Language impairment (aphasia)
Injury to language centres of the brain leads to a condition called aphasia. There are different levels of impairment and the term dysphasia refers to partial loss of language. However, in practise, the terms are interchangeable and here we will simply use the term aphasia.
Wernicke's area and Broca's area are two regions of the brain that are of importance for understanding and using language. These areas are found in the dominant side of the brain and for most people, particularly right-handers, they are in the left hemisphere. Injury to these areas leads to two main forms of aphasia: receptive aphasia and expressive aphasia.
In practise, it is quite rare for pure receptive or expressive aphasia to occur. Strokes can be associated with damage to very specific areas of the brain, including the language areas. However, most forms of acquired brain injury affect several brain regions and cause a combination of difficulties.
A Speech and Language Therapist will be able to assess individual patterns of aphasia. Treatment may then involve a mixture of therapy, advice and strategies.
Types of aphasia include:
Receptive aphasia is an impairment of the understanding of language. This usually occurs because of damage to Wernicke's area, so it is sometimes referred to as Wernicke's aphasia.
The term receptive aphasia is actually slightly misleading because the condition also affects aspects of speech output. People with receptive aphasia usually retain the ability to speak fluently and the term fluent aphasia is sometimes used. However, the content of speech is often jumbled or lacking meaning.
In its most severe form, the person will not recognise spoken and/or written words. They will not be able to understand sentences or follow conversations. However, usually people will retain some understanding. For example, the person may recognise some but not all words, or simple but not complex sentences. It may be that familiar words still have meaning (e.g. pill), but that less frequently used words are no longer understood (e.g. medication).
The person with receptive aphasia may have better ability in one area than another (e.g. they may be able to recognise written words more readily than spoken ones, or vice versa). They may also have retained some non-verbal skills (e.g. they may recognise gestures or pictures). Therefore, using nonverbal forms of communication may help the person's understanding.
As noted earlier, receptive aphasia also affects aspects of speech output. People may speak in long chains of words that have limited meaning (jargon), use incorrect words, or unintentionally create 'made-up' words. The problem with understanding language means the person may be unaware of their errors and expect the listener to respond.
Usually, when unable to think of a word, people can describe it instead, e.g. "oh, you know...it is a pet...and it barks!" It may be harder for someone with receptive aphasia to use this strategy, as they may not be able to effectively link 'meaning' with the object or person.
Problems with reading, when evident, may reflect the receptive spoken language issues. E.g. the person may:
- Be unable to recognise individual letters
- Be unable to recognise written words
- Read but not understand familiar words
- Be unable to fully understand simple written sentences
It is important to be aware that reading problems may also arise due to other difficulties, such as altered vision. Advice needs to be specific to the individual, and provided by the relevant specialist, e.g. an Orthoptist. Common strategies include enlarging print size, selecting a clear font, using a line guide to support looking at the full line of print, and increasing contrast between paper and print, e.g. black type on yellow paper.
Expressive aphasia is an impairment of the ability to use and express language. This is caused by damage to Broca's area, so the condition is sometimes referred to as Broca's aphasia. In its most severe form, the affected person may be unable to produce any meaningful speech. More commonly, speech output may lack fluency with relatively few words used. The speaker will use short, simple sentences, broken up by frequent pauses. However, they may be able to understand language normally and be aware of their own difficulties.
Output may be a struggle, but sometimes an individual can provide accurate if limited information. Speech may be 'telegraphic' omitting small words such as 'the'. So, 'tomorrow I'm going to the pub with my wife for our anniversary', may be expressed as 'tomorrow...pub... wife... anniversary'. This requires the listener to accurately piece the message together.
The person may struggle to name objects or people, even when aware of what or who they are. This can be extremely frustrating and cues or reminders may not work if the brain is simply unable to produce the correct output.
Problems with writing, when evident, may reflect the expressive spoken language issues.
For example, the person may:
- Be unable to write down a specific letter of the alphabet
- Write words with letters in the incorrect order
- Write down incorrect words, which are still connected to the intended ones, e.g. they may write 'wife' when they needed to write 'daughter'
- Be unable to write simple sentences
Writing problems may also arise due to other difficulties, such as altered vision and/or reduced physical control of the pen or pencil. Advice needs to be specific to the individual, and provided by the relevant specialist, e.g. an Orthoptist or Occupational Therapist. Common strategies include using a line guide to support writing across the full width of the page and increasing contrast between paper and print e.g. black type on yellow paper.