Background: Unilateral vestibular deafferentation (uVD), as performed in vestibular schwannoma surgery, results in a chronic vestibular deficit, though most of the insufficiency can be compensated by other sensory input. By vestibular training (prehabituation) performed before surgery, motor adaptation processes can be instigated before the actual lesion. The adaptation processes of the altered sensory input could be affected if the vestibular ablation and surgery was separated in time, by pre-treating patients that have remaining vestibular function with gentamicin.
Objective: To determine whether pre-surgical deafferentation would affect post-surgery postural control also in a long-term perspective (6 months).
Method: 41 patients subjected to trans-labyrinthine schwannoma surgery were divided into 4 groups depending on the vestibular activity before surgery (with no clinical significant remaining function n= 17; with remaining function n=8), whether signs of central lesions were present (n=10), and if patients with remaining vestibular activity were treated with gentamicin with the aim to produce uVD before surgery (n=6). The vibratory posturography recordings before surgery and at the follow-up 6 months after surgery were compared.
Results: The subjects pretreated with gentamicin had significantly less postural sway at the follow-up, both compared to the preoperative recordings and to the other groups.
Conclusion: The results indicate that by both careful sensory training and separating the surgical trauma and the effects of uVD in time, can adaptive processes develop more efficiently to resolve sensory conflicts, not only resulting in a reduction of symptoms directly after surgery, but also perhaps up to 6 month afterwards.