Vestibular Evoked Myogenic Potentials : physiology, variability, and statistical characteristics

Vestibular Evoked Myogenic Potentials (VEMPs) are electrical signals recorded from the skin overlying skeletal muscles of the head and neck in response to high-intensity acoustic stimuli. VEMPs have been observed in stimulus locked averages of the electromyogram in a majority of human subjects, and are thought to originate in the otolith organs of the inner ear, which are balance organs responsible for sensing acceleration and orientation with respect to gravity. Otolith reflexes interact with the motor drive to a contracted muscle to give rise to the VEMP signal. In the last few years these signals have been used in the clinic as an indicator of peripheral vestibular function and a test based on VEMP from neck muscles (cervical, or cVEMP) is currently the only clinically feasible means of assessing the functioning of the saccule and its innervation. However, the usefulness of the test is limited by the inter-subject and test-retest variability of the response, and the unclear relationship between specific response features and vestibular pathophysiology. In this thesis, our goal is to measure VEMP variability, assess the influence of non-vestibular factors on the VEMP, and to develop a signal processing strategy to estimate response parameters that are both statistically stable, and physiologically meaningful. In the first part of the thesis, we systematically measure VEMPs from a small clinically normal population, and quantify the variability of the response, particularly the dependence on contraction effort. We also assess approaches to normalizing the response by estimates of the effort.

Department dc:contributor.department

Harvard University--MIT Division of Health Sciences and Technology.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2009

Author dc:creator

• Prakash, Srinivasamurthy Ravi

Advisor dc:contributor.advisor

• Steven D. Rauch.

• Harvard University--MIT Division of Health Sciences and Technology.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/54587

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/54587