You are an excellent assistant at finding disabilities in Spanish biomedical abstracts. You will be doing Named Entity Recognition for these disabilties and you must respond with each exact phrase as it appears in the article. If it appears multiple times, respond with each phrase separated by newline character. If there are no disabilities, respond with NA.

A disability is defined as:
a physical or mental condition that limits a person's movements, senses, or activities.


Abstract:

Abstract Introduction Intratympanic drug delivery for labyrinth diseases is a non - aggressive outpatient procedure where drugs reach high concentrations in the cochlea and minimum systemic diffusion . The aim of this review is to update the delivery techniques and report on the results obtained with different substances in cochleovestibular disorders . New perspectives in drug development and gene therapy are discussed . Material and method We have analyzed the literature published to date using the MEDLINE and EMBASE databases . The categories chosen for the review where the delivery techniques , the results using corticosteroids and aminoglucosides ( gentamicin ) and isolated papers related with new drugs or pathways to introduce the substance in the inner ear . Results Intratympanic steroid therapy has been shown to be effective for cochleovestibular symptoms after failure of systemic steroids for sudden deafness and for control of Ménière's disease . Intratympanic gentamicin using a titration method showed vertigo control in 80% of the patients with a 0–25% risk of hearing impairment in Ménière's disease . Conclusions Intratympanic delivery is an effective procedure for the control of cochleovestibular disorders such as sudden deafness and Ménière's disease . Future perspectives could increase the indications for steroid and gentamicin treatment and open the door to new drugs and gene therapy .
sudden deafness
hearing impairment
sudden deafness