The Study Of The Increasing Stimulus Rate Brainstem Auditory Evoked Potential On The Diagnosis Of Vertebrobasilar Transient Ischemic Vertigo

[Objective] Vertebrobasilar transient ischemic attack (VBTIA) is thefamiliar cerebrovascular insufficient disease. With vertigo of VBTIA is called vertebrobasilar transient ischemic vertigo (VBTIV). Isolated vertigo in vertebrobasilar ischemia is diagnosed difficultly. There is of little diagnostic value of VBTIV when we make common auditory brainstem response (ABR) is very low. To increase the diagnostic value and monitor the process of VBTIV, this experiment makes use of the increasing stimulus rate ABR (ISRABR) diagnostic method for VBTIV. It studies the diagnostic clinical significant of VBTIV.[Methods] Healthy adults group is composed of 50 healthy adults.VBTIV group is composed of 50 VBTIV patients. We apply 2260 ABR system which is made by Madsen Company in Denmark. The record pole is placed on the mastoid region of the stimulus ear. The reference pole is placed on the headache. The opposite mastoid region is connected with ground pole. Alternative click with frequency 21/sec is given to the stimulus ear. Record the thresholds of two ears. Then we apply the same click. Parameter: paint time: 10 ms; pulse: 0.1 ms; hearing level: 75 dBSL; the largest output: 130 dBpeSPL; repeat:1000~3000; filter: 100— 2500Hz; The stimulus frequency: 11 / sec, 21 / sec, 51 / sec, 71 / sec. InVBTIV group, after the patients are treated for two weeks, their syndromes are improved. We examine ABR with the same method again. Statistical methods: SPSS11.0 statistical software, t-test, linear correlation, linear regression and chi-square test.[Results] (l)To the healthy adults, with the increase of the stimulus rate, the V wave peak latency (PL) prolongs. The two factors are linear correlation. The regressive equation is Y =5. 50 + 0. 00589X . (2)Thenormal reference numerical value is established in our lab. (3)The results show that the ISRABR diagnoses VBTIV significantly higher than those of the conventional ABR. The abnormal rate of the I , III, V wave PL are 19%, 40%, 51%, versus 7%, 8%, 6% of conventional ABR CP <0. 05) . The ISRABR abnormal rate of I — III, III~V, I ~V wave interpeak latency (IPL) are 18%, 15%, 30%, versus 4%, 5%, 5% CP <0. 05) . (4)When we apply the conventional ABR 11/sec, there is no difference of the wave IPL in healthy adults and patients. But when we apply ISRABR, the wave PL and IPL of patients are prolonged than those of healthy adults(jp<0. 001) . If we take the distinction of 51/sec and 11/sec regarded as the parameter, the wave PL and IPL of patients are prolonged than those of healthy adults CP <0. 001) , too. The upper limit of normal reference numerical value: I , IIL V wave PL: 0. 21ms, 0. 26ms, 0. 35ms;I ~III,III~V, I ~V IPL:0. 19ms, 0.24ms, 0.27ms. We can diagnose VBTIV when the numerical values exceed the upper limit. (5) After the patients are treated for two weeks, the wave PL and IPL are shortened than before. The comparison between the the paroxysmal group and the catabatic group revealed a significant shortened about PL and IPL in catabatic groupCP <0. 05) . We choose the distinction of 51/sec and 11/sec regarded as the parameter. The catabatic numerical value is established in our...