Evoked potentials and other guiding factors of conversion from radiologically isolated syndrome to definite multiple sclerosis

Year 2017, Volume: 4 Issue: 6, 44 - 50, 30.06.2017

Serkan Demir , Eyup Duzgun Cahit Kafadar Erdem Togrol Guney Senol Akin Cakir

https://doi.org/10.17546/msd.316511

Abstract

Objective: Radiologically Isolated Syndrome (RIS) has
become a popular subject recently with quite a number of follow-up and other
clinical studies being done. A consensus on the approach to the patient with
RIS is being tried to be established. The aim of our study was to assess the
role of visual evoked potential (VEP) and somatosensory evoked potential (SEP)
as a guiding factor for the conversion from Radiologically Isolated Syndrome
(RIS) to definite Multiple Sclerosis (MS).

Material and methods: 49 RIS patients who were referred to GATA
Haydarpasa Training Hospital Neurology Department between 2011-2015. All of the
patients fullfillied the 2009 Okuda criteria for RIS and other differential
diagnosis were excluded accordingly. VEP and SEP examinations made during the
pre-MS RIS period were scanned retrospectively. For the VEP examination, the
P100 latency and amplitudes, for the SEP examination, the P40 latency and
amplitude was analysed.

Results: 49 patients were included in this study, the mean time of follow-up was
21,8 months. 63% of patients were female, while 37% were male. The mean age was
31,2 years. Among the four patients with abnormal SEPs, MS developed in three
of them (75%) over time. This is statistically significant (p = 0.011). VEP
and/or SEP was abnormal in 8 patients and MS developed in 4 (50%) of those (p=0.017).
The following factors have a positive statistically significant correlation
with conversion to MS: Presence of active plaques (r=0.461, p<0.001),
presence of more than 9 plaques (r=0.287, p=0.046), VEP and/or SEP pathologies
(r=0.402, p=0.004) and number of plaques (r=0.309, p=0.031). The most important
factor for the transformation is the presence of active plaque which increases
the risk 8.1-fold. The second important factor seems to be the presence of VEP
and/or SEP abnormality, but this factor does not reach statistical
significance. 

Conclusion: In the conversion to MS risk from RIS, VEP- SEP
examinations are important and should take its place in the follow-up of these
patients.

Keywords

multiple sclerosis, evoked potantials, radiologically isolated syndrome

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