Spasmus nutans. A quantitative prospective study.

Spasmus nutans includes ocular oscillations, head nodding, and anomalous head positions. No quantitative longitudinal study verifying the natural history of this self-limited condition has appeared in the literature. Using infrared oculography, we prospectively examined the eye movements of otherwise neurologically normal infants in whom a diagnosis of spasmus nutans had been made. At this writing the ocular oscillations and head movements in two of the children were clinically absent, thereby confirming the diagnosis. The ocular movements are characterized by a phase difference between the oscillations of each eye that varies both during one recording session and during development. The dissociated, pendular nystagmus consists of high-frequency oscillations that may be disconjugate, conjugate, or purely uniocular.