also benefit from the cloning of the human myelin basic protein gene.

Question. We are in the second year of the Decade of the Brain. What have you done to accomplish the goals in MS research to date, and what do you plan for the next few years?

Answer. The recent finding that multiple sclerosis (MS) can progressively attack the nervous system even in the absence of clinical symptoms, sheds a new light on the disease process and has important implications for treatment and future research. We will follow up on this discovery with continued intramural studies and new extramural studies using magnetic resonance imaging (MRI), the technique that made this finding possible.

A central question in MS concerns myelin, the insulating covering of the brain and spinal cord that is damaged by the disease. The possible roles of viral, genetic, and immune system factors in the disease process are active areas of study. There appear to be specific, but currently unidentified, cellular and subcellular targets of immune attack on the brain and spinal cord. Once these targets are defined, new methods for halting or reversing and repairing the destruction of myelin that results in the symptoms of MS may be developed.

QUESTION SUBMITTTED BY SENATOR ARLEN SPECTER

GAUCHER'S DISEASE

If

Question. Dr. Goldstein, are funds included in the President's FY 1992 budget to expand the Gaucher's Disease research effort? not, how much would it cost to fully implement the trials necessary to complete the minimum dosage studies and the study of Type III treatment?

Answer. We plan to start enrolling patients in April 1991 for a study to determine the minimum dose of enzyme necessary to yield a therapeutic response in Type I Gaucher's disease. In addition, NINDS scientists are in the final phases of developing the protocol to study the maintenance dose needed to keep Type I Gaucher's patients healthy after they have been treated with enzyme replacement therapy. The FY 1992 President's Budget includes funds to continue the present work on the Type I studies, but not to conduct the full-scale trials. The additional costs to complete the Type I studies, over a three year period, are $200,000 in FY 1991; $1,340,000 in FY 1992; and $645,000 in FY 1993.

At the time the FY 1992 budget was developed, the main priority in Gaucher's disease research was expansion of the Type I studies. At this point, it is clear that planning for the Type III study is sufficiently advanced that we can move ahead this year to expedite the conduct of the trial, probably by July. Initial investigations needed to develop a human study protocol for Type III are under way. If a protocol is scientifically approved, NINDS will initiate a pilot investigation this year by transferring funds from other research areas ($565,000). The costs for this trial, over a 4 year period, are an estimated $5,535,000. Funds for the Type III trial, $1,680,000, were not included in the President's FY 1992 budget.

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QUESTIONS SUBMITTTED BY SENATOR MARK O. HATFIELD

SLEEP DISORDERS AND NARCOLEPSY

Question. Dr. Goldstein, would you summarize for the Subcommittee research being supported by the NINDS research on sleep disorders such as narcolepsy?

Answer. NINDS-supported sleep research includes investigation of how the brain controls the normal sleep-wake cycle and what occurs in disorders of this cycle, such as narcolepsy. A clinical research center supported by NINDS is conducting collaborative basic science and clinical research exploring molecular genetic, immunologic, and neurophysiologic hypotheses for the pathogenesis of sleep disorders. Other clinical investigators are developing improved drug therapy for narcolepsy, studying the mechanisms for "rebound insomnia" following discontinuation of sleep-promoting medications, and evaluating techniques to improve the sleep patterns of shift workers with rotating day and night schedules.

Linkage markers for the autosomal recessive gene responsible for canine narcolepsy have been identified and researchers are working to isolate and sequence the gene. When this is accomplished, the abnormal gene product can be identified and strategies developed to counter the activity of the abnormal gene product. This research with dogs should have important implications for human narcolepsy.

Question. Dr. Goldstein, it is my understanding that years ago many believed that because narcolepsy and epilepsy patients displayed similar symptoms, that a link existed between the two disorders. What is the present understanding today?

Answer. Years ago a number of neurological disorders, such as tics, muscle jerks, and narcolepsy were misclassified as epilepsy. It is fairly common for two disorders to have similar symptoms but entirely different causes, prognoses, and treatments. Narcolepsy and epilepsy are similar in that they are both episodic, or "paroxysmal" disorders of the brain, and in the case of most epilepsy and all narcolepsy, there is little anatomical change in the brain that can explain the disorder. Electrophysiologically and behaviorally there is overlap between epilepsy and sleep disorders, in that seizures can affect sleep, and sleep has a strong impact on the occurrence of seizures. However, testing with modern electrophysiological techniques has shown that the characteristic brain electrical features of narcolepsy and epilepsy are quite

distinct.

Question. Is it still prudent for research on narcolepsy to be conducted through the epilepsy branch or should a separate branch on sleep be established?

Answer. The Institute provides research support for a large number of neurological disorders. Each scientific division or branch of the NINDS is assigned responsibility for a variety of disorders not necessarily reflected in the name of that unit. The Epilepsy Branch presently has responsibility for the support of essentially all clinical and basic electrophysiological research related to a variety of paroxysmal or episodic disorders such as epilepsy, myoclonus, narcolepsy, and circadian rhythms. Because of similarities in the technical expertise needed to diagnose and manage these disorders, it is more efficient for the research support to be within the same unit. Creation of separate branches for sleep and other neurological disorders would fragment the research effort, and require extensive duplication of scarce scientific resources.

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 22 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 diag