Motor neglect associated with loss of action inhibition

Abstract

Motor neglect, underuse of one side of the body not explained by weakness or sensory impairment, is a common consequence of stroke that is surprisingly little understood. Behavioural and neuroanatomical hallmarks of the disorder are investigated. Using a masked prime task, it was shown that when patients with left motor neglect plan to move their left hand, irrelevant right limb motor programmes intrude, causing delay. Lesion analysis reveals that such asymmetry of motor programming occurs after infarcts of the right putamen and motor association areas. This demonstration of failure to inhibit ipsilesional limb motor plans suggests potential benefit from interventions that might act to restore balance in action planning.

Caloric vestibular stimulation and postural control in patients with spatial neglect following stroke

“…In the perceptual domain, it is well established that neglect is most apparent when there is competition between two stimuli (Driver & Vuilleumier, 2001). Evidence is now gathering to support analogous behaviour in the motor domain (Coulthard et al, 2008;Punt, Riddoch, & Humphreys, 2005). This study demonstrates the possible functional consequences of motor extinction for important postural abilities.…”

“…Motor disorders associated with spatial neglect following stroke are thought to be relatively common although poorly understood (Coulthard et al, 2008). The competitive element of neglect that is most clearly characterised via the associated problem of extinction (Mattingley, 2002) predicts 310 STURT AND PUNT that symmetrical bilateral motor activity will be the most challenging for affected patients.…”

“…Patients with spatial neglect appear to have additional challenges in this area. There is a growing recognition of the impact of motor neglect and motor extinction (Coulthard et al, 2008;Punt & Riddoch, 2006) on behaviour and recovery, and this study also highlights the functional consequences for postural control in affected patients.…”

“…Understanding of the neglect syndrome and a recognition of the related problem of extinction has led to suggestions to encourage a "unilateral" approach to rehabilitation (e.g., constraint-induced movement therapy) for affected individuals (Coulthard et al, 2008;Punt & Riddoch, 2006;Robertson & North, 1994) and there is some evidence that patients with neglect may be particularly well-suited to such interventions (van der Lee et al, 1999). However, such suggestions are largely directed towards rehabilitation of the upper limb.…”

“…Although the study of neglect has tended not to focus on the related challenges for movement, "motor neglect" was defined some years ago (Laplane & Degos, 1983) and has had increasing attention paid to it more recently (Coulthard, Rudd, & Husain, 2008;Garbarini, Piedimonte, Dotta, Pia, & Berti, 2012;Heilman, 2004;Punt & Riddoch, 2006). However, there are few data available that demonstrate the impact of motor neglect on functional tasks, recovery of function and, in particular, balance.…”