Cognitive Impairment After Cerebral Infarction And Its Effect On Recurrence Of Cerebral Infarction

BackgroundCognitive impairment after stroke has become one of the complications that seriously affects the prognosis and quality of daily life of stroke patients.The results of the study show that the proportion of cognitive dysfunction in stroke patients can reach 64%,and the number of patients suffering from dementia within 1 year of onset accounts for at least 25%^[1].According to the latest research^[2],stroke deaths account for 22.45%of all deaths in my country every year.In recent years,China has become one of the countries with the highest incidence of stroke.Up to 75%of stroke patients in my country are accompanied by physical defects,and the incidence of stroke in my country has increased by 8.7%per year^[3].With the increase in the median age of onset of stroke and the decrease in stroke mortality,the number of patients with cognitive impairment after stroke has also increased^[4],which also increases the economic burden of patients’families and the society.Therefore,it is very important to understand the influencing factors of cognitive decline after stroke and the relationship between cognitive impairment after stroke and the prognosis of stroke.The latest study found that among high-risk groups of stroke,cognitive impairment after cerebral infarction is related to the recurrence of ischemic stroke^[5].Stroke and recurrence are the main causes of disability^[6].But previous studies have focused on the recovery of neurological function after cerebral infarction,and there have been few studies on cognitive impairment after cerebral infarction and its effect on cerebral infarction recurrence.This study collected the clinical data of patients with cognitive impairment caused by cerebral infarction in our hospital and was followed up for a period of 12 months to explore the occurrence,development and influencing factors of cognitive impairment after cerebral infarction and its predictive role in the recurrence of cerebral infarction.Part 1 Characteristics and changes of cognitive impairment aftercerebral infarctionObjectiveTo observe the characteristics and changes of cognitive dysfunction after anterior circulation cerebral infarction,which expected to provide theoretical support for patients to formulate more accurate cognitive rehabilitation programs in the early stage of cerebral infarction.MethodsA total of 270 patients who were diagnosed as anterior circulation cerebral infarction were collected in the Department of Neurology of Zhengzhou University people’s Hospital from January 2018 to January 2019.All the patients underwent 3.0T magnetic resonance imaging（MRI,MRA,DWI）perfusion weighted imaging（PWI）examination and new lesions confirmed on magnetic resonance diffusion-weighted imaging（DWI）,and National Institute of Health stroke scale（NIHSS）score<16.Ninety patients（normal control group）who matched the age,gender,education level and risk factors of stroke during the same period were selected for physical examination,and none of them had brain disease,serious physical disease,anxiety,depression,hearing,and vision impairment.Patients with cerebral infarction were treated with NIHSS,MMSE and MoCA（Beijing version）on the 7th day,1st month±3 days,3rd month±5 days,6th month±7 days,and 12th month±10 days to assess the neuromotor function and cognitive status of the patients.The normal control group was evaluated with the same scale at the simultaneous period.And we compared and analyzed the scoring results at each time point.Results1.According to the MMSE scoring standard,there were 134 cases（57.8%）,126cases（54.3%）,115 Patients（49.6%）,93（40.1%）and 85（36.6%）patients with anterior circulation cerebral infarction had cognitive impairment on the 7th day,1st month±3 days,3rd month±5 days,6th month±7 days,and 12th month±10 days.According to the MoCA scoring standard,there were 170 cases（73.3%）and153 cases（65.9%）139 patients（59.9%）,110 patients（47.4%）and 98 patients（42.2%）had an impairment of cognitive function at each time point.2.At 12 months follow-up,among the factors of MoCA,the visual space and execution ability,delayed recall,language repetition,and language fluency were significantly lower than those of the normal control group,and the difference was statistically significant（P<0.05）.ConclusionAfter anterior circulation cerebral infarction,more than 50%of patients have cognitive decline,and the incidence of cognitive impairment at 6 months has dropped significantly.At 1 year,more than 1/3 of above patients still have cognitive impairment,which are mainly manifested in visual space Cognitive domains related to executive ability,delayed recall,language repetition,and language fluency.Part Two Cognitive impairment and low blood flow perfusionafter cerebral infarctionObjectiveTo explore the correlation between cerebral blood flow hypoperfusion and cognitive impairment after anterior circulation cerebral infarction and to study the possible mechanism of chronic cerebral hypoperfusion on cognitive function,which to provide a biological basis for early intervention in cognitive impairment after cerebral infarction.MethodsFrom January 2018 to January 2019,91 patients who were admitted to the Department of Neurology,Zhengzhou University People’s Hospital were diagnosed with cognitive impairment after cerebral infarction and completed a 12-month follow-up,and the patients had no abnormality of posterior circulation perfusion during follow-up.The inclusion criteria and exclusion criteria are shown in the first part.They were divided into two groups.Compared with the 6th month of the disease course,39 patients with significant cognitive decline at the 12th month belonged to the cognitive decline group,and 52 patients without cognitive decline belonged to the non-decreased cognitive function group.The first part of the healthy subjects（90cases）served as a normal control group.All patients underwent magnetic resonance perfusion weighted imaging（PWI）at 72 hours of onset and the 12th month of onset,and 4ml of peripheral blood was drawn on an empty stomach at 72 hours,7th day,14th day,and 1st month of onset.The normal control group was also given 4ml of peripheral blood on an empty stomach.The serum IGF-1 and S100B levels were determined by ELISA.Results1.MTT and TTP were prolonged,and CBV and CBF decreased in the cognitive decline group and the non-decreased cognitive function group on admission.The average values of r MTT are 1.49±0.31,1.50±0.32,the average values of r TTP are1.15±0.03,1.16±0.03,and the average values of r CBV are 0.87±0.02,0.87±0.02,the average values of r CBF are 0.86±0.05,0.86±0.05 respectively.The difference of relative perfusion value between the two groups at admission was not statistically significant and comparable.2.At the 12-month follow-up,the values of r MTT and r TTP decreased in the cognitive decline group and the non-decreased cognitive function group,and the r CBV and r CBF values increased.But the degree of decrease in the r MTT and r TTP values and increase in the r CBV and r CBF values in the non-decreased cognitive function group were significantly higher than those in the cognitive function decreased group.The difference was statistically significant（P<0.05）.3.At the time of admission（72 hours after onset）,there was no statistically significant difference in serum IGF-1 and S100B concentrations between the cognitive decline group and the non-cognitive decline group,and the IGF-1 levels of the two groups were lower than In the normal control group,the S100B level was higher than that in the normal control group.At 7th day,14th day,and 1 month,the serum IGF-1 and S100B concentrations of the cognitive function non-decreased group basically returned to normal.At 7th day,14th day,the concentration of serum IGF-1 in the cognitive decline group increased,but it was still lower than that of the non-decreased cognitive function group,and the S100B concentration decreased,but it still higher than that of the non-decreased cognitive function group.The difference are statistically significant（P<0.05）.At 1st month,serum IGF-1 and S100B concentrations in the cognitive decline group basically returned to normal.ConclusionThe continuous aggravation of cognitive impairment after anterior circulation cerebral infarction may be related to chronic cerebral hypoperfusion after infarction,and the effect of chronic cerebral hypoperfusion on cognitive function may be achieved through the low expression of serum IGF-1 and the high expression of S100B.Part Ⅲ Cognitive impairment after cerebral infarction increasesthe recurrence of cerebral infarctionObjectiveTo explore the relationship between cognitive impairment after anterior circulation cerebral infarction and recurrence of cerebral infarction,and to observe the role of cognitive impairment after cerebral infarction in the recurrence of cerebral infarction.MethodsA total of 270 patients who were diagnosed with cerebral infarction in the Department of Neurology of Zhengzhou University people’s Hospital from January2018 to January 2019 were collected.The inclusion criteria and exclusion criteria are shown in the first part.170 patients with MoCA<26 points on the 7th day of onset were in the low MoCA score group,and 100 patients with MoCA≥26 points were in the normal MoCA score group.Results1.Kaplan–Meier analysis showed that the low MoCA score of the experimental group was associated with the occurrence of ischemic stroke events;2.Through trend analysis,low MoCA score was associated with recurrent ischemic stroke（P<0.05）,after adjusting for covariates（age,gender,initial NIHSS score,education level,hypertension,diabetes,smoking history,drinking history）The low MoCA score after the first cerebral infarction is an independent risk factor for ischemic stroke recurrence（P<0.05）.ConclusionCognitive impairment after anterior circulation cerebral infarction may be an independent risk factor for recurrence of ischemic stroke.