Absence of spontaneous head tilt in superior oblique muscle palsy.

We used the head-tilt test--based on an imbalance between the function of a paretic superior oblique muscle and its homonymous superior rectus muscle, rather than on an anomaly of cycloversion-to test three patients with superior oblique muscle palsies. Spontaneous ocular torticollis was absent if a patient had poor vision in one eye or if his vertical fusional amplitudes were of such magnitude that he was able to overcome his vertical deviation in all positions of gaze. These latter instances, though rare, may be more common than reports indicate.