Active clinical trials for "Auditory Diseases, Central"

Perioperative hearing loss is a rarely reported phenomenon. However, it occurs more frequently than most anaesthesiologists suspect. Perioperative hearing impairment is often subclinical and may go unnoticed unless audiometry is performed. It can be conductive or sensorineural, unilateral or bilateral, and transient or permanent. Hearing loss has been reported following virtually every type of anaesthetic technique. The hearing mechanism may be less susceptible to acoustic trauma during general anaaesthesia. But other mechanisms are capable of causing both conductive and sensorineural hearing losses (SNHL) in the perioperative period. The aetiologies include mechanical, traumatic, noise-induced, changes in cerebrospinal fluid (CSF) pressure, embolism, pharmacologic, and other miscellaneous causes. Stress may influence central vestibular function in health and disease either directly through the actions of glucocorticoids (cortisol and corticosterone) on ion channels and neurotransmission in the brain, or indirectly through the effects of stress-related neuroactive substances (e.g., histamine, neurosteroids) on these structures. The auditory brainstem response (ABR) provides a good estimate of the shape of the behavioral audiogram [and is thus an extremely useful tool for studying hearing sensitivity as well as the functionality of the auditory system. An awareness of the potential for and the causes of hearing loss during anesthesia may permit the anesthesiologist to prevent or minimize the risk of significant hearing deficit. The suggestion that this risk be discussed in the preoperative period with patients who are at high risk for perioperative hearing loss may be good medical-legal advice. Better understanding of the incidence, causes, and prognoses for perioperative hearing loss is essential for the anesthesiologist. Much Concern has been raised about the effects of anaesthetic drugs on cognition. Postoperative cognitive dysfunction may manifest as impairment in attention, memory, language or executive functions following surgery, and can persist for weeks, months, or more with varying severity. Such post-operative cognitive dysfunction can be quite mild and only diagnosed through psychometric assessment using specific neuropsychological tests. AIM OF THE STUDY The aim of this work is to study the possible deleterious effect of propfol versus sevoflurane on auditory and cognitive function.

This study aims to increase our understanding of the difficulty people have recognizing the spoken word, especially in noisy situations. Subjects must be between 12 and 18 years old with no history of voice disorder, autism, stuttering, aphasia, multiple sclerosis, traumatic brain injury, severe language disorders, and psychiatric disorders. Group A subjects must show reduced speech-in-noise scores and Group B subjects must demonstrate speech-in-noise scores within normal limits. The child will perform a series of hearing tasks that will take from 1.5 to 2 hours, with a break halfway through. A routine hearing test will be given. The child will sit in a sound-treated room wearing earphones and will depress a button in response to sound or to repeat words. The words may be in quiet or mixed with noise. In a test called "immitance," air pressure change and tones will be sent through a miniature probe in the ear for about 1 minute. TEOAE (transient-evoked otoacoustic emission) testing will test the inner ear with clicking sounds. At times, noise will be presented through a probe in the opposite ear. The child will listen to a series of recordings of speech in quiet and in noise and will be asked to repeat what is heard. These recordings will include monosyllabic words with some part of the sounds cut out; words presented with several voices speaking together; two words presented at the same time, one to each ear (child must repeat both words); and two sentences presented at the same time, one to each ear (child must repeat sentence presented to chosen ear). The only risk in this study is tiredness from listening.