Applied Study Of Brainstem Auditory Evoked Potential And Magnetic Resonance Angiography In Patients With Vertebrobasilar Systemic Transient Ischemic Attack

Objective: To explore the early level diagnosis value of brainstem auditory evoked potential(BAEP) and Magnetic Resonance Angiography(MRA) in patients with verte brobasilar systemic transient ischemic attack(TIA). To investigate its contribution in appraisal prognosis and viewing curative effect.TIA is a frequent ischemic cerebrovascular disease. It is considered danger signal of cerebrovascular disease. It is the presymptom of cerebral apoplexy. The Risk factor which can be intervened is already common to recognize. If TIA of vertebral basilar system developed to arteria basilaris thrombus, the death rate will arrive at 20-30%. Studying the early diagnosis of TIA and to evaluate the patient's condition will have considerable instruction significance for clinical preservation and therapy.Methods: Sixty inpatients were selected(patients group), who were diagnosed with vertebrobasilar systemic TIA by clinical standards referred to the fourth national cerebro- vascular diseases meeting in 1995 in our hospital, including male 35 cases, female 25 cases, ages were from 35 to 68 years old, average was 53.75±9.35 years old. Thirty-six healthy people were selected (control group), whose age and gender were similar to the patients group, including male 19 cases, female 17 cases, ages were from 39 to 67 years old, average was 54.89±8.43 years old. BAEP were performed on both groups in quiet statein 25℃room with sound insulation. Subjects sat in soft chair, loosen, closed eyes. A1,A2 was reference point, Cz was record point respectively. Fz was ground electrode. The resistance of electrodes on skin was less than 5 kΩ. Auditory stimulation was alternative click sound. Subjective threshold was examined first. Those went beyond 60Db were excluded from this study. Two ears was given 60dB click over subjective threshold respectively. We overlapped 1000 repeatedly. Two times every side at least. The two better overlapping waves were selected and were filtered, then we marked every wave and measured peak latency(PL) and interpeak latency(IPL) ofⅠⅢⅤwith cursor. The data of two group were compared by t test. MRI,MRA was performed in patients group. The examination used the machine of MAGNETOM AVANTO produced by SIMENS company of germany, make use of head coil and phased-array coil, TOF MRA software and MIP reconstruction technique. Subjects are backlying on the scanner table, vertebral artery examine deploy the TOF-3D-multi-slab-taxy. Imaging parameter of MRA:TR 23ms TE 7ms, matrix 256×256, hadro-coat 0.9-1mm, collection frequency is only once, to add to affluxion anastate and forcezone of saturation, getting a series of original image after scaning, using MIP reconstruction technique to get multi-angular Cerebral vessels image on corona-position, int-position and anteroposterior axes position. Display vertebral artety from the vertebral artety initiation to the Willis circellus. We combined the patient's clinical manifestation and the results of BAEP to analyzed the relationship between the condition and the abnormal degree of MRA and BAEP. MRA and BAEP were performed instantly after hospitalization. The patients with abnormal results were checked again after a week's treatment. We compared the results among control group, pre-treatment and post-treatment patients group. Measurement data were expressed with (X|-)±s and dealt with t test. The size of test took a=0.05.Results: 1 forty-four cases were abnormal in patients group. The abnormal rate of BAEP was 73.3%, including 70.5%(31 cases) brainstem type, 6.8%(3 cases) internal ear type and 22.7%(10 cases) mixed type. The abnormal rate ofⅢ-Ⅴ/Ⅰ-Ⅲ>1 was the highest(53.3%), then was the prolon- gation ofⅢ-ⅤandⅠ-ⅤIPL. The abnormal rate was 31.7%, 23.3% respectively. 2 The abnormal rate of MRA was 58.3% in patients group. MRA showed vertebral arteria basilaris thinninz,straighten,winding crooked,aniso-caliber , and low bloodstream semaphore on the anomal- side. 3 The abnormal rate in both BAEP and MRA was 51.7%(31 cases) in patients group. Only abnormal MRA accounted for 6.7%(4 cases). Only abnormal BAEP accounted for 21.7%(13 cases). Normal BAEP and MRA accounted for 20%(12 cases). 4Ⅰ,ⅤPL ,Ⅲ-ⅤIPL,Ⅰ-ⅤIPL andⅢ-Ⅴ/Ⅰ-Ⅲwere increased very signify- cantly in patients group as compared with control group (P <0.01).ⅢPL were increased significantly(P <0.05).Ⅰ-ⅢIPL was no significance statisticly(P>0.05). 5 The abnormal rate after seven days therapy in patients group was 23.3%. There were improvement in BAEP after treatment than that of before treatment.ⅠⅢⅤPL were dealt with t test(P <0.01). The difference were all very significant. Compared with control group, the difference were no significant statisticly (P >0.05).Conclusions: 1 As functionality examination index,BAEP could provide objective evidence on the aspect of early level diagnosis for vertebral basilar system TIA patients. 2Ⅲ-Ⅴ/Ⅰ-Ⅲ>1 was the sensitive index to reflect brainstem ischemia. The bad form ofⅤmight be an early index of brainstem function damage. 3 MRA have conspicuous tech- nical advantages on vascular lesion diagnosis. The two exami- nations could raise the diagnostic rate siginificantly and help to identify ischemic localization. The abnormal degree of BAEP and MRA was correspondence with the condition of disease.they were of great importance in appraising prognosis. 4 The price of BAEP examination is cheap, so most patients could recheck any time.This can make it easier to observe the transmutation of patient's condition and to generalize this examination.