Comparison of the benefits of cochlear implantation versus contra-lateral routing of signal hearing aids in adult patients with single-sided deafness: study protocol for a prospective within-subject longitudinal trial

Background Individuals with a unilateral severe-to-profound hearing loss, or single-sided deafness, report difficulty with listening in many everyday situations despite having access to well-preserved acoustic hearing in one ear. The standard of care for single-sided deafness available on the UK National Health Service is a contra-lateral routing of signals hearing aid which transfers sounds from the impaired ear to the non-impaired ear. This hearing aid has been found to improve speech understanding in noise when the signal-to-noise ratio is more favourable at the impaired ear than the non-impaired ear. However, the indiscriminate routing of signals to a single ear can have detrimental effects when interfering sounds are located on the side of the impaired ear. Recent published evidence has suggested that cochlear implantation in individuals with a single-sided deafness can restore access to the binaural cues which underpin the ability to localise sounds and segregate speech from other interfering sounds. Methods/Design The current trial was designed to assess the efficacy of cochlear implantation compared to a contra-lateral routing of signals hearing aid in restoring binaural hearing in adults with acquired single-sided deafness. Patients are assessed at baseline and after receiving a contra-lateral routing of signals hearing aid. A cochlear implant is then provided to those patients who do not receive sufficient benefit from the hearing aid. This within-subject longitudinal design reflects the expected care pathway should cochlear implantation be provided for single-sided deafness on the UK National Health Service. The primary endpoints are measures of binaural hearing at baseline, after provision of a contra-lateral routing of signals hearing aid, and after cochlear implantation. Binaural hearing is assessed in terms of the accuracy with which sounds are localised and speech is perceived in background noise. The trial is also designed to measure the impact of the interventions on hearing- and health-related quality of life. Discussion This multi-centre trial was designed to provide evidence for the efficacy of cochlear implantation compared to the contra-lateral routing of signals. A purpose-built sound presentation system and established measurement techniques will provide reliable and precise measures of binaural hearing. Trial registration Current Controlled Trials http://www.controlled-trials.com/ISRCTN33301739 (05/JUL/2013

The renal system

The chapter reviews the alterations that occur in the body during the stress of acute exercise, including the decrease in renal blood flow, glomerular filtration rate, excretion of water and sodium/chloride, the release of renin-angiotensin and norepinephrine, increase in the excretion of proteins and other macromolecules, and changes in metabolic functions. Exercise alters renal hemodynamics, excretory function, and hormone release. Many of these changes can affect exercise performance. Renal function during exercise is usually not considered to be essential or critical in terms of limiting or determining exercise capacity. It is extremely difficult to assess the renal system during exercise. Changes in cardiovascular and thermoregulatory function with aging, point toward the alterations in kidney function with age. The problem of exercise or exercise and dehydration induce acute renal failure, which remains an issue. The role of the kidneys as an endocrine organ, not only for the release of renin-angiotensin but also norepinephrine, has profound implications, explaining the effects of chronic exercise on certain disease states. © 2003 American Physiological Society Published by Elsevier Ltd All rights reserved.SCOPUS: ch.binfo:eu-repo/semantics/publishe