Optokinetic response in patients with vestibular areflexia

Article type: Research Article

Authors: Huygen, Patrick L.M.^a | Verhagen, Wim I.M.^{b; *}

Affiliations: [a] Department of Otorhinolaryngology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands | [b] Department of Neurology, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands

Correspondence: [*] Corresponding author: W.I.M. Verhagen, MD, PhD, Canisius-Wilhelmina Hospital, Department of Neurology, Nijmegen, P.O. Box 9015, 6500 HB Nijmegen, The Netherlands. Tel.: +31 24 3658765; Fax: +31 24 3657329; E-mail: w.verhagen@cwz.nl

Abstract: Optokinetic nystagmus (OKN) responses (stimuli 40°/s and 60°/s) were evaluated in 121 patients with vestibular areflexia (VA) and were compared with a control group of 99 control subjects matched by age. The mean response levels were significantly higher in the VA group than in the control group: 1.7°/s at 40°/s stimulation, and 4.4°/s at 60°/s. The VA group showed a significantly wider scattering and greater variances and, as a group, they exhibited higher OKN gains than the control subjects. We suggest that the higher gain of OKN responses in VA patients can be attributed to an increased efficiency in signal processing by the cortical optokinetic system. This enhancement may be similar to the enhancement which, in healthy subjects, is produced by "optokinetic training".

Keywords: Cortical optokinetic nystagmus, optokinetic training, vestibulo-ocular reflex

DOI: 10.3233/VES-2011-0418

Journal: Journal of Vestibular Research, vol. 21, no. 4, pp. 219-225, 2011