Application of ellipsoid parameters for evaluation of nystagmus evoked during rotational chair test

This article describes the application of ellipsoid parameters for the purpose of evaluating the variability of amplitudes and periods between consecutive horizontal nystagmuses during bilateral stimulation on rotational chair. The evaluated parameters were volume, surface and surface/volume ratio of 95% confidence ellipsoids with dimensions deg·s
²
and deg
²
·s. The results of pilot study with 10 subject (5 males, 5 females) did not confirm the difference between per-rotational and post-rotational nystagmus during bilateral stimulation in any of the observed parameters. The reason of this conclusion is apparently a large inter-individual variability of amplitudes and periods between consecutive horizontal nystagmuses. In the future research, the possibility of normalizing or weighting the contributions of the individual ellipsoid axes should be considered, since the range of values of time and amplitude components varies substantially.