aphasia

Aphasia is a language disorder caused by brain injury or disease that impairs the ability to speak, understand, read, or write. It does not reflect a person’s intelligence or awareness. Aphasia typically results from damage to language areas in the left hemisphere.

Causes include stroke (the most common), traumatic brain injury, brain tumors, infections, and progressive neurological diseases.

Common types are categorized by fluency and comprehension. Broca's aphasia is nonfluent, with effortful speech and relatively intact comprehension. Wernicke's aphasia is fluent but typically has poor comprehension. Global aphasia involves severe deficits across language modalities. Other forms include conduction, anomic, and transcortical aphasias.

Diagnosis relies on language assessments, including bedside screening and standardized aphasia batteries. Neuroimaging, such as MRI or CT, helps identify the underlying lesion.

Treatment emphasizes tailored speech-language therapy to improve speaking, comprehension, reading, and writing. Therapy intensity and repetition matter. Augmentative and alternative communication (AAC) can support communication. Family involvement and communication strategies aid daily interactions.

Prognosis varies with cause, severity, and access to therapy. Some recovery occurs in the first months after onset, with slower gains possible later. Chronic aphasia may persist, but functional communication often improves with ongoing rehabilitation.