Head movement kinematics are differentially altered for extended versus short duration gait exercises in individuals with vestibular loss

Abstract

Head kinematics are altered in individuals with vestibular schwannoma (VS) during short duration gait tasks [i.e., Functional Gait Assessment (FGA)], both before and after surgery, yet whether these differences extend to longer duration gait exercises is currently unknown. Here we examined the effects of vestibular loss and subsequent compensation on head kinematics in individuals with VS during gait exercises of relatively extended versus short duration (< 10 versus 30 s), compared to age-matched controls. Six-dimensional head movements were recorded during extended and short duration gait exercises before and then 6 weeks after sectioning of the involved vestibular nerve (vestibular neurectomy). Standard functional, physiological, and subjective clinical assessments were also performed at each time point. Kinematics were differentially altered in individuals with vestibular loss at both time points during extended versus short duration exercises. Range of motion was significantly reduced in extended tasks. In contrast, movement variability predominately differed for the short duration exercises. Overall, our results indicate that quantifying head kinematics during longer duration gait tasks can provide novel information about how VS individuals compensate for vestibular loss, and suggest that measurements of range of motion versus variability can provide information regarding the different strategies deployed to maintain functional locomotion.

Effect of vestibular loss on head-on-trunk stability in individuals with vestibular schwannoma

“…This finding is of particular clinical importance since it reveals that head-on-trunk stabilization in pre-operative individuals with VS is impaired, contrary to the prevailing view that central mechanisms can provide virtually complete compensation due to the slowly progressing nature of the VS tumors 11 , 42 , 43 . In this context, our present findings contribute to the growing body of work 35 , 36 , 44 suggesting that the gradual adaptation of central mechanisms is not sufficient to provide full compensation. It has been previously addressed that initiating vestibular rehabilitation prior to the VS surgery can help alleviate long-term post-operative symptoms 45 , 46 .…”