**9. Results**

386 Hearing Loss

(24). When correcting for the lower Dexa concentration (4 mg/mL) compared to MP (40 mg/mL) in their study and for the higher potency, dexamethasone is expected to reach higher effective levels in perilymph after application to the round window membrane. In addition, contrary to Dexa, MP solution is not stable but hydrolyzed after some days in the

There is no standard protocol for IT corticosteroid injections; the frequency of injections, concentration and type of corticosteroid. Method of injection is determined by the

**Syringe delivery is a** simple method. However, direct injections do not allow for prolonged delivery. We can anesthetize the tympanic membrane with 10 percent Xylocaine. A drop of phenol on the ear drum is one method. Another is a topical anesthetic such as "Emla" cream.

The myringotomy is placed in the most superior and anterior location to allow maximal filling of the middle ear space with the corticosteroid solution while the patient is supine. Placement of the tube eliminates the need for a new myringotomy for each subsequent injection. For injection, we use a 25-gauge spinal needle attached to a 1-mL tuberculin-type syringe. To equalize pressure, two needle punctures were made in the anterior superior quadrant of the tympanic membrane, the first for injection and the second (superior) for air escap. The initial injection was followed by a second injection about 15 minutes later for a total volume of approximately 0.5 mL. The patient remained supine for 30 to 40 minutes, with the head turned to the side and the injected ear upright, and was instructed to swallow as little as possible to help maintain the fluid in the middle ear space for longer duration.

**Microwick** is the polyvinyl acetate wick (1 mm diameter by 9 mm length). It absorbs medication and transports it directly to the RWM. It's placed through a tube, at the round window niche. It allows instillation by the patient himself at home. The MicroWick should be removed or replaced after 4 weeks of treatment to prevent it from becoming adherent to

**Microcatheter** is composed of two tubes: one for injection and the other for the return of excess liquid. It ends with a bulge that is placed at the round window niche under general anesthesia. Some researchers propose to link the catheter to a pump. This would allow

Corticosteroids are indicated in several types of sensorineural affects. Indications are : sudden deafness, autoimmune Deafness, Deafness and Dizziness related to Meniere's

They are also available for otoprotection against physical and chemical aggressions of the inner ear. It seems that corticosteroids will respond to inner ear hair cells and nerve cells. They may prevent, limit and recover the damage caused by noise trauma (27). They may be

continuous irrigation and delivery of the product constantly at the round window.

pump cartridge (19) (25).

individual surgeon.

**7. Intratympanic delivery methods** 

the mucosa of the round window (26).

**8. Indications** 

disease and Tinnitus.

Multiple intratympanic delivery methods are descripted:

The drug is injected, left in the middle ear for 30 minutes.

Intratympanic corticosteroids for sudden hearing loss and Meniere's disease has been the subject of retrospective, uncontrolled studies and a few controlled studies with small numbers of subjects. Hamid in 2001 with a single injection of high concentration of Dexamethasone (24mg/ml) for patients with Meniere's disease, was able to get control of vertigo in 90% of cases with an improvement of hearing threshold, the percentage of discrimination and sensation of fullness (29) (26). In his study, 90% of patients had vertigo control, 90% had improved speech discrimination, and 90% had decreased aural pressure.

Garduno (30), compared intra tympanic Dexamethasone versus placebo in Meniere disease. He obtained full control of vertigo in 82% of cases against 57% with placebo with significant differences. He also noted a reduction of tinnitus in 48% of cases and hearing improvement in 35% of cases.

In sudden deafness, Ahn (31) compared two groups: systemic corticosteroids alone versus intratympanic corticosteroids associated with systemic treatment. He found no significant difference in overall response, but noted a significant improvement on the low frequencies in intratympanic treatment group. HONG (32) compared intratympanic corticosteroids alone versus systemic corticosteroids alone also found no difference, but noted a significant improvement over the low frequencies. Alatas (33) concluded that intratympanic dexamethasone is an effective therapy for low frequency hearing loss. Hunchaisri (34) concluded that it may have benefits for patients with sudden sensorineural hearing loss who failed systemic steroid therapy.

In diabetic patients with sudden sensorineural hearing loss, intratympanic corticoid injection is as effective as systemic steroid treatment and it can avoid undesirable side effects (35). Han studied three groups of diabetics and compared prednisolone administered by oral, intravenous and intra tympanic Dexamethasone. He noted a better outcome with intratympanic treatment without significant difference. However, systemic treatment was discontinued in 6 patients due to problems of hyperglycemia. This disadvantage is not observed with the intratympanic treatment.

Many studies concluded that using the continuous intratympanic dexamethasone by MicroWick is effective, safe and efficient for treatment of sudden idiopathic sensorineural hearing loss (26) (19).

There is an increasing number of series evaluating intratympanic (IT) steroids as first line or salvage therapy in ISSHL with some studies presenting control groups and randomized controlled trials (Table 1).

The effect of intratympanic corticosteroids on tinnitus is difficult to assess due to limited work. Shulman (37) treated tinnitus with intratympanic dexamethasone and obtained control of tinnitus in 50% cases (for 1 year and over).

Kara (52)

Plontke (19)

hearing loss

Randomized, double-blind, placebo controlled multicenter trial.

chemotherapeutic actions of cisplatin.

**10. Complications** 

otitis media and mastoiditis.

Intratympanic Corticosteroid for Neurosensorial Hearing Loss Treatment 389

injections with the dose of 4 mg/ml,

continuously applied for 14

days

Intratympanic steroids gave better hearing results than systemic steroids with no systemic side

better hearing improvement in the treatment group absence of serious adverse events

effects

**Author Type of study Steroid used Protocol Results** 

Dexamethasone 4 mg/ml

Table 1. Review of Literature on Intratympanic steroid Therapy for sudden neurosensorial

The effectiveness of steroids in reducing noise induced hearing loss has been inconclusive (13). Many types of steroids, antioxidants and growth factors have been studied to protect the ear from trauma or to minimize or reverse damage (38) (39). Some researchers have used antioxidants such as D-methionine and N-acetylcysteine to prevent noise induced hearing loss (40). A variety of growth factors and peptides, are being introduced to combat the effects of Noise induced hearing loss : Insulin-like growth factor-1 (IGF-1), neurotrophic

Steroids have also been tested for their otoprotective attributes during antibiotic treatment. The intracochlear infusion of dexamethasone before and after kanamycin delivery protected hearing (43). Hill (44) concluded that IT dexamethasone may be a safe, simple and effective intervention that minimizes cisplatin ototoxicity without interfering with the

A sudden or progressive hearing loss can occur during radiation treatment of head and neck tumors (45). Patients are commonly given steroids to reduce inflammation, but their local delivery would reduce the side effects associated with systemic steroid treatment (13).

Complications of intratympanic injections of corticosteroids are uncommon and banal (19). Those most often reported in the literature are: 1) some individuals experience intense pain during injection, 2) vertigo and tinnitus, 3) Other complications are rare and include acute

Patients who undergone trans-tympanic aerator to avoid multiple injections or to put in the microwick have an increasing risk of persistent eardrum perforation (47). In fact, 20% of

these patients had non healing perforations that needed repair using a fat graft (26).

factor-3 (NT-3) , AM-111 and D-JNKI-1 peptides (41) (42) (40).

Inflammation often results from inner ear surgical trauma, as well (46).

Prospective control Dexamethasone 5 intratympanic


treatment Steroids through a ventilation tube 4 separate occasions over the course of 10 to 14 days

treatment 40 mg/mL 4 times within a 15-day period

3, and 5

treatment 5mg/ml once a day for eight

days

diabetes

treatment 5 mg/mL, six injections over 2

weeks

four times within a two-week period

Hearing

Significant improvement

improvement in 44%

improvement (≥20dB)

hearing recovery rate compared with patients treated with

improvement at low

Total recovery rate was 73.3% and 70.0% in the control group better hearing improvement at 250 Hz than the control

group

oral steroids

frequencies

significant improvement for severe SNHL

no significant difference with systemic treatment no patients who failed to control their blood sugar level

**Author Type of study Steroid used Protocol Results** 

Methylprednisolone salvage

retrospective Dexamethasone 24 mg/mL 27.5% showed

Dexamethosone Primary

Dexamethasone SNHL with

prospective salvage

Ahn (31) controlled study Dexamethasone 0.3 mL on days 1,

Gianoli (48)

Xenellis (49)

Haynes (36)

Hong (50)

Randomized controlled study

Randomized controlled study

nonrandomized multicenter clinical

Lee (51) retrospective Dexamethasone salvage

Han (35) Prospective,

trial


Table 1. Review of Literature on Intratympanic steroid Therapy for sudden neurosensorial hearing loss

The effectiveness of steroids in reducing noise induced hearing loss has been inconclusive (13). Many types of steroids, antioxidants and growth factors have been studied to protect the ear from trauma or to minimize or reverse damage (38) (39). Some researchers have used antioxidants such as D-methionine and N-acetylcysteine to prevent noise induced hearing loss (40). A variety of growth factors and peptides, are being introduced to combat the effects of Noise induced hearing loss : Insulin-like growth factor-1 (IGF-1), neurotrophic factor-3 (NT-3) , AM-111 and D-JNKI-1 peptides (41) (42) (40).

Steroids have also been tested for their otoprotective attributes during antibiotic treatment. The intracochlear infusion of dexamethasone before and after kanamycin delivery protected hearing (43). Hill (44) concluded that IT dexamethasone may be a safe, simple and effective intervention that minimizes cisplatin ototoxicity without interfering with the chemotherapeutic actions of cisplatin.

A sudden or progressive hearing loss can occur during radiation treatment of head and neck tumors (45). Patients are commonly given steroids to reduce inflammation, but their local delivery would reduce the side effects associated with systemic steroid treatment (13). Inflammation often results from inner ear surgical trauma, as well (46).
