You have full access to this open access article. The different plasticity mechanisms underlying VC are first reviewed, and the authors present thereafter the dual concept of vestibulo-centric versus distributed learning processes to explain the compensation of deficits resulting from the static versus dynamic vestibular imbalance.
The main challenges for the plastic events occurring in the vestibular nuclei VN during a post-lesion critical period are neural protection, structural reorganization and rebalance of VN activity on both sides. Data from animal models show that modulation of the ipsilesional VN activity by the contralateral drive substitutes for the normal push—pull mechanism. On the other hand, sensory and behavioural substitutions are the main mechanisms implicated in the recovery of the dynamic functions.
These newly elaborated sensorimotor reorganizations are vicarious idiosyncratic strategies implicating the VN and multisensory brain regions. Imaging studies in unilateral vestibular loss patients show the implication of a large neuronal network VN, commissural pathways, vestibulo-cerebellum, thalamus, temporoparietal cortex, hippocampus, somatosensory and visual cortical areas.
Changes in gray matter volume in these multisensory brain regions are structural changes supporting the sensory substitution mechanisms of VC. Future challenges to understand VC are proposed. The vestibular system contributes to reflex generation for posture [ 1 ] and oculomotor [ 2 ] control, and interacts with high-level cognitive processes including spacial perception [ 3 ], spacial navigation [ 4 ] and body representation [ 5 ]. Indeed, vertigo and dizziness, and their associated neurovegetative symptoms nausea and vomiting, are extremely disabling for vestibular loss patients who exhibit increased anxiety and depression compared to healthy subjects [ 7 ].
Together with the physical disability and the psychological stress, the socio-professional consequences that accompany vestibular damage are major in many cases stop working, social isolation [ 8 ]. Fortunately, acute vestibular syndrome is ameliorated over weeks and months in both animals and humans through the process of vestibular compensation VC. Indeed, there is a spontaneous functional recovery after damages to the vestibular system, one of the best documented post-lesional neuronal and behavioural plasticity [ 9 — 12 ] for reviews.
