Objective oculomotor markers of mTBI: a three-timepoint case report

Mild traumatic brain injury (mTBI) is typically assessed using subjective symptom reports, yet subtle neurophysiological disruption may persist beyond clinical recovery. Eye-tracking provides an objective index of cognitive, sensorimotor, and autonomic function, particularly when implemented in immersive three-dimensional (3D) virtual reality (VR). This case report describes changes in 3D VR eye-tracking before, immediately following, and with recovery from mTBI.

A 49-year-old male completed baseline testing as part of a larger study, then sustained an mTBI 10 weeks later. Eye-tracking was repeated at 1 week ('Injury') and ~11 weeks post-injury ('Recovery'). The battery assessed fixation, pursuit, saccades, inhibitory control (anti-saccade and Stroop), vestibulo-ocular reflex (VOR), egocentric localization, and pupillary light reflex (PLR).

Injury-phase demonstrated widespread alterations in precision, inhibitory control, and autonomic metrics. Fixation BCEA increased 4.8-14.8%. Pursuit, fixation, and VOR error worsened. VOR gain worsened (1.04 to 0.79) but showed partial recovery (0.85). Anti-saccade accuracy declined (87.5% to 62.5%). Stroop accuracy improved; however, latency increased substantially, suggesting compensation. PLR constriction amplitude decreased by ~50%.

This case demonstrates multi-domain oculomotor disturbance post-mTBI, with persistent abnormalities despite symptom improvement. Immersive 3D VR eye-tracking may provide a sensitive, objective method for detecting neurophysiological dysfunction and monitoring recovery.