Computation of the Nystagmogram

Abstract

To study the interaction of the slow and fast component of the caloric nystagmus, the total velocity of the slow components were plotted against time. The individual quick components were added similarly into a continuous curve. Whereas increased stimulations create increased slow phase velocity, the fast component speed remains constant. Graded caloric stimuli alter with similar proportions the slow component speed as well as the frequency count at the culmination. Incongruence of these two phenomena, as well as traces on cathode ray oscilloscopes, indicates certain independence of the two phases of the vestibular nystagmus. Further evidence has been provided that both of these parameters, frequency count and slow phase velocity, are the best available expression of vestibular sensitivity.