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Jorge E. González, Ph.D.†
Alexander Kiderman, Ph.D. ^

† Dept. of Audiology & Speech Language Pathology, Bloomsburg University of Pennsylvania, Bloomsburg, PA
^ Neuro-Kinetics, Inc., Pittsburgh, PA

Normative data for rotational chair testing obtained by video-oculography (VOG) technique

The rotational chair has become more commonly used in the assessment of vestibular and balance disorders since its initial description by Bárány. Amongst the most useful results obtained in rotational testing are the gain, phase, and symmetry of the vestibulo-ocular reflex (VOR). Several researchers have collected normative data for these measures; however, the measurements made by those researchers were obtained using electro-oculography (EOG). There is a question as to whether normative data obtained by EOG can be used to assess results acquired by video-oculography (VOG) techniques.

This presentation will describe rotational chair normative data collected at Bloomsburg University of Pennsylvania. Data was collected for 4 types of rotational tests: Sinusoidal Harmonic Acceleration (SHA) from 0.01 to 1.75Hz, Step Testing at 100 and 240°/sec peak velocity, Visual Enhancement (VVOR) at 0.08 and 0.64 Hz and Visual Suppression (VF) at 0.08 and 0.64 Hz.

Thirty-one adults, ages 18-49 years (M=25.2, SD=7.1) without history of vestibular or neurologic disorders participated in this study. The data was collected using binocular goggles at 100 frames/second and 0.1° resolution in a Neuro-Otologic Test Center (NOTC) rotational chair. Results from the data obtained by VOG are compared to existing normative data obtained by EOG.

Howard T. Mango, Ph.D. ‡
Cara Makuta, Au.D. ‡
Alexander Kiderman, Ph.D. ^

Newport Mesa Audiology Balance & Ear Institute, Inc.
^ Neuro-Kinetics, Inc., Pittsburgh, PA

Interpretive considerations and corresponding practical implications upon conducting static Subjective Visual Vertical and dynamic Unilateral Centrifugation with Subjective Visual Vertical test

Subjective Visual Vertical (SVV) test measures the deviation between a patient’s vertical perception and actual gravitational perception. This test is an effective method to assess the lateral utricle reaction of ocular counter-rolling in response to gravity (static Subjective Visual Vertical, SSVV) or to the gravitational inertial acceleration (GIA) force generated during the Dynamic Unilateral Centrifugation test (dynamic Subjective Visual Vertical, DSVV). The patient sets a Subjective Visual Vertical line during static and dynamic conditions at full speed rotation while in each off-axis position (lateral right, lateral left and center).

There is a question as whether or not to consider the static SVV results during the dynamic SVV test. It is hypothesized that SVV results during dynamic UC has to be corrected by SVV static results.
133 adult patients ages 19-87 years (M=54.01, SD=17.1) were tested using both tests: static SVV (6 repetitions) and dynamic SVV at 300 deg/sec rotation velocity with right and left offset at 3.8 cm.
Corrected methods: DSVV*= DSVV-SSVV, if SSVV was positive and DSVV*= DSVV+SSVV), if SSVV was negative.

Results: In 103 patients (77.4%) the interpretation remained the same. In 30 patients the interpretation of the results was changed (22.6%).

Conclusion: It is recommended to consider results of the static SVV for analysis of dynamic SVV. Implications of the study reveals increased sensitivity and specificity of testing interpretations.