Transient analysis of vestibular nystagmus.

The significance of a nystagmus-dependent, transient component in the overall slow-phase response of the vestibulo-ocular reflex (VOR) is brought into focus. First, a simulated example is presented that shows how this transient component can bias current algorithms for the estimation of VOR parameters. Second, new algorithms are proposed that are able to estimate VOR parameters regardless of the presence of transients. Third, the new algorithms are applied to experimental data, and the results are compared with those from current algorithms. The results clearly show that the transient component can significantly alter the apparent VOR time constant, particularly when the reflex has been lesioned. The algorithms open new areas of research on the possible role of nystagmus in enhancing the compensatory function of the VOR.