The Oculomotor Battery
Before any vestibular stimulus is applied, you must rule out a broken oculomotor system. These four tests probe the cortex, brainstem, and cerebellum — and they do it in under five minutes.
Rapid, ballistic eye movements that re-fixate the fovea on a new target. Three parameters are analyzed: accuracy, velocity, and latency.
Accuracy: within ~5% of target · Velocity: scales with amplitude (main sequence), peak ~400°/s for 20° saccade · Latency: 200–250 ms.
Hypometric (undershoot, shaded in the trace) → cerebellar / basal ganglia · Slow saccades → brainstem (PPRF, MLF — internuclear ophthalmoplegia), white-matter disease, sedation · Increased latency → cortical or attentional deficit. Use a pseudorandomized target paradigm to defeat anticipation.