Elements of cognitive rehabilitation after right hemisphere stroke.

There are two basic approaches to cognitive training: (1) impairment training and (2) task specific training. Impairment training addresses impairments common to a number of tasks and attempts to offer a general benefit to all of the tasks at once. Task specific training focuses on the impairments that arise in a single task and attempts to improve performance on that task. Impairment training of spatial disorders following right hemisphere stroke has shown some success when curricula are properly designed. The success, however, is quite limited because of normal cognitive constraints and those occurring after brain damage. Task specific training in conjunction with the combined application of various cognitive principles appears more promising, but as yet, only a few studies exist. The neurologic factors are likely to be the same factors that influence recovery. The factors that influence trainability are lesion topography (size and location of the focus plus premorbid atrophy), lesion chronicity, and the presence of additional cognitive impairments (anosognosia, confusion, and abulia). Other interventions that may be beneficial, even for training resistant patients, include behavior modification, cognitive prostheses, and drugs.