[Agreement of automatically and manually determined parameters of the electronystagmogram]

Prerequisite for clinical use of programs for automatic analysis of nystagmus is a similar accuracy in determining parameters of electronystagmograms in comparison with manual evaluation. For examination of accuracy and reliability of our program NYSLYS, we compared maximal values of the slow phase velocity (SPV) and the number of beats in 10 s of responses from thermal tests, with 100 patients with equilibrium disturbances. The average difference between the automatically and manually evaluated values for SPV and the number of beats in 10 s is in the range of +/- 15%. Correlation coefficients are 0.97 for SPV and 0.95 for the number of beats in 10 s. Similar correlation coefficients are obtained for the ratio of responses after left and right ear stimulation. These results show that our automatic analysis can replace tedious manual evaluation in most cases. In addition the temporal course of SPV is obtained as a good aid in the judgement of nystagmus. Automatic analysis, however, cannot fully replace the ability to examine electronystagmograms. Especially if curves are disturbed by many artifacts or in cases with very irregular reactions the original electronystagmogram must be considered, too.