SPASMUS nutans is a clinical entity in which nystagmus is associated with head nodding and anomalous head positions. This triad is so characteristic that there can be little doubt of the diagnosis when present in its entirety, but the diagnosis may be less certain when only one or two of the features are present. The nystagmus is not identical in all patients and may vary in one and the same patient, but in general it tends (1) to be asymmetric in the two eyes, (2) to vary for different directions of gaze, and (3) to have extraordinarily fine and rapid excursions, often simulating a quiver. The head nodding is inconstant and irregular; it may be horizontal or vertical or both, but rarely has the abruptness that the name "spasmus nutans" would imply. The anomalous head positions consist of turning or tilting the head.
The literature on spasmus nutans has been
NORTON EWD, COGAN DG. SPASMUS NUTANSA Clinical Study of Twenty Cases Followed Two Years or More Since Onset. AMA Arch Ophthalmol. 1954;52(3):442-446. doi:10.1001/archopht.1954.00920050444012