title: Multimodality-evoked potential study of anti-aquaporin-4 antibody-positive and -negative multiple sclerosis patients.
abstract: Neuromyelitis optica (NMO) is claimed to be a distinct disease entity from multiple sclerosis (MS) because of its strong association with NMO-IgG/anti-AQP4 antibody; however, the in vivo role of the antibody remains unknown. Therefore, we aimed to clarify whether the presence of anti-AQP4 antibody is associated with any abnormalities in multimodality-evoked potentials in 111 patients with relapsing-remitting or relapsing-progressive MS, including the opticospinal form of MS, 18 of whom were seropositive for anti-AQP4 antibody. More patients with anti-AQP4 antibody showed a lack of the P100 component on visual-evoked potentials (VEPs) than those without the antibody (11/17, 64.7% vs. 20/84, 23.8%, p=0.003), whereas the frequency of delayed P100 latency was significantly higher in the latter group than in the former (1/17, 5.9% vs. 28/84, 33.3%, p=0.021). The frequencies of non-responses and delayed central sensory conduction times in median and posterior tibial nerve somatosensory-evoked potentials (SEPs) were not significantly different between anti-AQP4 antibody-positive and -negative patients. In terms of upper and lower limb motor-evoked potentials (MEPs), the frequencies of non-responses and delayed central motor conduction times did not differ significantly based on the presence or absence of anti-AQP4 antibody. The frequency of optic nerve lesions on MRI was significantly higher in anti-AQP4 antibody-positive patients than in anti-AQP4 antibody-negative patients (p=0.0137). Multiple logistic analyses revealed that anti-AQP4 antibody positivity (OR=8.406, p=0.02) and unevoked VEP responses (OR=35.432, p<0.001) were significantly related to development of severe visual impairment. Such an association of anti-AQP4 antibody with disability was not found for either severe motor or sensory impairment. These findings suggest a distinctive nature of optic nerve lesions between anti-AQP4 antibody-positive and -negative patients; lesions are supposed to be more necrotic in the former group and more demyelinating in the latter.
authors.affiliation: Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Watanabe
authors.forename: Takuya
authors.initials: T
authors.lastname: Matsushita
authors.forename: Hikaru
authors.initials: H
authors.lastname: Doi
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsuoka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shigeto
authors.forename: Noriko
authors.initials: N
authors.lastname: Isobe
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kawano
authors.forename: Shozo
authors.initials: S
authors.lastname: Tobimatsu
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Kira