Studies of motor learning in patients with hemiparesis after stroke have yielded mixed results.
Given the heterogeneity of stroke patients, it may be difficult to demonstrate a specific learning deficit in this population.
Furthermore, patients’ movements are often more variable than controls, which may limit the expression of learning. Despite this limitation, several studies have claimed preserved motor learning in stroke patients.
Hemiparetic stroke patients could successfully adapt to force field perturbations with both affected and unaffected arms using a similar strategy to healthy subjects (Scheidt and Stoeckmann, 2007).
Winstein and colleagues (1999), using a novel extensionflexion elbow reversal task to investigate skill learning in the unaffected arm, found no significant differences in acquisition, offline forgetting, and retention between healthy subjects and patients with middle cerebral artery territory strokes.
In the affected hand, Raghavan and colleagues (2006) demonstrated impaired learning despite preserved execution ability; stroke patients had impaired anticipatory scaling of grip force and load force rate to the object weight in a grasping task, although they could do so after performing the task with their unaffected hand.
Given the differences in tasks, amounts of practice, effectors, and patient characteristics in the above-mentioned studies, it is difficult to draw unifying conclusions from these results. Patients may retain the ability to learn certain tasks but not others, depending on the information and processing requirements of the task, and training with the unaffected side may offer a way to acquire the information needed to perform the task with the affected side.