Strategic Plan FY 2000-2002: Plain Language Version

What is the NIDCD?

In 1988, Congress established the National Institute on Deafness and Other Communication Disorders as a separate Institute within the National Institutes of Health (NIH). Commonly referred to as the NIDCD, this Institute conducts and supports research and research training in the areas of hearing, balance, smell, taste, voice, speech and language, and their disorders. These processes of sensing and interpreting are fundamental to the way individuals perceive the world around them and to their ability to communicate effectively with others.

In the last few years, NIDCD-supported scientists have made remarkable progress in research on human communication and its disorders. This progress has been further accelerated by research supported by other institutes at the NIH and is now providing the foundation for current and future research to achieve an important goal: to help individuals with communication and sensory system disorders.

The NIDCD has developed a strategic plan to draw attention to extraordinary research opportunities and compelling needs. While this plan assists the NIDCD in focusing on specific areas of research, it is not intended to be an all-encompassing master plan for funding. Our first priority is, and continues to be, the funding of high quality research conceived and initiated by members of the research community that will help achieve the goals and objectives of the NIDCD.

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What are Some of the Problems NIDCD Addresses?

In this information age, communication and technology skills will be central to a successful life for all Americans. The labor force of the 21st century will require intense use of these skills. However, for the 1 in 6 Americans with communication disabilities, and their families who support them, facing each day can be a challenge. The simple acts of speaking, listening, of making their wants and their needs understood, are often impossible. The days are often very challenging:

• For the individual who has dizziness (vertigo)

• For people who find themselves suddenly unable to hear

• For the person who cannot speak without stuttering, or for those who are unable to express ideas clearly after a stroke

• For the adult who cannot use his or her voice to talk with a friend on the phone due to the devastation of throat cancer

• For the child with autism or the young deaf child who struggles with language and speech

• For the individual whose ringing in the ear (tinnitus) is overwhelming

• For an older person with a loss of balance that results in falls and fractured bones

• For an older person whose loss of hearing results in isolation and depression, or whose diminished sense of taste or smell affects nutrition and poses a danger

Communication disorders have a major impact on education, employment and the well-being of Americans.

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A Few Vital Statistics:

Birth and Early Childhood

• More than 12,000 babies are born each year with a significant hearing loss, which can affect speech and language development.

• Two-thirds of children with acquired deafness also have some loss of balance.

• About 8 percent of American school age children have problems developing and using language. These language difficulties underlie not only speaking problems but also the ability to read and write.

• Middle ear infection (otitis media) is the most frequent reason that a sick child visits a physician. The estimated total cost of otitis media is $5 billion per year. Children with otitis media suffer hearing loss during infection and often for an extended period of time after treatment is initiated.

• An estimated 2 million Americans stutter. Ten percent of children entering the first grade have moderate to severe speech disorders, including missing and substituted speech sounds and stuttering.

Adulthood

• Nearly 1 million American adults have disorders of language due to stroke or other brain injury.

• An estimated 2 million adults with progressive dementia (e.g., Alzheimer’s) have significant language impairment.

• Tens of thousands of Americans each year develop cancer of the head and neck. Conventional cancer treatment usually damages organs critical for human speech and swallowing.

• Balance disorders may contribute to as many as half of all falls occurring in the elderly, with a cost for patient care in excess of $8 billion per year. For individuals over the age of 75 years, balance disorders are the single most common symptom presented to primary care physicians.

• More than 2 million adults have disorders of taste and smell. These problems are more prevalent in the elderly, and have an impact on everyday living. For example, a substantial fraction of older adults lose their ability to detect the foul smelling agent added as a warning to natural gas.

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What Progress Has Been Made?

What We Know. Past research has produced many significant discoveries and technologies that improve the ability to identify and help people with communication problems. As a result of research:

• Vaccines now prevent many illnesses such as measles, mumps, meningitis, and rubella, which were once major causes of significant hearing loss.

• Much more is known about inherited (genetic) forms of hearing loss.

• Much more is known about how exposure to noise and toxins can damage hearing.

• People with communication problems now have access to a wealth of new tools to improve communication, including cochlear (inner ear) implants, better hearing aids, electronic larynxes (voice boxes), and computerized speech devices.

• We can now identify newborn babies with hearing loss and toddlers with language problems at a much earlier age than in the past.

What We Don’t Know. Besides offering benefits to many people, these advances show us how much more we need to know. For example:

• We need studies to find out how best to help newborn children with hearing loss.

• We need research to determine which of the new devices or treatments is most beneficial for different people, and why a treatment works well for some individuals but not for the others.

• We must learn how new tools for diagnosis, such as brain imaging methods, can also help doctors choose the best treatment for people whose communication problems have different causes.

To distribute our finite research dollars to achieve the greatest benefit, we need to consider the effect that communication disorders have on the American people. We also must consider which areas offer the greatest opportunity for significant progress at this time. After weighing these factors with scientists and representatives of the public, the NIDCD has identified a number of future research opportunities.

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Future Research Opportunities

I. Why All This Interest in Research on Genes?

Doctors and scientists have long known that well-defined disorders of hearing and other aspects of human communication (i.e., language, speech, voice, etc.) often run in families. Changes called mutations in one or a few genes can have a dramatic effect on very complex functions including hearing, speech and language. Genes contain all the information that tells a cell how to make proteins. These proteins are the building blocks that determine the structure and function of all living cells, which in turn form organ systems within the human body. Humans have over one hundred thousand different genes. As research advances, and scientists and physicians define the structure of the human genome, it is becoming more straightforward to identify which of this enormous collection of genes are involved in human communication and communication disorders. Finally, learning about the nature of the proteins made from these genes allows us to understand more about new and unsuspected cellular processes that are essential for effective communication. Once understood, these proteins may someday be targets for new treatment strategies. It is the willingness and generosity of families with hereditary communication disorders who agree to participate in studies with clinicians and scientists that make this research on gene discovery possible.

Understanding Leads to Education and Prevention. Changes in genes contribute to many communication disorders, either directly by causing a critical group of cells to malfunction, or indirectly by increasing sensitivity to damage caused by environmental factors such as noise, drugs and medications, or infections. Research to understand the identity and function of these genes offers the future promise of diagnosing and classifying patients with communication disorders based on specific genetic changes, in addition to symptoms. This knowledge can be directly translated into the clinical setting. For example, children diagnosed at birth with a mild hearing loss, who have a gene mutation that will cause progressive hearing loss and deafness by their teens, might be given the educational help they need early in life to function better in the future. Such children and their parents might also be instructed to avoid noisy settings (rock concerts, loud radios, etc), occupations, or certain medications that could make the hearing loss progress more rapidly.

Scientists and Physicians Can Find the Genes. In order to use knowledge of genetics to prevent, diagnose and treat communication disorders, it is critical that we learn which genes are essential for normal function of the communication senses. Studying types of mice that are deaf due to mutations in specific genes provides another way for researchers to identify genes that are critical to hearing, since these same genes often affect hearing in humans. In mice, scientists can use new techniques to determine the function of a single gene by systematically altering the gene and observing changes in function. Much more can be learned using the powerful techniques of genetics in the mouse.

Many communication disorders are complex, with multiple components and causes. Some of these are due to complex genetic traits, where multiple genes are involved. Others are directly associated with a single underlying problem that has multiple effects. One gene can affect the functioning of other genes, or small differences in several genes can cumulatively affect susceptibility to a disorder. Thus, it is necessary to understand the complex interactions of these genetic factors. Such knowledge could lead to development of effective prevention and treatment strategies.

Non-Genetic Factors. Not all communication disorders have a genetic basis. For example, hearing loss can be caused by infections, noise damage or certain medications. Hearing loss in infants can result in difficulty learning to speak or understanding language later in life, if appropriate education and training are not provided. Impaired language skills affect all aspects of our ability to function in today’s complex communication-driven society. Language impairment can also be caused by brain injury or brain developmental problems, in addition to childhood hearing impairment. Diseases of the larynx (voice box) can be caused by infections or by the presence of a tumor. More research is needed to identify additional non-genetic causes of communication disorders.

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II. Increasing Potential for Recovery--How the Body Creates New Cells

Hair Cells in the Inner Ear. Most parts of the body which are damaged due to illness or injury have the ability to heal by regenerating healthy cells to replace those that have been damaged or lost. Until the recent past, the highly specialized "hair cells" of the inner ear which are critical to hearing and balance, were considered irreplaceable if injured or destroyed. Recent discoveries in birds, however, confirm that specialized inner ear hair cells that have been destroyed by very loud noises can be replaced by regeneration of healthy hair cells. This research has inspired hope that damaged inner ear hair cells in humans, one of the major underlying causes of hearing loss, could be repaired or replaced. Future research is needed to explore whether the same processes which produce inner ear hair cells during development of the human embryo could be reactivated to achieve hair cell regeneration in older individuals.

Sensory and Nerve Cells in the Nose. In contrast to the hair cells of the inner ear and many other sensory cells and neurons, the sensory nerve cells of the human olfactory system (nose) which respond to various odors show a remarkable ability to regenerate. The ability of these newly restored cells to make appropriate connections to brain regions that respond to specific odors needs to be intensively studied. Research identifying what factors make this possible could lead to the design of intervention strategies promoting similar nerve cell regeneration in other parts of the nervous system.

Recovering Speech and Language Ability. Adults who suffer brain damage as a result of a stroke often have problems expressing their thoughts. These speech and language disorders severely compromise their ability to communicate and decrease their quality of life. In contrast, infants and young children who have suffered comparable brain damage from birth injuries, childhood trauma, or extensive brain surgery sometimes develop or recover speech and language abilities. Research is needed to understand why young children have this ability to recover from severe brain damage, with a goal of helping adults do the same.

Sensory cells in the hearing and balance organs in the inner ear develop connections with specific brain regions early in life. We know that the brain is particularly receptive to forming these connections at certain times in the young child’s life. If these time-sensitive opportunities are missed because sensory information is not being transmitted to the brain, the ability to develop critical brain connections or pathways may be lost forever. This could occur, for example, in an infant with undetected severe hearing loss. Research is needed to identify these critical "windows of opportunity" for developing brain connections essential for communication. Important research findings in this area have already stimulated interest in major public health efforts, such as screening millions of newborn babies for hearing loss each year.

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III. From Sensing to Interpreting

Understanding Human Communication. Human communication relies on complicated perceptual skills--taking information from the outside world through the senses (hearing, vision, touch, taste and smell) and interpreting it in a meaningful way. Human communication also requires mental abilities, such as attention and memory. We still do not understand exactly how all of these processes work and interact, or how they malfunction in cases of communication disorders. But we do know that many communication disorders are caused by problems that occur even when the senses (such as hearing) are completely normal.

Recently, new ways have been developed to study what happens after information is received by the sense organs. It is now possible to view parts of the brain at work directly using computerized imaging technology, and to see changes as information flows from sensory organs to the brain. For example, a magnetic resonance imaging (MRI) scan of the brain can be used to observe activity as language information is received, processed and interpreted. Research studies taking advantage of this and other powerful imaging techniques are especially valuable in the study of speech and language in humans, because these important forms of human communication cannot be studied in animals.

Processing Information in the Brain. Aside from these advances in brain imaging and viewing parts of the brain involved in human communication, new ways are emerging for studying the basic organization and operation of human communication. Information processing in the brain involves successive activation or stimulation of nerve cells. In other words, information moves continuously from one nerve cell to another like electricity moving along a wire. This activation process takes place when chemicals in one nerve cell are released and stimulate activity in the adjacent nerve cell. Research advances have provided tools allowing scientists to determine the nature of these chemicals in nerve cell networks involved in human communication. This knowledge could lead to new treatment strategies for individuals with communication disorders caused by abnormalities in critical nerve cell networks.

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IV. Applying New Knowledge

As described in the previous sections, scientists have made great progress in recent years toward the goal of understanding human communication and its disorders. These advances have occurred due to unprecedented breakthroughs in genetics, other basic sciences, and technology. We can expect continued progress as additional genes associated with specific communication disorders are identified and their functions revealed, and as more is learned about the function of the brain and other organs important for communication.

Although of great theoretical and scientific importance, these advances in basic research represent only a first step toward the goal of improving the lives of individuals with communication disorders. The new knowledge obtained from basic research can be used to answer clinical questions with the ultimate goal of developing the most appropriate and effective means of prevention, diagnosis, and treatment of communication disorders.

Clinical research translates and transfers this new knowledge to studies of human behavior and disease. For example, hearing screening programs established around the country are beginning to identify infants and young children who have significant hearing loss. The technology for screening newborns was a result of basic laboratory studies measuring electrical signals from auditory centers in the brain (ABR) and tiny sounds generated by the inner ear (otoacoustic emissions). Researchers now can conduct clinical trials to establish and validate the most effective treatments (including hearing aids or cochlear implants) and educational programs for these hearing-impaired babies and to determine at what age treatment should begin to maximize success.

Clinical research is also needed to describe the range of differences that occur in human communication over the life span, such as production of speech sounds, hearing acuity, odor detection (sense of smell), or balance abilities. These differences may then be related to an underlying gene or genes which may help identify people who are at greater risk of developing problems. Once this information is obtained, clinical trials are necessary to tell us which medical and behavioral interventions are safe and effective ways of treating communication disorders. These may include evaluations of medications to treat Meniere’s disease and autoimmune hearing loss, light therapy to treat warts on the vocal cords (laryngeal papillomas), electrical stimulation and medications to treat ringing in the ears (tinnitus), imaging techniques to assess brain damage due to stroke and predict recovery, and physical therapy involving special positioning of the head for loss of balance (positional vertigo).

NIDCD is committed to supporting research to develop devices that improve or restore communication abilities, or prevent communication disorders. Advances in basic science research and in bioengineering contributed to development of the electrolarynx to restore speech after the removal of the voice box (larynx), digital programmable hearing aids that fit inside the ear canal, cochlear and brainstem implants to improve communication abilities of adults and children with severe-to-profound hearing loss, and video-game-like computer programs for treatment of disorders which may be associated with learning disabilities. Although these inventions emerged from basic knowledge of human communication, the ultimate success of current and future devices can only be determined by carefully designed clinical research studies. These clinical research studies are an important priority for the NIDCD.

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