Changes In Structure Of Gray Matter After Ischaemic Subcortical Stroke:A Longitudinal MRI Study

Objective:The changes of gray matter volume in patients with subcortical cerebral infarction have been reported in some studies,but most of them were carried out in patients with chronic cerebral infarction,at which time the patients' condition have been basically stable.At present,there are few studies on the dynamic changes of gray matter volume in patients with subcortical cerebral infarction,and there is no uniformity in lesion site and follow-up time,and there are differences between individuals,leading to inconsistent research results.The purpose of this study was to quantify the dynamic change of gray matter volume in patients with subcortical cerebral infarction and to explore the correlation between this change and functional recovery.Materials and methods:Twenty-two patients with first subcortical cerebral infarction(M:F=17:5,mean age52.9±7.0 years)admitted to the General Hospital of Tianjin Medical University and the First Affiliated Hospital of Zhengzhou University were included.23 age-and sex-matched healthy subjects were recruited as the control group.22 patients with acute subcortical infarction underwent longitudinal imaging examination and clinical assessment 4 times during a 6-month period(within1 week,1 month,3 months and 6months after the onset).The controls underwent the same MRI examination and assessments only one time.Voxel-based morphometry were used to preprocess the high resolution T1 images at 4 time points after the onset.The gray matter images of patients in acute phase(within 7 days of onset)and chronic phase(6 months)were statistically analyzed by the paired sample t test of spm8 to find out the brain regions with significant differences.And then selected the area of interest to extract the volume value of gray matter in this region.The dynamic changes of gray matter volume were evaluated by Repeated Measures Anova and post-hoc test.Partial correlation analysis was used to observe whether the change of gray matter volume in the area of interest was correlated with memory and motor function score.Results:1.Patients with subcortical cerebral infarction,from the acute phase to the chronic phase,except for the lesion area,decreased GMV following stroke was observed in ipsilesional insula,superior temporal gyrus,supramaginal gyrus,middle occipital gyrus,inferior parietal lobe,contralesional paracentral lobule,and the bilateral cerebellum,precuneus,supplementary motor area.2.Significant increases in GMV after stroke were found in ipsilesional hippocampus and middle cingulate gyrus.3.The gray matter volume of the ipsilesional hippocampus was correlated with short-term memory and motor function score,and most importantly,the gray matter volume of the ipsilesional hippocampus in the acute phase(within 7 days of onset)was correlated with short-term memory score in the chronic phase(6 months).Conclusions:Voxel-based morphometry was used to quantify the dynamic changes of gray matter volume in patients with subcortical cerebral infarction.In patients with subcortical cerebral infarction,there were both structural damage and remodeling in the remote area of the lesion,from the acute phase to the chronic phase,the bilateral cerebral hemisphere and cerebellum showed extensive gray matter volume reduction,while the GMV of ipsilesional hippocampus and middle cingulate gyrus gradually increased.The GMV of hippocampus is related to cognitive and motor function,and the hippocampal gray matter volume in acute phase can be used as predictors of cognitive impairment.