The Appilication Of CT Perfusion Imaging And Nerve Electrophysiological Examination Inposterior Circulation TIA

ObjectiveTo explore the value of CT perfusion imaging(CTPI)combined with brainstem auditory evoked potential(BAEP)and blink reflex(BR)in the etiological diagnoise,observation of curative effect and prognosis of patients with posterior circulation transient ischemic attack.MethodsCTPI-CTA and BAEP,BR examinations were performed in 40 patients with posterior circulation TIA(the experimental group)within 24 hours of onset.We obtained the TTP,MTT,rCBF and rCBV of the ROI and corresponding areas of the opposite side,got the average value with repeated measurement and made a perfusion stage.The maximum intensity projection,thin slice MIP and volume rendering image of the original image of the CTA were processed by the post-processing software,then determined the degree of vascular stenosis and made a classification.Record the waveform,amplitude and potential latency of BAEP I,III,V wave;the inter-potential latency of BAEP I-III,III-V,I-V wave;the potential latency and amplitude of BR R1,R2,R2’ wave.After two weeks’ treatment,the patients with abnormal CTPI,BAEP or BR would accept a review and make a comparion with previous results.Made the same examinations for 27 healthy persons as control group during the same period,record each index and got the reference value of BAEP and BR.There was no significant difference in the general information including gender,age and so on between the two groups.All subjects underwent brain MRI and DWI examinations to exclude hemorrhage,infarction or lesions.The statistics were made by SPSS17.0.The difference was statistically significant with P<0.05.Results⑴ In the experimental group,all subjects received brain MRI and DWI examinations,and no hemorrhage,ischemic lesions associated with clinical symptoms or space occupying were found.Abnormal perfusion areas were found in 23 cases corresponding to clinical symptoms,27 cases had posterior circulation responsibility vascular abnormalities.A total of 25 abnormal perfusion areas were found,1 case of stage I1,10 patients of stage I2,11 patients of stage II1,3 patients of stage II2.The differences of TTP and MTT of affected side compared with that of the contralateral side were significant(P<0.05),The differences of rCBF and rCBV(P>0.05)were not statistically significant between both sides.In the control group,abnormal perfusion areas were found in 2 cases,CTA showed that 9 patients with posterior circulation vascular stenosis.The abnormal rates of CTPI and CTA were statistically significant between the two groups(P<0.05).⑵ No abnormity of brain MRI and DWI was found in the 27 cases.There was no significant difference between the left and right side of BAEP and BR in the control group.Of the 40 patients with posterior circulation TIA,27 patients had abnomal BAEP,mainly with I-III,III-Vwave IPL extension.The III,V wave PL;I-III,III-V,I-V wave IPL in the experimental group were significantly different from those in the control group(P<0.05),the difference of I wave PL was not statistically significant between the two groups(P> 0.05).Of the 40 patients with posterior circulation TIA,30 patients had abnormal BR,mainly with R1,R2,R2’ wave PL extension.The R1,R2,R2’ wave PL in the experimental group were significantly different from those in the control group(P<0.05).⑶ Of the 23 patients with abnormal CTPI,the abnormal rate was 34.8% after treatment for two weeks.The differences of TTP,MTT and rCBF before and after treatment were significant(P<0.05).Of the 27 patients with abnormal BAEP,the abnormal rate was33.3% after treatment for two weeks.I,III,V wave PL;I-III,III-V,I-V wave IPL were significantly different before and after treatment(P<0.05).Of the 30 patients with abnormal BR,the abnormal rate was 36.7% after treatment for two weeks.R1,R2,R2’ wave PL were significantly different before and after treatment(P < 0.05).⑷ Before treatment in the experimental group,the abnormal rate of CTPI、BAEP and BR was 57.5%,67.5% and 75% separately,and the positve rate of the combination was 97.5%.The differences of abnomal rate of CTPI,BAEP or BR were not significant(P> 0.05).When it comes to the positve rate of the combination,the difference was significant(P <0.05).4 patients progressed cerebral infarction during the follow-up period of 6-months.The BAEP,BR and CTPI of the 4 patients before and after treatment were abnormal.Conclusion1.CTPI can be used to qualitatively and quantitatively evaluate cerebral blood flow perfusion of patients with posterior circulation TIA,and is helpful for early diagnosis and evaluation of therapeutic effect.The extension of TTP and/or MTT is the most sensitive among the parameters.2.BAEP reflects the abnormality of inner ear labyrinth and brainstem auditory pathway,that is of great value in the early diagnosis of posterior circulation TIA,and it’s helpful to locate ischemic region and observe the therapeutic effect.This study finds that of all kinds of abnormal index,I-III and/or III-V wave IPL extension were the most sensitive.3.BR can reflect the damage of brainstem in patients with posterior circulation TIA,and observe the improvement of brainstem hypoperfusion after treatment.The abnormalBR was mainly with the extension of wave PL.4.CTPI and BAEP,BR can reflect the state of perfusion and pathological physiological in patients with posterior circulation TIA during the intermittent period from different angles.The combination of the three methods can improve the evaluation of the patient’s condition and assist the choice of therapy.