What is Aphasia?

Aphasia is a condition where a person has difficulty understanding or formulating language due to damage to the brain’s language center. This could be caused by various brain conditions or diseases, but the most common cause is a stroke. Aphasia symptoms can vary greatly from mild difficulty to complete loss of fundamental language elements like understanding meanings, grammar, sounds, word forms, and sentence structure.

Language function involves the ability to understand and express spoken and written words. Usually, the part of the brain responsible for language, which includes Wernicke area, Broca area, and arcuate fasciculus, is located in the dominant hemisphere. Wernicke area, situated at the back end of the upper temporal gyrus, processes visual and auditory information and is the control center for understanding and planning words. Meanwhile, Broca area, located in the lower frontal area, oversees speech and sentence formation. Arcuate fasciculus is the neural pathway that connects Wernicke area and Broca area.

The type of aphasia a person gets depends on the exact location of the brain damage. In fluent aphasia, the person can form sentences that sound normal but may include made-up words or sounds. With non-fluent aphasia, people have difficulty forming words, may leave out words, and generally speak in very short sentences. Different non-fluent aphasia types include Broca, transcortical motor, mixed transcortical, and global, while fluent aphasia types include Wernicke, transcortical sensory, conduction, and anomic.

What Causes Aphasia?

Aphasia is a condition often observed in individuals who have suffered a stroke. However, it can also occur in people with certain brain conditions such as Alzheimer’s disease, frontotemporal lobar degeneration, vascular dementia or brain tumors, or in those who have had a traumatic brain injury.

It’s important to note that aphasia is not due to damage to motor or sensory functions. This means that it’s not caused by issues with movement or feeling, including paralysis affecting the muscles that enable us to speak or general problems with hearing.

Risk Factors and Frequency for Aphasia

Aphasia is a communication disorder that affects about 1 in 272 Americans, according to the National Institute on Deafness and Other Communication Disorders (NIDCD). Each year, 180,000 new cases of aphasia are recorded in the United States. Most of these cases, specifically one-third, are linked to cerebrovascular accidents (also known as strokes). Global aphasia is the most common type of this condition.

Aphasia affects both men and women equally when it results from a stroke. However, the chance of developing this condition depends on the individual’s age. People younger than 65 years old have a 15% chance of developing aphasia, while those older than 85 have a 43% possibility. Furthermore, between 25% to 40% of stroke survivors get aphasia due to damage in the parts of the brain responsible for processing language.

Signs and Symptoms of Aphasia

Aphasia is a condition that affects communication abilities and it comes in multiple forms, each having overlapping symptoms. A trained clinician can identify these different types and develop a personalised treatment plan for each patient. Here’s a brief overview of each type:

Wernicke Aphasia (Receptive): This type is characterised by difficulties in understanding spoken and written words, although the speech remains fluent but often meaningless. For example, a person might respond to the question “How are you doing today?” with a nonsensical answer like “We stayed with the water today.”
Broca Aphasia (Expressive): This refers to difficulties formulating grammatically correct sentences. For example, in response to the question “When did you graduate college?”, a person might say “I was umm… 7 years… ago”, omitting important grammatical links.
Conduction Aphasia: This is characterized by the inability to repeat what has just been said. For example, a person might jumble repeated words or numbers, like mistaking ‘seventy-nine’ for ‘ninety-seven’.
Transcortical Sensory Aphasia: This involves an inability to comprehend language, but with the surprising ability to repeat phrases verbatim.
Transcortical Motor Aphasia: This refers to speech difficulties, with the main exception being the ability to repeat long complex sentences.
Mixed Transcortical Aphasia: This is characterised by severe speaking and comprehension impairments, but the person can still repeat long, complex sentences.
Global Aphasia: This is the most severe form where a person can barely recognise words and has almost no understanding of written or spoken language.
Anomia: This is the mildest form of aphasia, characterised by difficulties finding words to express themselves.

In addition to these types, people with aphasia often show related behaviours such as self-repairs in their speech, disfluencies like repetitions, and automatic language responses.

Testing for Aphasia

If a patient is thought to have suffered a stroke which could be causing difficulty with language, known as aphasia, there are several steps in the evaluation process. Initially, a scan called a computed tomography (CT) is usually used to check for any issues. Later, a more specific type of scan called magnetic resonance imaging (MRI) helps pinpoint the problem area in the brain.

Next, experts known as speech and language pathologists evaluate the patient to figure out what kind of language issues they’re having. In this process, they use formal exams such as the Boston Diagnostic Aphasia Exam and the Western Aphasia Battery. The Boston Exam gives a rating from mild to severe. The Western Battery test helps figure out if the patient has aphasia, and if they do, it identifies the type and severity. It’s used as a starting point to then track improvement and recognize strengths and weaknesses.

Aphasia is tested by checking three parts of language. Speech fluency, or how easily the patient can speak; comprehension, or how well the patient understands spoken and written words; and repetition, or how well the patient can repeat written or spoken words.

There are different types of aphasia phenomenon which fall into two categories, Fluent and Non-Fluent Aphasia Syndromes:

In Fluent aphasia, the person can speak easily, but experiences other issues. For example, in Wernicke’s aphasia, the person can speak but struggles with comprehension and can’t repeat words. In contrast, in Anomic aphasia, the person can speak, understand, and repeat words, despite being fluent.

In Non-Fluent aphasia, speaking is difficult for the person. For example, in Broca’s aphasia, the person struggles to speak but can understand words, though they can’t repeat them.

Finally, a method known as the cognitive neuropsychological approach is sometimes used. This involves identifying the key language skills that aren’t functioning as they should. These are called modules, and a patient may have difficulty with one or many modules.

Treatment Options for Aphasia

The treatment of aphasia, a language disorder, depends on the underlying cause. In cases where a stroke caused the aphasia, strategies such as medication to dissolve blood clots, surgery to remove clots, or surgery to open narrow arteries may be used. If the aphasia was caused by a bleed in the brain, head injury, or a brain tumor, surgical relief of pressure in the brain might be necessary. Infections as the root cause may require medications like steroids, antivirals, or antibiotics. The main goal of treatment is to help patients regain as much independence as possible, so managing any other physical or mental health conditions the patient has is crucial. Providing social support and educating the patient’s care team can significantly improve the recovery process. Early diagnosis of depression is also important in managing aphasia, and emotional support from family, friends, and mental health professionals may be necessary. Speech-language pathologists will assess the patient’s strengths and weaknesses to create a tailored treatment plan, which may include short, intense treatment sessions and teaching compensatory strategies. For patients with non-fluent aphasias, melodic intonation therapy can be used to improve speaking fluency by leveraging the still working parts of the brain that handle singing. Advancements in technology, such as transcranial stimulation and drug therapies, are being studied for their potential in aphasia treatment.

Aphasia, a language disorder that affects the ability to communicate, can emerge gradually or suddenly. It can be brought on by several health conditions, including stroke, brain tumor, brain bleed, traumatic brain injury, and dementia caused by toxins, infection, or poor blood supply.

Other conditions that should be considered when diagnosing aphasia include:

A change in mental status due to brain diseases or delirium
Dysphonia (difficulty speaking)
Dysarthria (slurred or slow speech)
Apraxia of speech (struggle to move mouth and tongue to speak)
Cognitive communication disorder
Deafness

What to expect with Aphasia

How well a person recovers from aphasia (a condition that affects the ability to communicate) depends on several factors. These include the type and severity of the condition, its cause, and the person’s motivation. Usually, most improvements are seen two to three months after the condition starts, and recovery tends to be most significant at six months. After this point, the rate of recovery tends to decrease greatly.

The type of aphasia also affects recovery rates. People with Broca aphasia (which affects speaking and writing but not understanding) tend to recover better than those with global aphasia (which affects all language abilities). Furthermore, people with global aphasia generally recover better than those with Wernicke aphasia (which affects understanding but not speaking or writing).

Possible Complications When Diagnosed with Aphasia

People who have aphasia were once capable and literate, but now struggle to express basic wants and needs. Individuals with aphasia often fully realise their condition and this can lead to frustration and sometimes even violent behaviour. Feelings of loss of control and isolation can result in serious depression. Alongside aphasia, many people will also experience additional issues such as difficulties with mobility, completion of daily tasks, or potentially being bed-bound.

They might also have difficulties controlling their bowel or bladder movements, and may not be able to communicate when they have need to use the restroom. This can increase the risk of infection or pressure ulcers. Additionally, people with aphasia can experience untreated pain. Ultimately, the complexity of problems that arise from aphasia significantly depends on the root cause.

It’s also common for people with aphasia to struggle with non-linguistic cognitive problems. Often, this impacts their attention span and working memory, which can affect both their verbal and visuospatial abilities.

Preventing Aphasia

The most common cause of a brain condition called aphasia is often a stroke, and it’s important for patients to understand and address any risk factors that could lead to a stroke. High blood pressure is one of the main risk factors that can be controlled. Following guidance, such as the American College of Cardiology (ACC) or the Joint National Committee, can help patients manage their blood pressure.

Patients who have a heart condition known as atrial fibrillation should be using blood-thinning medications, based on their CAD VASC2 Score, a system used to gauge stroke risk. Those with diabetes need to manage their blood sugar levels. It’s also highly recommended for patients to stop smoking. In the end, the necessary steps to prevent aphasia will depend on each patient’s individual health and risk factors.