Effect of -deficiency constitution on cognitive impairment in cerebral small vessel disease and its neuroimaging mechanism.

Objective: To explore the effect of Traditional Chinese Medicine (TCM) constitution on cognitive impairment (CI) in patients with cerebral small vessel disease (CSVD) and its underlying neuroimaging mechanism and to provide countermeasures for health management of CSVD patients.

Methods: A total of 241 CSVD patients were recruited from the Department of Neurology. All subjects underwent head magnetic resonance imaging (MRI), Chinese Medicine Questionnaire (CCMQ) and cognitive function examination. The CSVD patients were divided according to the Montreal Cognitive Assessment (MoCA) score into a normal cognitive group (73 cases) and a CI group (168 cases). Logistic regression was used to analyse the risk constitution of CSVD-CI and to construct a risk prediction model. 3DT1 MRI images and FreeSurfer 6.0 software (Athinoula A. Martinos, Boston, MA, USA) were used to further explore the involvement of hippocampal subregion volume in patients with at-risk constitution and its correlation with cognitive function.

Results: Logistic regression analysis showed that Yang-deficiency constitution (YADC) (P = 0.020), older age (P = 0.008) and hypertension (P = 0.011) were risk factors for CSVD-CI but that balanced constitution (P = 0.003) and education (P < 0.001) were protective factors. A receiver operating characteristic curve (ROC) was drawn, and the area under the curve was 0.820. Further comparison of overall hippocampal and 12 hippocampal subregion volumes between YADC and non-YADC patients revealed decreased total volume of the left and right hippocampus, bilateral subiculum, presubiculum, molecular layer and right fimbria in the YADC group (P < 0.05/13, 13 is the number of hypothesis tests). Moreover, in the YADC group, the cognitive function of CSVD patients correlated positively with the overall volume of the left hippocampus (r = 0.304, P < 0.05) and the molecular layer volume of the left hippocampus (r = 0.288, P < 0.05).

Conclusion: CSVD patients with YADC are more prone towards developing CI, and asymmetric atrophy of the hippocampus might be the underlying neuroimaging mechanism. In particular, the volume of the left whole hippocampus and the left hippocampal molecular layer correlated significantly with general cognitive function.