Slowing of Motor Imagery after a Right Hemispheric Stroke

Abstract

The temporal congruence between real and imagined movements is not always preserved after stroke. We investigated the dependence of temporal incongruence on the side of the hemispheric lesion and its link with working memory deficits. Thirty-seven persons with a chronic stroke after a right or left hemispheric lesion (RHL : n = 19; LHL : n = 18) and 32 age-matched healthy persons (CTL) were administered a motor imagery questionnaire, mental chronometry and working memory tests. In contrast to persons in the CTL group and LHL subgroup, persons with a RHL had longer movement times during the imagination than the physical execution of stepping movements on both sides, indicating a reduced ability to predict movement duration (temporal incongruence). While motor imagery vividness was good in both subgroups, the RHL group had greater visuospatial working memory deficits. The bilateral slowing of stepping movements in the RHL group indicates that temporal congruence during motor imagery is impaired after a right hemispheric stroke and is also associated with greater visuospatial working memory deficits. Findings emphasize the need to use mental chronometry to control for movement representation during motor imagery training and may indicate that mental practice through motor imagery will have limitations in patients with a right hemispheric stroke.

Towards the integration of mental practice in rehabilitation programs. A critical review

“…Patients with hemorrhagic strokes imagined the tasks 2–3 times faster than when they executed them physically (Wu et al, 2010), suggesting that they had difficulty in representing mentally complex tasks with accuracy (Guillot and Collet, 2005a). These findings, however, are at variance with those from diverse sources that observed some slowing (about 20–40%) of MI during hand pointing (Malouin et al, 2004c; Stinear et al, 2007) and stepping movements (Malouin et al, 2004c, 2012), especially after right hemispheric strokes (Malouin et al, 2004c, 2012; Stinear et al, 2007) or in patients with sensory deficits (Liepert et al, 2012). The large timing discrepancies reported by Wu et al (2010) are worrisome and warrant the requirement of regular chronometric checks in future studies.…”

“…In fact, screening for cognitive problems and MI ability should be mandatory given the role of working memory in MI and documented working memory problems with aging and stroke (Malouin et al, 2004b, 2010, 2012; Schott, 2012). Both reduced working memory and poor attention skills can make the teaching of MI more difficult (Braun et al, 2010, 2012).…”

Motor imagery training improves precision of an upper limb movement in patients with hemiparesis

“…It is of clinical relevance to know whether patients differ in their level of benefit from motor imagery training. Mutsaarts, Steenbergen & Bekkering (2007) suggest that patients with left hemispheric brain damage have impaired motor imagery abilities while another study suggests the opposite (Malouin, Richards, & Durand, 2012). Yet other studies report specific motor imagery deficits in the stroke-affected hand after both left and right hemispheric damage (Daprati, Nico, Duval, & Lacquaniti, 2010;Sabate, Gonzalez, & Rodriguez, 2004;Stinear, Fleming, Barber, & Byblow, 2007) but propose a more dominant role of the left hemisphere for motor planning (Sabate et al, 2004).…”

Introduzione

“…Gli studi riportano prove dell'efficacia della riabilitazione basata sulle immagini motorie in casi di malattia di Parkinson, dolore cronico, dolore connesso all'arto fantasma, ictus (Birbaumer et al, 1997;Chan et al, 2007;Tamir et al, 2007;Malouin et al, 2012). Come accennato in precedenza, un fattore determinante per la riuscita del training basato sulle immagini motorie è l'integrità dei processi di base dell'imagery nei pazienti.…”