الفهرس 
Introduction and Rationale
Clinical Course in Meniere’s diseaseOnly 14 pages are availabe for public view
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Abstract
Meniere’s disease (MD) is a chronic disorder affecting the inner ear, characterized by fluctuating sensorineural hearing loss (SNHL), episodes of vertigo lasting from minutes to hours, tinnitus, and aural fullness. Endolymphatic hydrops is accepted as the most possible pathophysiologic mechanism of the disease; however, not all cases with hydrops become clinically apparent. Recently, it has been suggested that the hydrops interfere with the recycling K+ ions and results in osmotic imbalanced expansion of the endolymphatic component.
Diagnosis of Meniere’s disease is based on a combination of the right set of symptoms [according to diagnostic criteria proposed by committee of Hearing and Equilibrium (1995)], Audiological evaluation, Electrocochleography (ECOG), Vestibular work up that includes: vestibular evoked myogenic potential (VEMP) and Videonystagmography (VNG) test.
Intratympanic (IT) steroids have been utilized as a therapeutic option for Meniere’s disease. It appears to be increasing in clinical practice. This is a convenience and easy office-based treatments. Minimal side effects have been reported related to the IT steroid therapy including tympanic membrane perforation and inflammatory middle ear changes.
The present study was designed to study the long term patient performance (continuation study) after intratympanic (IT) dexamethasone injection (at different doses) 2 years and 2.5 years after the last injection of the previous study The present study was conducted on twenty patients diagnosed with definite Meniere’s disease. They were divided into two subgroups according to the injected dose of Intratympanic (IT) dexamethasone;
Subgroup A: 10 patients with active Meniere’s disease were injected with dexamethasone 4 mg/ml in the previous study.
Subgroup B: 10 patients with active Meniere’s disease were injected with dexamethasone 10 mg/ml in the previous study.
Follow up of the patients for subjective control of vertigo was done for 2 years (FU1) & 2.5 years (FU2) and the collected data were obtained from these two levels .
The equipments used were Two channel audiometer Madsen otometrics Astera 2 ,Sound treated room model IAC series 120,Immittance Otometrics Otoflex 100,Four channel VNG-Micromedical Technology version 4& Two channels evoked potential system Biologic model .
All the patients of both study subgroups were submitted to the following: full history taking, otological examination, pure tone audiometry including air and bone conduction, speech audiometry (speech reception threshold and word discrimination score), immitancemetry including tympanometry and acoustic reflex threshold, Videonystagmography (VNG), Cervical Evoked Myogenic Potential (C-VEMP) and Dizziness Handicap Inventory (DHI) scale.
Follow up of the patients was done for 54 months. The above measures were recorded 2 years and 2.5 years after the last intratympanic dexamethasone injection done in the previous study.
Pure tone audiometry showed mild improvement in study subgroup B more than subgroup A after FU1 & FU2 regarding Speech Reception Thresholds , pure tone average (average of 500, 1000, 2000, 4000 Hz) and Word Discrimination scores .
In comparison between the first and second follow up in both subgroups, subgroup B showed mild improvement of one (10%) of patient in both word discrimination score and pure tone average respectively than subgroup A with no statistically significant difference.
After the first & second follow up of our study patients, the Audiometric configuration showed that the most common audiometric pattern in both study subgroups was the steeping curve(70% and 50% )in subgroup A & B respectively and also noted that all the audiometric patterns in each subgroup were the same as the basal level and remained the same values during our study period.The percentage of all types of nystagmus showed nearly no difference between both subgroups A&B in the previous study and after our continuation study .
In comparison between FU1 and the FU2, the percentage of all types of nystagmus in both subgroup A increased by one patient (10%) while, the percentage of all types of nystagmus in both subgroup B remained the same values reflecting more stability& vertigo control of patients in subgroup B than subgroup A with no statistical significant difference
No statistical significant difference was observed in C-VEMP wave latencies (P13-N23) after FU1&FU2 in both subgroups. The mean of difference in the latency of P13 and N23 between FU1 and FU2 was 0.15 and 0.55 respectively in subgroup A while the mean in subgroup B was 0.18 for P13 and 0.53 for N23 with no statistically significant difference.
As regards the asymmetry ratio, both subgroups did not show a stastically significant difference after our continuation study in comparison with the previous study. The mean of the difference in the asymmetry ratio between FU1 and FU2 in subgroup A & B was 2% & 3% respectively with insignificant stastically difference.
Data obtained from both subgroups in all items of The Dizziness Handicap Inventory (DHI) scale (physical, emotional , functional and total subscale) show insignificant statistical difference values before and after our continuation study.The Mean of difference in the Dizziness Handicap Inventory scale of both study subgroups & B between FU1 and FU2 was 0.18 & 0.32 respectively with insignificant statistical difference There was no change in Meniere’s disease vertigo associated symptoms which have been disappeared completely in both study subgroups before and even after the continuation study.
After our first continauation study (FU1) in comparison with the previous study and also in after our second follow up (FU2) in comparison with the previous one, both subgroup A and B showed improvement of subjective hearing loss of 7 (70%) of patients & (100%) of patients showed improvement in tinnitus, and vertigo characteristics (frequency, duration, interruption with daily activities and prescence of associated symptoms) with no deterioration.
The above results showed that the intratympanic dexamethasone injection is helpful in controlling Meniere’s disease subjectively and objectively and also that the dosage of 10mg/ml dexamethasone gives more stability in signs and symptoms of Meniere’s disease than the dosage of 4 mg/ml dexamethasone in follow up study.