Complaints of dizziness and disequilibrium are common in older people yet it is often difficult to determine the cause. Associated falls and fear of falling affect the quality of their lives and limit their daily activities. We hypothesize that dizziness and disequilibrium are not a result of normal aging but rather the result of specific pathophysiologic changes involving the inner ear and brain. Our goal is to better understand the causes of dizziness and disequilibrium in older people. We propose to continue a longitudinal study of patients complaining of dizziness and disequilibrium and age-matched controls with yearly examinations including quantitative visual-vestibular testing and posturography. The goal of the first specific aim is to a) document changes in vestibular function and balance associated with normal aging; b) define the natural history of the common causes of dizziness and disequilibrium in older people; and c) document the clinical course in patients with dizziness and disequilibrium of unknown cause.
The second aim i s to correlate function with morphology in normal subjects and patients who come to postmortem examination with the goal of explaining changes in balance in terms of identifiable changes within the inner ear and brain. How accurate were the clinical diagnoses? Do patients with dizziness and disequilibrium of unknown cause show changes in the inner ear or brain different from those of age-matched controls? The unique features of this research are a) the longitudinal design and b) the correlation of histopathologic findings at the time of postmortem examination with the results of quantitative test information obtained during life. There have been few prior longitudinal studies of dizziness and imbalance in older people and none that includes serial measurements of auditory and vestibular function, and quantitative measurements of balance, semiquantitative neuro-logical examinations and serial magnetic resonance images (MRI's) of the brain. Prior histopathological studies in older people with balance dysfunction have focused on the temporal bone or brain but not both, have lacked detailed clinical data, and rarely have contained quantitative information regarding vestibular function during life. By continuing this longitudinal study of carefully studied older patients and controls, our multidisciplinary research team is in a good position to achieve our goals.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG009693-15
Application #
6887747
Study Section
Special Emphasis Panel (ZRG1-IFCN-6 (01))
Program Officer
Chen, Wen G
Project Start
1991-04-01
Project End
2008-03-31
Budget Start
2005-04-01
Budget End
2008-03-31
Support Year
15
Fiscal Year
2005
Total Cost
$539,539
Indirect Cost
Name
University of California Los Angeles
Department
Type
Other Domestic Higher Education
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Ishiyama, Gail; Tokita, Joshua; Lopez, Ivan et al. (2007) Unbiased stereological estimation of the spiral ligament and stria vascularis volumes in aging and Meniere's disease using archival human temporal bones. J Assoc Res Otolaryngol 8:8-17
Tian, Jun-Ru; Ishiyama, Akira; Demer, Joseph L (2007) Effect of unilateral vestibular deafferentation on the initial human vestibulo-ocular reflex to surge translation. Exp Brain Res 176:575-87
Tian, Jun-ru; Ishiyama, Akira; Demer, Joseph L (2007) Temporal dynamics of semicircular canal and otolith function following acute unilateral vestibular deafferentation in humans. Exp Brain Res 178:529-41
Ishiyama, Gail; Lopez, Ivan; Baloh, Robert W et al. (2007) Histopathology of the vestibular end organs after intratympanic gentamicin failure for Meniere's disease. Acta Otolaryngol 127:34-40
Kerber, Kevin A; Ishiyama, Gail P; Baloh, Robert W (2006) A longitudinal study of oculomotor function in normal older people. Neurobiol Aging 27:1346-53
Kho, Soochuen T; Lopez, Ivan A; Evans, Christopher et al. (2006) Immunolocalization of orphanin FQ in rat cochlea. Brain Res 1113:146-52
Ishiyama, Gail; Lopez, Ivan A; Ishiyama, Akira (2006) Aquaporins and Meniere's disease. Curr Opin Otolaryngol Head Neck Surg 14:332-6
Ishiyama, Gail; Ishiyama, Akira; Kerber, Kevin et al. (2006) Gentamicin ototoxicity: clinical features and the effect on the human vestibulo-ocular reflex. Acta Otolaryngol 126:1057-61
Kerber, Kevin A; Whitman, Gregory T; Brown, Devin L et al. (2006) Increased risk of death in community-dwelling older people with white matter hyperintensities on MRI. J Neurol Sci 250:33-8
Lopez, Ivan; Ishiyama, Gail; Tang, Yong et al. (2005) Regional estimates of hair cells and supporting cells in the human crista ampullaris. J Neurosci Res 82:421-31

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