Torsional optokinetic nystagmus: normal response characteristics

EXTENDED REPORT Torsional optokinetic nystagmus: normal response characteristics

Background/aims: Few studies have investigated normal response characteristics of torsional optokinetic nystagmus (tOKN). The authors have investigated the effect of stimulus velocity and central/peripheral stimulation on tOKN. Methods: Torsional OKN was elicited using a sinusoidal grating rotating at velocities of 3 /̊s to 1000 /̊s in clockwise and anticlockwise directions. To investigate the ef...

Torsional Optokinetic Nystagmus: Response Characteristics Measured in the Normal Population and Patients with Ocular Motor Disorders

Effects of a fixation target on torsional optokinetic nystagmus.

PURPOSE To investigate the effects of an imaginary and a visual target on torsional optokinetic nystagmus (tOKN) and directional symmetry of tOKN. METHODS Torsional OKN was induced by a rotating random dot pattern (52 degrees in diameter, constant angular velocity: +/-30 deg/sec to +/-52 deg/sec) with an imaginary or a visual target in 11 eyes of 10 healthy humans by dual-search coil methods....

Torsional optokinetic nystagmus after unilateral vestibular loss: asymmetry and compensation.

The aim of this study was to analyse torsional optokinetic nystagmus (tOKN) in 17 patients with Menière's disease before and after (1 week, 1 month and 3 months) a curative unilateral vestibular neurotomy (UVN). The tOKN was investigated during optokinetic stimulations around the line of sight directed towards either the lesioned or the healthy side, at various constant angular velocities. Dyna...

Vertical optokinetic nystagmus and saccades in normal human subjects.

PURPOSE Optokinetic stimulation induces nystagmus that can be used to test the saccadic and visual-tracking systems in some patients with voluntary gaze palsies. The purpose of this study was to characterize vertical optokinetic nystagmus (OKN) in normal human subjects, comparing the dynamic properties of the quick phases with voluntary saccades of similar size and measuring the slow-phase resp...