The Investigation Of The Relationships Between Cognitive Impairment And Serum Thyroid Hormones Level After Acute Ischemic Stroke

Background and Objective:The incidence of cognitive impairment after ischemic stroke is high. It is of great significance to explore the pathophysiological mechanism and control the preventable factors of the cognitive impairment for better cognition. Thyroid hormones, performing quiet an important role on the cognition in the adult, change significantly after stroke. And there have been both clinical researches and animal experiments that conformed the obvious correlation between cognitive impairment and thyroid hormones changes after chronic cerebral ischemia. The objective of this research is to identify the relationships between cognitive impairment and serum thyroid hormones after acute ischemic stroke preliminarily, through comparing the thyroid hormones levels in the cognition impaired and normal groups, the incidence of cognitive impairment in low and normal FT3 groups and analysising the factors that could contribute to the cognitive impairment by logistic regression. Then we can provide the basis for further revealing the mechanisms of post ischemic stroke cognitive impairment, regulating thyroid hormones levels and improving cognition.Methods:1.We collected the study objects according to the cases entry criterion.2.We collected the general informations(age,sex,education,smoking nd drinking history) and previous disease history of the cases, recorded the infarction location and size. Then we assayed the fast venous serum concentration of thyroid hormones the next morning in admission. NIHSS and MoCA were used to evaluate the neurological deficits and cognition impairment.3.The objects were divided into 2 groups(cognition impaired and normal groups) on the basis of MoCA scores. And the other 2 groups(low FT3 level and normal FT3 level group) according to the FT3 levels.4.The concentration of thyroid hormones, TSH, general informations, characteristics of the infarction and neurological deficits were compared between the cognition impaired and normal groups. The incidences of cognitive impairment were compared betweenlow and normal FT3 level groups. The risk factors that could contribute to the cognitive impairment were analysed by logistic regressionResults:1.Prevalence of cognitive impairment. There were 81 cases in our study and 49 cases arose cognitive impairment, with a percentage of 60.5%.2.Thyroid hormone levels in different cognition states. Compared with cognition normal group, the cognition impaired group had lower concentrations of TT3, FT3, FT4, TSH and a higher TT4. The divergence of FT3 is significant, P=0.020.3.The incidence of cognition impairment in different FT3 levels. Compared to the normal FT3 group, the low FT3 group had a significant higher incidence of cognitive impairment (78.6% VS 50.9%), P=0.016.4.Cognition and other materials. The cognition impaired group had significant higher ages, lower educations, ischemic stroke histories and higher NIHSS scores. The differences of else information were insignificant.4. Logistic regression.Previous history of cerebral infarction, lower FT3 serum concentration are important risk factors for the incidence of post cerebral infarction cognitive impairment.Conclusions:1.There was a high incidence of cognitive impairment after acute cerebral infarction.2.Cases with cognitive impairment after cerebral infarction often had higher ages and lower education.3.Those who had lower serum FT3 level, histories of ischemic stroke and higher NIHSS scores suffered from cognitive impairment more easily after acute ischemic stroke.4.The concentration of serum FT3 was an important impact factor of post ischemic stroke cognitive impairment, and the lower the FT3 concentration, the more possible the cognitive impairment arise. The case with a history of cerebral infarction had a greater risk of cognitive impairment after acute ischemic stroke.