2型糖尿病患者局部脑血流灌注与认知功能障碍的关系

目的：探讨无低血糖发作的2型糖尿病（DM）患者的局部脑血流灌注特性及其与认知功能障碍的关系。方法 符合WHO糖尿病诊断标准的中年2型DM患者11例，年龄46－59岁，对照组为11例无神经精神疾病史的健康人，年龄41－58岁，认知功能测定选用韦氏成人记忆量表（WMS），连线测验A，威期康星卡片分类试验（WCST），常规99Tc^m-双半胱乙酯（ECD）SPECT脑血流灌注显像，半定量分析在横断面图像7－11帧进行，结果（1）2DM组各项认知测验成绩普遍低于对照组，差异有显著性，表现在记忆量表中反映长时记忆的累加项，反映短时记忆的视觉再认项，联想学习项和总记忆商均显著低于对照组，连线测验完成时间较对照组慢；WCST成绩明显低于对照组，（2）2型DM患者存在局部脑血流灌注的减低，尤其是额叶，颞叶和顶叶。（3）2型DM患者的脑血流灌注显像右额叶局部脑血流（rCBF)值分别与WMS中的累加项，理解项呈正比相关，与WCST中的坚持性错误（％）成负相关；右颞叶rCBF值与韦氏记忆量表中的背数项呈正相关，结论 （1）血糖控制较好，无反复低血糖发作的2型DM患者仍然存在中枢神经系统损害，临床表现为记忆力，注意力减退，推断判断及概括能力下降等认训技能损害，（2）2型DM患者存在不同程度的额，颞，顶叶血流灌注减低，并且额颞叶的血流灌注与记忆力，判断力，概括力，思维的灵活性有相关关系。

Relationship between regional cerebral perfusion and cognitive disorders in type 2 diabetes mellitus

Objective　To investigate the characteristic rCBF abnormalities and the relationship between rCBF and cognitive disorders in type 2 diabetes mellitus patients. Methods　The study subjects were 11 middle aged, glycemic controlled type 2 diabetes mellitus patients. Age range of type 2 diabetes mellitus patients was 46～59 years.Eleven age-, sex-, education- and occupation- matched normal controls (age range 41～58 years) were studied under identical conditions. Cognitive functions were evaluated by Wechsler Memory Scale (WMS), Trail Marking Test A and Wisconsin Card Sorting Test (WCST),respectively.99Tcm-ECD (ethylcysteinate dimer) SPECT imaging was performed on all patients and normal controls. Results　①Cognitive test scores of type 2 diabetes mellitus patients were lower than that of normal controls. Diabetic patients were scored lower in memory test than controls (accumulation adding, visual recognition, learning and total memory quotient of WMS, P<0.05). Type 2 diabetes mellitus patients needed much more time to complete the trail marking test (74.2 s vs. 48.7 s). WCST scores were significantly different between two groups. ②The rCBF values of frontal, temporal and parietal lobe were decreased significantly in type 2 diabetes mellitus patients. ③For type 2 diabetes mellitus patients, there was a correlation between rCBF values of right frontal lobe and adding, understanding scores of WMS (positively correlated), persevarative errors(%) of WCST (negatively correlated). The rCBF values of right temporal lobe were positively correlated with inverted counting. Conclusions　①Impairments of central nervous system are existed in glycemic controlled (lack of repeated hypoglycemia) type 2 diabetes mellitus patients. Abnormalities in CNS can express as cognitive dysfunction,such as decrement of memory, attention, thinking and conceptual reasoning abilities. ②Hypoperfusions of frontal, temporal and parietal cortex can be identified in patients of middle aged type 2 diabetes mellitus patients. Decreased perfusion of right frontal and temporal cortex may associate with memory, thinking flexibility impairment.