Kristal M Riska1,2, Owen Murnane1,2, Faith W Akin1,2, Courtney Hall1,3. 1. Vestibular/Balance Laboratory, Auditory and Vestibular Research Enhancement Award Program, VA Medical Center, Mountain Home, TN. 2. Department of Audiology and Speech-Language Pathology, East Tennessee State University, Johnson City, TN. 3. Department of Physical Therapy, East Tennessee State University, Johnson City, TN.
Abstract
BACKGROUND: Vestibular function (specifically, horizontal semicircular canal function) can be assessed across a broad frequency range using several different techniques. The head impulse test is a qualitative test of horizontal semicircular canal function that can be completed at bedside. Recently, a new instrument (video head impulse test [vHIT]) has been developed to provide an objective assessment to the clinical test. Questions persist regarding how this test may be used in the overall vestibular test battery. PURPOSE: The purpose of this case report is to describe vestibular test results (vHIT, rotational testing, vestibular evoked myogenic potentials, and balance and gait performance) in an individual with a 100% unilateral caloric weakness who was asymptomatic for dizziness, vertigo or imbalance. DATA COLLECTION AND/OR ANALYSIS: Comprehensive assessment was completed to evaluate vestibular function. Caloric irrigations, rotary chair testing, vHIT, and vestibular evoked myogenic potentials were completed. RESULTS: A 100% left-sided unilateral caloric weakness was observed in an asymptomatic individual. vHIT produced normal gain with covert saccades. CONCLUSIONS: This case demonstrates the clinical usefulness of vHIT as a diagnostic tool and indicator of vestibular compensation and functional status. American Academy of Audiology.
BACKGROUND: Vestibular function (specifically, horizontal semicircular canal function) can be assessed across a broad frequency range using several different techniques. The head impulse test is a qualitative test of horizontal semicircular canal function that can be completed at bedside. Recently, a new instrument (video head impulse test [vHIT]) has been developed to provide an objective assessment to the clinical test. Questions persist regarding how this test may be used in the overall vestibular test battery. PURPOSE: The purpose of this case report is to describe vestibular test results (vHIT, rotational testing, vestibular evoked myogenic potentials, and balance and gait performance) in an individual with a 100% unilateral caloric weakness who was asymptomatic for dizziness, vertigo or imbalance. DATA COLLECTION AND/OR ANALYSIS: Comprehensive assessment was completed to evaluate vestibular function. Caloric irrigations, rotary chair testing, vHIT, and vestibular evoked myogenic potentials were completed. RESULTS: A 100% left-sided unilateral caloric weakness was observed in an asymptomatic individual. vHIT produced normal gain with covert saccades. CONCLUSIONS: This case demonstrates the clinical usefulness of vHIT as a diagnostic tool and indicator of vestibular compensation and functional status. American Academy of Audiology.