Reliability of mobile video-oculography in multiple sclerosis patients using an iPad: A prospective validation study

Video-oculography (VOG) could be useful for monitoring neurodegenerative diseases and multiple sclerosis (MS), as a high prevalence of subclinical eye movements abnormalities (EMA) has been previously reported, with a potential prognostic value regarding disease evolution. However, access to VOG is limited in clinical practice.

To evaluate the reliability of VOG recordings performed using eVOG, a mobile application developed on an iPad.

Patients with MS or related disease without clinically detectable EMA were enrolled in a cross-sectional study during which two VOG exams (classical VOG and eVOG) were performed on the same day. We examined reflex saccades, antisaccades, smooth pursuit and fixation. The total number of deficits, saccadic latencies and velocities, qualitative smooth pursuit were compared.

30 patients were included. The mean number of EMA per patient on classical VOG was 4.1 and 2.3 on eVOG. We found a statistical association between the number of EMA for each exam (r = 0.66, p < 0.0001). Saccades latencies (r = 0.57, p < 0.0001) and velocities (r = 0.45, p < 0.0001) were also well correlated. Assessing eVOG accuracy, we found a sensitivity ranging from 44% to 100% and a specificity ranging from 71% to 88.9% depending on the considered abnormality.

eVOG could be an easily accessible solution to screen MS patients for the presence of EMA. We plan to use eVOG on a larger cohort of patients, in a prospective study to assess the prognostic value of subclinical EMA in MS. We also plan to investigate the use of eVOG in other neurological conditions.