Visual evoked potential in multiple sclerosis and neuromyelitis optica spectrum disorder: A comparative study

• Published in: Neurophysiologie clinique Vol. 48; no. 3; p. 133
• Main Authors: Hamza, Nouha, Hdiji, Olfa, Farhat, Nouha, Kacem, Hanen Haj, Sakka, Salma, Bouattour, Nadia, Dammak, Mariam, Mhiri, Chokri
• Format: Journal Article
• Language: English
• Published: Paris Elsevier Masson SAS 01-06-2018; Elsevier Science Ltd
• Subjects: Aquaporin 4; Diagnosis; Epidemiology; Eye; Latency; Multiple sclerosis; Neurological disorders; Neuromyelitis; Neuromyelitis optica spectrum disorder; Neuropathology; Visual evoked potentials; Visual evoked potentials; Multiple sclerosis; Neuromyelitis optica spectrum disorder
• ISSN: 0987-7053; 1769-7131
• DOI: 10.1016/j.neucli.2018.05.015

The neuromyelitis optica spectrum disorder (NMOSD) was differentiated from relapsing-remitting multiple sclerosis (MS) by clinical, laboratory and physiopathological findings, including the presence of anti-aquaporin 4 (AQP4-Ab) antibody. Visual evoked potentials (VEP) are often used for the diagnosis of MS. However, the features of these VEP in the NMOSD have not been studied in detail. Our aim is to determine the epidemiological, clinical and especially neurophysiological (VEP) differences between MS and NMOSD.
Fourteen patients with NMOSD and 14 patients with RRMS were included in this study. The patients’ neurological symptoms and signs were examined and their VEP recorded.
The mean age at onset of the patients with NMOSD was 43.21 years, which was older than that of the patients with RRMS (P=0.017). The ratio of female patients with NMOSD was higher than that with RRMS (P=0.012). The periods from onset to diagnosis were similar between the two groups. The prevalence of bilateral visual disturbance was higher in the NMOSD group (78.57%). Patients with RRMS presented a P100 latency and/or amplitude impairment in 6 asymptomatic eyes (21.42%). While in patients with NMOSD, there were 4 asymptomatic eyes that had all normal VEP. In VEP, 17.9% of NMOSD eyes presented no response and only 3.6% of MS eyes and the P100 amplitude impairment was predominant in NMOSD.
Sometimes, it remains critical to differentiate a MS from an NMOSD especially when the specific antibody is negative. VEP results can point to one of the two diseases even at an early stage.