Time-course investigation of postural sway variability: Does anxiety exacerbate the sensory reweighting impairment in chronic stroke survivors?

Publication date: Available online 8 March 2019Source: NeuropsychologiaAuthor(s): Shamsi Jamali, Akram Azad, Hajar Mehdizadeh, Asgar Doostdar, Fatemeh Hoseinpour, Maryam Mehdizadeh, Javad Niazi-Khatoon, Mohammad Reza Shokouhyan, Mohamad Parnianpour, Ghorban Taghizadeh, Kinda KhalafAbstractAlthough anxiety is one of the most prevalent psychological disorders in stroke survivors, its effect on sensory reweighting has not yet been fully studied. The aim of this work was to investigate how anticipation of collision avoidance events affects sensory reweighting in chronic stroke survivors with low and high levels of anxiety (LA-stroke and HA-stroke, respectively), as compared with healthy controls (HC), under the condition of perturbed proprioception. Eighteen LA-stroke and 18 HA-stroke survivors, as well as 18 gender- and age-matched HC, participated in this study. Postural sway variability (i.e. Root Mean Square (RMS) of the COP velocity) was measured for a duration of 180 s under two conditions: quiet standing and standing while predicting random virtual spheres to be avoided. Proprioceptive perturbation was simulated using bilateral Achilles tendon vibration at mid duration (60 s) for both conditions. The results showed that the HC were able to timely use visual anticipation to reduce the postural sway variability induced by tendon vibration. However, marked delay in using such anticipation was observed in stroke participants, especially in the HA-stroke group, as indicated...
Source: Neuropsychologia - Category: Neurology Source Type: research