Aphasia

The process of language acquisition is often viewed as a natural process that develops in a person's early years and then continues to develop over time. It's not always plain sailing, though, and there are cases where a person may develop a communication disorder such as aphasia which can impact their ability to communicate with others.

There are a few areas of aphasia you need to know about to understand the language disorder fully, which we'll learn about today. They are:

• Causes of aphasia

• Types of aphasia

• Potential treatments

• The difference between aphasia and other language disorders, such as dysphasia

Aphasia Language Disorder

Aphasia is a language disorder that can affect a person's ability to produce and interpret language. This means that the affected person may have difficulties speaking, interpreting language, reading, and writing. Aphasia can occur in people of all ages; however, it is more often seen in those over the age of 65 and those who have suffered trauma or neurological condition.

The main cause of aphasia is damage to the brain's left hemisphere.

Symptoms of Aphasia

The main symptoms of aphasia can be seen in a person's difficulties in communication. This can be split into four main areas:

• Reading

• Writing

• Speaking

• Listening

In each of these areas, a person with aphasia may have trouble with interpreting and producing language.

Symptoms of aphasia can differ in different people. For example, one patient with aphasia may have difficulty interpreting spoken language, and another may have difficulty expressing what they want to say through speech.

Different Categories of Aphasia

Aphasia can be referred to as either receptive or expressive.

Effects of Aphasia

The symptoms of aphasia can have a massive impact on a person's life and cause many adverse knock-on effects, such as:

• Frustration when they can't express the words and ideas they want

• Frustration and anxiety when they can't properly interpret what others are saying

• Lack of confidence when speaking to others

• Loneliness and withdrawal from society

• Impatient family members or interlocutors when waiting to understand what a person with aphasia is saying

• potentially depression caused by prolonged frustration, anxiety, and loneliness

Fig 1. Someone suffering from aphasia can end up feeling anxious, frustrated, and lonely.

Causes of Aphasia

Earlier, we mentioned that the main cause of aphasia is damage to the left hemisphere of the brain. To understand this further, let's have a look at what the left hemisphere is responsible for.

Left Hemisphere of the Brain

The left hemisphere of the brain has four lobes (sections): the frontal lobe, the parietal lobe, the temporal lobe, and the occipital lobe.

Fig 2. The temporal, frontal, parietal, and occipital lobes are in the left hemisphere of the brain

Each of these lobes has a different set of functions and plays a part in a person's ability to use and interpret language. Let's have a look at the functions of each lobe:

So, what causes damage to the left hemisphere?

Causes of Left Hemisphere Damage

There are four main causes of left hemisphere damage that can cause aphasia. These are stroke, head trauma, brain tumor, and progressive neurological conditions. We'll have a quick look over what each of these is.

Stroke

A stroke is caused when the blood supply to part of the brain is cut off, causing brain cells to die. This can cause permanent damage to the brain and damage to the language center of the brain (especially if the left hemisphere is the affected region). Strokes can affect people of any age, although they are more likely in people over 65.

Head trauma

A severe fall, impact injury or blow to the head can potentially cause serious brain damage. This is because it may lead to pressure being placed on the brain from bleeding or a clot. If this damage is on the left hemisphere of the brain, the patient's language abilities can be severely impacted. Brain damage sustained through a head trauma injury may be either permanent or temporary and can occur when a person is at any age.

Brain tumor

A brain tumor occurs when the growth of cells multiplies abnormally. Brain tumors can occur in people of any age; however, the risk of them developing increases as you get older. A brain tumor can impact any part of the brain and will mainly affect a person's language use and interpretation if it occurs in the left hemisphere.

Progressive neurological condition

Progressive neurological conditions are those that cause the brain to become damaged over time. As these conditions develop over time, they often only cause aphasia in older adults.

Types of Aphasia

Now that we understand what causes aphasia, let's look at the different types that can occur. Aphasia can present itself as three different types; Broca's Aphasia, Wernicke's Aphasia, and Global Aphasia.

Broca's Aphasia

Broca's aphasia occurs when there has been damage to the frontal lobe¹. This affects a person's ability to speak and causes the following:

• Broken, awkward-sounding speech

• Problems with finding the right words

• Incomplete utterances

• Increased pauses

A patient with Broca's aphasia will have a relatively good understanding of language and will be aware of what they are saying. This can make them feel frustrated as they understand what they want or need to say but are aware of their limitations and can't always produce the correct language when needed. A person with Broca's aphasia may sometimes produce Fixed Expressions or phrases perfectly when they are stored as a single unit in the brain (meaning the components don't need putting together).

Wernicke's Aphasia

Wernicke's aphasia occurs when there is damage to the temporal lobe, affecting a person's hearing and understanding of language². A person with Wernicke's aphasia may seem able to communicate normally at first, as they can usually still produce fluent spoken language.

Wernicke's aphasia has the following effects:

• Fluent spoken language

• Lack of comprehension

• Unrelated utterances

• Confidence when speaking

• Speaker is unaware of their condition

• May echo what someone else has said

• Speech often seems unrelated or jumbled

A Wernicke's aphasia patient will often have very little understanding of what they're saying and how it relates to what someone else has said. Although someone with Wernicke's aphasia may appear to speak fluently, it can be very difficult for people to maintain a conversation as the subject or topics may seem very disjointed and random.

Global Aphasia

Global aphasia is the most severe type of aphasia a patient can experience. Global aphasia patients will have damage to the brain in multiple lobes and therefore display elements of both Broca's and Wernicke's aphasia. This means they will have difficulties with the production and interpretation of language³.

Fig 3. Global aphasia occurs when a person has difficulties in both using and interpreting language

Aphasia Treatment

There is no specific cure for aphasia; however, there are treatments available that can help a patient recover some (if not all) of their language ability. Some research into medications to treat aphasia has also been conducted; however, more research is needed before these medications can be viewed as solid treatments. The most common aphasia treatments include speech and language therapy or computer-based treatments.

Speech and Language Therapy

Speech and language therapy can help patients to recover some of their language skills through exercises such as imitating what others say. Speech therapists will tailor their form of treatment to each patient; patient interaction is crucial to find out where specifically a therapist can help⁴. Therapy can also help patients to learn new ways to communicate when they find that their speech is too severely impaired.

Fig 4. Speech and language therapists can help aphasia patients to learn new ways to communicate

Computer-Based Treatment

Some computer-based treatments allow patients to practice and relearn the production of words and phrases. This is done on an action, observation, and imitation basis.

Computer-based treatments such as this are usually carried out with the guidance of a speech and language therapist. Patients benefitting from this form of therapy can be seen to go from imitating the speech to anticipating it and producing the correct word or phrase before the video shows them.

Aphasia vs. Dysphasia

When carrying out your study of aphasia, you may also come across the term dysphasia.

When the two terms are used separately, dysphasia is often used to refer to a partial loss of language, while aphasia refers to complete or more severe language loss. It is common for the term aphasia to be used as an umbrella term for all types of language loss caused by brain damage.