Sinusoidal harmonic acceleration testing in normal humans

Abstract

Forty-one normal humans were tested with sinusoidal harmonic acceleration. Phase lag at 0.01, 0.02, and 0.04 Hz was the most stable parameter, with less test-retest variability than gain and asymmetry. There was no significant difference between men and women for phase lag, gain, or asymmetry at any of the five testing frequencies. Gain decreased as age increased. Age had no effect on phase lag at most test frequencies or on asymmetry at any frequency.

The Effect of Age on the Sinusoidal Harmonic Acceleration Test, Pseudorandom Rotation Test, Velocity Step Test, Caloric Test, and Vestibular-evoked Myogenic Potential Test

“…Decreasing gain values with advancing age have been described for the sinusoidal rotation test, sometimes more pronounced in the lower frequencies (Wall et al 1984;Peterka et al 1990;Paige 1992;Furman & Redfern 2001), in the higher frequencies (Li et al 1991), or with the use of higher stimulus velocities (Paige 1991;Baloh et al 1993). For the phase parameter, the most reported trend encloses increasing phase values with increasing age (Baloh et al 1993), sometimes more consistent at the higher (Peterka et al 1990;Furman & Redfern 2001) or at the lower frequencies (Li et al 1991;Paige 1991Paige , 1992.…”

“…For the phase parameter, the most reported trend encloses increasing phase values with increasing age (Baloh et al 1993), sometimes more consistent at the higher (Peterka et al 1990;Furman & Redfern 2001) or at the lower frequencies (Li et al 1991;Paige 1991Paige , 1992. On the other hand, Wall et al (1984) were not able to demonstrate age-dependent phase changes.…”

“…On the other hand, Wall et al (1984) were not able to demonstrate age-dependent phase changes. No significant agerelated asymmetry differences have been reported (Peterka et al 1990;Li et al 1991). For the velocity step test (VST), and in parallel with the increasing phase trend, decreasing timeconstant values have been described by Baloh et al (1993), although not confirmed by all reported studies.…”

Bilateral Vestibular Hypofunction: Challenges in Establishing the Diagnosis in Adults

“…It is therefore necessary for each vestibular laboratory to have its own normative data [131,133,134]. Furthermore, in the SHAT and the VST, gain is considered to be the most variable parameter between and within subjects, probably as a consequence of factors such as fatigue, alertness, stress and habituation [119,131,135,136]. Gain is also reduced by the test itself; rotating in the dark is an artificial condition that reduces gain [137,138].…”

“…Parameters that are believed to be more consistent and reproducible are ‘phase' in the SHAT and ‘time constant' in the VST. They are not influenced by the arousal state of the patient [131,135,140,141,142]. The literature about the influence of sex differences on response parameters is not really consistent [135].…”