A stroke is a sudden rupture or obstruction in a blood vessel of the brain. A stroke may also be called a cerebrovascular accident (CVA). If it is caused by a rupture it is called a haemorrhagic stroke, and if it is caused by an obstruction it is called an ischaemic stroke. In either case, a stroke deprives the brain of its vital blood supply and causes symptoms such as numbness or weakness on one side of the body, slurred speech, difficulty understanding speech and blurred vision. A stroke that causes symptoms which last only a short time is called a transient ischaemic attack (TIA).
- How can it affect speech?
A stroke can cause speech and language difficulties during the attack and lasting impairments afterwards. A communication difficulty called aphasia may result from a stroke. Aphasia is a language impairment that affects the comprehension and production of language.
Other disorders that can occur after a stroke affect the movements required to speak. Dysarthria creates muscle weakness in areas that are necessary to produce speech sounds, so people with dysarthria often have slurred or weak speech. Acquired dyspraxia produces loss of knowledge about how to perform skilled, coordinated movements such as those necessary for speech.
Aphasia is an acquired disorder that affects understanding and formulating language. It results from brain injury, commonly after a stroke but also after incidents such as head injury, TBI (traumatic brain injury) or encephalitis.
Aphasia can be described as fluent aphasia, also called Wernicke’s aphasia, or non-fluent aphasia, also called Broca’s aphasia. People with fluent aphasia can usually produce different kinds of words, but their speech may not make sense, and they may have difficulty understanding what is said to them. People with non-fluent aphasia can usually produce speech that makes sense, but they find it difficult to do this in long phrases. They can usually understand what is said to them.
Though these are two main types of aphasia, many people with aphasia have some difficulty both understanding and producing language. People with acquired aphasia may also have difficulties with numbers and maths, music or the ability to control their emotions.
Some people with aphasia may find an AAC system helps them to plan and produce what they want to say. This may be picture or word based.