Posts tagged hearing impairment
More and more studies are showing that older adults who have a loss of hearing are at increased risk of developing dementia, and/or Alzheimer disease. Studies also show that the risk for developing dementia increases significantly as hearing loss becomes worse. Several studies have been conducted with the express intention of exploring potential solutions for the soaring incidence of dementia, with estimates now predicting that more than 100 million people will be affected globally, when the year 2050 is reached.
Researchers claim that any kind of interventions which would have the effect of deferring the onset of dementia by as little as a single year, could lead to at least a 10% decrease in the widespread occurrence of the disease over the next four decades. The problem with that is that a great deal more research is necessary before those potential interventions can be identified, since at present, there is very little evidence that interventions can be beneficial in this area.
The reason that the concept of interventions is so appealing to medical personnel is because of the universal understanding that dementia would be far easier to prevent than it is to cure or reverse. It is known that people are more likely to develop dementia when they have relatively little participation in leisure activities or any kind of social interactions.
Other risk factors for developing dementia occur in people who are relatively sedentary, or those who develop diabetes mellitus. It’s also known that one of the most prevalent reasons for elderly people not participating in social events and activities is that they have experienced some level of hearing loss, and are reluctant to become involved, because of the potential for embarrassment.
Testing for Hearing Loss
Given the fact that hearing loss is one of the precursors to social disengagement, and that social disengagement is a precursor to dementia, researchers have considered it very important to explore the causes of hearing loss. A landmark study conducted by Dr. Frank R Lin of Johns Hopkins Medical Institution has examined the effects of hearing loss on almost 700 people aged between 36 and 90, none of whom had dementia when the study began.
Participants were all required to undergo cognitive and hearing tests for approximately five years beginning in 1990, and were re-tested in the year 2008 for the possibility of having developed dementia or Alzheimer’s. Of all the participants in the program, almost 200 had some level of hearing loss when the study began.
When participants were re-tested more than a decade later, 58 of them had full-blown dementia, including 37 who had Alzheimer’s disease. The precise statistics taken during the study indicated that the risk for dementia increased significantly for participants who had at least a 25 dB hearing loss, and the dementia risk escalated right along with the level of hearing loss. In effect, those participants who had the worst level of hearing loss were also those most likely to be diagnosed with dementia.
Particularly for the study participants who were older than 60, there was a 37% risk of developing dementia which was linked to hearing loss. A strong correlation was found between the level of hearing loss and the likelihood of diagnosing dementia in these older citizens, and it was found that for every 10 dB more of hearing loss, the increased risk of developing dementia went up by 20%.
The Link between Dementia and Hearing Loss
The clear association between hearing loss and dementia found in this study and others conducted afterward, show that there is at least a possibility there is a common cause which underlies both conditions. Some scientists and medical personnel theorize that the link between the two stems from the fact that the more profound hearing loss is in an individual, the more likely that individual is to avoid social interaction.
When social interaction is avoided to a significant degree, and borders on isolation, the risk factors for developing dementia rise dramatically. This has led scientists to consider the possibility of experimenting with an intervention to improve the hearing of senior citizens at the earliest stage possible, so that no further damage occurs to hearing, and so hearing loss does not worsen.
There will undoubtedly be studies in the near future which explore the connection between a hearing loss intervention and the possible reduced risk of developing dementia. It’s entirely possible that by early detection of hearing problems in seniors, and taking aggressive corrective measures, the risk of developing dementia can be significantly reduced.
This is a tantalizing proposition, because hearing loss in most cases is a very preventable condition, and it can be effectively addressed using modern technology such as hearing aids or cochlear implants. Rehabilitative interventions might also be implemented which would create social environments that are optimal for better hearing, so that seniors would have few reservations about participating.
If this theory is found to have relevance and accuracy, it may represent one of the very best ways of intervening to reduce the runaway development of dementia in the elderly. At present however, this must remain in the realm of conjecture and theory, and it will be necessary for scientific study and research to establish the accuracy of the theory.
Hearing loss is the third most common health problem in this country, behind only arthritis and heart disease, so it’s apparent that a great many people are finding it difficult to maintain good hearing health by the time they reach their later years. It is especially important that good hearing health be observed because a number of studies have discovered a strong link between reduced hearing capability and dementia.
Once people in their later years have experienced a significant level of hearing loss, they tend to become less social and less engaged with others, and this is one of the primary triggers for the development of dementia. That being the case, it just makes good sense for every American to do whatever is possible to maintain good hearing health, both for the present and for senior years.
While nothing you can do will really guarantee that your hearing remains extremely good as a senior, there are some things you can do which will increase your chances of maintaining good hearing throughout your life. Below are described a few simple things that everyone can do to have a better chance of retaining optimal hearing, now in the future.
Avoid Loud Noises
It’s important to have an understanding of the sound level of your environment, as well as any special environments you walk into. Some of these scenarios include rock concerts, construction sites, and loud noises from city traffic. When you are exposed to situations like these, it’s a good idea to wear ear protection such as foam plugs, which will reduce the level of noise which reaches the middle ear. Keep in mind that anytime your ears are exposed to a situation where extremely loud noises are present, it takes at least 16 hours of quiet in order for the ears to recover from the sensory experience.
By placing either a rubber plug or a foam plug in your outer ear, the level of noise can be reduced by as much as 30 dB, thereby sparing the middle ear from significant damage. If you work in a setting which has a consistent level of relatively loud noise, it would be a good idea to take periodic breaks, so that your ears have recovery time.
Most people enjoy listening to music on their phones, and to personalize the experience, headphones or earbuds are generally used. If you are in this category, you should make a point of keeping the volume on your device to either low or midrange, especially if you’re going to have the earbuds in place for a prolonged period of time.
If you set the volume on high, you run a risk of causing damage to your ears, especially if this is something you do daily, and for several hours each day.
Adopt a Healthy Lifestyle
A number of studies have linked heart health with hearing health, and it has even been said that the ear is the window to the heart. Being physically active is a great way to maintain heart health, and to keep the heart muscle strong, so as to avoid the many different kinds of disease and other issues which can impact the heart.
A regular program of exercise that benefits the heart will also indirectly benefit your ears, so making exercise a priority is a good idea. However, before you embark on any strenuous program of exercise, make sure to consult with your doctor, so that you can be sure of activities which are appropriate to your age and to your health status.
One other factor related to maintaining a healthy lifestyle is that you should quit cigarette smoking, and if you haven’t yet started, make sure that you don’t. Researchers have found that cigarette smoking may have a direct bearing on hearing because it affects antioxidative mechanisms as well as the vasculature which supplies the entire auditory system.
Good Ear Care
Avoid physical damage as much as possible by resisting the temptation to put things into your ears, even seemingly harmless objects like Q-tips. If your ear canal becomes scratched somehow, your hearing is likely to be degraded. Sharp objects should never be put into the ears, because these can cause scratches, and can even puncture the eardrum, in addition to causing hearing loss.
You should make a point of removing earwax regularly because any kind of buildup will cause the sound to be muffled. However, care must be used in removing earwax, because cotton swabs may have the undesirable effect of pushing the earwax further into the ear canal, and that may necessitate professional expertise in removing it.
Have your hearing checked periodically so that you are aware of any incremental hearing loss since your last checkup. As a general rule, less than 15% of Americans actually have their hearing checked during their annual physical exam – and yet as mentioned above, hearing loss is the third most common health complaint in the country.
There are certain medications which can cause damage to the ear, especially those medicines taken by older adults routinely. Prescription medications should all be checked by your doctor to make sure they won’t have any impact on your hearing health.
Whenever you suspect that you are observing a sign of hearing loss, it should be reported to your doctor for further examination. Some of these warning signals might include speech which sounds muffled, difficulty interpreting conversation, or frequently requesting others to talk louder.
Sometimes you may have difficulty hearing certain consonants, and this may prompt you to avoid conversations. Be aware that such behaviors can be warning signs of hearing loss, and any sign of reduced hearing health should be checked out at an early stage, so it doesn’t have a chance to become significantly worse.
People who have hyperacusis hear things a little differently than people with relatively normal hearing. With this medical condition, ordinary sounds like running water, the ticking of a clock, or the timer alarm on your microwave not only sound extremely loud, but also can actually be painful. This doesn’t mean that their hearing is more acute, or that patients with this condition are able to hear more sounds than the rest of us – it just means that all normal sounds you may hear in a typical day are heard at a higher level of volume. This is not just a temporary inconvenience a with minor impact; it can literally have a profound effect on a person’s quality of life, because the condition doesn’t ever take a break – it’s there all the time.
How Does Hyperacusis Develop?
Scientists are not exactly sure what causes this condition to develop in any one person, but studies which have been conducted seem to point to exposure to one of several triggering conditions as a cause. One of the most prominent of these is noise related to a daily job routine: for instance, someone working in a factory with heavy machinery, or where a repetitive loud noise recurs throughout the eight-hour shift.
Traumatic head injuries are another possible cause of hyperacusis, with many of today’s hyperacusis patients having experienced some significant blow to the head in their past. Chronic ear infections are another culprit, because even though they can be cleared up with medication, the damage they do while the infection is rampaging can persist beyond the duration of the infection itself.
Migraine headaches are thought to be another possible cause of hyperacusis, since many current hyperacusis patients also experience migraines, or have had them in their medical history. There also seems to be a correlation between patients who have contracted Lyme disease or TMJ Syndrome in their past, although it is not known exactly what from those two conditions leads to the development of hyperacusis. Lyme disease is spread by a tick which can commonly be found in fields and woods, and may be brushed up against by a person. Temporomandibular Joint (TMJ) Syndrome is a disorder which causes pain in the muscles and joints of the jaw.
As far as the physiology behind the actual triggering of hyperacusis, that’s the part of the equation that scientists and researchers have yet to confirm. At present, it seems likely that the fibers of the ear which regulate sound have been somehow compromised, and that the auditory nerve has suffered significant damage. Another school of thought holds that the brain’s central processing system affects how the brain evaluates sound, and for some reason magnifies it beyond its true level. And naturally enough, since there are primarily these two major theories about what actually happens in hyperacusis, there is also another group of scientists who believe that a combination of those two is the real answer to the problem.
Relationship to Tinnitus
While most people have probably not heard of hyperacusis, the medical condition of tinnitus is probably much more well-known. While these two conditions are not at all same thing, they do have a relationship, in that both represent departures from the norm in the way that sounds are heard. People with tinnitus experience several different abnormal sounds in their hearing, sometimes even when there is no actual noise being generated in the surroundings.
This can be felt as a ringing noise, or some kind of whistling, hissing, or buzzing, and it’s easy to see how this can be so distracting that a person’s quality of life could easily be diminished. Although hard statistics are not available to support this, it is estimated that more than 60% of patients who have tinnitus also have hyperacusis. So in addition to hearing a persistent buzzing or whistling sound in the ears, a patient who experiences both of these medical conditions would also sense ordinary sounds at several times their true volume.
Having either one of these medical conditions could have a profound impact on your daily life, but just imagine being troubled by both of them at the same time! Patients who are known to suffer from both medical conditions generally find it extremely hard to just get through a normal day. As a result, there’s a strong tendency for such individuals to withdraw from life to a significant extent, and become socially isolated. This in turn, can easily slide into depression and add to the list of medical conditions the individual would have to deal with.
Treatment for Hyperacusis
Treating hyperacusis requires a two-pronged approach, but it does not really result in a cure for the condition. People who have hyperacusis are generally counseled so as to help lower their reactions to loud sounds, and a process known as acoustic therapy helps to retrain the ear to hear sounds at a more normal level. While there are no actual medical or surgical procedures at present which can offer significant help, some success has been achieved by the counseling/retraining program. Not surprisingly, the same approach has been used with tinnitus, with similar success.
If you’ve never heard of the term ‘hyperacusis,’ it refers to a condition in which a person’s normal tolerance to sounds in their everyday environment is severely diminished. With hyperacusis, the sound of a car braking at a traffic light can sound like a horrible screech, and a group of people applauding a speaker can sound like a huge thunderclap in a storm. In short, it’s as though someone was toying with the volume control of Life, and left it stuck on the highest setting – just about everything sounds extremely loud.
On the flip side, someone who has hyperacusis usually has lost most of the dynamic range generally associated with hearing, which means there isn’t much difference in the loudness of various sounds. For example, an actual explosion might sound very much like a book dropping off the edge of a table.
Most hyperacusis patients have a sensation of inner ear pain or a feeling of pressure in the ears which is similar to what you might feel when making a rapid descent in a commercial jetliner. On an airplane, this feeling can be easily overcome by yawning or chewing gum, but a hyperacusis patient feels this ear pressure all the time. This constant discomfort can have an enormous impact on a person’s life, affecting their job as well as their home life and relationships.
For someone with hyperacusis, operating a lawn mower, listening to the radio in the car, or running a vacuum cleaner at home may not be possible. This condition has less to do with volume, and more to do with particular sound frequencies, which can make attempts to muffle out noise entirely futile as well.
What can be done to help people who have hyperacusis?
Noise Has Color
The pink spectrum of noise is the one which most closely matches the broad range of sounds which we hear in our normal environment. That’s why treatment for patients with hyperacusis generally involves building up a tolerance to pink noise, rather than white noise, which includes higher frequencies. The higher frequencies are the ones most troubling for hyperacusis patients, so trying to build a tolerance to white noise is not nearly as effective an approach.
The goal of any program of sound therapy is to slowly and incrementally build up a tolerance to noise, but this can be a very frustrating and difficult experience for someone with hyperacusis. Many patients find that they just don’t have the patience to undergo this kind of slow therapy, and search for something that will produce faster, less uncomfortable results. If nothing helps, a patient may have few options other than to wear earplugs a majority of the time during waking hours.
How Sound Therapy Works
The whole idea of sound therapy is to get a person re-familiarized and tolerant of the noises which populate our day-to-day world. Sounds are delivered to the ears by one of the several methods, like listening to CDs with recorded everyday sounds. But this can be an inconvenient kind of session for the hyperacusis patient because therapy sessions should last at least two hours per day, and if you’re stuck with one CD for that long, it can get to be uncomfortable and restrictive.
An alternative method of sound delivery calls for custom-fitted sound generators made for your head and ears and having pre-recorded pink noise sounds played for the duration of your therapy sessions. With a sound generator, you’d be free to walk around and do other things, but it can be quite expensive. Whereas a pink noise CD costs less than $100, a sound generator delivering the same pink noise sounds might cost several thousand dollars.
Counseling: A Critical Part of Hyperacusis Therapy
Whichever kind of sound delivery system you choose, there is another essential part of sound therapy: counseling. Having a trained counselor or advisor can make all the difference sometimes, which can ease the difficulties and frustrations that come with sound therapy.
To begin, any sound therapy program requires a high degree of self-motivation from the participant, since no amount of cajoling will persuade a patient to undergo the uncomfortable sessions required. There will be days when the patient wants to shorten or skip the course, or even quit the process altogether. Those are times when a skillful counselor can serve as a cheerleader, and convince the patient to keep eyes on the prize and continue to forge ahead.
It is quite normal for hyperacusis patients to feel that the therapy is hurting them instead of helping since pink noise can be torturous to their hyper-sensitive ears. At times, it takes some skilled counseling to assure a patient that the process is doing them some good, and not harming their ears at all.
It is often a long and uncomfortable process getting re-acquainted with the sounds of our everyday world, but for the patient who sticks with it, it is possible to lessen and maybe even cure the adverse effects of hyperacusis.
According to the most recent report, tinnitus affects around 50 million people in America (to some extent). For the most part, people learn to live with the condition, but there are solutions available. This being said, some medications will make the issue worse which is why we recommend talking to a medical professional before you take action. For example, large doses of aspirin are a bad idea, and thousands of people go wrong every year thinking it will work.
What Is Tinnitus?
Firstly, we should address how tinnitus affects us and the best way to describe it would be a constant noise disturbance coming from inside your ears. Whether it’s a ringing or a whistling, the tinnitus patient is the only person who hears the sounds, making the condition border on maddening.
For most people, it’s a high-pitched ringing that causes the frustration, but you should know it doesn’t generally mean anything larger. Although there are misconceptions that tinnitus is a signal of something deeper in the ears or brain, this isn’t normally the case. As mentioned, only the sufferer will hear the noise, but there are rare cases where the noise comes from a musculoskeletal movement which will allow others to hear it too.
Ultimately, the only real symptom is the problem itself: the perpetual ringing in your ears. However, it’s important to note that the pitch and formation of the sound can differ from one person to the next. While some people note a low-pitched screech, others will suggest a clicking, chirping, hissing, whistling, whooshing, buzzing, pulsing, static, roaring, and perhaps even a musical tone to the sound.
Through the day and night, the volume can fluctuate, and patients notice it most at night. Tinnitus worsens at night mostly because they have nothing else to distract them. When at work and talking to people, we’re concentrating on other things but, when we’re trying to go to sleep, the ringing becomes the center of attention.
A little later, we’re going to take you through the treatment for tinnitus, but we first need to know the cause of the condition. With the word ‘tinnitus,’ we have a term that describes the actual sound regardless of its cause, which is important to remember. For proper treatment, it’s important to locate the cause to prevent the condition from returning.
If we were to look at averages and the most common problem, this would come down to damage/loss of the sensory hair cells in the cochlea of the inner ear. While the aging process is typically responsible for this, it can also occur after exposure to loud noises for an extended period. However, the sound we experience will alter depending on the loss of certain audio frequencies.
Once the brain receives fewer external stimuli around the lost frequency, it must adapt and replace the sound itself, and this is thought to be the reasoning for tinnitus. Since the auditory system isn’t providing all the right sound frequencies, the brain has to pick up the slack.
Elsewhere, other causes include traumatic brain injuries, ear infections, head/neck injuries, foreign object in contact with the eardrum, cardiovascular diseases, middle ear issues, temporomandibular joint (TMJ) disorders, and diabetes. As we said earlier, some medications will exacerbate the tinnitus, and these include some antibiotics, diuretics, aspirin, and ibuprofen.
If left untreated, tinnitus can lead to social isolation, depression, anxiety, and other problems, so treatment is important. With tinnitus, the first step will always be to locate the cause of the issue. After doctors run their tests and discover the problem, they’ll care for the ear infection, drop the ototoxic medications, treat the TMJ problems, etc.
There is no apparent cure for tinnitus induced by old age, so the focus moves to dealing with the sound and making it more bearable. With tinnitus retraining therapy (TRT), this retrains the auditory system, so the tinnitus sounds are accepted rather than disrupting your hearing. Although success isn’t guaranteed, 80% of people find some level of relief from tinnitus with TRT.
If this doesn’t work, your doctor will start dealing with the side effects such as depression, anxiety, and social isolation. With cognitive behavioral therapy (CBT), this ensures depression doesn’t get on top of tinnitus patients. Finally, ENT doctors suggest sound therapy, which exposes patients to constant low background noise to counteract the unpleasant inner ear audio disturbances. With some, they find relief in hearing aids because they amplify external sounds and drown out the tinnitus.
Cognitive issues usually accompany hearing loss. That’s because hearing impairment makes it difficult for some to understand what others are saying. As you can imagine, this makes it hard to hold a conversation. During moments where a person with hearing loss is in a crowded or noisy place, understanding speech becomes an increasingly taxing. In order to solve this issue, scientists are developing cognitive hearing aids. The hope is that these devices can filter background noise and enhance voice recognition to make it easier for people to understand speech.
How Hearing Aids Work
Hearing aids are the primary medical devices used to improve hearing. They are used by people who have hearing damage or have developed hearing loss at some point in their lives. Around 48 million Americans report having hearing loss. Unfortunately, only 20 percent of these people actually use hearing aids.
While these devices cannot fully correct hearing loss, they make is easier to understand and process sound. Some hearing aids can cancel noise and the wind, enhance your spatial region, and highlight voice. These devices still have a long way to go. While some hearing aids are capable of suppressing background noise, they have trouble focusing on the speech of a specific person.
Working on Cognitive Hearing Aids
The goal of creating cognitive hearing aids is to focus on hearing one speaker over voices of many others. Hearing aids that can focus on a singular person can make it easier to understand someone in a crowded place. The cognitive hearing aids would have to connect to the brain to understand where to focus. They would also be quite the achievement.
At the Columbia University School of Engineering and Applied Science, researchers came together to determine how they can achieve this kind of auditory focus with hearing aids. The scientists looked at deep neural network models, which helped them separate multiple voices and determine which one the brain is focusing on. The speaker is then amplified so the user can hear them better. Ultimately, this improves auditory attention decoding (AAD).
“This work combines the state-of-the-art from two disciplines: speech engineering and auditory attention decoding,” says Nima Mesgarani, associate professor of electrical engineering and lead of the study. “We were able to develop this system once we made the breakthrough in using deep neural network models to separate speech.”
Previous studies helped the research team develop this new method. “Translating these findings to real-world applications poses many challenges,” notes James O’Sullivan, a postdoctoral research scientist working with Mesgarani and lead author of the study.
“Our study takes a significant step towards automatically separating an attended speaker from the mixture,” O’Sullivan continues. “To do so, we built deep neural network models that can automatically separate specific speakers from a mixture. We then compare each of these separated speakers with the neural signals to determine which voice the subject is listening to, and then amplify that specific voice for the listener.”
Final Thoughts on the Study
“Our system demonstrates a significant improvement in both subjective and objective speech quality measures — almost all of our subjects said they wanted to continue to use it,” Mesgarani says. “Our novel framework for AAD bridges the gap between the most recent advancements in speech processing technologies and speech prosthesis research and moves us closer to the development of realistic hearing aid devices that can automatically and dynamically track a user’s direction of attention and amplify an attended speaker.”
Hopefully, the cognitive hearing aids will convince those with hearing loss to use these devices. Hearing impairment can occur around the age of 65 years old. Using these devices can significantly improve their quality of life.
Hearing aids are enough to combat mild-to-moderate damage. While this option works for a majority of people with hearing loss, it simply isn’t enough for those who have suffered trauma to their hearing nerve. In the case of nerve deafness, a cochlear implant is necessary for hearing preservation.
People with this severe degree of deafness need as much help as they can get. That’s why scientists strive to improve the technology that returns hearing to normal. Let’s look at the latest study from the Mount Sinai Hospital, which narrows down the best practice for cochlear implants.
Hearing Preservation: Finding the Better Option
Cochlear implants are medical devices that connect directly to the auditory ear. By bypassing the damaged structures of the inner ear, the implant can improve the hearing of people with severe hearing loss. They help more than 188,000 people worldwide.
Lead investigator and researcher at Mount Sinai, George Wanna, MD, Site Chair, Department of Otolaryngology-Head and Neck Surgery at New York Eye and Ear Infirmary of Mount Sinai (NYEE) and Mount Sinai Beth Israel, found that a certain design of cochlear implants worked better than others. After examining 230 patients with every type of cochlear implant, Dr. Wanna’s team of researchers discovered that implants without wires in the electrode worked best.
These implants are called lateral wall electrodes. Not only do they provide better hearing for those wearing them but they do less damage to the ear. The device is less likely to cause internal fractures to the inner ear, making it less traumatic. In order to prove this point even further, the team tested several different brands of the same cochlear implant, finding the same results.
Dr. Wanna had this to say about the study, “”This is the largest clinical study done in the world on conventional electrodes and will have major implications for doctors and their patients who need their long-term hearing restored. This study is a breakthrough for patients with hearing loss, and improvements in practice and techniques will allow them to enjoy many hearing benefits such as music enjoyment, listening in complex environments, and sound localization.”
The research team at Mount Sinai also made another important discovery – the best surgical approach to inserting the cochlear implant. Most implants are surgically inserted under the skin and behind the ear by drilling through the bone. What the research team found was that other options, without drilling through the bone were better.
The two surgical approaches the team examined are called the “round window” and “cochleostomy.” The round window approach involves surgeons opening the membrane without removing the bone or drilling into the inner ear. On the other hand, the cochleostomy approach does drill into the bone.
“The cochleostomy approach causes fibrosis and scarring, leading to hearing loss over time,” said Dr. Wanna. “Our results also revealed that using oral steroids also helped in the long term to preserve hearing by preventing inflammation.”
Dr. Wanna and his team hope surgeons will put this information to good. This research can help by giving patients the best implants available for hearing preservation. “This is an exciting time in this field, and the advancement in hearing technology and continued improvements in techniques and outcomes will benefit patients and their families,” said Dr. Wanna.
As adults grow older, they become more likely to develop hearing and balance disorders. Hearing loss can result from a multitude of factors, including bacterial and viral infections, environmental and work-related noise exposure, genetics, medication toxicity and trauma.
Some of these conditions affect the cochlea, which is the inner ear. As the innermost part of the vertebrate ear, this section of the body is responsible for sound detection and balance. If this part of the body is damaged, your ability to hear suffers greatly.
New research at the Indiana University School of Medicine has developed a way to grow inner ear tissue from human stem cells. The researchers’ findings may lead to better methods of treating hearing loss. Find out how they were able to achieve this success and what it means for the those with hearing impairments.
Research Into the Inner Ear
“The inner ear is only one of few organs with which biopsy is not performed and because of this, human inner ear tissues are scarce for research purposes,” said Eri Hashino, Ph.D., Ruth C. Holton Professor of Otolaryngology at IU School of Medicine. “Dish-grown human inner ear tissues offer unprecedented opportunities to develop and test new therapies for various inner ear disorders.”
In the past, researchers have had difficulties growing inner ear tissue. Traditionally, scientists cultivate human stem cells in a flat layer on a culture dish. However, this method proved unsuccessful in producing viable tissue. Research leads, Karl R. Koehler and Dr. Hashino, instead tested a different culturing technique called three-dimensional culture.
The three-dimensional culture is a technique that grows stem cells in a floating ball-shaped aggregate. This method allows the cells to grow more naturally. They incubate in an environment similar to the body. Through expert guidance, the scientists were able to create structures called “organoids.” These structures contain sensory and supporting cells akin to the ones in the inner ear.
What Does This Research Mean for the Future?
“This is essentially a recipe for how to make human inner ears from stem cells,” said Dr. Koehler, lead author of the study and whose research lab works on modeling human development. “After tweaking our recipe for about a year, we were shocked to discover that we could make multiple inner ear organoids in each pea-sized cell aggregate.”
“We also found neurons, like those that transmit signals from the ear to the brain, forming connections with sensory cells,” Dr. Koehler said. “This is an exciting feature of these organoids because both cell types are critical for proper hearing and balance.”
Dr. Hashino and his colleagues hope to use this new knowledge to study diseases and disorders that affect hearing. In addition to learning more about the ear, the scientists hope to develop new therapies and drugs.
“We hope to discover new drugs capable of helping regenerate the sound – sending hair cells in the inner ear of those who have severe hearing problems,” Dr. Hashino said. If successful, then this is another step towards healing people with hearing impairments.
As we grow older the risk of developing debilitating conditions increases. As a result, staying healthy becomes more and more of a pressing concern for older adults. The truth is that the body doesn’t work as well as it used to and some of our functions may potentially fail as we age. Thankfully, scientists and researchers are always looking into how to treat and detect these situations before they arise.
Take dementia for instance. There are several causes of this degenerative disorder, including neurological diseases, vascular disorders, brain injuries, and more. However, there is one commonality that patients with these diseases share – their age. Approximately 5 percent to 8 percent of adults over 65 have some form of dementia. Even worse, that risk doubles every five years after people reach the age of 65.
One important aspect of treating this disease is detecting it early. Researchers have found a new way to determine if patients are affected by the disease.
Symptoms of Dementia
Dementia comes in two different forms. The first is cortical dementias, which usually shows up in the form of Alzheimer’s or Creutzfeldt-Jakob disease. This form of dementia can cause server memory loss, cognitive issues and may impair your ability to remember words.
The second form of dementia is subcortical. The diseases that are most commonly associated with this are Parkinson’s disease, Huntington’s disease, and HIV. Patients with these diseases are very likely to difficulty thinking quickly or starting a task.
Detecting the Disorder
The hard part about detecting dementia is that these changes may not appear at first or can develop slowly over time. This can lead to some people not detecting signs of the disorder until it is too late. The biggest indicator of the condition in its early stages is memory and thinking problems. Now, scientists at the Baycrest-University of Memphis are saying that hearing and communication issues are a sign as well.
The brainstem and the auditory cortex are the regions of the brain known to process speech. Once thought to resistant to dementia’s effects, the region has shown trouble processing speech from sound to words. In order to look more into this change, researchers used an electroencephalogram (EEG) to measure the brain’s electrical activity in the brainstem and auditory cortex. With 80 percent accuracy, they were able to predict mild cognitive impairment (MCI), a condition that can develop into Alzheimer’s.
“This opens a new door in identifying biological markers for dementia since we might consider using the brain’s processing of speech sounds as a new way to detect the disease earlier,” says Dr. Claude Alain, the study’s senior author and senior scientist at Baycrest’s Rotman Research Institute (RRI) and professor at the University of Toronto’s psychology department.
Dr. Alain continues, stating that “Losing the ability to communicate is devastating and this finding could lead to the development of targeted treatments or interventions to maintain this capability and slow progression of the disease.”
There is no cure for dementia but with continued study, scientists can find new and innovative ways to help people with the disease live normally.
Sometimes, hearing loss occurs because of damage to the tiny hair cells within the inner ear. Using a cochlear implant device allows deaf patients to bypass the effects of inner ear damage, giving them the ability to hear some form of sound. A cochlear implantation requires drilling a hole behind the ear, through the skull bone, and to the inner ear. Researchers may have found another way to perform this procedure.
Using Robotics for Cochlear Implantation
During a cochlear implantation, the hole is drilled to allow the device access to the inner ear. To improve the drilling procedure, scientists at the University of Bern turned to robotics. They developed a high-precision surgical robot to create the entryway for the cochlear device. Their hope is that it provides better hearing outcomes.
The surgical robot would make the hole about 2.5mm in diameter. In order to perform a task of such magnitude, the robot has the do the surgery by itself and without any hands-on interaction or visual from a surgeon. This obviously presents concerns. Surgeons need to be able to track the drill’s progress to make sure in is on track and just in case there is an error.
The researchers built the robot with interlocking safety components. This allows the drill to avoid damaging key areas like the nerves and inner ears.
Prof Weber of the University of Bern, explains: “The robot relies on a number of sensors which are a high-accuracy, optical tracking system, a sensor for resistance that can “feel” the texture of the bone while drilling, and a radar-like nerve stimulation probe that sends small electric pulses into the bone from which the robot can compute whether or not it is on the preplanned track.”
This may be the next major development in cochlear implantation. It has proven effective for one patient and hopefully, it will prove helpful for future patients.