Description Module
The Description Module contains narrative descriptions of the clinical trial, including a brief summary and detailed description. These descriptions provide important information about the study's purpose, methodology, and key details in language accessible to both researchers and the general public.
Description Module path is as follows:
Study -> Protocol Section -> Description Module
Description Module
Ignite Creation Date:
2025-12-24 @ 3:01 PM
Ignite Modification Date:
2025-12-24 @ 3:01 PM
NCT ID:
NCT01976559
Brief Summary:
This research is being done to determine the accuracy of two noninvasive methods of measuring the pressure of the spinal fluid, also known as intracranial pressure (ICP).
Detailed Description:
Recently, astronauts in long-duration spaceflight have been found to have a syndrome consisting of swelling of the optic nerve, impaired vision, and elevated cerebrospinal fluid pressure (also known as intracranial pressure \[ICP\]) via lumbar puncture (LP), which is similar to the syndrome of idiopathic intracranial hypertension (IIH). In astronauts, this syndrome is called Visual Impairment/Intracranial Pressure (VIIP). It is not possible to perform an LP on astronauts in space. Noninvasive methods of estimating ICP exist but have not been tested against continuous ICP methods in a patient cohort that is physiologically similar to that of astronauts.
The primary objective of this study is to determine the validity, reliability, accuracy, and precision of two noninvasive methods of ICP measurement (tympanic membrane displacement (TMD, Marchbanks Measurements Systems, UK) and distortion product otoacoustic emissions (DPOAE) in comparison to a reference standard, invasive ICP measurement, in human subjects undergoing diagnostic cerebrospinal fluid (CSF) infusion testing.
The two noninvasive methods are based on the responses of the inner ear and middle ear to changes in ICP. The first method is TMD, which measures tiny movements of the ear drum, and the second is DPOAE, which is routinely used for newborn hearing screening.
Adults with hydrocephalus, shunt malfunction, or other disorders of CSF circulation who have been recommended on the basis of standard clinical criteria to have CSF infusion testing are eligible.
Study:
NCT01976559
Study Brief:
Protocol Section:
NCT01976559