Video-oculography in multiple sclerosis: Links between oculomotor disorders and brain magnetic resonance imaging (MRI)

•Video-oculography is a useful technic to confirm early demyelinating process.•Eye movement abnormalities are common in all MS phenotypes even at the early stage.•These disorders are more prominent in progressive phenotypes.•This technique can be useful to follow the progression of the demyelinating disease.•Eye movement abnormalities may not be correlated with MRI lesions (INO for example). Eye movement abnormalities (EMA) are common in multiple sclerosis (MS). However, type and severity according to the MS stage are poorly known, especially in Radiologically Isolated Syndrome (RIS) and in Clinically Isolated Syndrome (CIS). Although MRI has been included in the MS diagnostic criteria, there may be clinical-radiological dissociation. To analyze by video-oculography (VOG) prevalence of EMA in different MS phenotypes and study correlations with brain and cervical cord MRI T2 lesions location. 76 participants were prospectively recruited (12 RIS, 10 CIS, 11 relapsing-remitting-MS, 10 secondary progressive-MS, 10 primary progressive MS and 23 gender and age-matched healthy controls). We analyzed fixations, anti-saccades, horizontal and vertical reflex saccades and smooth pursuit. EMA were frequent and of gradual severity from RIS to progressive forms. Internuclear ophthalmoplegia (INO) and centripetal hypermetria were strong arguments for the diagnosis of a demyelinating disorder versus a control population. Some EMA were linked to infratentorial T2 lesion location, but others like INO were not. This study confirm that EMA are common in all MS phenotypes, even at the earliest stages. VOG can be useful to detect demyelinating process at preclinical stage by highlighting subclinical EMA even in absence of characteristic lesions visible on MRI.