3 Types of Aphasia (and Less Common Ones)

The three main types of aphasia, which involve trouble speaking, writing, or understanding language, include Broca's, Wernicke's, and global aphasia.

Aphasia happens when a part of the brain associated with language (the frontal lobe, the temporal lobe, or the parietal lobe) is damaged. It is most common after a stroke but can also be caused by a traumatic brain injury, a brain tumor, or an infection of the brain. Less common types of aphasia also exist.

Aphasia and the Brain

Several regions of the brain control language. The language function is located in one hemisphere (half) of the brain, which is called the dominant hemisphere. Typically, the dominant hemisphere of the brain is on the opposite side as your dominant hand (the hand you write with).

Areas of your brain are important for communication in different ways:

• The frontal lobe of your brain controls your cognitive (thinking) abilities.
• The temporal lobe processes memories.
• The parietal lobe is in charge of information about taste, touch, movement, and temperature.

If one of the language regions of the brain is injured but the others are healthy, only some language functions are affected. Each type of aphasia has a unique set of symptoms based on the affected blood vessels and areas of the brain. The three most common types of aphasia include:

• Broca's aphasia
• Wernicke's aphasia
• Global aphasia

Of the three main types of aphasia, global aphasia is considered the most severe form. It affects all aspects of language, including reading, writing, talking, and comprehension.

Broca's Aphasia

Some systems for classifying aphasia refer to fluent and nonfluent types, depending on how speech and language are affected. Broca's aphasia, named after the person who discovered the area of the brain responsible for creating speech, is the most common nonfluent type.

Broca's aphasia is also called expressive aphasia or motor aphasia. The term indicates that the ability to speak is damaged but other language abilities stay mostly the same. It can be frustrating for people with Broca's aphasia, who are aware of speech changes that include:

• Struggling to form words
• Speaking in incomplete sentences
• Repeating words and phrases over and over
• Using words that are close to the right one

Damage to Broca’s area happens when a stroke interrupts blood flow to the dominant frontal lobe of the brain. Other post-stroke problems related to the affected areas include:

• Hemiparesis (weakness) or hemiplegia (paralysis) on the right side of the body
• Alexia (inability to read) and agraphia (inability to write)

Wernicke's Aphasia

Wernicke’s aphasia, also known as receptive aphasia, is the most common type of fluent aphasia. It is named after the person who discovered temporal lobe areas of the brain used to understand language.

Wernicke's aphasia is challenging because when people speak, they usually feel as though other people should be able to understand them. They do not realize that their language is impaired, and they don't understand others—or even themselves—when they speak. Those who have it may:

• String together words that don't make sense (logorrhea)
• Use words that are unrecognizable
• Have difficulty repeating words back to someone

However, people with Wernicke’s aphasia after a stroke may eventually learn that others cannot understand them when they speak—a realization that can lead to anger or fear. Depression is common after a stroke, affecting between 30% and 60% of post-stroke individuals.

Global Aphasia

Global aphasia after a stroke occurs when the brain damage is so widespread that it involves more than one left-hemisphere language area, leading to both Broca's and Wernicke’s aphasia symptoms.

Global aphasia affects all aspects of language, with some people unable to speak or communicate at all. This can affect different domains of language, leading to:

• Problems speaking or repeating words
• Severe difficulty with understanding words, sentences, and concepts
• Inability to read or write

People experiencing global aphasia often rely on facial expressions or hand gestures to communicate.

Other Types of Aphasia

Other types of aphasia can result from different areas of damage in the brain. They include:

• Anomic aphasia: Patients struggle to find the right names for objects that they know. This is typically the least severe, mildest type of aphasia.
• Conduction aphasia: Patients have difficulty repeating words, even with the ability to understand and speak fluently.
• Mixed non-fluent aphasia: Patients have trouble with speech and comprehension, and read and write at an elementary level.
• Primary progressive aphasia: This form of aphasia is caused by neurodegenerative disease. It results in a decline in language and speech skills as well as memory loss.
• Crossed aphasia: Rarely, in the brains of some people, the damage crosses into the other hemisphere (typically the right) but with similar symptoms despite the "mirror" effect in the brain.
  

Diagnosis

After a physical exam and review of your medical history, imaging studies, and evaluative tests would be ordered to help confirm the cause and characterize the nature and severity of aphasia.

Imaging studies typically include:

• Computed tomography (CT) scan: This is a technology that uses multiple X-rays to create a three-dimensional image of the brain.
• Magnetic resonance imaging (MRI): This imaging study used powerful magnetic and radio waves to create highly detailed images of soft tissues like the brain.

MRI is the most accurate way to detect signs of a stroke, but a CT scan is faster and more widely available. Healthcare providers often use CT first in people with a suspected stroke and MRI afterward to get a more detailed image.

You would likely be referred to a speech-language pathologist to undergo a battery of spoken and written tests to characterize the nature and extent of aphasia. The aim of the Comprehensive Aphasia Test and other language assessment tests is to determine if you can:

• Read and write
• Follow instructions
• Understand and use words correctly
• Repeat words that are spoken to you
• Name common objects
• Answer to yes or no questions
• Respond to open-ended questions
• Answer questions about something you just read
• Engage in a back-and-forth conversation

These tests help to determine if you have aphasia or another disorder with similar symptoms. Some conditions that can also cause communication difficulties include:

• Apraxia: The person is unable to make gestures when asked, like waving hello, even though they understand the request.
• Apraxia of speech: The person has difficulty articulating words or mastering the timing or rhythm of speech.
• Dysarthria: This speech disorder is caused by weakness or incoordination of the muscles used to talk.
• Dysphagia: The person has difficulty swallowing liquids, foods, and saliva.
  

Treatment

Aphasia treatment depends on individual needs, and people have different or more than one type of treatments. For example, a person living with post-stroke aphasia may benefit from:

• Speech-language therapy
• Occupational therapy
• Counseling and mental health support
• Medications, like Aricept (donepezil), Namenda (memantine), and Razadyne (galantamine)

Unquestionably, the most important aspect of treatment for post-stroke aphasia is speech-language therapy. This can be done with individual or group therapy, with the aim of:

• Restoring language skills as much as possible
• Finding alternate means of communication, such as gestures or pictures
• Using assistive technologies, such as speech-generating devices (SGD) and teletypewriters (TTY)

Some researchers are also exploring whether experimental techniques like deep brain stimulation can help people with aphasia.

Summary

Aphasia is a language disorder that is caused by an injury to specific parts of the brain that control language. The three most common kinds of post-stroke aphasia are Broca's aphasia, Wernicke's aphasia, and global aphasia, which all affect your ability to speak and/or understand language.

Aphasia after a stroke is common but a traumatic brain injury or brain infection can also cause aphasia. Treatment may include speech-language therapy, medications, counseling, and mental health support.