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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.

Forty 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

Ultimately, this research may make it

alterations in neurotransmitter levels.

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

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.

We are

studying whether the hearing loss is a result of the AIDS virus or the CMV.

А

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

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 data in a systematic and comprehensive manner.

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

The NIDCD is establishing an

Epidemiology Branch in FY 1991 to coordinate these efforts.

The NIDCD is continuing research and development of devices to improve the

quality of life for hearing-impaired persons.

The Institute has mad

a major

investment in improving technology of auditory prostheses for the deaf.

A new

interleaved-pulse speech processor, developed and tested by NIDCD supported

investigators, is capable of sampling the speech signal at high rates for use by

patients fitted with multichannel cochlear implants. The processor provides

impressive gains in understanding speech so important to these individuals.

The

cochlear implant program has developed limited clinical trials of auditory

prosthetic devices which have promise for major progress for individuals with

congenital and acquired hearing impairment. Furthermore, the application of

patterned electrical stimulation appears to help maintain the integrity of the

central auditory pathways when the inner ear has been damaged.

Another device, the

digital hearing aid, is being studied with great intensity.

NIDCD will continue its initiatives in support of minority-related research

and minority scientists.

In several NIDCD-supported clinical trials on otitis

media, specific attention has been devoted to minority populations. For reasons

not yet clear, there is a higher incidence of otitis media among minority

populations.

Although all clinical trials supported by NIDCD include both males and

females, recent findings in diseases that affect women differentially include

Meniere's disease, otosclerosis, and voice tremor.

Currently, NIDCD is supporting balance-related research on the micromechanical

properties of inner ear sensory cells that may explain how these cells detect

forces acting upon them during movement of the head and transform this information

into neural signals.

Basic scientists studying the sense of smell have found an indication that

some forms of Parkinson's disease and Alzheimer's disease may be caused by

environmental agents that enter the brain through the olfactory nerve.

Recent research results indicate that normal language learning occurs only

when exposure to the language begins early in life for both signed and spoken

languages.

In language research on adult aphasia, recent findings suggest that the

immediate administration of Type I gangliosides in stroke patients may prevent

gross aphasia.

NIDCD investigators continue to study the onset and development of stuttering

in early childhood.

Preliminary results show that girls have a significantly

earlier onset, were

more likely to have sudden onset, and show a stronger tendency

for amelioration than boys.

NIDCD intramural scientists have demonstrated that botulinum toxin injections

are effective in reversing the effects of muscle reinnervation and restoring the

voice in the treatment of spasmodic dysphonia.

The first three National Multipurpose Research and Training Centers have been

established.

The Centers will stimulate important areas of basic and clinical

research while providing needed research training opportunities. They will

increase the numbers and broaden the capabilities of investigators in the

communication sciences.

Continuing education programs will disseminate research

results to physicians, other health professionals and the public.

As we approach the new century, the age of communication is coming into

maturity. Every aspect of human life is dependent upon skilled communication.

Communication processes and technologies have become increasingly critical to

success in the workplace.

Persons with disabilities have been guaranteed the

rights they have always deserved.

However, when a child is born with a

communication disorder or acquires one later in life, that child faces undeniable

challenges throughout his or her lifetime.

Often the challenges are economic.

The

earliest possible diagnosis and intervention are critical to improving the quality

of life for individuals with communication disorders.

Research in molecular biology and, specifically, molecular genetics holds

great promise for the use of gene therapy in hereditary deafness and other

disorders of human communication that are clearly hereditary.

NIDCD has an ongoing commitment to research that develops strategies and

devices to ensure the best possible outcomes for individuals with communication

disorders.

To the degree that these individuals are able to improve their

productivity and independence, research will have contributed to major savings and,

more importantly, to the quality of their lives.

It is of the greatest importance

that the age of communication is truly accessible to all Americans.

Mr. Chairman, the FY 1992 budget request is $146,321,000.

I will be pleased

to try to answer any questions you have.

BIOGRAPHICAL SKETCH OF DR. JAMES B. SNOW, JR.

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B.S., University of Oklahoma, Norman, Oklahoma, 1946-49;
M.D., Harvard Medical School, Boston, Massachusetts, 1952-56

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