Clinical Research: Pattern Reversal Visual Evoked Potentials: Influence of age, Gender and Check Size in the Diagnosis of Multiple Sclerosis

Abstract

The visual evoked potentials (VEP) of a group of 105 multiple sclerosis (MS) patients and a control group of 257 healthy subjects were analysed in order to investigate the influence of age, gender, and check size on the VEP latencies and amplitude. Check sizes of 17′, 10′, and 7′ were used. The best recordings were made by using the 10′ check size. The age-effect of the N100 latency is more complex than the linear increase of the P80 latency with age. In the first two decades the N100 latency slightly decreases, it then remains more or less stable in the period 20-60 years of age, and finally it increases after 60 years of age. For the P80/N100 amplitude in the first two decades a considerable decrease in amplitude can be seen, whilst it remains more or less stable in the years after 20. In the classification of the MS group vs. the control group the authors found the percentage correctly classified subjects to be 87.6%, when they used both the P80 latency and the P80/N100 amplitude in a discriminant analysis technique. The P80 latency is a more sensitive parameter than the N100 latency in the detection of MS for the check size of 10′. Amplitude is not of useful complementary value to latency in the detection of MS.

Key Words:

• Visual evoked potential
• pattern reversal
• latency
• amplitude
• age
• sex
• check size