The Study Of The Characteristics Of Ocular Vestibular-Evo Ked Myogenic Potentials In Acoustic Neuroma Patients

Objects: To creat the normal oVEMP in our deparment by observing the characteristics of ocular vestibular-evoked myogenic potentials in normal young population and analysting the parameter index. To observe the the application of ocular vestibular-evoked myogenic potentials in acoustic neuroma patients and to investigate the clinical diagnostic value of ocular vestibular-evoked myogenic potentials for acoustic neuroma patients.Method: 1、20 cases of acoustic neuroma and 30 cases of normal healthy people matched with age and sex were selected to perform ocular vestibular evoked myogenic points(oVEMP) test, the lead-out rate and parameter index of oVEMP were analysed and compared.Result:(1) 40 cases of normal, healthy young people all can lead to oVEMP, which leads to the rate of 100%. Statistical parameters: latency for N1(11.55±1.32)ms, latency for P1(16.43±1.27)ms, latency for N1-P1(4.87±1.041)ms, the amplitude(4.36±2.43) μV, amplitude ratio(max/min) 1.18±0.17, oVEMP asymmetry 0.12±0.06.(2) All 30 cases of normal healthy people could lead out oVEMP, the lead out rate was 100%.Statistical parameters: latency for N1(11.98±0.99)ms, latency for P1(17.10±1.01)ms, latency for N1-P1(5.11±0.88)ms, the amplitude(3.46±1.52)μV, amplitude ratio(max/min)1.19±0.16, oVEMP asymmetry 0.09±0.06. 19 of 20 cases of acoustic neuroma had abnormal oVEMP, the lead out rate was 25%. Statistical parameters for the affected side: latency for N1(11.83±1.23)ms, latency for P1(17.16±1.57)ms, latency for N1-P1(4.46±1.42)ms, the amplitude(1.9±0.74)μV. Statistical parameters for the unaffected side: latency for N1(11.86±1.37)ms, latency for P1(17.05±1.53)ms, latency for N1-P1(4.18±1.44)ms, the amplitude(2.66±1.85)μV; amplitude ratio(max/min)1.45±0.35, the asymmetry 0.17±0.12.(3) The difference of the amplitude and the ratio of the oVEMP between affected side and unaffected side was statistically significant(P<0.01); The difference of the amplitude and the ratio of the oVEMP between unaffected side and the control group had no statistical significance(P>0.05); the difference of P1 incubation period, the incubation period the N1 and P1-N1 interphase between pations and healthy controls were no statistical significance(P>0.05); Incubation period P1 and N1 latency in the control group there was no statistically significant difference between the different gender and different age groups(P>0.05); There was no statistically significant difference between the amplitude of the degree of hearing loss(P>0.05); Amplitude ratio and the asymmetry in the difference between the case group and the control group was statistically significant(P<0.05); Amplitude in the control group between different gender and different age difference was statistically significant(P<0.01).(4)the results of oVEMP higher specificity than the results of such as pure tone audiometry, acoustic impedance, otoacoustic emission, auditory brainstem response, intercooler hearing test and other examinations;Conclusion: OVEMP in normal population rate is high, the derivation can be used as a screening test, and other inspection to improve the rate of pass in and out of acoustic neuroma.