Perspectives Winter/Spring 2018

24 Nova Southeastern University Audiology Fort Lauderdale Tests Measure Stress on the Vestibular System By Patricia A. Gaffney, Au.D., Associate Professor of Audiology A RESEARCH STUDY is investigating the effects of stress on the vestibular system and vestibular testing. The hypothalamic–pituitary–adrenal axis (HPA) is part of the neuroendocrine system that controls stress and regulates other body systems that are known to react to stress (e.g., digestive system, immune system, and mood regulation). In the presence of stress, the HPA axis is activated and alters the body’s sensitivity to adrenocorticotropic hormone, which increases the production and release of cortisol. There are pathways that lead from the vestibular nuclei to the HPA—specifically, the fiber extensions to the amygdala. In response to stress, previous research has shown that patients under stress or anxiety report higher levels of dizziness and lightheadedness, as well as a decreased ability to compensate after vestibular loss. Given this information, there has not been previous research demonstrating how stress can affect or alter vestibular test results. The benefit of this academic study environment is that stress is more likely to occur around high-pressure situations, such as exams or major presentations, resulting in easy prediction based on student syllabi. Participants are prescreened for otologic vestibular disorders and the use of anti-anxiety medications. Each participant is seen for two visits. The baseline visit is completed when the student has more than a week prior to any academic stressor, and the follow-up takes place within 24 hours of a major exam or presentation. The battery of tests evaluates postural control while the participant is standing on foam with eyes open and closed, oculomotor testing (random saccades, pendular tracking, and optokinetic nystagmus), positional testing, and caloric vestibular responses. In addition to this testing, participants complete questionnaires regarding their current state of anxiety, stress indicators, and other factors, such as hours of sleep, medications, and caffeine. The study is still in the data-collection phase. The value of the study is that many patients are experiencing significant stress after a vestibular impairment, as it can change the way they feel and attend to activities of daily living. This can provide an understanding of minor changes in testing that can be seen with this stressed population. ● Third-year Au.D. student Chelsea Foglio demonstrates the video goggles used for vestibular testing.