Efect of post-stroke spasticity on voluntary movement of the upper limb

Solomon, John M (2021) Efect of post-stroke spasticity on voluntary movement of the upper limb. Journal of NeuroEngineering and Rehabilitation, 18. pp. 1-14. ISSN 1743-0003

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Abstract

Background: Hemiparesis following stroke is often accompanied by spasticity. Spasticity is one factor among the multiple components of the upper motor neuron syndrome that contributes to movement impairment. However, the specifc contribution of spasticity is difcult to isolate and quantify. We propose a new method of quantifcation and evaluation of the impact of spasticity on the quality of movement following stroke.Methods: Spasticity was assessed using the Tonic Stretch Refex Threshold (TSRT). TSRT was analyzed in relation to stochastic models of motion to quantify the deviation of the hemiparetic upper limb motion from the normal motion patterns during a reaching task. Specifcally, we assessed the impact of spasticity in the elbow fexors on reaching motion patterns using two distinct measures of the ‘distance’ between pathological and normal movement, (a) the bidirectional Kullback–Liebler divergence (BKLD) and (b) Hellinger’s distance (HD). These measures difer in their sensitivity to diferent confounding variables. Motor impairment was assessed clinically by the Fugl-Meyer assessment scale for the upper extremity (FMA-UE). Forty-two frst-event stroke patients in the subacute phase and 13 healthy controls of similar age participated in the study. Elbow motion was analyzed in the context of repeated reach-tograsp movements towards four diferently located targets. Log-BKLD and HD along with movement time, fnal elbow extension angle, mean elbow velocity, peak elbow velocity, and the number of velocity peaks of the elbow motion were computed.Results: Upper limb kinematics in patients with lower FMA-UE scores (greater impairment) showed greater deviation from normality when the distance between impaired and normal elbow motion was analyzed either with the BKLD or HD measures. The severity of spasticity, refected by the TSRT, was related to the distance between impaired and normal elbow motion analyzed with either distance measure. Mean elbow velocity difered between targets, how‑ever HD was not sensitive to target location. This may point at efects of spasticity on motion quality that go beyond efects on velocity.Conclusions: The two methods for analyzing pathological movement post-stroke provide new options for studying the relationship between spasticity and movement quality under diferent spatiotemporal constraints

Item Type: Article
Uncontrolled Keywords: Stroke, Spasticity; Hemiparesis; Kinematics; Stochastic model; Gaussian mixture model; Hellinger’s distance; Kullback– Liebler divergence
Subjects: Allied Health > MCOAHS Manipal > Physiotherapy
Depositing User: KMC Library
Date Deposited: 28 Jan 2022 04:21
Last Modified: 28 Jan 2022 04:21
URI: http://eprints.manipal.edu/id/eprint/158063

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