Imagined actions in multiple sclerosis patients: evidence of decline in motor cognitive prediction

Exp Brain Res (2013) 229:561570 DOI 10.1007/s00221-013-3617-y

RESEARCH ARTICLE

Imagined actions in multiple sclerosis patients: evidence of decline in motor cognitive prediction

Andrea Tacchino Marco Bove Ludovico Pedull Mario Alberto Battaglia Charalambos Papaxanthis Giampaolo Brichetto

Received: 11 February 2013 / Accepted: 10 June 2013 / Published online: 28 June 2013 Springer-Verlag Berlin Heidelberg 2013

and mental movement durations in PwMS with respect to HS. An index of performance (IP) was used to examine actual/mental isochrony properties in the two groups. Statistical analysis on IP showed in PwMS signicantly longer actual movement durations with respect to mental movement durations (anisochrony), more relevant for the non-dominant than dominant arm. Mental prediction of motor actions is not well preserved in MS where motor and cognitive functional changes are present. Differences in performing imagined task with dominant and non- dominant arm could be related to increased cognitive effort required for performing non-dominant movements.

Keywords Multiple sclerosis Motor imagery Forward internal model Isochrony Motor cognition

Introduction

Motor imagery (MI) is a mental process during which subjects internally simulate a movement without any motor output. At the neurophysiological level, imagined actions engage neural networks, such as parietal and prefrontal cortices, supplementary motor area, premotor and primary motor cortices, basal ganglia, and cerebellum, which largely overlap with those activated during actual actions (Decety 1996; Fadiga and Craighero 2004; Jeannerod 2001). It is of interest that similarities between actual and mental movements also exist at the behavioral level by obeying the same motor rules (Decety and Jeannerod 1995; Gentili et al. 2004; Skoura et al. 2008). These neurophysiological and behavioral ndings are in agreement with the simulation theory developed by Jeannerod (Jeannerod 2001) postulating that mental actions are motor representations that are not overtly executed. Imagined actions are

Abstract Motor imagery is a mental process during which subjects internally simulate a movement without any motor output. Mental and actual movement durations are similar in healthy adults (isochrony) while temporal discrepancies (anisochrony) could be an expression of neurological decits on action representation. It is unclear whether patients with multiple sclerosis (PwMS) preserve the capacity to simulate their own movements. This study investigates the ability of PwMS to predict their own actions by comparing temporal features of dominant and non-dominant actual and mental actions. Fourteen...