Aphasia is a language disorder that occurs when the part of the brain that is responsible for language becomes damaged. The damage usually happens to the left hemisphere of the brain and can happen quite quickly in cases such as head injury or stroke. Brain tumors can also cause aphasia, but the symptoms of these may only be seen gradually over a longer period of time.
Sufferers can also develop impairments in facial expressions and the understanding of language. They also have difficulty with reading and writing. A stroke is a very common cause of aphasia. A stroke occurs when brain cells die due to a lack of blood reaching the brain, resulting in a lack of vital nutrients and oxygen. Other causes of brain injury are brain infections and serious blows to the head.
Aphasia usually occurs in the middle to later years of life. It can occur in both men and women. It is estimated that about 80,000 people are afflicted every year, and there are over 1 million sufferers in the United States. Some individuals recover completely without treatment, but a large amount of sufferers require treatment such as speech therapy. At the moment, there are also a large number of research studies being undertaken, as well new drugs available to help sufferers now and in the future.
The three most common types of aphasia are:
Broca's aphasia
Wernicke's aphasia
global aphasia
These are described below.
Sufferers of Broca's aphasia, also known as non-fluent aphasia, have had damage to the frontal lobe of the brain. They must make a great effort to talk and speech is usually in short, meaningful sentences. They have usually great difficulty speaking and can only manage to string a small number of words together in short, halting sentences. The person will often leave out short words such as "is" and "the". However, it is usually possible to understand the meaning of their speech. For example, a person with Broca's Aphasia might say, "Want...coffee... no...milk".
People with Broca's can usually understand the speech of others. They are also aware of their own speech and how others hear them. This can cause sufferers great frustration as they try to produce longer sentences. People with Broca's usually suffer from paralysis or weakness of the right arm or leg. This is because the frontal lobe of the brain is also responsible for movement of the body.
People who have had damage to the temporal lobe of the brain can suffer from Wernicke's aphasia. Wernicke's aphasia, also known as fluent aphasia, is where a person is able to speak normally and use long, complex sentences, but the actual words that they use do not make sense, or they include nonsense words in their speech.
One example of speech recorded by a researcher was, "Mother is away here working her work out of here to get her better, but when she's looking, the two boys looking in other part".
Many people with Wernicke's aphasia are often unaware that their spoken language makes no sense to others and they can become angry or frustrated by the lack of understanding that is shown by others. They also usually have no body weakness, as the temporal lobe is not needed for body movement.
A third type of aphasia is known as global aphasia. This results from damage to large parts of the brain. Sufferers have extreme difficulty communicating verbally and understanding language.
Global aphasia is the most severe form of aphasia. Someone with the condition has difficulty with all forms of communication, including speaking, reading, writing, correctly naming objects or people and understanding other people's speech.
Aphasia is caused by damage to the parts of the brain that are responsible for:
speaking
understanding others
reading and writing
Collectively, these parts of the brain are known as the brain's language center.
The most common cause of aphasia is brain damage resulting from a stroke — the blockage or rupture of a blood vessel in the brain. This disruption of the blood supply leads to brain cell death or damage in areas of the brain controlling language. Brain damage caused by a severe head injury, a tumor, an infection or a degenerative process can also cause aphasia.
Primary progressive aphasia is the term used for language difficulty that develops gradually. This is due to the gradual degeneration of brain cells located in the language networks. Sometimes this type of aphasia will progress to a more generalized dementia.
The language center is not a single area of the brain. It is a network of specific sections of the brain that work together in a similar way to a computer network.
The language center is made up of the following areas:
Broca's area, which is responsible for the production of speech
Wernicke's area, which is responsible for understanding spoken and written language
the sensory cortex, which is responsible for processing the various signals that the body receives, such as sounds (for language) and images (for reading)
the auditory cortex, which is responsible for converting the actual physical sounds of spoken language into meaningful information
the motor cortex, which is responsible for controlling the various parts of the body that are used to generate speech, such as the muscles, tongue and voice box
In the past it was thought that damage to a specific part of the brain would always result in a specific type of aphasia, for example, damage to the Broca's area would always result in Broca's aphasia. However, the way the language center works is now thought to be less straightforward than this.
Damage to specific areas of the language centre does not always lead to the expected symptoms. Also, the after effects of brain damage can vary considerably from person to person, making them unpredictable.
Damage to many sections of the brain will usually result in more severe types of aphasia, such as global aphasia.
Ways that the brain can become damaged include the following.
stroke: during a stroke the brain is deprived of blood and oxygen, which leads to the death of brain tissue
severe head injury: for example, the sort of injury that occurs as a result of a road traffic accident or following a serious fall from height
brain tumor: where an abnormal growth of cells develops inside the brain
health conditions that cause progressive damage to the brain, such as Alzheimer's disease, other forms of dementia or rarer conditions, such as progressive supranuclear palsy or corticobasal degeneration (two related conditions that are associated with both physical and mental disabilities as a result of brain damage)
infections that affect the brain, such as meningitis (an infection of the outer layer of the brain) and encephalitis (an infection of the brain itself), although this is a much rarer cause of aphasia
Aphasia is a sign of some other condition, such as a stroke or a brain tumor.
A person with aphasia may:
Speak in short or incomplete sentences
Speak in sentences that don't make sense
Speak unrecognizable words
Not comprehend other people's conversation
Interpret figurative language literally
Begin to make spelling errors
Write sentences that don't make sense
In cases where aphasia has been caused by a sudden brain injury, such as a stroke or a severe head injury, the symptoms will usually develop straight after the injury.
In cases where there is gradual damage to the brain as a result of a condition that gets worse over time, such as dementia or a brain tumor, the symptoms may develop gradually.
Symptoms of specific types of aphasia is discussed below.
Someone with Broca's aphasia will usually have the following signs and symptoms:
slow and halting speech
they may struggle to get certain words out, such as the names of objects, places or people
the content of their speech is usually stripped down to the barest elements and only contains some basic nouns and verbs, for example, "want drink" or "go town today"
their writing ability is often similarly affected
A person with Broca's aphasia may be able to understand spoken language to some degree, but have difficulty understanding grammar. For example, they may be unable to tell the difference in meaning between, "Maureen went out for a walk with Eric" and "Eric went out for a walk with Maureen."
Their ability to read is usually affected. For example, they may assign different meanings to written words, such as reading 'symphony' when the word is actually 'concert'. They may also lose the ability to sound out written words in their head.
Additional symptoms that are not directly connected to speech and language but can occur in people with Broca's aphasia include:
an inability to control facial muscles and one or both limbs
weakness down one side of their body (usually the right side)
A person with Wernicke's aphasia will usually have the following signs and symptoms.
They may be able to speak fluently using long sentences, but their speech contains a lack of meaning and often includes nonsense words. For example, they might say "That was just like time for the next week when the bait".
People with Wernicke's aphasia are often unaware of their language problems, especially soon after a stroke, and become frustrated that other people are unable to understand them. However, they may recognition their problems if presented with evidence, such as a video or audio recording of them speaking.
They may have difficulty understanding spoken language.
Some people also have similar difficulties with reading written language.
Their ability to write is affected in a similar way to their speaking ability in that they can write fluently but what they write makes little or no sense.
Additional symptoms can include:
some loss of vision
difficulties with arithmetic, such as adding, subtracting, multiplying or dividing numbers
difficulties with spatial orientation, which is the ability to judge accurately where you are positioned in relation to other physical objects, and is often referred to as your sense of direction
loss of voluntary limb control
People with global aphasia usually have more brain damage, so they often have symptoms of both Broca's aphasia and Wernicke's aphasia. This can cause problems with all aspects of communication, including:
speaking
understanding the speech of others
naming objects, people and places
repeating other people's speech
reading and writing
Additional symptoms can include:
paralysis of the right side of the body
some loss of vision
loss of voluntary control of their limbs
problems pronouncing certain sounds and words, which is due to difficulties controlling the mouth, tongue and voice box (so it is not specifically associated with aphasia)
Aphasia treatment is an extremely important aspect of life after a stroke which has affected someone's ability to speak. In general terms, aphasia is a disturbance in the production, processing, or understanding of language due to brain damage, most commonly from stroke. Although multiple forms of treatment exist for the different types of aphasia, only a few of them have been studied rigorously enough to have proven efficacy. As a result, most forms of aphasia treatment are based on theoretical grounds which await further testing to prove their benefits. However, based on their experience with patients, most speech pathologists and physicians attest to the benefits of aphasia therapy.
Most cases of aphasia can be improved with treatment, even severe cases of global aphasia. However, a complete return to pre-aphasia communication levels is not always possible.
Speech and language therapy (SLT) is the main treatment for aphasia. SLT is a general term that is used to describe a number of different techniques that can help improve a person's ability to communicate.
SLT for people with aphasia has three main goals:
to help the person to relearn any communication skills that have been lost or damaged (if this is possible)
to make the best use of the person's remaining communication abilities
to find new ways of communicating
There is no single way to treat aphasia, but most experts agree that a course of SLT tends to be more successful if it is based on the principles that are described below.
Intensive
Research has found that a short-term course of intensive SLT, for example, eight to ten hours a week over the course of two months, is usually more effective than a longer, less intensive course, for example, one to two hours a day for five or six months. However, not everyone has the energy to participate in intensive therapy, particularly elderly people who are recovering from a stroke.
Cumulative
SLT works best when the therapist sets relatively modest goals and then moves on to more complex goals. For example, they might start with naming a specific person, before describing their relationship with that person.
Personalized
Research has found that using teaching material and aids that have a personal significance to the person being treated produces a more engaged response than using generic materials.
For example, using photographs of people or situations that a person would remember is more effective than using stock photographs.
Provide alternatives
Spoken and written language is not the only way that a person with aphasia can communicate. Therefore, it is important that a therapist discusses potential alternative communication methods, such as simple gestures, more complex sign language, or technology, such as electronic speech synthesizers.
Group work
It can be beneficial for someone with aphasia to work in a group with other people with the condition. As well as providing a non-threatening opportunity to practice communication skills, it can also lessen the feelings of loneliness and isolation experienced by many people with aphasia.
In addition, research carried out in 2010 suggested that SLT does not always have to be provided by a fully qualified therapist to be successful. Trained and supervised volunteers can also provide effective treatment or they can work with professional therapists to improve the effects of therapy.
The Stroke Association provides training for volunteers.
Promoting Aphasics' Communicative Effectiveness (PACE)
Promoting Aphasics' Communicative Effectiveness (PACE) is a type of SLT that uses conversation to improve a person's communication skills.
The therapist will use a picture or drawing to stimulate a conversation, while the person with aphasia is encouraged to use any means of communication to respond.
Early PACE sessions will focus on relatively simple topics of conversation, such as where the person was born. As the sessions progress, the topics of conversation become more complex and abstract, including, for example, the person's favorite film and why they like it.
Melodic intonation therapy (MIT)
Melodic intonation therapy (MIT) is a type of SLT that is often used in the treatment of non-fluent forms of Broca's aphasia.
MIT is based on a common observation that many people with aphasia who have speaking difficulties do not have similar difficulties when singing. This may be because the parts of the brain that are used when singing are different to those that are used when speaking, so the singing areas of the brain and the associated ability may remain undamaged.
During MIT sessions, a person with non-fluent aphasia is encouraged to hum and to sing words or phrases that they find difficult to recall, while tapping out a rhythm. This technique has been shown to increase the number of words a person can recall.
Computerized script training (CST)
Computerized script training (CST) is a type of SLT that involves using a computer. CST uses scripts that simulate real-life conversations and social activities, allowing a person with aphasia to practice their communication skills and to relearn abilities.
Constraint-induced aphasia therapy (CIAT)
Constraint-induced aphasia therapy (CIAT) is a type of SLT that is designed for people with chronic (long-term) aphasia (usually defined as aphasia that lasts longer than two years).
CIAT is based on a type of
physical therapy, known as constraint-induced motor therapy (CIMT),
which is sometimes used to help people recovering from a stroke.
People recovering from a stroke often have weakness on one
side of their body. This causes them to use the other side of their
body more. CIMT uses equipment, such as splints, to prevent them from
relying on the stronger side of their body, and forces them to make
use of the weakened side in an effort to get them to relearn how to
use it.
CIAT is based on a similar premise. People with
chronic aphasia may adopt a number of basic compensatory strategies
to help them to communicate, for example:
pointing
gesturing (but not complex sign language)
making sound effects, such as saying "brrrrm" for car
These strategies may be useful in the short to medium term, but relying on them can cause a person with aphasia to forget previously learnt communication skills and delay their recovery.
Therefore, CIAT usually involves a short course of intensive therapy where the therapist will work with the person with aphasia to identify these types of basic compensatory strategies and encourage them to adopt more complex ways of communicating. This may not necessarily be full speech, but may include methods that force the person's brain to make use of its language center, such as drawing or using communication tools, such as a speech synthesizer.
Transcranial stimulation is a type of painless treatment that may benefit some people with aphasia.
There are two types of transcranial stimulation:
transcranial direct current stimulation (tDCS), which is where electrodes (small metallic discs) are placed on the surface of the scalp and a small electrical current is passed through them
transcranial magnetic stimulation (TMS), which is where magnetic coils are placed above the scalp and used to generate magnetic fields, which create short-lasting electrical currents in the brain below the stimulation site
It has been suggested that both tDCS and TMS may help to stimulate parts of the language center that have been damaged and encourage a certain degree of recovery and repair. For example, initial research has found that these types of treatment may help people to improve their ability to remember the names of certain objects, people and places.
As transcranial stimulation is a new method of treatment, access is currently limited to people who are willing to take part in a clinical trial. A clinical trial is where researchers compare a new treatment against an existing treatment or a dummy treatment (placebo) to see whether the new treatment is effective and safe.
Researchers have also been studying the effects of medication for improving the language skills of people with aphasia.
One type of medication that has proved reasonably effective in some people with Broca's aphasia, when used in combination with SLT, is called bromocriptine.
It is thought that bromocriptine may help stimulate some sections of the brain's language center, leading to an improvement in communication skills.
Another medication that has proved reasonably effective in improving language skills, particularly the ability to name objects, people and places correctly, is called donepezil.
Donepezil increases the levels of a chemical called acetylcholine in the brain. This is thought to lead to an increase in cognitive ability (the ability to think, reason and plan).
Again, it is likely that access to these sorts of treatment will only be available in clinical trials.
If you live with, or care for, a person with aphasia, you may be unsure about the best way to communicate with them. You may find the advice listed below helpful.
After speaking, allow the person plenty of time to respond. If a person with aphasia feels rushed or pressured to speak, they may become anxious, which can affect their ability to communicate.
Use short, uncomplicated sentences and do not change the topic of conversation too quickly.
Avoid asking open ended questions. Closed questions that have a yes or no answer are better.
Avoid finishing a person's sentences or correcting any errors in their language. This may cause resentment and frustration for the person with aphasia.
Keep any possible distraction to a minimum, such as background radio or TV noise.
Use paper and a pen to write down any key words, diagrams or pictures to help reinforce your message.
If you do not understand something that a person with aphasia is trying to communicate, do not pretend that you do understand. The person may find this type of behavior patronizing and upsetting. It is always best to be honest about your lack of understanding.
Try to remember that despite their change in speech pattern, the person's personality is unchanged. They may appear emotionally distant or abrupt, but how they speak to you does not necessarily reflect how they feel about you.