Optokinetic nystagmus provoked by an angular acceleration of 1°/sec2 using a optokinetic stimulator of Jung type was analyzed on an electronystagmogram to measure the number of nystagmus beats, the nystagmus frequency, the optokinetic adaptation limit and the maximal eye speed of nystagmus slow phase. The optokinetic nystagmus potential (OKNP) which was the product of the slow phase eye speed of optokinetic nystagmus (°/sec) and the number of nystagmus beats in 10 seconds was calculated in 3 velocity divisions of the optokinetic stimulation, that is, 0°to 60°/sec, 60°to 90°/sec and 90°to 120°/sec.
The OKNPs of the subjects with equilibrium disorders were plotted on the graph and compared with those of the normal subjects. The patterns of the optokinetic nystagmus potentialogram (OKNPG) of the patients were classified into 5 types: normal type, hypernystagmic type, hyponystagmic type, recruiting type and decrescent type.
The OPNP will be an important indicator of the optokinetic activity, when it is possible to utilize the advantage of a computer.
