Walsh & Hoyt: Seesaw and Hemi-Seesaw Nystagmus

In seesaw and hemi-seesaw nystagmus, one half-cycle consists of elevation and intorsion of one eye and synchronous depression and extorsion of the other eye; during the next half-cycle, the vertical and torsional movements reverse. The waveform may be pendular or jerk. In the latter case, the slow phase corresponds to one half-cycle. A seesaw component is present in many central forms of nystagmus. Seesaw nystagmus may be congenital, or acquired. Quantitative studies have done much to clarify the characteristics and pathogenesis of seesaw nystagmus.