Aphasia is a loss of ability to produce or understand language. The most common cause of aphasia is cerebrovascular disease, particularly cerebral infarction. Aphasia complicates 15 to 38 percent of ischemic strokes [1-4]. Other structural pathologies (infection, trauma, neoplasm) and certain neurodegenerative diseases (primary progressive aphasia) can also cause aphasia.
Aphasia can be a devastating condition and is one of the most feared consequences of cerebral infarction and other brain injuries . Although quality of life in patients with aphasia is difficult to measure directly, the disruption in communication with its likely effects on employment status and social networks suggests that its impact can be profound [6-8]. Caregivers of stroke survivors are likely to experience more stress when caring for a family member with, rather than without, aphasia [9,10]. Comprehension deficits can also limit rehabilitation efforts targeting other post-stroke deficits such as hemiparesis [11,12]. Patients with post-stroke aphasia have greater morbidity and mortality than stroke patients without aphasia . While most, if not all, patients with post-stroke aphasia have some functional recovery, residual deficits are common. Unfortunately, there is limited evidence that therapeutic interventions are effective.
This topic reviews the prognosis and management of aphasia, focusing on post-stroke aphasia, which is the most common etiology. The evaluation of aphasia, the management of primary progressive aphasia and other aspects of stroke prognosis and management are discussed separately. (See "Approach to the patient with aphasia" and "Initial assessment and management of acute stroke" and "Frontotemporal dementia: Clinical features and diagnosis".)
Recovery from aphasia is influenced by lesion location and type of aphasia. As an example, large lesions in the left hemisphere with global aphasia have a much poorer recovery than small, subcortical lesions with anomia.
The prognosis for aphasia recovery depends in large part upon the underlying etiology. This has been best studied in cerebrovascular disease. Most patients with post-stroke aphasia improve to some extent [1-4,14,15]. Most improvement occurs within the first few months and plateaus after one year. The severity of the initial aphasia strongly correlates with the long-term deficit; those with milder degrees of aphasia at onset are the most likely to recover completely [16-18]. Nonetheless, patients with significant aphasia may benefit from intensive treatment regimens even after the period of spontaneous recovery [19,20]. Smaller studies in patients with aphasia resulting from traumatic brain injury indicate that the clinical course is similar to post-stroke aphasia .