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Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
Funded by The Federal Ministry for Economic Affairs and Energy; Grant: 01MD19013D, Smart-MD Project, Digital Technologies
Treatment options that offer “cures” for NIHL are under research and development. Currently there are no commonly used cures, but rather assistive devices and therapies to try and manage the symptoms of NIHL.
Several clinical trials have been conducted to treat temporary NIHL occurring after a traumatic noise event, such as a gunshot or firework. In 2007, individuals with acute acoustic trauma after firecracker exposure were injected intratympanically with a cell permeable ligand, AM-111. The trial found AM-111 to have a therapeutic effect on at least 2 cases of those with acute trauma. Treatment with a combination of prednisolone and piracetam appeared to rescue patients with acute trauma after exposure to gunshots. However, those who received the treatment within an hour of exposure had higher rates of recovery and significantly lower threshold shifts compared to those who received treatment after 1 hour.
Additionally, clinical trials using antioxidants after a traumatic noise event to reduce reactive oxygen species have displayed promising results. Antibiotic injections with allopurinol, lazaroids, α-D-tocopherol, and mannitol were found to reduce the threshold shift after noise exposure. Another antioxidant, Ebselen, has been shown to have promising results for both TTS and PTS. Ebselen mimics gluthathione peroxide, an enzyme that has many functions, including scavenging hydrogen peroxide and reactive oxygen species. After noise exposure, gluthathione peroxide decreases in the ear. An oral administration of ebselen in both preclinical tests on guinea pigs and human trials indicate that noise induced TTS and PTS was reduced.
Several methods of prevention exists to eliminate or reduce the hearing loss caused by workplace exposure. Occupational hearing loss is very preventable, but currently the interventions to prevent noise-induced hearing loss are complex, having many of the components described above. A 2017 Cochrane review found that hearing loss prevention programs revealed that stricter legislation might reduce noise levels. Earmuffs and earplugs can reduce noise exposure to safe levels, but, instructions are needed on how to put plugs into the ears correctly to achieve potential attenuation. Giving workers information on their noise exposure levels by itself was not shown to decrease noise. Engineering solutions might lead to similar noise reduction as that provided by hearing protection. Better evaluation of the noise exposures resulting from engineering interventions is needed, as most of the available information is limited to observations in laboratory conditions. Overall, the effects of hearing loss prevention programs are unclear. Better use of hearing protection as part of a program but does not necessarily protect against hearing loss. The review concluded that in order to prevent noise-induced hearing loss in the workplace the quality of the implementation of prevention programs affects results, and that better quality of studies, especially in the field of engineering controls, and better implementation of legislation are needed. While the 2017 systematic review concluded there is a lack of conclusive evidence it highlighted that this should not be interpreted as evidence of lack of effectiveness. The implications is that further research could affect conclusions reached.
The hierarchy of controls provides a visual guide to the effectiveness of the various workplace controls set in place to eliminate or reduce exposure to occupational hazards, including noise or ototoxic chemicals. The hierarchy includes the following from most effective to least effective:
- Elimination: complete removal of the hazard
- Substitution: replacement the offers a smaller risk
- Engineering controls: physical changes to reduce exposure
- Administrative controls: changes in work procedures or training
- Personal protective equipment (PPE): individual equipment to reduce exposure, e.g. earplugs
At high doses, quinine, aspirin and other salicylates may also cause high-pitch tinnitus and hearing loss in both ears, typically reversible upon discontinuation of the drug.
The erectile dysfunction medications Viagra, Levitra, and Cialis have also been reported to cause hearing loss.
Ototoxic effects are also seen with quinine, pesticides, solvents, asphyxiants and heavy metals such as mercury and lead. When combining multiple ototoxins, the risk of hearing loss becomes greater.
Ototoxic chemicals in the environment (from contaminated air or water) or in the workplace interact with mechanical stresses on the hair cells of the cochlea in different ways. For organic solvents such as toluene, styrene or xylene, the combined exposure with noise increases the risk of hearing loss in a synergistic manner. Carbon monoxide, has been shown to increase the severity of the hearing loss from noise. Given the potential for enhanced risk of hearing loss, exposures and contact with products such as paint thinners, degreasers, white spirits, exhaust, should be kept to a minimum. Noise exposures should be kept below 85 decibels, and the chemical exposures should be below the recommended exposure limits given by regulatory agencies.
Drug exposures mixed with noise potentially lead to increased risk of ototoxic hearing loss. Noise exposure combined with the chemotherapeutic cisplatin puts individuals at increased risk of ototoxic hearing loss. Noise at 85 dB SPL or above added to the amount of hair cell death in the high frequency region of the cochlea In chinchillas. The American Academy of Audiology includes in their position statement that exposure to noise at the same time as aminoglycosides may exacerbate ototoxicity. The American Academy of Audiology recommends people being treated with ototoxic chemotherapeutics avoid excessive noise levels during treatment and for several months following cessation of treatment. Opiates in combination with excessive noise levels may also have an additive affect on ototoxic hearing loss.
Previous noise exposure has not been found to potentiate ototoxic hearing loss.
Vitamins A, C and E have been shown to be 'free radical scavengers' by studies looking for protective tendencies of antioxidants. In addition, NAC, or N-acetyl-L-cysteine (acetylcysteine), has been shown to reduce ROS formation associated with the excessive vibrations induced by the noise exposure.
At present, presbycusis, being primarily sensorineural in nature, cannot be prevented, ameliorated or cured. Treatment options fall into three categories: pharmacological, surgical and management.
- There are no approved or recommended pharmaceutical treatments for presbycusis.
Furosemide injections prior to noise exposure have been shown to decrease the endocochlear potential. This decrease results in a reduction of active cochlear displacements and it is believed that the protection by furosemide stems from the limitation of excessive vibrations while the cochlear amplifier is depressed.
About half of people with SSNHL will recover some or all of their hearing spontaneously, usually within one to two weeks from onset. Eighty-five percent of those who receive treatment from an otolaryngologist (sometimes called an ENT) will recover some of their hearing.
- vitamins and antioxidants
- vasodilators
- betahistine (Betaserc), an anti-vertigo drug
- hyperbaric oxygen
- anti-inflammatory agents, primarily oral corticosteroids such as prednisone, methylprednisone
- Intratympanic administration - Gel formulations are under investigation to provide more consistent drug delivery to the inner ear. Local drug delivery can be accomplished through intratympanic administration, a minimally invasive procedure where the ear drum is anesthetized and a drug is administered into the middle ear. From the middle ear, a drug can diffuse across the round window membrane into the inner ear. Intratympanic administration of steroids may be effective for sudden sensorineural hearing loss for some patients, but high quality clinical data has not been generated. Intratympanic administration of an anti-apoptotic peptide (JNK inhibitor) is currently being evaluated in late-stage clinical development.
Presbycucis is the leading cause of SNHL and is progressive and nonpreventable, and at this time, we do not have either somatic or gene therapy to counter heredity-related SNHL. But other causes of acquired SNHL are largely preventable, especially nosocusis type causes. This would involve avoiding environmental noise, and traumatic noise such as rock concerts and nightclubs with loud music. Use of noise attenuation measures like acoustic ear plugs is an alternative.
Pharmacological treatment options are limited, and remain clinically unproven. Among these are the water-soluble coenzyme Q10 formulation, the prescription drug Tanakan, and combination antioxidant therapy.
- In a study performed in 2010, it was found that the water-soluble formulation of coenzyme Q10 (CoQ10) caused a significant improvement in liminar tonal audiometry of the air and bone thresholds at 1000 Hz, 2000 Hz, 4000 Hz, and 8000 Hz.
- Antioxidant therapy - age-related hearing loss was reduced in animal models with a combination agent comprising six antioxidant agents that target four sites within the oxidative pathway: L-cysteine-glutathione mixed disulfide, ribose-cysteine, NW-nitro-L-arginine methyl ester, vitamin B12, folate, and ascorbic acid. It is thought that these supplements attenuate the decline of cochlear structure due to prolonged oxidative stress. However, more recent studies have had conflicting results. In 2012, a study was done with CBA/J female mice. They were placed on an antioxidant-rich diet for 24 months consisting of vitamins A, C, E, L-carnitine, and α-lipoic acid. While this increased the inner ear’s antioxidant capacity, the actual hearing loss was unaffected. Therefore, in this study, antioxidants were shown not to improve presbycusis mechanisms.
- The effects of the pharmaceutical drug Tanakan were observed when treating tympanophonia in elderly women. Tanakan was found to decrease the intensity of tympanitis and improve speech and hearing in aged patients, giving rise to the idea of recommending treatment with it to elderly patients with presbycusis or normal tonal hearing.
- AM-111, an otoprotective peptide, was shown in a chinchilla study to rescue and protect against hearing loss following impulse noise trauma. AM-111 acts as a cell-permeable inhibitor of JNK-mediated apoptosis. IP injections or local injections into membrane of the round window were given, and permanent threshold shifts (PTS) were measured three weeks after impulse noise exposure. AM-111 animals had significantly lower PTS, implicating AM-111 as a possible protective agent against JNK-mediated cochlear cell death and against permeant hearing deficits after noise trauma.
- The anti-inflammatory, anti-oxidant substance Ebselen was observed to reduce hearing loss in a study done in 2007. . It has been previously shown that noise trauma correlates with decreases in glutathione peroxidase (GPx) activity, which has been linked to loss of the outer hair cells. GPx1, an isoform of GPx, is predominantly expressed in stria vascularis, cochlea, spiral ligament, organ of Corti, and spiral ganglion cells. The stria vascularis displayed significant decreases in GPx1 immunoreactivity and increased swelling following noise exposure in rats. There was also significant outer hair cell loss in the cochlea within five hours of noise exposure. Administration of Ebselen before and after the noise stimulus reduced stria vascularis swelling as well as cochlear outer hair cell loss. This implicates Ebselen as a supplement for GPx1 in the outer hair cell degradation mechanism of hearing loss. This treatment is currently in active clinical trials.
- A γ-secretase inhibitor of Notch signaling was shown to induce new hair cells and partially recover hearing loss . Auditory hair cell loss is permanent damage due to the inability of these cells to regenerate. Therefore, deafness due to this pathology is viewed as irreversible. Hair cell development is mediated by Notch signaling, which exerts lateral inhibition onto hair cells. Notch signaling in supporting hair cells leads to prevention of differentiation in surrounding hair cells. After identifying a potent γ-secretase inhibitor selective for stimulating differentiation in inner ear stem cells, it was administered in acoustically injured mice. The animals who received the injury and treatment displayed an increased hair cell number and stimulated hearing recovery. This suggests that γ-secretase inhibition of Notch signaling can be a potential pharmacological therapy in approaching what was previously viewed as permeant deafness.
While there is no cure, most people with tinnitus get used to it over time; for a minority, it remains a significant problem.
As of 2012 there has only been one small-scale study comparing CROS systems.
One study of the BAHA system showed a benefit depending on the patient's transcranial attenuation. Another study showed that sound localisation was not improved, but the effect of the head shadow was reduced.
Management falls into three modalities: surgical treatment, pharmaceutical treatment, and supportive, depending on the nature and location of the specific cause.
In cases of infection, antibiotics or antifungal medications are an option. Some conditions are amenable to surgical intervention such as middle ear fluid, cholesteatoma, otosclerosis. If conductive hearing loss is due to head trauma, surgical repair is an option. If absence or deformation of ear structures cannot be corrected, or if the patient declines surgery, hearing aids which amplify sounds are a possible treatment option. Bone conduction hearing aids are useful as these deliver sound directly, through bone, to the cochlea or organ of hearing bypassing the pathology. These can be on a soft or hard headband or can be inserted surgically, a bone anchored hearing aid, of which there are several types. Conventional air conduction hearing aids can also be used.
"Ginkgo biloba" does not appear to be effective. The American Academy of Otolaryngology recommends against taking melatonin or zinc supplements to relieve symptoms of tinnitus. In addition, a 2016 Cochrane Review concluded that evidence is not sufficient to support taking zinc supplements to reduce symptoms associated with tinnitus.
One possible treatment for hyperacusis is retraining therapy which uses broadband noise. Tinnitus retraining therapy, a treatment originally used to treat tinnitus, uses broadband noise to treat hyperacusis. Pink noise can also be used to treat hyperacusis. By listening to broadband noise at soft levels for a disciplined period of time each day, patients can rebuild (i.e., re-establish) their tolerances to sound.
Another possible treatment is cognitive behavioral therapy (CBT), which may also be combined with retraining therapy.
In cases where the causes are environmental, the treatment is to eliminate or reduce these causes first of all, and then to fit patients with a hearing aid, especially if they are elderly. When the loss is due to heredity, total deafness is often the end result. On the one hand, persons who experience gradual deterioration of their hearing are fortunate in that they have learned to speak. Ultimately the affected person may bridge communication problems by becoming skilled in sign language, speech-reading, using a hearing aid, or accepting elective surgery to use a prosthetic devices such as a cochlear implant.
Earlier workers suggested the use of calcium fluoride; now sodium fluoride is the preferred compound. Fluoride ions inhibit the rapid progression of disease. In the otosclerotic ear, there occurs formation of hydroxylapatite crystals which lead to stapes (or other) fixation. The administration of fluoride replaces the hydroxyl radical with fluoride leading to the formation of fluorapatite crystals. Hence, the progression of disease is considerably slowed down and active disease process is arrested.
This treatment cannot reverse conductive hearing loss, but may slow the progression of both the conductive and sensorineural components of the disease process. Otofluor, containing sodium fluoride, is one treatment. Recently, some success has been claimed with a second such treatment, bisphosphonate medications that inhibit bone destruction. However, these early reports are based on non-randomized case studies that do not meet standards of clinical trials. There are numerous side-effects to both pharmaceutical treatments, including occasional stomach upset, allergic itching, and increased joint pains which can lead to arthritis. In the worst case, bisphosphonates may lead to osteonecrosis of the auditory canal itself. Finally, neither approach has been proven to be beneficial after the commonly preferred method of surgery has been undertaken.
AIED treatment is a rapidly changing field. Several medical therapies have been proposed in the treatment of AIED, with corticosteroid therapy being the most effective. However, corticosteroid therapy (specifically with prednisone and dexamethasone) has demonstrated limited effectiveness in some patients, suggesting the need for novel treatment methods. The goal of most AIED treatments is to administer corticosteroids over a certain period of time, re-evaluate hearing at each appointment, and eventually taper off corticosteroid administration. Ideally, patients can be tapered off with hearing fully recovered, though this is the least likely outcome. Often, tumor necrosis factor-α (TNF-α) inhibitors must be administered alongside corticosteroids to achieve a favorable outcome and eventual end to corticosteroid treatment. Recent papers have indicated that the TNF-α inhibitor, infliximab, has the potential to allow for sustained patient improvement and alleviation of symptoms.
Cytotoxic agents such as cyclophosphamide and methotrexate have been used in AIED treatment in the past; however, findings have suggested limited symptom alleviation from these drugs.
Universal Newborn Hearing Screenings (UNHS) is mandated in a majority of the United States. Auditory neuropathy is sometimes difficult to catch right away, even with these precautions in place. Parental suspicion of a hearing loss is a trustworthy screening tool for hearing loss, too; if it is suspected, that is sufficient reason to seek a hearing evaluation from an audiologist.
In most parts of Australia, hearing screening via AABR testing is mandated, meaning that essentially all congenital (i.e., not those related to later onset degenerative disorders) auditory neuropathy cases should be diagnosed at birth.
The most common cause of hyperacusis is overexposure to excessively high decibel (sound pressure) levels.
Some come down with hyperacusis suddenly as a result of taking ear sensitizing drugs, Lyme disease, Ménière's disease, head injury, or surgery. Others are born with sound sensitivity, develop superior canal dehiscence syndrome, have had a history of ear infections, or come from a family that has had hearing problems.
Some psychoactive drugs such as LSD, methaqualone, or phencyclidine ("angel-dust") can cause hyperacusis. An antibiotic, ciprofloxacin has also been seen to be a cause, known as "ciprofloxacin-related hyperacusis".
It is estimated that half of cases of hearing loss are preventable. A number of preventative strategies are effective including: immunization against rubella to prevent congenital rubella syndrome, immunization against "H. influenza" and "S. pneumoniae" to reduce cases of meningitis, and avoiding or protecting against excessive noise exposure. The World Health Organization also recommends immunization against measles, mumps, and meningitis, efforts to prevent premature birth, and avoidance of certain medication as prevention.
Noise exposure is the most significant risk factor for noise-induced hearing loss that can be prevented. Different programs exist for specific populations such as school-age children, adolescents and workers. Education regarding noise exposure increases the use of hearing protectors. The use of antioxidants is being studied for the prevention of noise-induced hearing loss, particularly for scenarios in which noise exposure cannot be reduced, such as during military operations.
Some medications may reversibly affect hearing. These medications are considered ototoxic. This includes loop diuretics such as furosemide and bumetanide, non-steroidal anti-inflammatory drugs (NSAIDs) both over-the-counter (aspirin, ibuprofen, naproxen) as well as prescription (celecoxib, diclofenac, etc.), paracetamol, quinine, and macrolide antibiotics. The link between NSAIDs and hearing loss tends to be greater in women, especially those who take ibuprofen six or more times a week. Others may cause permanent hearing loss. The most important group is the aminoglycosides (main member gentamicin) and platinum based chemotherapeutics such as cisplatin and carboplatin.
On October 18, 2007, the U.S. Food and Drug Administration (FDA) announced that a warning about possible sudden hearing loss would be added to drug labels of PDE5 inhibitors, which are used for erectile dysfunction.
School-age children with unilateral hearing loss tend to have poorer grades and require educational assistance. This is not the case with everyone, however. They can also be perceived to have behavioral issues.
People afflicted with UHL have great difficulty locating the source of any sound. They may be unable to locate an alarm or a ringing telephone. The swimming game Marco Polo is generally impossible for them.
When wearing stereo headphones, people with unilateral hearing loss can hear only one channel, hence the panning information (volume and time differences between channels) is lost; some instruments may be heard better than others if they are mixed predominantly to one channel, and in extreme cases of sound production, such as complete stereo separation or stereo-switching, only part of the composition can be heard; in games using 3D audio effects, sound may not be perceived appropriately due to coming to the disabled ear. This can be corrected by using settings in the software or hardware—audio player, OS, amplifier or sound source—to adjust balance to one channel (only if the setting downmixes sound from both channels to one), or there may be an option to outright downmix both channels to mono. Such settings may be available via the device or software's accessibility features. As hardware solutions, stereo-to-mono adapters may be available to receive mono sound in stereo headphones from a stereo sound source, or some monaural headsets for cellphones and VOIP communication may combine stereo sound to mono (though headphones for voice communication typically offer lower audio quality than headphones targeted for listening to music). From the standpoint of sound fidelity, sound information in downmixed mono channel will, in any case, differ from that in either of the source channels or what is perceived by a normal-hearing person, thus technically some audio quality is lost (for example, the same or slightly different sound occurrences in two channels, with time delay between them, will be merged to a sound in the mono channel that unavoidably cannot correspond to the intent of the sound producer); however, such loss is most probably unnoticeable, especially compared to other distortions inherent in sound reproduction, and to the person's problems from hearing loss.