (73.33%) had no change on their cognitive function (MCI-MCI subgroup), and 13 cases (17.33%) were considered returning to normal (MCI-normal subgroup). The Glx/Cr ratio of MCI-MCI subgroup was significantly higher than that of MCI-AD subgroup (P = 0.040). In normal control group, 13 cases (13/17) had no change on their cognitive function, and 2 cases (2/17) progressed into MCI. However, none of them converted to AD.  Conclusions  The decline of Glx/Cr ratio in left hippocampus and left frontal lobe could possibly be the sensitive biological indicator of worsened cognitive function in MCI patients. Further study with enlarged samples and prolonged follow-up is still needed.

Key words: Cognition disorders, Magnetic resonance spectroscopy

摘要：

目的 回顾分析并总结轻度认知损害（MCI）患者认知功能转归及脑组织代谢物氢质子磁共振波谱（¹H-MRS）特点。方法 采用简易智能状态检查量表（MMSE）和蒙特利尔认知评价量表（MoCA）评价75 例轻度认知损害患者和17 例性别、年龄、受教育程度相匹配的正常对照者的认知功能，¹H-MRS 检测左侧海马和左侧额叶代谢物［包括N-乙酰天冬氨酸（NAA）、胆碱（Cho）、肌酸（Cr）、肌醇（mI）、谷氨酸复合物（Glx）］表达变化。结果 与正常对照者相比，轻度认知损害患者左侧海马和左侧额叶Glx/Cr 比值均降低（P = 0.030，0.030）。至随访结束时，MCI 组7 例（9.33%）进展为阿尔茨海默病、55 例（73.33%）认知功能无变化、13 例（17.33%）逆转为认知功能正常；正常对照组13 例（13/17）认知功能功能无变化，2 例（2/17）进展为轻度认知损害，无一例进展为阿尔茨海默病。不同认知功能转化亚组中仅MCI?MCI组患者Glx/Cr比值高于MCI-AD 组（P = 0.040）。结论 左侧海马和左侧额叶Glx/Cr比值降低可能是轻度认知损害患者认知功能恶化较敏感的生物学指标，尚待扩大样本量、延长随访时间深入研究。

关键词: 认知障碍, 磁共振波谱学