Analysis Of The Vestibular-evokede Myogenic Potential Parameters Of Perceptive Deafness Patients

Objective:Collect perceptive deafness patients, get and analyze the parameters of their vestibular-evokede myogenic potential(VEMP)examinations.Grouping them by the time course of the hearing lost or grouping them to the patients with vertigo or without vertigo.Get the relationship between the time course of hearing lost and the parameters of the patients.Analyse the difference of VEMP between the patients with vertigo and the patients without vertigo.Analyse the difference of VEMP between the patients with low audio frequency hearing lost and the patients with high audio frequency hearing lost.Analyze the relationship between the average audibility threshold and the amplitude of VEMP.Compare the VEMP of patient's two ears of the patients with one healthy ear.Methods:Examine the patients with electric auriscope,hearing threshold test, acoustic immitance examination,otoacoustic emission examination and ABR examination to eliminate the disease of outer ear,middle ear and central nerve.Then do the VEMP examinatione on them to get the parameters. Analyze the parameters with SPSS11.5 software.Electromyogram activity was recorded from the upper half of the SCM muscle using surface electrodes, with a reference electrode on the upper edge of the sternum and a ground electrode on the forehead. Care was taken to place the bilateral electrodes symmetrically. During each recording session, the subject raised the head 15~20cm away from the bed to keep the SCM muscle under tension. Rarefaction clicks of 0.1-millisecond duration were presented at a rate of 3.1 per second through a headphone. The EMG signal was amplified and band pass filtered (30 to 3000Hz) and it was averaged on computer using the SmartEP software package .The analysis window was 100 ms wide and the sampling rate was 500 Hz per second. The responses to 128 stimuli were averaged and repeated twice.Patient selection:47 patients with nerve hearing lost were invesgated in this study.They have no history of otitis media,ototoxicity drug used or trauma of ear.They have no other symptomes except vertigo and tinnitus.Their everage audibility threshold are all lower than 60dB. The subject age was distributed between 18 and 40 years old,the average was 33.58 years old.Fourty three of them are single ear deafness,four of them are double ears deafness.All the ears have hearing lost are fifty one.Seventeen of them have the symptome of vertigo.Twenty of them with the course of disease less than three years and the others are more than one year.Results:1. There is no difference between the VEMP parameters of the nerve hearing lost patients and the parameters of normal people.The p13and n23 of the sick ear's VEMP of the sensorineural hearing lost patients with vertigo have no difference with them of the healthy ear.2. To compare the parameters of VEMP between the patients with the course less than three days and the patients with the course more than one year,we can see that the p13,n23 and the amplitude have no significant difference.3. To compare the parameters of VEMP between the patients with only low frequency hearing lost and the patients with only high frequencey hearing lost,we can see that their p13,n23 and the amplitude have no significant difference.4. To analyze the dependabilty between everage auditory threshold and the amplitude of VEMP,we get the conclusion that there is no dependability between them.Conclutions:1. There is no significant relationship between the course of the sick and the change of the ability of inferior vestibular nerve system of the sensorineural hearing lost patients. 2 We didn't find significant destroy signs on inferior vestibular nerve system of the sensorineural hearing loss patients without vertigo.But most of the sensorineural hearing loss patients with vertigo have the ability destroy of their inferior vestibular nerve system destroy of the sick ear.3 The location of the cochlea have been destroied has no significant relationship with the condition of inferior vestibular nerve system in the same ear.4 The VEMP parameters of a ear have no relationship with the condition of it's cochlea.5 VEMP should be used as a routine examination and a follow-up examination on the sensornineural hearing loss patients.