Postural responses without versus with acute external cervical spine fixation: a comparative study in healthy subjects and patients with acute unilateral vestibular loss.

Using a diagnostic prospective cohort single center study design, the influence of a cervical collar on standing balance during dynamic postural perturbations in healthy adults and patients with acute unilateral vestibular dysfunction was measured in 31 healthy subjects and 27 patients with acute unilateral vestibular loss. The main outcome measures were completed standard protocols on the Sensory Organization Test (SOT) and Motor Control Test (MCT) of the NeuroCom Equitest(®) computerized posturography platform measured without and with acute cervical fixation, respectively. Paired t test showed no significant difference during the six conditions of neither the SOT scores nor analyzing the SOT strategies or during the MCT between the non-fixed and fixed neck in healthy subjects and in the patients (all p > 0.05). Older healthy subjects showed decreased SOT scores but equal MCT results. The age effect was more dominant in the patients when wearing the collar. Gender had no influence whether in healthy individuals nor in patients. In almost all conditions of the SOT but only in some MCT subtests patients had significantly lower scores than healthy subjects without collar and with collar (all p < 0.05). In conclusion, the SOT but only some subtest of the MCT could clearly distinguish between healthy adults and patient with acute unilateral vestibular loss. Equilibrium scores did not change significantly when the cervical spine was fixed with a collar. Acute fixation of the neck with a collar seems not to affect standing balance, even not when vestibular, visual and/or somatosensory input are also reduced.