Page images
PDF
EPUB

NATIONAL INSTITUTE ON DEAFNESS AND OTHER COMMUNICATION

DISORDERS

STATEMENT OF DR. JAMES B. SNOW, JR., DIRECTOR

BUDGET REQUEST Senator HARKIN. Dr. Snow, your budget request of $146.3 million is 8.4 percent above 1991.

We are now close to your first anniversary as the first Director of the National Institute on Deafness and Other Communication Disorders. The committee is delighted to have you back here with us today, and please proceed with your statement.

Dr. SNOW. Thank you very much, Senator. It is a privilege to be here before the committee to discuss the programs of the National Institute on Deafness and Other Communication Disorders.

In the past 242 years since the creation of the Institute, we have seen an increased vigor in part of the scientific community. There has been an outpouring of very high quality applications to our Institute. We received 254 applications in 1989, 350 in 1990, and 472 this year, and we conservatively estimate that there will be 546 in 1992. And this represents an increase of over 100 percent since 1989.

As we discussed last year, 1 in 1,000 infants are born deaf, and 50 percent of those have a cause that is attributable to a genetic defect. Just yesterday, I learned from the Waardenburg syndrome consortium that we organized and support that they have now located the gene within one centiMorgan on chromosome 2, and this is an important breakthrough in hereditary deafness.

REGENERATION OF SENSORY CELLS We are also making progress in understanding the regeneration of sensory cells, unlocking ways to accelerate their repair and return to normal function. This progress has resulted from the study of avian auditory and balance related hair cells. The research has stimulated the hope that similar mechanisms can be initiated in mammals and ultimately in humans leading to the ability to reverse acquired hearing loss.

The olfactory neuroepithelium is known to have a remarkable capability of regenerating olfactory receptor neurons throughout life. The olfactory neuroepithelium also produces another cell that migrates into the brain during adult life, and we are supporting scientists studying the characteristics of these cells and defining the limits of their migration.

The early identification of hearing loss in infants is critical to language acquisition and development. The NIDCD is searching for reliable and cost-effective ways to reduce the average age of diagnosis of hearing impairment in infants from the current 242 years to the first several months of life.

The NIDCD has made major investments in the development and improvement of multichannel cochlear implants, including a new interleaved-pulse speech processor capable of sampling speech at high rates. This processor provides impressive gains in understanding speech so important to these individuals. Scientists studying the sense of smell have found an indication that some forms of Parkinson's disease and Alzheimer's disease are caused by environmental agents that enter the brain through the olfactory nerve.

The NIDCD will continue to support minority-related research and minority scientists. In several NIDCD-supported clinical trials on otitis media, specific attention has been devoted to minority populations.

Although all clinical trials, supported by the NIDCD include both males and females, recent findings indicate that there are diseases affecting women differentially including Meniere's disease, otosclerosis, and voice tremor.

PREPARED STATEMENT This budget request places emphasis on basic research to improve our understanding of human communication while supporting clinical trials for prevention, therapeutic intervention, and the development of devices that will improve the quality of the lives of those who already are experiencing the challenges of communication disorders.

Mr. Chairman, the fiscal year 1992 budget request is for $146,321,000.

I will be pleased to try to answer any questions you have. [The statement follows:)

STATEMENT OF DR. JAMES B. SNOW, JR.

It is a privilege to appear before this Committee as the Director of the

National Institute on Deafness and Other Communication Disorders (NIDCD). In the

past two and a half years since the Institute was created, we have witnessed an

increased vigor in the pursuit of answers to questions about the nature of human communication. The NIDCD has supported research and research training on both the normal and disordered functions of hearing, balance, smell, taste, voice, speech and language primarily through investigator-initiated research and by supporting mechanisms of research training designed to encourage scientists to work on the

challenging problems confronting this field.

The NIDCD continues to monitor its

progress through close attention to and scheduled updating of the National Strategic Research Plan and by fostering critically needed basic research to improve our understanding of human communication while supporting research protocols for prevention, therapeutic intervention and development of devices that

will improve the quality of life for those who already have communication

disorders.

One in one thousand infants is born deaf.

Approximately 2 million persons are

profoundly deaf. Porty to sixty percent of profound neonatal deafness can be

attributed to genetic causes.

More than 50 different forms of hereditary deafness

are known. The NIDCD has made important progress on two forms of hereditary deafness, Usher syndrome and Waardenburg syndrome. NIDCD investigators have recently located the Usher type 2 gene on chromosome 1 and have begun to fine map and to clone and characterize the gene. A team of scientists in the NIDCD Intramural Research Program and a network of clinicians are at work studying Waardenburg syndrome. Geneticists, otolaryngologists and audiologists throughout the country have been enlisted to bring together intramural scientists and families with hearing loss due to Waardenburg syndrome who would like to participate in the research. Initially, the focus will be on the mapping of the gene involved in Waardenburg syndrome. This information can be used subsequently to improve diagnosis and genetic counseling and eventually may lead to gene therapy for syndromes of hereditary deafness.

Basic scientists supported by NIDCD are continuing to make important progress on understanding the regeneration of sensory cells, unlocking the ways to accelerate their repair and return to normal function. This progress has resulted from the study of auditory and balance-related hair cells in birds. The research has stimulated hope that similar mechanisms can be initiated in mammals and, ultimately, humans, leading to the ability to reverse acquired hearing loss. Other important NIDCD supported basic research has demonstrated that the olfactory

neuroepithelium, located in the roof of the nose is known to have the remarkable

capability of regenerating olfactory receptor neurons throughout life.

The

olfactory neuroepithelium produces another type of cell that migrates into the

brain during adult life.

Using both transplants and explants, scientists are now

identifying the characteristics of these cells and defining the limits of their migration. The olfactory neuroepithelium is not only a source of olfactory

receptor neurons,

which have a powerful chemical trophic effect on the brain, but

may also be a direct source of additional migratory cells for the brain.

Noise-induced hearing loss is the most common preventable cause of hearing

loss and remains of great concern to the Institute.

As a result of a NIDCD

sponsored Consensus Development Conference on Noise and Hearing loss, the Institute

is engaged in an ongoing public education campaign.

The first year of this effort

to increase public awareness will be designed to reach intermediate elementary school children about high-risk activities.

The NIDCD recommends screening infants for hearing impairment; screening

children prior to entering school; screening adolescents in the late teenage years

when otosclerosis may set in; and, in the sixth decade of life, screening adults

for presbycusis.

Early identification of hearing loss in infants is critical to language

acquisition and development.

NIDCD will sponsor a conference on reliable and cost

effective ways of reducing the average age of diagnosis of hearing impairments in infants from the current two and one half years to the first several months of

life.

In addition, investigators are currently attempting to identify other

factors present at age two which place a child at risk for long-term delay in

talking. This research may identify which toddlers will benefit most from early.

intervention.

The most common cause of progressive, conductive hearing loss in the adult with a normal eardrum is otosclerosis. An NIDCD-sponsored physician-scientist has found that a class of drugs, biphosphonates, act effectively to inhibit bone

remodeling

If shown to be effective, these drugs could be used to prevent the

onset of otosclerosis or to arrest the progression of the disease in persons who

already have it.

Research is now in progress to correlate age-related hearing loss with alterations in neurotransmitter levels. Ultimately, this research may make it possible to delay the onset of presbycusis. Presbycusis is estimated to affect

half of all persons between 51 and 91 years of age.

The Institute supports ongoing research in otitis media as it is the leading cause of acquired hearing loss in children under the age of ten. We were heartened by the release of a new vaccine for infants to prevent meningitis, a major cause of deafness in children.

Congenital cytomegalovirus (CMV) infection is a well-established cause of disorders of the auditory, visual and central nervous systems. The NIDCD will continue to support research on the CMV in association with disorders such as infant hearing loss, Meniere's disease, perilymphatic fistulae, sudden deafness, and hearing and balance disorders emerging in AIDS patients. CMV is the most

common secondary infection among AIDS patients and is estimated to occur in more

We are

than 90 percent of all such patients. Persons who have AIDS are known to develop communication disorders the most prominent of which is loss of hearing. studying whether the hearing loss is a result of the AIDS virus or the CMV. model for studying congenital CMV inner ear infection has been developed, and therapeutic strategies have evolved for the prevention of the loss of hearing from

A

CMV infection.

Additionally, the NIDCD is concerned with CMV in children. Approximately 72,000 children are born with CMV each year. CMV is the single largest cause of

acquired, congenital hearing loss and is estimated to cause deafness in 2,000 to

4,000 infants annually in the United States.

In September 1990, the NIDCD held the first of a series of working group meetings designed to look at the needs of the several constituencies served by the Institute. Each working group has an opportunity to inform the Institute of their special research and research training needs. The first working group provided perspectives of the deaf community; the second, scheduled for April 1991, will

provide the perspectives of oral, auditory hearing-impaired persons; the third, to

be held in October 1991, will address the research and research training needs of

women and women's health issues. The fourth meeting, planned for April 1992, will present the needs of minority persons and minority health issues; and, the final meeting in the series, scheduled for September 1992, will assess the impact of visual impairment on deaf and hard of hearing persons.

The Institute's National Strategic Research Plan has identified that there is

insufficient incidence and prevalence data on communication disorders.

After

holding planning meetings with the National Center for Health Statistics (NCHS),

the NIDCD is preparing a 10- to 15- year epidemiologic research strategy. This

strategy in collaboration with the NCHS will yield incidence and prevalence data in the Institute's seven program areas and will provide reliable and cost-effective

« PreviousContinue »