Res Vestib Sci.
2023 Mar;22(1):19-22. 10.21790/rvs.2023.22.1.19.
Visual Fixation-Induced Hemi-Seesaw Nystagmus
- Affiliations
-
- 1Department of Neurology, Gyeongsang National University Changwon Hospital, Gyeongsang National University School of Medicine, Changwon, Korea
- 2Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea
- KMID: 2540390
- DOI: http://doi.org/10.21790/rvs.2023.22.1.19
Abstract
- Seesaw nystagmus (SSN) is characterized by conjugate torsional nystagmus with opposite vertical components in the two eyes. The waveform may be pendular or jerk (hemi-seesaw nystagmus, HSSN), in which the slow phase corresponds to one half-cycle and the quick phase to the other. Pendular SSN and HSSN have distinct clinical presentations and underlying causes. The pathophysiology of pendular SSN may be instability of visuovestibular interactions, while the underlying mechanism for HSSN may be related to the ocular tilt reaction or an imbalance in vestibular pathways. We report a patient with HSSN due to unilateral mesodiencephalic infarction that becomes apparent during visual fixation only.
