The effect of optokinetic and galvanic vestibular stimulations in reducing post-stroke postural asymmetry

• Published in: Clinical neurophysiology Vol. 127; no. 1; pp. 842 - 847
• Main Authors: Bonan, I.V., Leblong, E., Leplaideur, S., Laviolle, B., Tassel Ponche, S., Yelnik, A.P.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2016; Elsevier
• Subjects: Adult; Aged; Female; Galvanic Skin Response - physiology; Humans; Life Sciences; Male; Middle Aged; Neurology; Nystagmus, Optokinetic - physiology; Paresis - diagnosis; Paresis - physiopathology; Paresis - therapy; Photic Stimulation - methods; Postural Balance - physiology; Postural control; Rehabilitation; Sensory stimulation; Stroke; Stroke - diagnosis; Stroke - physiopathology; Stroke - therapy; Treatment Outcome; Vestibule, Labyrinth - physiology; Sensory stimulation; Stroke; Rehabilitation; Postural control
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/j.clinph.2015.03.026

•Both optokinetic and galvanic vestibular stimulations modulate the position of the centre of pressure (CP) in people with hemiparesis.•The correction action of sensory stimulation for postural asymmetry is more effective in RHL suggesting a high level cortical effect on body’s representation of space.•The effect of both sensory stimulations is significantly correlated suggesting a common or at least overlapping central mechanism in relation to postural control. To investigate the postural effect of 2 types of sensory stimulation in patients with a left hemispheric lesion (LHL) or right hemispheric lesion (RHL) compared with controls. 35 patients (18 LHL, 17 RHL) and 27 controls (mean age 54.1years), with a mean delay post-stroke of 3.0months were enrolled. Subjects stood on a force platform and were stimulated on the left and right side by optokinetic (Okn) and galvanic vestibular (Gv) stimulation. Lateral displacement following stimulation toward the right and left directions was calculated as the mean position of the centre of pressure (CP) during the stimulation period minus the mean position at rest. Postural asymmetry was reduced in LHL and RHL patients. CP displacement was higher in cases of left-sided stimulation in the RHL group compared with control subjects and LHL patients (respectively 2.8 and 2.4 times higher, group effect, p<0.001, group×direction of stimulation interaction, p=0.007). The magnitude of displacement under Okn significantly correlated with Gv in all cases (ρ=0.635, p<0.001). Both GV and Okn stimulations can modulate hemiparetic’s CP and their postural effects are correlated. Results support a high level cortical postural effect of sensory stimulation on supramodal spatial network.