Evidence for cortical visual substitution in chronic bilateral vestibular failure (fMRI)

Bilateral vestibular failure (BVF) is a rare disorder of the labyrinth or the eighth cranial nerve of various etiologies. To compensate for the diminished vestibular input the patients learn to rely more on somatosensory and visual cues. One of the subsystems involved in visual tracking a moving target is that for the optokinetic nystagmus (OKN). Recent imaging studies have identified the neuronal network in the human cortex activated during the execution of OKN. The aim of our study was to identify how the disturbed vestibular-visual interaction in patients with bilateral vestibular failure influences their pro…