Study On TCM Syndrome Classification And Risk Factors Of Vascular Cognitive Impairment

Background: The global burden of diseases, injuries, and risk factors study 2010(GBD 2010) showed that the incidence rate of stroke was highest in China around the world. And cerebrovascular disease is the second most common cause of acquired cognitive impairment and dementia. One in three individuals will experience a stroke,dementia or both, which is one of the most important causes about burden of illness. So early identification and early intervention is the primary task, which is to delay and prevent the development and progression of dementia. But now, the characteristics of TCM syndromes of vascular cognitive inpairment (VCI) are not clear. And lack of diagnostic method for vascular cognitive impairment-no dementia (VCIND).Objective: To study the traditional medical subtype for vascular cognitive impairment,and evaluate the relationship between pattern element and cognitive function. Investigate pattern element in the role of different course of VCI to provide evidence for TCM treatment.And characterize the executive function and arteriosclerosis for stroke and vascular cognitive impairment no dementia.Methods: The authors examined 359 patients with stroke from Dongzhimen Hospital and communities from Jul 2010 to Jan 2013. The subjects were diagnosed as having vascular dementia (VaD), VCI, or stroke without cognitive impairment by consensus. All subjects accepted neuropsychological tests, brain MRI, biochemical test. And syndrome differentiation was done to analyze the characteristics of pattern element of three groups and their risk factors, and the correlation between the pattern element and cognitive function as well. Then receiver operation characteristic curve (ROC curve) analyses were used to evaluate sensitivity and specificity of executive function. We performed linear regression analyses adjusted for age, level of education, global cognitive function, and executive function. The correlation between demographic, vascular risk factors, cognitive and arteriosclerosis were calculated by linear regression analyses.Results:1. Comparing with stroke group,the occurrence rates of subtype of brain confused by phlegm, and subtype of blood stasis in brain in VCI group was significantly higher(p < 0.05).And the score of subtype of brain confused by phlegm and subtype of blood stasis in brain in stroke group,VCIND group,and VaD group was incremented. In stroke group,it was mainly the single pattern element, while in VCIND group and VaD group, it was mostly multi-subtypes. The Logistic Regression Analysis showed that subtype of brain confused by phlegm and subtype of blood stasis in brain increased the risk of VCIND and VaD. The Odds Ratio (OR) of subtype of brain confused by phlegm was 1.155 (p=0.002, 95%CI: 1.052-1.267)and 1.170 (p=0.000, 95%CI: 1.088-1.259) respectively. While the OR of syndrome of blood stasis in brain was 1.212 (p=0.000, 95%CI: 1.120-1.311) and 0.918 (p=0.011, 95%CI:0.859-0.981).2. In VCIND group, the subtype of deficiency of kidney essence was correlated to ADL(p<0.05), and inversely correlated to MMSE, instant word recall(IWR), and delayed word recall(DWR)(p < 0.05). There were negative correlation between subtype of brain confused by phlegm and MMSE, CDT(p< 0.01), and significantly correlated to ADL(p<0.01). While the score of orientation, attention, calculation, and executive function inpatient,which has the subtype of brain confused by phlegm, was lower than those without this subtype(p < 0.05).3. ROC curve analysis results: the area under curve (AUC) of the ROC curve for discriminating VCIND and stroke was sorted from high to low: TMT-B connection error(0.785), TMT-B time to completion (0.749), TMT-B omission error (0.704), TMT-A time to completion (0.681), TMT-A connection error (0.584), TMT-A omission error (0.561). MMSE and CDT had small AUC. Linear regression analyses showed that, TMT A and B time to completion were correlated to age, and inversely correlated to MMSE (TMT-A: r=-0.384,p, <0.01; TMT-B: r=-0.483,p < 0.01), but no correlated to education. TMT-B connection error had inversely correlation with education (r=-0.296, p=0.019) and MMSE(r=-0.368, p=0.004).While TMT-B omission error had inversely correlation with MMSE(r=-0.268, p=0.038).4. Logistic regression analysis showed that, ABI related to VCI (OR= 0.000, p=0.045,95%CI: 0.000-0.810). And the higher level of low-density lipoprotein cholesterol, the higher risk of VCI (OR=46.933,p=0.033, 95%CI: 1.367-1611.140). ABI was significantly correlated with serum homocysteine level (r=-2.732,p=0.010).Conclusion:1. The primary traditional medical subtypes of VCI are brain confused by phlegm, and blood stasis in brain. And brain confused by phlegm and blood stasis in brain serves as an independent risk factor for VCIND and VaD. The more complicated pattern element is, the worse the cognitive impairment becomes.2. The subtype of brain confused by phlegm is closely related with executive function,orientation, attention, and calculation. It's the risk factor for VCI and the main cause of the disease fluctuations. The subtype of deficiency of kidney essence is related with ADL, IWR,and DWR3. Comparing with stroke, the score of MMSE, CDT, TMT-A time to completion,TMT-B time to completion, TMT-B omission error and TMT-B connection error is lower in VCIND group. TMT-B is more sensitive for identifying stroke and VCIND. And TMT is significantly correlated with global cognitive function.4. Arteriosclerosis plays roles in vascular cognitive impairment. The lower ABI level is risk factor for VCI. And the higher low-density lipoprotein cholesterol level is also related to VCI.