What Is Aphasia?
Aphasia is a debilitating speech and language disorder that stems from brain damage. It's as common as some other neurological conditions -- such as Parkinson's disease -- but aphasia isn't nearly as well known. "Very few people have heard about it, and I think it's because aphasia is a communication problem. Quite literally, people can't speak up for themselves. There hasn't been a strong advocacy system for people with aphasia," says Nina Dronkers, a neuropsychologist, aphasia researcher and professor of neurology at the University of California--Davis.
What Is Aphasia?
Aphasia is an umbrella term for the many types of language impairments that keep people from speaking or comprehending. The syndromes are triggered by:
-- A stroke (interruption of blood flow to the brain due to a blockage or hemorrhage).
-- Traumatic brain injury (such as a head injury caused by an accident).
-- Neurodegenerative disease, like Alzheimer's.
-- A brain tumor.
-- Infectious disease, such as herpes encephalitis.
[See: 10 Questions Doctors Wish Their Patients Would Ask.]
When someone has aphasia, it may be hard to:
-- Find the right word for a sentence.
-- Produce sounds.
-- Grasp the meaning of words.
-- Read or write.
But the types of aphasia symptoms you experience depend on the location of brain damage. For example: "Damage to the parietal lobe in the back of the brain may cause reading and writing problems," Dronkers notes. "Damage to the left temporal lobe may affect your ability to match concepts and words. Damage to the frontal lobe may cause difficulty with speech production."
Fluent Aphasia
Types of aphasia fall into two general categories: fluent aphasia and nonfluent aphasia.
People with fluent aphasia are able to produce connected speech, but it may lack meaning. Types of fluent aphasias include:
-- Anomic aphasia. This is considered the most common form of aphasia. People with anomic aphasia may be able to talk and understand language, but they have difficulty retrieving words. They may misname objects or mispronounce words.
-- Conduction aphasia. People with conduction aphasia also have difficulty finding words. This syndrome is marked by an inability to repeat phrases and sentences, due to auditory short-term memory loss.
-- Wernicke's aphasia. This type of aphasia is marked by speech that is well-formed but makes no sense. People with Wernicke's aphasia may not comprehend others and may be unaware that they're speaking without being understood.
-- Transcortical sensory aphasia. People with transcortical sensory aphasia will sound like they have a Wernicke's aphasia, but their ability to repeat words and sentences is remarkably preserved.
[Read: How Early Memory Loss Shows Up in Everyday Speech.]
Nonfluent Aphasia
People with nonfluent aphasia have difficulty producing speech. "It's hard to get the words out. People struggle to pronounce words or find the name of an object," Dronkers explains.
Types of aphasias that are nonfluent include:
-- Broca's aphasia. People with Broca's aphasia have slow, effortful speech and may mispronounce words. They also have a hard time forming complete sentences or understanding sentences with complex grammar. They also struggle with reading and writing.
-- Global aphasia. This is considered the most severe form of aphasia. People with global aphasia are unable to produce or understand words and sentences. They're also unable to read or write. Global aphasia typically occurs after a stroke.
-- Transcortical motor aphasia. A person who has transcortical motor aphasia may understand language but have a hard time forming sentences properly or spontaneously answering questions. Like transcortical sensory aphasia, their ability to repeat full sentences is remarkably intact.
Primary Progressive Aphasia
Unlike other kinds of aphasias, primary progressive aphasia is a form of dementia that progressively damages brain regions associated with language. The condition is marked by obvious difficulties finding words beyond age-related cognitive decline. Patients may stop talking in the middle of a sentence and pause frequently in speech to find the right words.
But it's unclear why people develop this form of dementia. "In general, there are all sorts of different hypotheses as to the trigger of neurodegenerative disease. One we favor is that a kernel or seed protein in the brain takes on an abnormal shape and converts other proteins so that they no longer do their job," says Dr. Zachary Miller, assistant professor of neurology with University of California--San Francisco who treats patients at the UCSF Memory and Aging Center.
Miller says primary progressive aphasia is not typically inherited. "But there are instances where individuals from families that possess known genetics for neurodegenerative disease can develop primary progressive aphasia," he notes.
What we do know is that primary progressive aphasia typically remains isolated as a language difficulty for a few years before it takes on other characteristics of dementia (such as memory problems). The condition has three forms:
-- Nonfluent variant primary progressive aphasia. People with nonfluent variant primary progressive aphasia can understand words but they have problems forming words, understanding complex sentences and getting grammar right.
-- Logopenic variant primary progressive aphasia. Logopenic variant primary progressive aphasia is marked by difficulty finding words and repeating sentences due to auditory short-term memory problems.
-- Semantic variant primary progressive aphasia. This aphasia causes people to lose conceptual knowledge. Patients with semantic variant primary progressive aphasia may have profound difficulties understanding written or spoken language. "Someone might say, 'Pass me a bowl,' and the patient will ask, 'What's a bowl?' They can speak fluently, but they lose the connection of concepts," Miller explains.
[Read: Which Doctor Should I See for Dementia and Cognitive Decline?]
Treatment and Prognosis
When it's caused by a stroke or traumatic brain injury, aphasia often evolves into a milder form. "As a person recovers, the aphasia becomes less severe within the first year," Dronkers says.
The prognosis isn't as encouraging for people with primary progressive aphasia, which continues to cause cognitive decline and dementia.
No matter what the cause of aphasia, treatment involves working with a speech language pathologist. "The goals of treatment are to try to teach other areas of the brain to help take over the functions that were lost, and also to teach the patient strategies to compensate for their deficits," Dronkers says.
"You may work on moving your mouth and lips to overenunciate or work on certain words and phrases that are important for you to say," Miller says.
Another strategy is giving the brain cues to find a missing word. For example, describing the word you can't think of -- if you can't remember the word hat, say the thing you wear on your head -- or hearing the first syllable of the missing word. "At some point, you'll activate cell clusters in the brain that have information about the object, and it triggers the missing word," Dronkers says.
Attending an aphasia support group is also helpful. "It's a safe environment," Dronkers points out. "You won't be embarrassed. Everyone has the same problem." Your doctor will be able to refer you to a support group.
That's important to consider, since talking about the challenges of aphasia help to make them less frightening. And that's a first step toward tackling the brain changes that can have a devastating impact on your quality of life.
Heidi Godman reports on health for U.S. News, with a focus on middle and older age. Her work has appeared in dozens of publications, including the Harvard Health Letter (where she serves as executive editor), the Chicago Tribune, Baltimore Sun, Orlando Sentinel and Cleveland Clinic Heart Advisor.
Heidi spent more than 20 years as a TV news anchor and health reporter at ABC affiliate WWSB and more than five years as the host of a daily health talk radio show on WSRQ-FM. Heidi has interviewed surgeons in operating rooms, scientists in laboratories and patients in all phases of treatment. She's earned numerous awards for outstanding health reporting and was the first TV broadcaster in the nation to be named a journalism fellow of the American Academy of Neurology. Heidi graduated from West Virginia University with a degree in journalism.
Connect with Heidi on Linkedin or email her at health@heidigodman.com.
