The Effect of Aging on Torsional Optokinetic Nystagmus

Farooq, S.J.; Gottlob, Irène; Benskin, Sherwin; Proudlock, Frank A

doi:10.1167/iovs.07-0899

Cited by 3 publications

(2 citation statements)

References 15 publications

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“…Other reports have also documented abnormalities in OKN function (increased latency to circular vection, increased rate of OKN asymmetry, and decreasing torsional OKN) with advancing age. 19,53,65 Finally, Calder provides a good summary on the effects of aging for various ocular motor tests from numerous published reports, which are summarized in Table 1. 52 Overall, prolonged saccadic latencies and reduced smooth pursuit and OKN gains are observed in elderly patients when compared against younger adults.…”

Section: Ocular Motor Testingmentioning

confidence: 99%

Aging of the Human Vestibular System

Zalewski

2015

Semin Hear

111

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Aging affects every sensory system in the body, including the vestibular system. Although its impact is often difficult to quantify, the deleterious impact of aging on the vestibular system is serious both medically and economically. The deterioration of the vestibular sensory end organs has been known since the 1970s; however, the measurable impact from these anatomical changes remains elusive. Tests of vestibular function either fall short in their ability to quantify such anatomical deterioration, or they are insensitive to the associated physiologic decline and/or central compensatory mechanisms that accompany the vestibular aging process. When compared with healthy younger individuals, a paucity of subtle differences in test results has been reported in the healthy older population, and those differences are often observed only in response to nontraditional and/or more robust stimuli. In addition, the reported differences are often clinically insignificant insomuch that the recorded physiologic responses from the elderly often fall within the wide normative response ranges identified for normal healthy adults. The damaging economic impact of such vestibular sensory decline manifests itself in an exponential increase in geriatric dizziness and a subsequent higher prevalence of injurious falls. An estimated $10 to $20 billion dollar annual cost has been reported to be associated with falls-related injuries and is the sixth leading cause of death in the elderly population, with a 20% mortality rate. With an estimated 115% increase in the geriatric population over 65 years of age by the year 2050, the number of balanced-disordered patients with a declining vestibular system is certain to reach near epidemic proportions. An understanding of the effects of age on the vestibular system is imperative if clinicians are to better manage elderly patients with balance disorders, dizziness, and vestibular disease.

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Section: Ocular Motor Testingmentioning

confidence: 99%

Aging of the Human Vestibular System

Zalewski

2015

Semin Hear

111

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“…We concentrated on the special case in which the monitor was positioned so that the axis of this rotation passed midway between the two eyes and the observer’s gaze was directed at the center of the display. This meant that, although the visual rotation was defined with respect to the head, each eye saw rotation about its optic axis, and many studies have shown that this induces torsional tracking of the two eyes in the direction of the seen rotation, often termed cycloversion (Cheung & Howard, 1991; Cheung, Money & Howard, 1995; Collewijn, van der Steen, Ferman & Jansen, 1985; Farooq, Gottlob, Benskin & Proudlock, 2008; Farooq, Proudlock & Gottlob, 2004; Houben, Goumans & van der Steen, 2006; Howard, Sun & Shen, 1994; Howard & Templeton, 1964; Ibbotson, Price, Das, Hietanen & Mustari, 2005; Kertesz & Jones, 1969; Lopez, Borel, Magnan & Lacour, 2005; Morrow & Sharpe, 1993; Seidman, Leigh & Thomas, 1992; Suzuki, Shinmei, Nara & Ifukube, 2000; Thilo, Probst, Bronstein, Ito & Gresty, 1999; van Rijn, van der Steen & Collewijn, 1992; 1994a; 1994b; Wade, Swanston, Howard, Ono & Shen, 1991; Washio, Suzuki, Sawa & Ohtsuka, 2005; Zupan & Merfeld, 2003). …”

Section: Introductionmentioning

confidence: 99%

The initial torsional Ocular Following Response (tOFR) in humans: A response to the total motion energy in the stimulus?

2009

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We recorded the initial torsional Ocular Following Responses (tOFRs) elicited at short latency by visual images that occupied the frontal plane and rotated about the lines of sight. Using 1-D radial gratings, the local spatio-temporal characteristics of these tOFRs closely resembled those we previously reported for the hOFRs to horizontal motion with 1-D vertical gratings. When the 1-D radial grating was subdivided into a number of concentric annuli, each with the same radial thickness, tOFRs were less than predicted from the sum of the responses to the individual annuli: spatial normalization. However, the normalization was much weaker than that which we previously reported for the hOFRs. Further, when the number, thickness and contrast of these concentric annuli were varied systematically, the latency and magnitude of the tOFRs were well described by single monotonic functions when plotted against the product of the Total Area of the Annuli and the Square of their Michelson Contrast (“A*C 2”), consistent with the hypothesis that the onset and magnitude of the initial tOFR are determined by the Total Motion Energy in the stimulus. When our previously published hOFR data were plotted against A*C 2, a single monotonic function sufficed to describe the latency but not the magnitude.

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