Types of Aphasia
There are many different types of aphasia. Language is stored in several areas of the brain, so the type of language difficulty someone has depends on the part of the brain that was affected.
In reality, everyone’s brain is different, and each aphasia is slightly different too. Sometimes people will have aphasia that does not fit neatly into one of these categories. This is especially true for people who are multilingual, or people who are left-handed. Nonetheless, learning about common types of aphasia can be helpful.
Blumenfeld’s “Neuroanatomy Through Clinical Cases” has a diagram that illustrates some of the most common types of aphasia.
Global aphasia is very severe. People with global aphasia will have difficulty with all language domains: talking, understanding, reading, and writing. They will say very few words, or they may say no recognizable words at all. They will understand very few words, or no words at all. They are unable to read or write. People with global aphasia can often evolve toward a different subtype of aphasia with time and/or speech therapy, but prognosis depends on the extent of the damage that caused the aphasia.
Mixed Transcortical Aphasia
Mixed transcortical aphasia is similar to global aphasia, but with the ability to repeat. A person with this type of aphasia will likely have very little voluntary speech, poor comprehension, and difficulty reading and writing. However, they will quasi-automatically repeat back words that they hear. The main areas of language are typically not damaged, but the brain tissue nearby is, which leaves the language areas isolated from the rest of the brain.
Broca’s aphasia is a very common type of aphasia. People with Broca’s aphasia know what they want to say, but have difficulty getting their words out. Speech is slow and effortful. They can often understand most of what is said – especially clear, direct sentences, but may struggle to understand more complex grammar and/or longer sentences. Concrete nouns and verbs are easier to say than small grammatical words.
Transcortical Motor Aphasia
People with transcortical motor aphasia have significant difficulty producing spontaneous speech, but they can repeat phrases and sentences. Comprehension is largely preserved, but writing is difficult and often mirrors their spoken language. People with transcortical motor aphasia have a very hard time initiating speech, and sometimes, difficulty initiating other motor movements too.
Wernicke’s aphasia is characterized by difficulty with auditory comprehension. This aphasia occurs when the area of the brain responsible for processing spoken words and attaching meaning to them is damaged. People with Wernicke’s aphasia are typically unaware that they are having difficulty. They can talk at a normal rate and rhythm. However, they often string together words that don’t make sense and include seemingly random or made up words.
Transcortical Sensory Aphasia
People with transcortical sensory aphasia also have significant difficulty with auditory comprehension. They can talk at a normal rate and rhythm, but typically have lots of errors in their speech. They are able to repeat words and phrases, sometimes repeating a question or part of a question back to the listener. They may have visual field deficits, or difficulty recognizing visually presented objects. They may have difficulty copying a line drawing.
Conduction aphasia is a type of aphasia where people can typically understand most of what’s being said and speak at a normal rate and rhythm. They still have errors in their speech, but have a high level of awareness of these errors. A hallmark of conduction aphasia is to attempt to fix errors in their speech, often getting closer and closer to the target word with repeated attempts. They have difficulty repeating, but can typically paraphrase what they’ve heard.
Anomic aphasia is the most mild form of aphasia. A person with this type of aphasia is relatively functional with speaking, understanding, reading, and writing. However, they have difficulty with word finding. Their speech is fluent, but with frequent pauses for word finding. When they have difficulty thinking of words, they tend to use vague language, such as “those things” and “the stuff over there” or attempt to describe the object they are thinking of. This also occurs in writing.
There is one more type of aphasia that is different from those mentioned above.
Primary Progressive Aphasia (PPA)
Despite its name, Primary Progressive Aphasia (PPA) is a type of frontotemporal dementia. It is caused by a deterioration of the areas of the brain that are involved in speech and language. This condition progresses slowly. People with PPA can lose the ability to speak and write and, eventually, to understand written or spoken language. There are also various subtypes of PPA.