Aphasia

Aphasia is impaired expression or comprehension of oral or written language due to acquired brain damage. Treatment is with speech rehabilitation.

Aphasia can affect expression or comprehension of oral and written words or nonverbal equivalents (eg, sign language). Aphasia is a language rather than a speech disorder, but it may coexist with a speech disorder. Of speech and language disorders, aphasia is the most common among the elderly; it occurs in about 40% of patients who have had a stroke affecting the left cerebral hemisphere.

Aphasia is caused most often by a nonprogressive disorder (eg, stroke, trauma, encephalitis) but sometimes by a progressive disorder (eg, brain tumor).

Aphasia always causes anomia (difficulty naming objects) and may affect other aspects of language use.

Aphasia can be classified based on expression (fluent or nonfluent) and comprehension (good or poor). Common types are anomic (fluent; affecting only the ability to name objects, not any other aspect of expression or comprehension), Broca's (nonfluent; affecting primarily expression), Wernicke's (fluent; affecting comprehension), or global (substantially affecting expression and comprehension--see Table 45-1). More detailed classification includes the ability to repeat phrases (repetition). Repetition is impaired in Broca's and Wernicke's aphasias. Impaired repetition plus anomia with otherwise fluent speech and good comprehension is called conduction aphasia. In transcortical aphasias, which are rare, comprehension and expression (including naming and reading) are impaired, but repetition is intact. No aphasia classification is completely satisfactory, and summarizing findings (eg, for Broca's aphasia: nonfluent speech and writing, impaired repetition, but good comprehension) is often preferable.

Writing and speech are usually affected to about the same degree, but occasionally, impairment of reading (alexia) or writing (agraphia) occurs in isolation or to a disproportionate degree.

Most spontaneous recovery of language occurs during the first 3 mo, but it can continue for >= 6 mo. If aphasia is due to a nonprogressive brain disorder, intensive speech therapy usually starts as soon as patients are well enough to begin, but patients can benefit even when therapy is initiated much later. Bilingual patients often regain their native language to a greater extent than learned languages, but the language that they hear during recovery and rehabilitation also influences how much of each language they regain.

Therapy focuses on establishing the most effective means of communication. Some patients with severe aphasia cannot recover basic language skills. These patients and their caregivers are sometimes able to convey messages with augmentative communication devices (eg, a book or communication board that contains pictures or symbols of a patient's daily needs, computer-based devices). Choice of device depends on the patient's auditory and reading comprehension, articulatory skills, attention span, fine motor skills (required to use the device), visual acuity, and daily routine.

Family members and friends can usually provide essential care at home (see Table 45-2), but they may experience stress, frustration, anger, or depression. The clinician and speech pathologist can help by explaining that aphasia is a physical disorder that the patient has little control over.

This topic was last updated March 2006.