Modulation of vestibulo-ocular reflex gain-symmetry induced by osteopathic manipulations on the fascial system in young healthy subjects: a three-arm randomized controlled trial

Abstract

BACKGROUND
The vestibulo-ocular reflex (VOR) gain-symmetry is fundamental for gaze control. VOR is a multisensorial integrated reflex that combines vestibular, visual, and proprioceptive inputs. Osteopathic manipulative treatment (OMT) approaches fascial system for the treatment of somatic dysfunction. Fascial system was recently described as body-wide proprioceptive organ. Hence, we performed a single-blinded, with third rater-blinded, three-arm randomized controlled trial to investigate the OMT interaction with VOR-gain-symmetry (VGS) of young healthy subjects, with the aim to evaluate the interaction between: proprioception, VOR and osteopathic manipulations on fascial-system.
METHODS
Participants were treated and examined in the SOMA institute outpatient clinic. According to the randomization list, the subjects received a sham OMT, an OMT and no interventions. The primary endpoint was the VGS variation (VGS01), assessed by video head impulse test, after 30 minutes from the interventions. Besides, VGS after 1 week from the interventions was the secondary endpoint.
RESULTS
One-hundred and eighty subjects were randomized; of those, 171 subjects completed the trial. Subjects who underwent OMT reduced them VGS01 asymmetry about 3.89% with a significant difference between groups (P=0.002). At follow-up, subjects who receive OMT maintained a 2.29% asymmetry reduction in contrast to the other groups that presented no delta with baseline (P=0.011).
CONCLUSIONS
OMT compared to placebo and time control demonstrated a plausible modulatory effect on VOR asymmetry of healthy subjects, which it might be mediated by proprioceptive inputs and multisensorial integration of vestibular system. A proof-of-concept trial should be performed to test the OMT in chronic dizzy patients.