Fig. 4.
A typical secondary VCUS in the same subject of Fig. 1, who had right UVD. The subject was rotated ipsilesionally while fixing a central target. a Primary and secondary VCUSs were identified by corresponding peaks in horizontal eye velocity. b In the horizontal-torsional quaternion plane, trajectories of both primary and secondary VCUS paralleled LP, while the VOR slow phase added non-LL torsion