Stem cell trial for hearing loss begin in the USA

Sensorineural hearing loss affects approximately six per 1,000 children, and there is no available medical treatment. — Photo by AP

WASHINGTON: US researchers have begun a groundbreaking trial to test the potential of umbilical cord blood transplants, a kind of stem cell therapy, to treat and possibly reverse hearing loss in infants.

The phase I trial follows promising studies on mice showing that such transplants were able to rebuild the structures of the inner ear, and some anecdotal evidence from humans, sparking hope of a cure for some forms of deafness.

One of those people is two-year-old Finn McGrath, who suffered brain damage after being deprived of oxygen during a prolonged and complicated delivery, according to his mother, Laura.

“His doctors told us he was at high risk for cerebral palsy, vision issues, hearing problems and mental retardation,” she said in an interview with AFP.

Finn’s early days were an all-out struggle to survive, so for his parents, learning that he had failed his hearing tests and had damaged hair cells — the sensory receptors in the inner ear that pick up sounds — was almost an afterthought.

He had organ failure, breathing problems, and his cerebral palsy left him unable to roll, crawl or walk, hold his head up, talk or eat.

As his parents searched for ways to help him, they came upon stories online that told of studies using cord blood to help children with cerebral palsy and other disorders.

Prior to his birth, the McGraths had arranged to privately bank his umbilical cord blood, a procedure that costs around $2,000 plus storage fees, and remains controversial among paediatricians.

Private companies such as the Cord Blood Registry, which is funding the Texas study on hearing loss, urge expecting parents to bank their umbilical cord blood and reserve it for personal use as a way to protect their family.

That advice runs counter to the guidelines issues by the American Academy of Paediatrics in 2007, which calls such claims “unsubstantiated” and says banking for personal or family use “should be discouraged” but is “encouraged” if it is to be stored in a bank for public use.

Since Finn’s parents had already banked his, they enrolled him in cord blood trial for cerebral palsy in North Carolina and he received his first transplant in November 2009 when he was about seven weeks old.

A second transfusion followed and by May, his parents began to notice a change. Night-time noises, like an alarm on his food pump or the sound of ripping medical tape, would suddenly startle him awake, his mother recalled.

“He started vocalising sounds and we could tell that he was anticipating things that we would say. Like, if he had heard a story a number of times or a song, he would smile like he recognised the song or the story.”

Finn had a third infusion in September 2010, when he was one year old. Four months later, an otoacoustic emissions test (OAE), which plays a sound and picks up vibrations in the cochlea and hair cells, came back normal.

The early hearing tests that showed hearing loss were not exactly the same as the later tests that came back normal, so McGrath is cautious about comparing them directly, but she believes the cord blood transfusions may have helped.

“All I can tell you is anecdotally he was not able to hear for probably the first three or four months of his life, and then when he was about six to eight months old, he started hearing.”

The hearing trial in Texas aims to take a first step in testing the safety, and later the efficacy, of transfusing cord blood in children age six weeks to 18 months who have sustained post-birth sensorineural hearing loss.

Some reasons that children lose their hearing at or after birth may include oxygen deprivation, head injury, infection, strong doses of antibiotics or loud noises.

Sensorineural hearing loss affects approximately six per 1,000 children, and there is no available medical treatment.
Hearing aids or cochlear implants are typically offered to boost the ability of the damaged tissues.

“Stem cell therapy may potentially repair the damaged structures of the inner ear and restore normal hearing,” lead investigator Sami Fakhri told AFP.

“We are at the initial stages of this process and the results are looking promising,” Fakhri added.

Research using stem cells in cord blood, known as hematopoietic cells, is already under way on some types of brain injury, cerebral palsy, juvenile diabetes, kidney and lung disease, he said.

The new study at Memorial Hermann-Texas Medical Center is being funded by the Cord Blood Registry, a private bank, and those eligible must have already banked their own umbilical cord blood with CBR.

But to Stephen Epstein, an otolaryngologist in Maryland, that does not pose a conflict of interest, because separate medical institutions in Texas and Georgia are conducting the Food and Drug Administration-approved research.

“If both of them can reproduce the same results then I would say it has some validity to it,” said Epstein, who is not involved in the study.

“This is certainly a welcome, acceptable experiment, but it should be looked at with caution and time will tell.”

One patient is already enrolled and the study, which runs for one year, has room for nine more.

While Finn McGrath still faces many challenges due to his cerebral palsy, his mother is grateful for the things he can do.

“I don’t know how much worse off he would have been without the stem cell transfusion,” McGrath said, pointing to his normal cognition, lack of seizures, good hearing and vision.

“We remain hopeful that he will continue to improve.”

Research shows touch-sensing nerve cells may fuel ‘ringing in the ears’

U-M researcher Susan Shore and graduate student Seth Koehler discuss hearing data. Credit: University of Michigan Health System

A series of articles by various writers on medical topics this one is from medicalxpress.

We all know that it can take a little while for our hearing to bounce back after listening to our iPods too loud or attending a raucous concert. But new research at the University of Michigan Health System suggests over-exposure to noise can actually cause more lasting changes to our auditory circuitry – changes that may lead to tinnitus, commonly known as ringing in the ears.

U-M researchers previously demonstrated that after hearing damage, touch-sensing “somatosensory” nerves in the face and neck can become overactive, seeming to overcompensate for the loss of auditory input in a way the brain interprets – or “hears” – as noise that isn’t really there.

The new study, which appears in the Feb. 1 issue of The Journal of Neuroscience, found that somatosensory neurons maintain a high level of activity following exposure to loud noise, even after hearing itself returns to normal.

The findings were made in guinea pigs, but mark an important step toward potential relief for people plagued by tinnitus, says lead investigator Susan E. Shore, Ph.D., of U-M’s Kresge Hearing Research Institute and a professor of otolaryngology and molecular and integrative physiology at the U-M Medical School.

“The animals that developed tinnitus after a temporary loss in their hearing after loud noise exposure were the ones who had sustained increases in activity in these neural pathways,” Shore says. “In the future it may be possible to treat tinnitus patients by dampening the hyperactivity by reprogramming these auditory-touch circuits in the brain.”

In normal hearing, a part of the brain called the dorsal cochlear nucleus is the first stop for signals arriving from the ear via the auditory nerve. But it’s also a hub where “multitasking” neurons process other sensory signals, such as touch, together with hearing information.

During hearing loss, the other sensory signals entering the dorsal cochlear nucleus are amplified, Shore’s earlier research found. This overcompensation by the somatosensory neurons, which carry information about touch, vibration, skin temperature and pain, is believed to fuel tinnitus in many cases.

Tinnitus affects up to 50 million people in the United States and millions more worldwide, according to the American Tinnitus Association. It can range from intermittent and mildly annoying to chronic, severe and debilitating. There is no cure.

It especially affects baby boomers, who, as they reach an age at which hearing tends to diminish, increasingly find that tinnitus moves in. The condition most commonly occurs with hearing loss, but can also follow head and neck trauma, such as after an auto accident, or dental work. Tinnitus is the number one disability afflicting members of the armed forces.

The involvement of touch sensing (or “somatosensory”) nerves in the head and neck explains why many tinnitus sufferers can change the volume and pitch of the sound by clenching their jaw, or moving their head and neck, Shore explains.

While the new study builds on previous discoveries by Shore and her team, many aspects are new.

“This is the first research to show that, in the animals that developed tinnitus after hearing returned to normal, increased excitation from the somatosensory nerves in the head and neck continued. This dovetails with our previous research, which suggests this somatosensory excitation is a major component of tinnitus,” says Shore, who serves on the scientific advisory committee of the American Tinnitus Association.

“The better we understand the underlying causes of tinnitus, the better we’ll be able to develop new treatments,” she adds. If you have any questions about any aspect of hearing loss contact Hidden Hearing.

Women with diabetes may experience more hearing difficulties

Woman at risk with diabetes

New US research has shown that women with diabetes may experience more hearing difficulties as they get older, particularly if their diabetes is not well controlled.

Doctors from the Henry Ford Hospital in Detroit discovered that women aged between 60 and 75 years, who had their diabetes well managed with medication and diet, had better hearing than women with poorly controlled diabetes. In fact their hearing levels were same the same as women of similar age who did not have diabetes.

The study also revealed that hearing loss was more pronounced in diabetic women younger than 60 years of age, even if they had their condition well under control.

However, the research team found that men had a greater degree of hearing loss compared to women, irrespective of their age or whether they had this chronic disease or not.

“A certain degree of hearing loss is a normal part of the aging process for all of us, but it is often accelerated in patients with diabetes, especially if blood-glucose levels are not being controlled with medication and diet,” said Dr Derek Handzo, one of the research leaders at Henry Ford’s Department of Otolaryngology-Head and Neck Surgery.

He added: “Our study really points to importance of patients controlling their diabetes, especially as they age, based on the impact it may have on hearing loss.”

The number of people with diabetes in Ireland is growing rapidly. At present there are arlound 200,000 people with the condition with approximately 30,000 of these undiagnosed.

One in six adults suffers from adult-onset hearing loss in Europe, according to recent statistics released by the World Health Organization.

The study was presented recently in Miami at the annual Triological Society’s Combined Sections Meeting.

What’s the secret of healthy aging?

Is there a formula for healthy ageing that I can help my 76-year-old widowed dad implement to keep him well longer?

Eileen

Researchers recently identified four healthy lifestyle factors that could go a long way toward reducing your father’s risk of contracting common and life-threatening diseases.  Those successful ageing practices are not smoking, maintaining a healthy weight, exercising regularly and following a healthy diet.

Together, these four lifestyle attributes appear to be associated with as much as an 80 percent reduction in the risk of developing such diseases as diabetes, heart disease, stroke and cancer, according to a report in Archives of Internal Medicine.

The article explains that cardiovascular disease, cancer and diabetes-chronic diseases, which account for many deaths, are largely preventable. “An impressive body of research has implicated modifiable lifestyle factors such as smoking, physical activity, diet and body weight in the causes of these diseases,” the authors write.

After adjusting for age, sex, education level and occupation, individuals with more healthy lifestyle factors were less likely to develop chronic diseases.  Participants who had all four healthy ageing factors at the beginning of the study had a 78 percent lower risk of developing any of the chronic diseases during the follow-up period than those who had none of the healthy factors.

Although it was not included in the study, companionship also is an important part of a senior’s healthy lifestyle.  Since your father is alone, make sure that he has the kind of meaningful social interaction that will help him continue to live an independent and healthy life.

That means encouraging him to participate in activities outside the home. These could include things like a bridge club or active seniors group or even learning a new skill. Some secondary schools look for interested local seniors to come into the school to be trained on using the internet by transition year students. Your local library may be a source of useful information on clubs and associations in your area.

If he’s not able to get out and about so easily consider ways of bringing the companionship to him. Does he have a few friends who could come to the house regularly? Try and find something that will appeal to his existing interests. If he loves his garden, perhaps some members of the local gardening club could drop by?

Seniors who are alone, particularly those who need help with the activities of daily living, are at risk of developing unhealthy lifestyle habits without this important support.

 

You can book a hearing test free of charge at any of Hidden Hearing’s 60 clinics nationwide. Freephone 1800 882884 or visit www.hiddenhearing.ie.

 

Chewing, talking or singing might potentially help protect your hearing!

Simple actions may activate the tiny muscles in your ear to muffle loud sounds

Chewing, talking or singing might potentially help protect your hearing, suggests an Australian researcher.

These simple actions may activate the tiny muscles in your ear to muffle loud sounds, says Dr Andrew Bell from the Research School of Biology at the Australian National University.

In a paper published in the Journal of Hearing Science, Dr Bell suggests conventional models of hearing do not explain why contracting the muscles of the ear – which some people do voluntarily – can reduce sound by 30 decibels.

The answer, he says, lies in a discarded 19th-century theory that suggests the middle ear muscles work like a hydraulic pump.

This theory may explain why some people seem to have “tough” ears that are impervious to hearing loss while others are more sensitive, he says.

“The sound of an opera singer singing can be 100 decibels, so why doesn’t an opera singer go deaf?,” Dr Bell said.

“The explanation is that when an opera singer sings, the middle ear muscles contract.”

The middle ear consists of three tiny bones – including the smallest bone in the body – two miniature muscles and tendons.

“If you close your eyes tightly you’ll hear a fluttering sound and that’s your middle ear muscles at work,” Dr Bell said.

Under current theories of how the ear muscles work, the muscles and bones of the middle ear stiffen up in reaction to a loud noise, dampening sound waves that travel into the cochlea where fine hairs detect the vibration.

“Obviously [the bones and muscles of the middle ear] have got some sound control function because they’re activated when the sound gets loud,” Dr Bell said.

“But that doesn’t quite tell you about the fact that when you close your eyes or activate your middle ear muscles you can get a 30-decibel or 1,000 times change in the amount of sound that goes through.

“If you do the model of how that process works in terms of sound conduction, the best you can get is about 100 times. So that doesn’t quite seem to be a good explanation of what is going on,” he said.

Hydraulic ‘pump’

Instead, the pressure theory proposes the middle ear muscles work like a hydraulic pump, pushing the last bone into the cochlea and increasing the pressure of the watery fluid that fills it. In turn, that pressure squeezes the sensing cells inside and reduces their sensitivity.

Dr Bell says better understanding of this mechanism could help prevent hearing loss.

“We might be able to find ways of making the middle ear muscles more activated. Even if you’re chewing or singing along to music you’re actually doing something that might encourage middle ear muscle activity that might give you more protection than otherwise,” he said.

It is an issue he says is very important in an age where use of mp3 players is causing hearing loss but people do not heed the warnings.

“Jimi Hendrix sounds awesome when it’s loud and people don’t want to turn it down,” he said.

“Here we have the middle ear with this natural inbuilt protective mechanism.”

“I think it’s worthwhile to open up the question and see what all the options are given that things are going to get steadily worse if we don’t do something.”

In the meantime, Dr Bell advocates taking precautions such as limiting exposure to loud music and using over-the-ear ear phones with noise cancellation instead of bud-style ear phones to help prevent hearing loss.

If you have any questions about hearing loss contact Hidden Hearing.