Progressive, irreversible hearing loss can result from radiation therapy and platinum-based chemotherapy drugs such as carboplatin and cisplatin. The drugs damage the hair cells of the inner ear, making the ear less responsive to sound waves. A 2010 study by German scientists showed that hearing loss is worst among patients who were younger when they were diagnosed, probably because they have taken in higher doses of platinum drugs over their lives. Children and adolescents receiving platinum-based chemotherapy should have regular audiometric follow-up exams, especially for frequencies above 2 kHz, even long after treatment has wrapped up, the researchers said. Cochlear implants are one way to remedy hearing loss that becomes serious.
Sudden sensorineural hearing loss (SSNHL) is a term to describe a dramatic decline in hearing over a period of hours or days. The usual outcome is little or no recovery or further decline in hearing. Some presentations are due to an acoustic neuroma, trauma, infection, autoimmune disease affecting the inner ear or circulatory disorders resulting in an inner ear stroke, but in most cases no specific underlying cause can be found. Several treatments have been proposed such as steroids, infusions of dextran and heparin, carbogen inhalations, histamines, calcium channel blockers and several antiviral agents have all been tried, but no treatment has resulted in a consistent recovery of the lost hearing. In a Taiwan study of 66 patients, researchers found a somewhat greater chance of recovery in the zinc supplemented patients. However, the sample size is too small to make firm recommendations about general treatment of SSNHL patients. Further investigation with a larger trial will need to be conducted. This may involve several centres simultaneously gathering a more substantial volume of data. In Australia, the current recommendation for SSNHL is to regard it as a medical emergency and seek urgent medical attention. The initial treatment would be a course of high dose oral steroid for a period of 10 days. If there is no recovery, as is often the case, a dose of steroid injected into the middle ear through the ear drum should be considered. Further investigation in the form of a blood test, thyroid and immune function test and a MRI of the inner ear should be carried out in time. Long term follow up will be required to manage the residual hearing loss with a hearing aid or in the case of bilateral SSNHL, a cochlear implant.
The idea that dietary supplements can maintain ear health and prevent hearing loss seems attractive, given that the use of various dietary supplements to maintain good general health and eyesight is being recommended. However to date there is little evidence to extend the recommendation to the use of supplements to prevent hearing loss. In animal experiments there is some evidence that the effect of temporary noise-induced hearing loss (the hearing loss you might feel immediately after attending a loud concert but that goes away in a day or two) can be prevented by a combination of antioxidants like beta- carotene, vitamin C, vitamin E and the mineral magnesium when administered before exposure to loud sound. Researchers now know noise-induced hearing loss is largely caused by the production of free radicals, which destroy healthy hair cells within the cochlea. The free radicals literally punch holes in the membrane of the hair cells, causing them to malfunction and eventually die, leading to a permanent hearing loss. The antioxidant vitamins may prevent hearing damage by mopping up the damaging free radicals. Magnesium, which is not an antioxidant, may help by improving blood flow to the inner ear. Further investigation with a whole range of antioxidant agents has been undertaken in animals including green tea, aspirin, and N acetyl cysteine, with the aim of identifying otoprotective agents. Further investigation in this field is required. To date there are no formal human trials that have documented a convincing hearing preservation effect with dietary supplements of any kind.
According to a population study performed in the Blue Mountains, 30% of people over the age of 55 years have some tinnitus. The problem is that there are structures within the brainstem that can perpetuate and amplify the tinnitus sound. These structures increase the tinnitus when you think about it or become anxious and stressed. Hopefully your tinnitus will subside gradually with the TRT treatment. There are many causes of dizziness and your normal MRI result excluded the more horrifying causes. The most common cause is
associated with a sudden drop in blood pressure, especially in people taking medications to lower their blood pressure, and is usually worse on suddenly standing up after lying down. Tinnitus can be associated with Meniere’s disease, a condition associated with too much fluid in the endolymph compartment of the inner ear. The dizziness or vertigo comes as attacks that last from 10 minutes to several hours and cause a sensation that the world is spinning around associated with nausea and usually vomiting. The attacks may be heralded by increased tinnitus in the affected ear and a feeling of fullness in the ear. If your dizziness has these characteristics, you should ask an ENT surgeon to investigate further. Another common cause of similar attacks of vertigo is migraine. Usually there is a past history of classic migraine or a strong family history. Often, some years after the last ‘headache’ migraine attack, the person begins to suffer attacks of vertigo due to changes in the blood flow through the vestibular nuclei (brainstem structures associated with balance). The attacks can be associated with tinnitus and a mild headache over the entire scalp. The hearing remains unaffected although some high frequency loss can occur in older age. An ENT surgeon or a neurologist can help establish the diagnosis and treat the problem.
Deaf adults could benefit from Auditory-Verbal Therapy or an auditory-verbal approach to assist cochlear implant (CI) rehabilitation. AVT could be appropriate for those adults who have had a deteriorating loss or a sudden loss of hearing. In addition it could also assist those adults who have had a congenital hearing loss and were educated using an auditory-verbal approach and then transferred from hearing aids to a cochlear implant. The rationale for suggesting AVT is because the adult CI recipients described would have already developed an ability to communicate through listening. That is their auditory cortex has been developed for listening and they will have a memory of spoken language. The AVT approach could facilitate the redevelopment of auditory skills with a cochlear implant. AVT was pioneered and introduced by Doreen Pollack and Helen Beebe because their belief was that children with hearing impairment could learn to listen and speak. They understood that the child’s parents or carers would need to be educated in the AVT techniques. These included understanding the audiological needs of the child and the development of speech and language. To this end they developed the first AVT programs for hearing impaired children and their parents.
Judy Simser the mother of a deaf child and subsequently a world leader of AVT stated the following: “AVT is the link between theory and practice. It teaches parents how to create an auditory learning environment for their child to develop spoken language through listening alone during natural, meaningful communication.” AVT was intended for children but could be adapted for adults. Children require a parent or carer to facilitate listening and communication. Without that support the child would find it very difficult to acquire spoken language. Fortunately the adult CI recipient would have acquired speech and language. However, due their significant hearing loss the ability to hear spoken language and other auditory information such as music and environmental signals has been lost or diminished. In most cases the hearing impaired adult loses the confidence to fully participate in the regular ‘hearing world’. Unfortunately they can often become withdrawn and lonely. If the CI recipient wishes to maximise the benefits of cochlear implantation it would be an advantage to have a personal mentor in addition to their audiologist and speech pathologist. The mentor could be the person’s partner or close relative or friend - someone whom the CI recipient has a positive and trusting relationship. AVT approach could enhance the CI recipient’s ability to regain their auditory skills to facilitate auditory comprehension of language and the confidence to use spoken language for everyday function. This enables the CI recipient with the ability to participate with family, friends, colleagues and community members. AVT has a hierarchy of listening skills and both the mentor and the CI recipient would need to understand what this means as they are guided through the rehabilitation process.
I think it is a good idea to have an up-to-date record of any auditory processing deficits you may have.
Being the link between the sounds we hear, and our understanding of the meaning of the sound, auditory processing skills are an important aspect of a student’s learning experience. The good news is that most universities now offer many resources that will assist students with hearing or listening difficulties. Recorded lectures, for example, are now widely employed across faculties and allow the student to listen to lecture content in quiet and at their own pace. There is also a greater move towards interactive online course content
that you may find beneficial. Adult auditory processing assessments are not offered as commonly as those for children, but are available. I recommend you contact your local audiologist. As it is a specialised service you may need to make a few enquiries before you find a practice able to help. Your audiologist may also be able to recommend assistive strategies or a rehabilitation program to strengthen your auditory processing skills. Adult auditory processing assessments are offered at the University of Melbourne Audiology clinic (www.umac. org.au). This includes a comprehensive assessment of the skills required for effective listening to speech, particularly in noisy environments. Your Disability Liaison Unit will require a full report, so make sure that is included in the assessment when you are making your enquiries.
The name of the test is the Listening in Spatialized Noise - Sentences test, or LiSN-S. It is available in English-speaking countries from Phonak. LiSN-S is used to diagnose a specific type of CAPD known as spatial processing disorder, or SPD. This is a reduced ability to selectively attend to sounds coming from one direction and suppress noise coming from other directions. You might expect a child to have SPD if they are having difficulty understanding speech in noisy situations, such as in the classroom. The cause of SPD is so far unknown, but it is more likely to be present in children who have had prolonged or repeated middle ear infections (otitis media) during early childhood, despite full recovery of their hearing thresholds. Research at NAL with the LiSN-S has also shown that all people with a sensorineural hearing loss experience some degree of SPD. As with any form of CAPD, children with SPD can have an FM system fitted to improve the signal-to-noise ratio. NAL has also developed the LiSN & Learn auditory training software to remediate this condition in children with normal hearing thresholds. Research and clinical trials have found, for all children who completed the training, no evidence of SPD remaining by the end of the training. The LiSN & Learn is available directly from the NAL website at http://shop.nal. gov.au/store/lisn-learn.html.
Auditory neuropathy was once thought to be rare but it may be quite common and account for up to 10% of childhood cases of hearing loss, and can also be seen in older children and adults. It is an unusual cause of hearing loss. The understanding of how it occurs is still changing and is a source of some controversy amongst hearing specialists, as is its diagnosis and treatment. The most common progressive and severe hearing losses involve hair cell failure within the cochlea while leaving the auditory nerve intact and working well. This is why a cochlear implant usually works so well for most profound hearing losses. It stimulates a nerve which is still functioning. In Auditory Neuropathy Spectrum Disorder (ANSD) some of the hair cells (or at least the outer hair cells) may be functioning well but inner hair cells and/or the junction with the auditory nerve (the synapse) along with the auditory nerve itself seems to have failed. ANSD seems to occur in several clusters of patients. One cluster involves infants who are born preterm and spend some time in the neonatal intensive care. They may have been affected by some degree of birth trauma (hypoxia), high levels of jaundice and exposure to a variety of medications during their treatment. A second group generally develops later onset symptoms during childhood, adolescence or early adulthood. This group (the minority) often have associated neurological disorders with neuropathy affecting other parts of the body. Disorders such as Charcot- Marie-Tooth disease fit this category. Genetic defects with failure of the otoferlin gene, which is required for normal inner hair cell function, may also be underlying factors. As one can imagine, the diagnosis of such a variable and complex condition requires several sophisticated hearing test. This involves an audiogram (and speech perception test in older children or adults), otoacoustic emission studies (a test of outer hair cell function) and an auditory brain stem response test (ABR). The classical test results in ANSD are a variable degree of hearing loss on the audiogram, but poor speech discrimination, particularly in background noise; poor or absent ABR wave forms and intact otoacoustic emission. The problem with ANSD is that the outcomes of children and adults with the disorder is highly variable. The long term outcomes range from normal hearing, speech and language development, to such disordered hearing that a cochlear implant is considered. The response to hearing aids and cochlear implantation is also highly variable. At this stage of our understanding, patients with disorders limited to the cochlea (hair cell failure) may have good outcomes, while those involving poor auditory nerve function have outcomes which are more varied and difficult to predict. Much work is being done in furthering the understanding and diagnosis of ANSD as well as more strongly predicting the outcomes of treatments.