The Factors Relevant To The Progression Of Isolated Pontine Infarction:A Retrospective Clinical Study

Objective Through the study of the clinical and imaging data of patients with isolated pontine infarction(IPI)to investigate the correlation between multiple factors,especially the atherosclerosis of the intracranial macrovascular and the imaging characteristics of the lesions,and the progression of IPI,in order to explore convenient and accurate predictors for progressive IPI.Methods Patients with acute ischemic stroke admitted to Dalian Central Hospital from January 1,2015 to June 30,2017 were screened out through clinical manifestations,diffusion weighted imaging(DWI)and apparent diffusion coefficient(ADC).IPI cases were identified according to the isolated hyperintensity lesions of pons in DWI and their clinical and imaging data were analyzed retrospectively.The severity of neurological deficits was evaluated by the National Institutes of Health Stroke Scale(NIHSS)scores,and the patients were divided into two groups according to their changes of the NIHSS scores.Patients in the progression group had NIHSS scores increased by 2 points or more than the initial values,and patients in the non-progression group had NIHSS scores increased by less than 2 points,unchanged or lower than the initial values.The following parameters were compared between the two groups: the severity of the initial neurological deficits,the duration of hospitalization,the short-term prognosis,the risk factors(especially the intracranial macrovascular atherosclerosis),laboratory results(such as: low density lipoprotein cholesterol(LDL-C),homocysteine(HCY),fibrinogen(FIB))and imaging features of the lesions(whether the maximum diameter of the lesions ?15 mm,whether the ventral surface of the pons was affected and the left or right distribution).The suspicious related factors were screened out through statistical analysis,and their correlation with the neurological deterioration of IPI was analyzed.Results Among 2180 acute ischemic cerebral stroke patients,313(14.4%)cases were diagnosed as acute IPI.Patients who had new infarction in other sites,bilateral pontine infarction,no intracranial vascular examination during the hospitalization and who did not meet the other research criteria were excluded,and 249 patients were finally enrolled.There were 149 patients(59.8%)in the non-progression group and 100 cases(40.2%)in the progression group.Univariate analysis showed that patients in the progression group had higher NIHSS scores at admission(4.5±3.1 vs 5.8±3.4,P=0.004),longer hospitalization((9.9±2.3)d vs(11.2±3.8)d,P=0.001),and more cases with the Modified Rankin Scale(mRS)scores ?2 at discharge(20(13.4%)vs 36(36.0%),P<0.001)than those in the non-progression group.In the analysis of risk factors,the proportion of females in the progression group was significantly higher than that in the non-progression group(41(41.0%)vs 42(28.2%),P=0.036),while drinkers were less in non-progression group(16(16.0%)vs 43(28.9%),P=0.019),and there was no significant difference between the two groups in terms of other risk factors.The comparison of the intracranial macrovascular atherosclerosis between the two groups revealed that the percentage of patients with MCA atherosclerosis in the progression group was significantly higher than the non-progression group(52(52.0%)vs 43(28.9%),P<0.001),and other intracranial macrovascular atherosclerosis between the two groups had no significant difference.The laboratory results(LDL-C,HCY,FIB,etc.)of the progression group and the non-progression group had no significant difference(P>0.05).By comparing the imaging features of the two groups,the proportion of patients in the progression group with the maximum diameter ?15 mm and the lesion involving the pontine ventral surface were significantly higher than those in the non-progression group(36(36.0%)vs 35(23.5%),P = 0.032;71(71.0%)vs 72(48.3%),P<0.001).The binary Logistic regression analysis showed that the MCA atherosclerosis(OR=2.136,95%CI=1.234~3.697,P=0.007)and lesions involving the ventral surface of the pons(OR=2.198,95%CI=1.257~3.843,P=0.006)were independently correlated with the progression of IPI.Conclusion Patients with acute IPI had a higher rate of progression.Progreeive IPI patients had not only more severe initial neurological deficits,but also longer hospitalization and worse short-term prognosis.The atherosclerosis of MCA and lesions involving the pontine ventral surface may be the relevant factors of progressive IPI.