Improving Recovery After Stroke

Abstract

Although stroke is a leading cause of death in the United States and around the world, many people fear this disease because of its nonfatal neurological impairments that lead to disability or dependency. Considerable research has focused on lessening the neurological effects of the acute brain injury. To date, success is limited. Despite these research efforts, only intravenous thrombolysis and endovascular interventions are accepted as effective in limiting the acute effects of ischemic stroke. Although these therapies are efficacious, only 3% to 5% of patients with stroke are receiving reperfusion-based therapies due to the very short time windows for treatment.1 No medical or surgical intervention is useful in improving outcomes after intracerebral hemorrhage. Annually, approximately 400 000 Americans need rehabilitation to help with recovery after stroke.2 Given the magnitude of the problem, effective new therapies are needed to augment the process of recovery. These therapies could be given as adjuncts to conventional rehabilitation to these patients who have potentially disabling residual neurological impairments. Because many more patients could be treated, an effective therapy that maximizes neurological recovery might have a much bigger societal impact than emergency reperfusion therapy alone.3,4 Unfortunately, relatively few clinical studies have tested interventions that might augment recovery. The basic science understandings of the process of recovery after stroke have advanced.5–10 It is now clear that the adult brain has a real capacity for physiological and anatomic modifications that lead to motor and cognitive recovery.11 This complex process is mediated by multiple mechanisms including enhanced regional metabolism and resolution of diaschisis. Cellular changes after stroke include proliferation of neural and glial cell precursors, activation of astrocytes and inflammatory cells, migration of blood vessels, increased axonal sprouting, increased branching of dendrites, and development of new synapses.12–14 …