Correlational Research On Asymptomatic Middle Cerebral Artery Stenosis With Cerebral Blood Flow Hypoperfusion And Cognitive Disorder

BackgroundAsymptomatic middle cerebral artery（MCA）stenosis often refers to vascular lumen stenosis of the middle cerebral artery which is examined and confirmed by imageological examination,but there are no clinical manifestation including specific symptoms such as dizziness,headache,neck stiffness,anxiety,depression,and insomnia as well as any neurological abnormalities^[1].Many studies have found that patients with asymptomatic carotid artery stenosis（CAS）have cognitive disorder in executive function,psychomotor speed and testing^[2].MCA is not only an important branch of the internal carotid artery in the intracranial artery,but also an important blood vessel for intracranial stenosis that tends to cause cerebral ischemic thrombosis^[3].Different from European and American people,Asian people,especially in Chinese people,have a higher incidence^[4]intracranial artery stenosis,especially middle cerebral artery stenosis.Cognitive dysfunction caused by symptomatic middle cerebral artery stenosis has been studied.With the development of imaging,especially the wide application of TCD、MRA、CTA imaging techniques,the number of patients diagnosed as asymptomatic MCA stenosis is increasing,and whether asymptomatic MCA stenosis causes cognitive impairment is not clear.In this study,the cognitive function of patients with asymptomatic middle cerebral artery was observed and measured by magnetic resonance cerebral blood flow perfusion,local brain structure,and its correlation was explored to find new therapeutic targets and intervention directions for the prevention and treatment of vascular cognitive impairment.PART1 Correlational Observation on Asymptomatic Middle Cerebral Artery Stenosis with Cerebral Blood Flow Hypoperfusion and Cognitive DisorderObjectiveTo compare whether there are changes in cerebral blood flow parameters in patients with asymptomatic MCA moderate to severe stenosis and whether there is cognitive function disorder.And to analyze the relationship between changes in cerebral perfusion and cognitive function.In order to improve clinical treatment effect of patients with early cognitive disorder.MethodsIn accordance with the research of patients who attended the Department of Neurology,Henan Provincial People’s Hospital from September 2017 to September 2019,there were total 121 patients who had unilateral middle cerebral artery through magnetic resonance angiography（MRA）but no previous TIA（Transient ischemic attack）or thrombosis.These patients were divided into 57 cases in perfusion decompensation,44cases in perfusion compensation,and 20 cases in normal perfusion on the basis of the results of magnetic resonance perfusion weighted imaging（PWI）.General information was recorded for all patients.MMSE and Mo CA scales were used to detect cognitive function and magnetic resonance perfusion measurement was performed.Comparing their scores of MMSE and Mo CA and their changes of perfusion parameter r MTT and r CBF,and analyzing their correlation.Results1.The total scores of MMSE and Mo CA in the perfusion decompensation group were25.48±1.01,21.84±1.21 respectively;that in the perfusion compensation group were29.28±0.98,28.96±0.89 respectively;and that in the normal perfusion group were29.36±0.91,29.05±0.87 respectively.This difference had statistical significance.（P<0.05）2.57 patients in the perfusion decompensation group had a prolonged r MTT,r TTP and a decreased r CBF,r CBV;44 patients in the perfusion compensation group had a prolonged r MTT,r TTP and a normal r CBF,r CBV and 20 patients in the normal perfusion group had both normal r MTT,r TTP and r CBF,r CBV.3.The difference of orientation force,immediate memory,computational force and delayed recall between decompensation group and compensatory group and normal group by measuring MMSE scale was statistically significant.（P<0.05）4.The difference of visual space ability,attention,language,abstraction and delayed recall between decompensation group and compensatory group and normal group by measuring Mo CA scale was statistically significant.（P<0.05）ConclusionCerebral blood flow hypoperfusion caused by severe asymptomatic middle cerebral artery moderate to severe stenosis is the trigger for extensive cognitive impairment.PART2 Asymptomatic Middle Cerebral Artery Stenosis with Cerebral Blood Flow Hypoperfusion and Cerebral AtrophyObjectiveTo explore the correlation between symptomatic middle cerebral artery moderate to severe stenosis with cerebral blood flow hypoperfusion and cerebral atrophy.MethodsIn accordance with the research of patients who attended the Department of Neurology,Henan Provincial People’s Hospital from February 2018 to February 2020,There are total 160 patients who had severe unilateral middle cerebral artery through magnetic resonance angiography（MRA）but no previous TIA or thrombosis stenosis.And these patients were divided into 76 cases in perfusion decompensation,58 cases in perfusion compensation,and 26 cases in normal perfusion on the basis of the results of magnetic resonance perfusion weighted imaging（PWI）.MRI、MRA、PWI examination was performed to measure brain atrophy in FLAIR sequence images of cranial MRI,MRA to evaluate intracranial artery stenosis,and to analyze regions of interest based on whole brain perfusion（ROI）.ResultsThe incidence of cerebral atrophy in the perfusion decompensation group was 89.4%（68/76）,that in perfusion compensation was 8.6%（5/58）,and in normal perfusion was7.6%（2/26）.The overall comparative differences between the three groups were statistically significant（?²=4.964,P=0.0023<0.05）.There were significant differences between decompensation group and compensatory group（χ²=86.713,P<0.001）;decompensation group and normal group（χ²=60.179,P<0.001）;compensatory group and normal group（χ²=0.000,P=1.000）.The lateral diameter difference value of the bilateral cerebral hemispheres of patients with cerebral blood loss in the loss compensation group was greater than or equal to 10mm.There were 58 people had a difference value ranging from 10 to 11mm（including 10mm,excluding 11mm）,16 had that ranging from11 to 12mm（including 11mm,excluding 12mm）,and 2 people had a difference value ranging from 12 to 13mm（including 12mm,excluding 13mm）.ConclusionPatients with middle cerebral artery moderate to severe stenosis have a higher incidence of ipsilateral cerebral atrophy,and the degree of cerebral blood flow hypoperfusion may be related to the degree of brain atrophy.