Multiple sclerosis with normal neuro-ophthalmological work-up: results of focal stimulations induced by a scanning laser ophthalmoscope.
OBJECTIVE
Visual evoked potentials (VEPs) are a very useful tool in diagnosis of multiple sclerosis (MS). Nevertheless, in some cases of the disease, VEPs are normal. The aim of this study was to evaluate the diagnostic value of focal checkerboard reversal stimulation based on opto-acoustic modulation generated by a scanning laser ophthalmoscope (SLO) in patients whose standard neuro-ophthalmological work-up was normal.


METHODS
We prospectively studied 185 MS patients. In this cohort we found 30 patients with definite MS and normal neuroophthalmological work-up and we studied the diagnostic yield of focal visual stimulation in these patients. We performed focal SLO-elicited VEPs with two different spatial distributions: a central 8 x 8 degrees square field and a central 8 x 8 degrees exclusion square. The results were analysed in terms of age of the patient, course of the disease, and disability evaluated on the Expanded Disability Status Scale (EDSS).


RESULTS
Mean latencies of focal VEPs were increased in MS patients compared to controls. In MS, focal stimulation allowed dysfunction of the visual system to be detected in 50% of patients who have been classified as normal according to conventional VEPs. VEP abnormalities were found to be correlated with the EDSS score (P<0.001) and the course of the disease (P<0.05).


CONCLUSIONS
We have demonstrated the value of focal VEPs in MS diagnosis using SLO-based techniques. Further prospective work in patients with possible and probable MS should enable an evaluation of the sensitivity and specificity of this method in the early diagnosis of MS.
de Seze
J
J
Department of Neuro-ophthalmology, Hôpital Roger Salengro, CHRU de Lille, France.
Arndt
C F
CF
Stojkovic
T
T
Lebrun
T
T
Debruyne
P
P
Hache
J C
JC
Vermersch
P
P
D000328:Adult; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D005072:Evoked Potentials, Auditory; D005074:Evoked Potentials, Visual; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D007834:Lasers; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis* / Q000503:physiopathology; D009887:Ophthalmoscopy / Q000379:methods*; D012680:Sensitivity and Specificity