Principal Investigator: Michael A. Williams, MD
Sponsor: National Space Biomedical Research Institute (NSBRI); Project Number SMST02802
Recently, astronauts returning from long-duration spaceflight have been found to have a syndrome of swelling of the optic nerve, impaired vision, and elevated spinal fluid pressure (also known as intracranial pressure [ICP]), which is similar to the syndrome of idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri. In astronauts, this syndrome is called visual impairment/intracranial pressure (VIIP). It is not possible to perform a spinal tap on astronauts in space to measure spinal fluid pressure. Noninvasive methods of estimating ICP exist but have not been tested compared to ICP methods in patients who are physiologically similar to astronauts.
The primary objective of this study is to determine the accuracy of two noninvasive methods of ICP measurement in comparison to standard, invasive ICP measurement. The two methods to be tested are:
- Tympanic membrane displacement (TMD, Marchbanks Measurements Systems, UK)
- Distortion product otoacoustic emissions (DPOAE)
Brief Protocol Summary
Adults with hydrocephalus or pseudotumor cerebri who have been recommended on the basis of standard clinical criteria to have ICP monitoring either by insertion of a temporary spinal catheter or by insertion of a needle into an existing shunt reservoir are eligible for this study.
The two noninvasive methods are based on the responses of the inner ear and middle ear to changes in ICP. The first method, TMD, measures tiny movements of the ear drum, and the second, DPOAE, is routinely used for newborn hearing screening.
After insertion of the spinal catheter or the needle in the shunt, subjects will undergo testing with the TMD and DPOAE in the lying, sitting, standing, and head-down tilt (10 degrees) position. In addition, testing will be performed during sleep, when normal fluctuations of ICP occur.
You may qualify to participate if:
- You are an adult man or woman, 18–65 years of age
- You have hydrocephalus or idiopathic intracranial hypertension (pseudotumor cerebri)
- Your doctor, on the basis of standard clinical criteria, has recommended monitoring your spinal fluid pressure.
For more information, please contact:
|Alanvin Orpia, BSN, RN
|Carol Wamboldt, CRNP
|Michael A. Williams, MD
Listen to Dr. Michael A. Williams
John Patti of WBAL radio talks to& Michael A. Williams, M.D., medical director of The Sandra and Malcolm Berman Brain & Spine Institute at LifeBridge Health, about how his team is researching the cause of eyesight problems that are experienced by astronauts during long-distance space travel.