Sudden sensorineural hearing loss [SSNHL] is known as a hearing loss of 30 dB or more, affecting at least 3 consecutive frequencies, and occurring within 3 days without any identifiable cause. It is considerd one of the reversible SNHL1. SSNHL is almost always unilateral and mostly associated with aural fullness and tinnitus with high rate of spontaneous recovery, up to 65% 2. But spontaneous recovery of flat curves was 20%3. Although systemic steroid is considered as one of the effective treatment of sudden SNHL, their short and long term sequels represent obstacles for their use. On the other hand, intra tympanic steroids [ITS] have the advantage of directed therapy with high concentration to the inner ear with avoidance the side effects of systemic one 4. The ITS use has been applied in 3 main protocols for managment of sudden SNHL; as the only treatment without systemic steroids, as a concomitant treatment with systemic steroids, and after failure of systemic steroids. ITS injection is a tolerated procedure that can be easily performed under local [topical] anesthesia. Unlike systemic steroids, ITS can target the affected ear but its initial disadvantage is the lack of proven efficacy or superiority over systemic steroids. Some complications have been recorded with ITS such as pain, acute otitis media, tympanic membrane perforation, otorrhea, vertigo, and further HL 2. We aimed at assessment of effectiveness of systemic steroids in treating sudden SNHL, assessment of concomitant treatment using ITS and systemic steroids as the initial treatment of sudden SNHL. And finally in cases with failed systemic steroid, any added efficacy of using ITS injection after failure of systemic steroids was investigated.

Patients complaining of sudden [developing within less than 72 hours] SNHL of less than 3 days duration in the period from January 2015 to January 2017 were examined using pure tone audiometry [PTA] revealed unilateral severe SNHL with very poor speech discrimination [SD] scores [less than 32%] [table 1] their ages ranged between [45- 55 years].

Patients with evidence of retro-cochlear disease [evident on magnetic resonance imaging], or history of ear surgery, Meniere disease, radiation-induced hearing loss, acoustic trauma or barotrauma, genetic SNHL or known inner ear anomaly and those with evidence of acute otitis media or chronic otitis media on examination were excluded from the study. Patients had general disease that might cause hearing loss or have effect on the efficacy of treatment like renal problems, diabetes mellitus, hypertension, noise exposure or concomitant ototoxic drug intake were also excluded.

All participants in this study were submitted to the following tests

• Full history taking including personal, medical, ontological to assess the presence or absence of exclusion criteria.
• Otological examination: to exclude obvious anomalies.
• Basic audiological evaluation:
• PTA; air and bone conduction audiometry.
• Speech audiometry. [Two-channel audiometer Madsen, model Orbiter 922].
• Immattancemetry including tympanogram and acoustic reflex thresholds [Acoustic immittance meter Interacoustics, model AZ

For PTA, air conduction thresholds were tested at frequencies from 0.25- to 8 KHz and bone conduction thresholds were tested from 0.5- to 4KHz. [Two-channel audiometer Madsen, model Orbiter 922].

Speech audiometry included speech reception threshold [SRT] testing and word discrimination testing [WD %]. [Two-channel audiometer Madsen, model Orbiter 922].

Immattancemetry included tympanometry at varying pressure from +200 to -400 mm H2O and acoustic reflex threshold testing using pure tones of 500, 1000, 2000 and 4000 Hz. [acoustic immittance meter interacoustics, model AZ 7].

Sixty patients were categorized into 3 groups [20 patients in each group];

Group I: patients in this group were treated with systemic corticosteroid in the form of oral prednisone 1 mg/kg body weight [maximum dose 80 mg] for 10 days followed by gradual diminishing dose over the subsequent ten days [75% of the dose was given in the first 3 days, then 50% in following 3 days, lastly 25% in the last 4 days].

Group II: patients in this group were subjected to concomitant systemic steroid [same as given in group I] and ITS injection.

Intratympanic steroids [ITS] injection was performed under local anesthesia while the patient was in supine position and turned his head 30o away from the surgeon. Via a syringe connected to a 25 gauge spinal needle, 0.5 ml methylprednisolone [Depo-medrol 40 mg/ml, EPICO-Egypt, PHARMACIAUP JOHN-BELGIUM] was injected into the middle ear through the postero-inferior tympanic membrane quadrant, under microscopic or otoendoscopic visualization [figure 1]. Patient was kept with head turned posteriorly for approximately 30 minutes after injection without swallowing5- 8. ITS injection was given immediately once the patient was seen and diagnosed and was repeated once weekly for 3 weeks.

Group III: patients in this group were treated with ITS injection after failure of systemic treatment [patients in this group agree to ITS injection a week after they initially refused to ITS injection]. Failure of therapy was determined by the absence of significant threshold shift after one week of systemic steroid intake.

Patients were permitted to choose between receiving treatment with either systemic steroid alone or combined ITS and systemic steroids together [some patient refused to have local injection despite full explanation of the procedure and possible added effect]. So groups were passively identified based on the treatment modalities chosen by the patients.

PTA follow up for all groups was conducted for all groups after 3 days after starting the systemic treatment and then every 4 days.

Statistical analysis was performed using tests from the SPSS program version 17 [Chicago, Illinois, USA]. P value ≤ 0.05 is considered significant

Sixty patients, 33 females and 27 males, were included in the current study. Their age ranged between 45 and 55 years [mean: 50.3 ± 4.3]. Group I included 20 patients [11 females and 9 males] with a mean age of 50.5 ± 3.5 years. Group II included 20 patients, 10 females and 10 males, with a mean age of 51.1 ± 2.5 years. While group III comprised 20 patients; 12 females and 8 males with mean age of 50.8 ± 2.1. There were non-significant difference between the 3 groups as regard sex [chi square test [X2] = 0.4, P= 0 .817], age [Fisher test [F] = 0.236, P= 0.791] and the pretreatment PTA and speech discrimination [SD] [Tables 2,3]. 20 patients received systemic steroid only showed failure of therapy with absence of significant threshold shift after one week of systemic steroid intake and so they were shifted to group III. While no patient in group II [combined systemic and IT steroids] showed failure of therapy. On the other hand, no significant improvement was detected in group III [systemic steroid then IT steroids after no response] at PTA of frequencies 1000 and 2000 Hz while significant improvement was detected at other frequencies; 250 Hz, 500 Hz, and 4000 Hz. Moreover near significant improvement [p= 0.0774] was detected in SD% [Table 4]. No complication was detected form ITS in any of our cases with tolerable post-procedure pain that was relieved by oral paracetamol over 3 days.

Figure 1:Intratympanic Steroids [ITS] Injection.

The benefit of systemic steroids in hearing recovery of SSNHL have been recorded in current study and also demonstrated in previous studies [1-10].

The main mechanism by which steroids can improve hearing still unknown; both glucocorticoid and mineralcorticoid receptors may be present in the inner ear [11]. The suggested roles of steroids in management of sudden SNHL are:

• The protection of cochlea from the inflammatory mediators, such as the tumor necrosis factor (TNF-α and NF-κB) and cytokines (interleukin 1 and 6), which have harmful effects and these factors are elevated in infection and flogosis [12].
• Increasing cochlear circulation [13] thereby protecting the cochlea from ischemia [14].
• Avoiding hearing loss induced by noise.
• Regulating the inner ear protein synthesis [15].

In addition, systemic steroid therapy improves the function of vascular stria and maintains its morphology that may play a role for recovery from the sudden SNHL [16]. On the other hand, Silverstein in 1996 [17] was the first who reported using of IT injection in treatment of SSHL It is demonstrated that ITS infusion leads to a much higher perilymph steroid concentration than the systemic route. Additionally, after round window application, substantial basal-apical concentration gradient of steroid in the scala tympani perilymph has been found [18].

Table 1: Comparison between pre-treatment pure tone audiometry (PTA) and speech discrimination (SD) in the three groups.

Table 2: Comparison between pretreatment and post-treatment pure tone audiometry (PTA) and speech discrimination (SD) in group I..

Table 3: Comparison between pretreatment and post-treatment pure tone audiometry (PTA) and speech discrimination (SD) in group II.

Table 4: Comparison between pretreatment and post-treatment pure tone audiometry (PTA) and speech discrimination (SD) in group III..

Usually, there are three main protocols for using ITS for SSHL. ITS could be used as a primary treatment (ITS alone without systemic steroid when it is contraindicated), as a part of the primary treatment (as concomitant treatment with systemic steroids) or as a secondary treatment after failure of systemic steroid. As shown in the results of the current study, there was significant improvement on using systemic steroids only in the first group at all hearing frequencies and SD in the improved cases. We used ITS injection as concomitant primary treatment in the second group and after failure of treatment with systemic steroid in the third group. We found that there was a statistically significant improvement in PTA and SD in group II when the systemic steroid taken with ITS injection. In addition, 20 patients received systemic steroid only showed failure of therapy while no patient received systemic steroid with ITS showed failure of therapy. In addition, intratympanic therapy may limit systemic steroid side effects [19]. Similar results were obtained by Chu et al [20]. On the other hand, Lauterman et al [21] reported that the addition of IT steroids had no benefit in hearing recovery and Piñones, et al [22]. Noted that the efficacy of combination therapy was not significantly higher than that of systemic steroid therapy. Thus, systemic steroids has effective role in the treatment of SSNHL Concomitant ITS with systemic steroid limit therapy failure. Furthermore, after failure of systemic steroids therapy, significant better hearing could be achieved with subsequent ITS in some frequencies. So, we recommend to use ITS as a minimally invasive procedure even after no hearing recovery with systemic steroid. Small number of the studies patients represents a limitation in the current study.

Systemic steroids could have effective role in the treatment of sudden SNHL but still failure of therapy might occur. Concomitant primary use of ITS with systemic steroid significantly might avoid therapy failure achieving significant improvement of hearing. Thus it is needed to be studied on a wide scale to use ITS as part of primary treatment of sudden SNHL. Furthermore, after failure of systemic steroids therapy, significant better hearing could be achieved in some frequencies. So we recommend to give ITS even after no response with systemic steroid.

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