Stroke

Stroke results in irreversible brain damage, with the type and severity of symptoms dependent upon the location and the amount of injured brain tissue. The most common neurological impairment caused by stroke is partial weakness, called paresis, reflecting a reduced ability to voluntarily activate spinal motoneurons. In conjunction with the general reduced ability to voluntarily activate spinal motoneurons, there is often a reduced ability to selectively activate the spinal motoneuron pools, i.e. turning on some neurons while not turning on others. Together, these mechanisms result in altered movement control of many muscles, especially the contralesional hand and arm muscles used for grasping. Because of the altered muscle control, a variety of kinematic and kinetic alterations are observed during grasping in people with paresis post stroke. Impairments in grasping are related to the inability to use the hand for functional activities during daily life. In rare instances, stroke affects the posterior parietal lobe, resulting in distinct grasping deficits that are substantially different from grasping deficits seen after corticospinal system damage. Future studies investigating grasping post stroke could include the examination of both kinematic and kinetic aspects of grasping in the same subject samples, the examination of different types of grasping (e.g. palmar, precision), and the examination of different time points post stroke.: General information about stroke: Stroke is an acute neurological event that is caused by an alteration in blood flow to the brain.