Clinical Assessment of Otolith-Ocular Function: A Practical Guide and Review of the Video-Ocular Counter-Roll.

Otolith organs play a central role in gaze stabilization, spatial orientation, and postural control. Advances in video-oculography have created new opportunities to assess this key aspect of vestibular function directly at the bedside. Using this technology, the video ocular counter-roll (vOCR) test extends vestibular evaluation to the otolith-ocular system by measuring ocular counter-roll (OCR), a torsional vestibulo-ocular response during lateral head tilt. This review provides a practical guide to the clinical application of vOCR, including setup, analysis, and interpretation, and discusses its diagnostic utility for assessing otolith-ocular function, characterizing patterns of vestibular loss, and monitoring recovery.