| Research Abstract |
Visual conduction disorders consist of (1) conduction block, (2) conduction delay, and (3) fatiguability. This study was performed to produce a new laboratory test for detecting slight or subclinical abnormality of visual conduction process. For these three years, we established a new method of "paired pattern reversal stimulation." Subjects consisted of 70 healthy adults. Interstimulus intervals (ISI) were 40, 60, 80, 100, 120, 140, 160, and 180 msec. Waveform X was defined as the response after subtracting the response B (single stimulation) from the response A (paired stimulation). Both latency and amplitude were compared between the response B and X.Both ERG and VEP were recorded in this study. ERG was recorded from the gold foil electrode in the eyelid, and VEP was recorded from the mid-occipital scalp electrode. The results are following ;
1. ERG latency (1) a(p)latency, B<X, (2) b(p)latency, B<X, (3) c(p)latency, B<X
2. ERG amplitude (1) b(p)amplitude, B<X, (2) c(p)amplitude, B>X
3. VEP latency (1) P50 latency, B<X, (2) N75 latency, B<X, (3) P100 latency, B<X (4) N145 latency, B<X
4. VEP amplitude (1) N75 amplitude, B<X (2) P100 amplitude, B>X (3) N145 amplitude, B>X
The difference of latency or amplitude was the most largest between B and X, at the ISI of 40-80 msec.
This particular method was applied to two MS patients. The results showed delayd VEP latency in both B and X.
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