Weak jerk nystagmus in a patient with resolving vestibular neuritis
The eyes are first in primary position of gaze, and modest spontaneous left-beat nystagmus is present. When the patient directs gaze rightward, no nystagmus is present. When the patient directs gaze leftward, left-beat nystagmus is more pronounced than it had been on primary position of gaze. This pattern is in accordance with the Alexander law for a right-sided vestibular weakness.