Researchers believe that the new findings may provide ways to conduct trials to test bone disease medications as a treatment for hearing loss. Hearing loss, up till now, is irreversible, no matter what the cause is. There are no medications approved by the Food Administration and Drug to reverse it, whether it is due to sound exposure or aging.
The findings from Harvard Medical School researchers at Massachusetts Eye and Ear were published on July 14 in Frontiers in Molecular Neuroscience.
Sensorineural hearing loss (SNHL) is the most common type of hearing loss. For this reason, the new animal study may provide the necessary information for future trials to double-check if its safety and effectiveness.
Age and increased sound exposure result in poor synaptic connections. It disturbs the synapses between nerve cells and sensory hair cells. The name for this type of SNHL is cochlear synaptopathy.
Out of the 466 million deaf people in the world, 56 million people are from the United States. The number would further raise in the coming years. Hearing loss is not only a downside for health but savings too. A family spends around $750 billion in health care annually on emergency visits and hospital stays.
The new study directed by Konstantina Stankovic, HMS associate professor of otolaryngology-head and neck surgery at Mass. Eye and Ear, and Albert Edge, the Eaton-Peabody Professor of Otolaryngology-Head and Neck Surgery at Mass. Eye and Ear, found bisphosphonates medications effective for hearing loss.
Bisphosphonates are taken to maintain bone density and prevent bone loss. In mice with SNHL, this medication was able to deal with the neuropathy in the inner ear. The researchers injected bisphosphonates a day after noise exposure.
It fixed the synaptic connection between inner hair cells and spiral ganglion neurons. It also restored the cochlear function in the inner ear.
Stankovic, director of the Division of Otology and Neurotology at Mass. Eye and Ear., says that this significant research has revealed the double purpose of the Bisphosphonates. The medication, which was first typically for osteoporosis and metastatic bone cancer, may now be useful for sensorineural hearing loss. He hopes that this clinical study in the future will help to have clinical trials in the next few years.
Even though it was able to overcome the damaged nerve connections, experts want to study further in the animal models. It has given promising targets for the researchers to do extend researching with the people having SNHL.
Future of the Research
Analysis of the pre-existing research in Stankovic’s lab lays down a possible pathway to overcome SNHL. As per the reports, the osteoprotegerin is highly found and produced by the cochlear nerves. Osteoprotegerin is a constituent of the osteoblasts and osteogenic stromal stem cells to inhibit bone remodeling.
The previous study of the drug’s influence on the rapid increase of cochlear cells has helped researchers study the effects of bisphosphonates on cochlear synaptopathy. Also, the team says that their findings have discovered possible mechanisms, which can find out why some people have started showing improvement in speech after the bisphosphonate treatment.
Stankovic still asserts that the study is in its early phase, and clinical trials are important before this becomes the recommended treatment. Also, they hope that in the future, they will be able to help those patients who are currently suffering from irreversible hearing loss and do not have any medications.