Vestibulopathy remains poorly recognized and difficult to diagnose, often leading to major impacts on quality of life through symptoms such as oscillopsia, imbalance, and spatial disorientation. Treatment options remain limited and mainly rely on vestibular rehabilitation and compensatory strategies.
Vestibular implants have recently emerged as a promising therapeutic option inspired by cochlear implants. These devices aim to restore vestibular function through electrical stimulation of the vestibular nerve. Although previous studies demonstrated the feasibility of restoring vestibular reflexes, knowledge of patients’ functional impairments and long-term outcomes remained limited.
The aim of this doctoral work was to characterize functional impairments in patients with bilateral vestibulopathy (BV) and unilateral vestibulopathy (UV), and to investigate the effects of prolonged vestibular implant stimulation. Five studies addressed two main objectives.
The first objective focused on gait and movement impairments in standardized and daily-life conditions. Studies showed that BV patients did not present major gait deficits but rather compensatory strategies, including increased gait variability and rigid head stabilization relative to the trunk. Dynamic stability analyses identified clinically relevant tasks and parameters for shorter and more efficient assessment protocols. Using wearable inertial sensors during ecological tasks such as walking on uneven terrain or in darkness improved discrimination between patients and healthy subjects. Head movement analyses further demonstrated reduced head mobility in BV patients, confirming compensatory head-trunk rigidity strategies.
The second objective explored the effects of prolonged vestibular implant stimulation. Continuous baseline electrical stimulation delivered through implanted electrodes did not produce measurable improvements in gait, posture, or visual stability. However, some patients reported subjective improvements in quality of life, suggesting that constant stimulation may still provide partial benefits while more physiological stimulation paradigms are under development.
Overall, this doctoral work improved the understanding of locomotor impairments and compensatory mechanisms in BV and UV, identified objective and clinically applicable assessment methods using wearable sensors, and highlighted the importance of vestibular implant strategies that better reproduce natural vestibular physiology.
