Aphasia, also known as dysphasia, is an acquired language disorder. Aphasia affects people's understanding and/ or expression of language. People can acquire aphasia from a variety of different conditions. Read on to learn more about aphasia.
Aphasia vs dysphasia
Aphasia refers to the total loss of language. Dysphasia refers to impaired language.
Technically speaking, the term dysphasia is more appropriate for most people. However, a lot of the terminology is very similar (e.g. dysphasia, dysphagia, dysarthria, dyspraxia, dyslexia, dysgraphia etc.) and so that is why I typically use the term aphasia.
Why do people get aphasia?
Aphasia is caused from damage to the language centres in the brain. This can be from a variety of condition such as:
A different type of brain injury (e.g. traumatic brain injury, subdural haematoma or subdural haemorrhage)
Brain tumour or brain metastasis
Most people have their language centres in the left side of their cerebral cortex (the ‘top’ bit of your brain). Damage to this cortex can result in aphasia. People’s own individual profiles of their receptive and expressive abilities depends upon where was damaged in their brain.
There is much debate as to which areas of the brain are involved in different language functions; Tremblay and Dick’s (2016) paper ‘Broca and Wernicke are dead, or moving past the classic model of language neurobiology’ includes a great summary of research implicating different brain regions and argues that many more areas are involved than previous models include.
Receptive vs expressive aphasia
Discussing aphasia in terms of someone having either receptive or expressive aphasia can mean different things to different people. For example, some people will use expressive aphasia to refer to Broca’s aphasia and receptive aphasia to refer to Wernicke’s aphasia. However, this can be confusing because people with Broca’s aphasia can still have difficulties with understanding language and difficulties with understanding language is called receptive aphasia.
The terms fluent and non-fluent aphasia are now more commonly used. This then allows for the individual’s receptive and expressive language abilities to be defined across the four different language modalities. Doing so, can provide a much more detailed picture of the individual and their aphasia.
Non-fluent aphasia with moderate receptive aphasia (understanding of spoken SVO sentences and written SV sentences), and severe expressive aphasia (able to say some single words (nouns) and unable to write or copy single words).
Before an overview of some of the different types of aphasia, we should consider the four different language modalities.
The Four Language Modalities
Receptive language refers to understanding spoken and written language.
This is assessed at the single word level, sentence level and paragraph and discourse level. There are different abilities within these different levels; for example, at the sentence level, people are assessed as to whether they understand active and passive sentences, sentences with embedded clauses and different phrases (e.g. prepositional phrases). Higher level language assessments look at the ability of individuals to inference from spoken and written language.
Higher level receptive language difficulties can be ‘hidden’ if you are having, for example, a social chat with someone. For some individuals it is not until they return to doing higher level tasks, such as returning to work, that these difficulties may become apparent.
It is important to have a clear idea of what a person is and is not understanding so that information can be tailored to them. For example, to have discussions around medical procedures, decisions such as assigning a Power of Attorney.
Expressive language refers to people’s use of spoken and written language, that is their talking and writing. This is also assessed at the single word level, sentence level and paragraph and discourse level.
A person’s ability to use spoken language is different to a speech disorder, such as dysarthria or apraxia of speech. For example, a person with dysarthria will be saying words but they will be unclear; whereas a person with expressive language difficulties will have difficulties accessing the words they want to say or saying a whole sentence (versus a few words). People may have expressive language difficulties in isolation or in conjunction with a speech disorder.
Types of aphasia
There are several different types of aphasia. For the purposes of this article, we will cover an introduction to non-fluent and fluent aphasia as well as anomic and global aphasia. Further articles will discuss different subtypes of aphasia.
Non-fluent aphasia (Broca’s aphasia)
Generally speaking, non-fluent aphasia is when a person’s understanding is better then expression.
That is, they may understand sentences but only be able to say single words. This does not mean that people in non-fluent aphasia understand everything. In fact, most people with non-fluent aphasia still have some difficulties understanding spoken and written language; these difficulties may be higher level and therefore not instantly obvious, e.g. if you are having a social chat with them.
People with non-fluent aphasia may only be able to say or write single words or short phrases. Typically, nouns are easier to access, thus people with non-fluent aphasia may only say nouns. For example, instead of saying “The boy plays with the car”, a person with non-fluent aphasia may only say “boy … car”. Some people may be at say more than this but generally complete sentences are not said or written. Swear words are often easier to access and so a person with aphasia may start swearing more than they did previously.
People may also have a few phrases that they can access; this can be social phrases such as “good morning” or “thank you”. Sometimes these phrases can be meaningful, but sometimes these are not what the person means at all. For example, a lady I worked with would often say “which”
when trying to say other words.
People with non-fluent aphasia can have good insight into their difficulties.
Broca’s aphasia is one type of non-fluent aphasia.
Fluent aphasia (Wernicke’s aphasia)
Generally speaking, fluent aphasia is when people's expressive abilities are better than their understanding. That is, they speak and write better than they understand spoken and written language.
For example, I worked with a lady who could not understand a single word. If I gave her an instruction such as to point to her nose or look to the ceiling, she could not do it. When I put two objects in front of her, e.g. a cup and a pen, and modelled to her that I wanted her to select the object which I named, she could not do it. I then gave her the single written words e.g. pen, and she could not match the word to the object.
This lady love to carry around her handbag. When I gestured to her handbag she picked it up and began getting out the objects one by one. As she got out the objects, she named them. She said “brush” when she got out hairbrush and then used it on her hair. She got out her purse and said “money” before placing it aside. She called out a bag of pistachios and said “I don't know where these are from”.
But when I said something to her, e.g. “Do you like pistachios?”, she could not respond.
How can this happen?
When she had an object or a point of reference, she can make appropriate comments. However, she does not understand what people say to her; she doesn’t understand any words. So, she could make comments if you were sat completing an activity with her, but she couldn’t engage in a conversation with you because she cannot understand what you say.
Also, if she tried to talk more about items or things that did not have a point of reference, she would begin saying non-words (neologisms). People with fluent aphasia may produce ‘full sentences’, yet they may contain non-words that can make it difficult to understand what they are trying to say.
Not all people with fluent aphasia have this severity of understanding spoken words and written words. This is why it is important to map the individual's strengths and difficulties.
Wernicke’s aphasia is one type of fluent aphasia.
People with anomic aphasia typically have intact understanding of spoken language but their expression is characterised by word finding difficulties; word finding difficulties is also known as anomia and so this is where the name for this subtype comes from. For some people, these word finding difficulties can be really distressing.
In anomic aphasia, reading and writing can be either intact or impaired.
(N.B. All people experience word finding difficulties some times; other factors can affect this such as our stress and tiredness levels.)
Global aphasia can refer to either of the following:
A person is not understanding any spoken or written language and have an unreliable yes/no response
Having language impairment all domains (listening, reading, speaking and writing). The extent of the impairment in the domains can vary.