Journal of Neuro-Ophthalmology, March 1981, Volume 1, Issue 1

Periodic alternating skew deviation.

A 78-year-old hypertensive woman suddenly developed blurred vision, followed shortly by dizziness, difficulty walking with a tendency to veer to the left, and vertical diplopia. Examination 3 weeks later revealed a unique neuro-ophthalmologic motility pattern, which may be described as periodic alternating skew deviation. This previously unreported motility disturbance was associated with downbeat nystagmus in our patient, and a focal lesion at the level of the interstitial nucleus of Cajal was demonstrated on computed tomography. The spectrum of physiologically related motility patterns--including periodic alternating nystagmus, cyclic oculomotor paralysis, see-saw nystagmus, periodic alternating gaze deviation, ""ping-pong"" gaze, and intermittent aperiodic alternating skew deviation--has been considered and is helpful in topical neuro-ophthalmologic diagnosis.