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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).
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
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
One in one thousand infants is born deaf.
Approximately 2 million persons are
Forty to sixty percent of profound neonatal deafness can be
attributed to genetic causes.
More than 50 different forms of hereditary deafness
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
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
Initially, the focus will be on the mapping of the gene involved in
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.
from the study of auditory and balance-related hair cells in birds.
has stimulated hope that similar mechanisms can be initiated in mammals and,
ultimately, humans, leading to the ability to reverse acquired hearing loss.
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.
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
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
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
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
This research may identify which toddlers will benefit most from early,
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
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.
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
Additionally, the NIDCD is concerned with CMV in children.
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
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,
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.
holding planning meetings with the National Center for Health Statistics (NCHS),
the NIDCD is preparing a 10- to 15- year epidemiologic research strategy.
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
investment in improving technology of auditory prostheses for the deaf.
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.
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
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
In language research on adult aphasia, recent findings suggest that the
immediate administration of Type I gangliosides in stroke patients may prevent
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
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
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.
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
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.
B.S., University of Oklahoma, Norman, Oklahoma, 1946-49;