American Speech-Language-Hearing Association (ASHA): Smokers are at greater risk for hearing damage

It is known fact that smoking tobacco can increase risk of stroke, heart attack, pulmonary disease emphysema and cancer.  Researchers at the Annual ASHA conference in Philadelphia (November 2010) revealed that both men and women smokers are at higher risk for permanent cochlear damage than non-smokers. This study showed that nicotine appears to reduce the blood supply to the cochlea, which is crucial for normal function of the cochlea. It was found by researchers that reduction of the blood supply occurs regardless of the number of cigarettes smoked per day. 

It is important to keep up with such research developments to bring awareness to the population we serve. This information can help us identify at-risk individuals and provide the appropriate education to promote overall well-being. 

The publication is not yet available for review, but you can find the press release on ASHA's website. 

Link between Viagra and Hearing Loss

Ever closely pay attention to the list of quickly-spoken possible side effects during erectile dysfunction (ED) drug commercials? Yep, hearing loss is mentioned in the list of possible side effects and this has been the case since 2007. 

History of Viagra

Viagra a phosphodiesterase type 5 (PDE-5i) inhibiter, was initially developed by Pfizer to treat hypertension or high blood pressure by increasing blood flow to the heart. Researchers did not intend for the drug to also increase blood flow to other parts of the body, but it did and patients reported that side effect. This was back in the years 1986-1990. Viagra is now one of the most popular treatments for ED after being approved for this specific use in 1998. During the first 3 months it became available, 2.9 million prescriptions were filled! 

Recent Study

A long-term study published in the Archives of Otolaryngology-Head and Neck Surgery and conducted at the University of Alabama at Birmingham (UAB) shows a relationship between hearing loss and use of Viagra. The problem lies in the fact that the increase is blood flow is not exclusive to the heart and penis only. Therefore, the PDE-5i may also increase blood flow to the ears. Note: this is the first long term study to show a relationship between the drug and hearing loss.

The study was performed by Dr. McGwin between 2003 and 2006. It looked at about 11,500 males older than 40 years. The study found that "men who take Viagra are twice as likely to experience hearing loss than those who don't take PDE-5i drugs." Although the specific mechanism that causes the hearing loss is unknown at this time, it has been hypothesized that an increase in blood flow to the inner ear can cause damage to the hearing system. 

The results of this study cannot be generalized to the other drugs on the market to treat ED, such as Levitra and Cialis since they are not PDE-5i drugs. However, their intention is to also increase blood flow. In my limited clinical experience, I have seen hearing loss caused by ED drugs to present itself as a sudden decrease in a person's ability to hear. 

Hearing Loss Awareness

It is known fact that all medications have potential side effects and as with any medication, it is crucial to be aware of the risks involved and discuss possible side effects with a physician. Having said that, awareness about hearing loss should be put on the radar for those taking ED drugs. 

Individuals can have a basic idea of some symptoms of hearing loss. Some symptoms include, complaining of difficulty hearing in quiet and background noise, experiencing tinnitus or ringing in the ears and people showing concern about your ability to hear. Check out other symptoms at Healthy Hearing. If there are any concerns regarding hearing, consider having a comprehensive hearing test performed by an audiologist and an evaluation by an ENT. It is a good idea to have your hearing checked regularly anyway. 

Via Healthy Hearing

Image source

Universal Newborn Hearing Screenings

Image via Grossman Family West 

The Joint Committee on Infant Hearing (JCIH) in 2000 issued a statement that recommended universal screening for hearing loss before a newborn is discharged from the hospital. The statement also included guidelines for state and hospital programs. Research supports that the earlier a child is identified with hearing loss and intervention is provided, the better the child will be able to develop normal speech and language skills. The ultimate goal is that all infants are identified with hearing loss before 3 months old and receive intervention services initiated by 6 months old. 

The Newborn Hearing Screening typically involves a Auditory Brainstem Response (ABR), which objectively measures the brain's response to sound and Otoacoustic Emissions (OAE), which measure emissions from the sensory cells in the cochlea. Here is a good summary comparing the two measures at About.com ABR vs. OAE. 

The California Newborn Hearing Screening Program "helps identify hearing loss in infants and guide families to the appropriate services needed to develop communication skills." Read more about the program on their website. 

It's important to remember that if an infant does not pass their Newborn Hearing Screening, it does not mean that he or she is deaf or has a hearing loss. More testing is necessary to determine if there is a hearing impairment and therefore, further testing will be recommended before hearing status is determined. 

Science Daily: Structure of inner-ear protein is key to both hearing and inherited deafness

Thousands of microscopic hair cells located in the cochlea of the inner ear are extremely sensitive structures. Stereocilia are hair-like structures located on the hair cells and tip-links are filaments that connect the stereocilia in bundles. These structures are involved in the depolarization process, which ultimately leads to the excitation of the auditory nerve resulting in physiologic percept of sound.

ScienceDaily.com released an article on April 17, 2010 about new studies from the labs of David Corey, professor of neurobiology at Harvard Medical School and Howard Hughes Medical Institute investigator, and Rachelle Gaudet, associate professor of molecular and cellular biology at Harvard University's Faculty of Arts and Sciences. The group performed studies on one of two proteins, cadherin-23, that join to form each tip-link. Their studies show how mutations of the protein can make this otherwise extremely strong protein to weaken in its calcium bonding, resulting in inherited deafness. When weak, stress can cause this bond to "break in billionths of a second."

"Still image from a simulation that "stretches" the two end-most segments of the cadherin-23 protein, much as loud noise might do to its real-life counterpart in the inner ear. Such extreme stress can cause cadherin-23 to break in billionths of a second. (Credit: Marcos Sotomayor)"

Read the awesome article: Structure of inner-ear protein is key to both hearing and inherited deafness

via Science Daily