Ocular lateropulsion as a central oculomotor sign in acute vestibular syndrome is not posturally dependent.

Horizontal conjugate gaze deviation (h-CGD) in acute vestibular syndrome (AVS) may be detected clinically or radiographically. While upright clinical ocular lateropulsion (OL) predicts central lesions, supine radiographic h-CGD does not. We sought to investigate the cause for this discordance by comparing upright to supine OL in AVS. We prospectively recorded clinical and radiographic h-CGD in 17 AVS patients. Horizontal eye position after brief eyelid closure was tested clinically following postural shifts. Radiographic h-CGD was assessed on axial magnetic resonance imaging (MRI) or computerized tomography (CT) images. All maintained central fixation with eyes open in light. OL was present in 8 (7 strokes, one central demyelination) and radiographic h-CGD in 14 (including all 6 with peripheral lesions). OL was unchanged after static postural testing. OL predicts central pathology and does not vary with postural shifts, regardless of lesion location. Radiographic h-CGD does not help localize, and this is not a positional effect.