Long-term effects of vestibular compensation on balance control and sensory organisation after unilateral deafferentation due to vestibular schwannoma surgery.

The time-course of central adaptive mechanisms after vestibular schwannoma surgical removal allows, 3 months after surgery (middle term), a satisfactory recovery of balance control. However, the long-term evolution of postural control beyond the end of usual medical follow-up remains unknown. This longitudinal prospective study aimed to assess the long-term effects of vestibular compensation on balance control and sensory organisation in patients operated on for vestibular schwannoma. Thirty-six patients with vestibular schwannoma underwent vestibular and sensory organisation tests, shortly before and 3 months, 6 months and 1 year after surgery. Postural control performances improved 3 months after surgery compared with before surgery; they continued to improve at 6 and 12 months after surgery, especially in conditions highly soliciting vestibular information. In the long term, strategies based on sensorimotor and/or behavioural substitution seem to be reinforced and fine-tuned, particularly in complex postural situations, for which only vestibular information is reliable to control balance.