In extremely severe cases, treatments that deaden the inner ear such as gentamicin injections or surgery may be considered. This is a last resort for persons who have severe attacks which are disabling. At present, we favor gentamicin for most instances where destructive treatments are being considered. Injections of gentamicin are given through the ear drum, through a small hole or through a small tube. This procedure allows the doctor to treat one side alone, without affecting the other. Typically, about four injections are given over a period of one month. Some authors have reported improvements in 60 to 90 percent of patients with gentamicin (Driscoll et al., 2009; Bodmer, 2007; Boleas-Aguirre, 2007; Chung, 2007), and Chung reported equally effective results with a single injection compared to multiple injections (Chung, 2007). Dizziness may reoccur one year later, requiring another series. Gentamicin injection can also result in hearing loss (Silvertein 2009; Colletti, 2007).
Depending on timing, intra-tympanic steroid injection is also offered (dexamethasone 10-24mg/cc). Intra-typmpanic steroid injection is performed by inserting a needle through the eardrum and injecting about of highly concentrated steroids directly into the middle ear space. The patient is than instructed to keep the affected ear up for 30 minutes without swallowing, yawning, or popping the ear. After injection, the patient is allowed to immediately resume normal activities. This steroid injection has also been used to treat Meniere's Disease flare-ups.
A single trial containing 22 patients, with a low risk of bias was included. This trial found that after 24 months, compared with placebo , the use of intratympanic dexamethasone demonstrated a statistically significant improvement in vertigo as defined by a respective improvement in functional level (90% versus 42%), class (82% versus 57%), change in Dizziness Handicap Inventory scores ( versus ) and mean vertigo subjective improvement (90% versus 57%). The treatment regime described by the authors involved daily injections of dexamethasone solution 4 mg/ml for five consecutive days. These results were clinically significant. No complications were reported.