2003-09-10 LIKS IS seminaras

1. Sparse multifocal stimuli and FDT perimetry for the detection of
multiple sclerosis
Rasa RUSECKAITE,
Centre for Visual Sciences,
RSBS, ANU,
Canberra, ACT - 2601
Australia.
Purpose of our work was to examine contrast reversing and Sparse
multifocal visual evoked potentials (mfVEPs), frequency doubling (FD)
illusion based perimeter and FD mfVEPs in Normal subjects and Multiple
Sclerosis (MS) patients. Multifocal responses were obtained from 19
Normal subjects, 26 Optical Neuritis (ON) subjects and 24 MS patients.
We employed multiple regression, principal components (PCA) and
discriminant data analysis to define differences between Normal and MS
study groups in terms of response sizes, waveforms and latencies.
Compared to Normal subjects the ON patients had delayed VEP waveforms
(~30ms), especially for the sparser stimuli. The responses of MS
subjects were smaller than those of Normal subjects.
Multifocal VEPs recorded to temporally sparse stimuli, perimeter and FD
mfVEPs obtained from Normal and ON subjects showed a significant
diagnostic value in MS subjects and are a useful tool to describe the
cortical responses of MS and ON patients.