Aphasia. Conceptual computer artwork of a blindfolded and gagged man representing the disability of aphasia. Aphasia is an impairment of language affecting the production or comprehension of speech and the ability to read and write. It is most commonly caused by stroke, but can also occur due to head trauma, a brain tumour or an infection that causes tissue damage to the language centres of the brain. The location of the damage determines the extent of aphasia experienced by the patient. There is no cure for aphasia. However, speech therapy can help a patient to best utilise their remaining communication skills.