When actor Bruce Willis was diagnosed with aphasia in the spring of 2022, it ignited interest in what exactly the condition is and how it affects those who have it.

While Willis later received a more specific diagnosis of frontotemporal dementia in February of this year, the two conditions are closely linked.

Primary Progressive Aphasia

In general, aphasia is classified as a neurogenic language disorder that causes a loss of language — both the ability to produce language and the ability to understand it. The condition can be caused by a stroke, head injury, brain tumor, or other brain-based infection or disease.

Primary progressive aphasia (PPA), which Willis was diagnosed with, is a progressively worsening form of aphasia that is also recognized as a sub-type of frontotemporal dementia. Unlike some other forms of aphasia, there is no way to slow this condition down and there is no way to cure it. 

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Early Symptoms of Aphasia

PPA is considered to be rare: Less than 50,000 people in the U.S. have it, according to the Genetic and Rare Diseases Information Center.

But Aaron Wilkins, a doctor of speech language pathology and assistant clinical professor at Northwestern University, has particular expertise in such degenerative communication conditions. He says most people who develop PPA first become aware there’s a problem when they exhibit difficulty finding words, or anomia. 

“We all have difficulty in finding words on occasion, but it’s the frequency that really changes in [PPA],” Wilkins says. “It’s about every conversation, or even every sentence, that it’s difficult to find a word.”

Early on, those with PPA may fill sentences with pauses and hesitation, while others may use the wrong words entirely — resulting in sentences that make little sense. The progressing anomia usually leads to medical referrals, during which tests are conducted, and then diagnosis.

Later Symptoms of Aphasia

Although PPA typically begins with a person’s inability to speak properly, these symptoms gradually become much worse as the left temporal lobe (the part of the brain responsible for language recall) degrades. Patients often lose the ability to write, read and even understand the words spoken by other people.

“As their communication partner is talking, they might not understand anything that is being said,” Wilkins says. “They will know that the person is talking, but not be able to put meaning to those words.”

Despite this loss of language function, the disease often carries with it no other loss of cognitive function — especially for the first two years after onset. PPA changes the brain at the cellular level, Wilkins says, but only at the areas involving language. This differs drastically from other forms of dementia like Alzheimer’s, which encompass far more of the brain’s overall structure.

Only about half of PPA diagnoses, in fact, ever lead to behavioral or cognitive changes. While these patients don’t lose the concept of how the world works or who someone is — and are still able to function normally in many other ways — they are forced to endure the gradual cessation of communicating forever.

Read More: The Different Diseases Behind Language Impairment

Primary Progressive Aphasia Stages

The typical onset of PPA occurs around age 60, but can strike anywhere between ages 40 and 80.

The disease progresses in a highly variable manner, and Wilkins has seen both rapid and gradual declines in the patients he treats. The average rate of progression is five to 10 years, he says, though some people experience total language loss in four to five years and others won’t get there for 15 or 20.

Cognitive testing, independent of language function, is generally conducted to confirm a PPA diagnosis during the first two years. But if other cognitive or behavioral changes occur within that same timespan, Wilkins says, that indicates some other condition.

And while PPA is usually related to frontotemporal dementia, rarer cases can be related to Alzheimer’s. In this case, patients typically see symptoms advancing beyond language loss over time.

Behaviorally, about half of PPA patients experience depression due to the immense frustration and nature of their condition. Others with more advanced PPA may find difficulty inhibiting certain behaviors, as the brain’s frontal lobe — responsible for executive functioning — is affected, Wilkins says.

Treatment for Aphasia

Even with such a dire prognosis, Wilkins and other speech therapists have seen positive effects while helping patients deal with the gradual loss of language skills.

“We’re trying to keep communication as natural as possible while transitioning to a more global way of communicating,” he says. “And then, eventually, it’s really confined to these alternative systems that we’ve set up.”

While a person can still speak but is having trouble finding words, for example, therapists often encourage workarounds: like describing things or using associations and synonyms for words they can’t recall.

Relying on multiple methods of communication as early as possible, Wilkins says, helps both patients and families adjust better to their new normal.

Other Aphasia Therapies

Patients are also encouraged to use their hands while communicating, he adds, employing functional gestures like pantomime, body language and facial expressions. Therapists also employ pictorial methods to aid communication; at the low-tech end, this includes pictographic books that allow a person to simply point at what they need or want.

On the high-tech end, devices like cell phones and electronic tablets can speak for a patient when they activate pictures by touch. In some cases, Wilkins says, patients have recorded their own voices while still able — allowing them to digitally preserve words in their own voice for the future.

Working with communication partners like loved ones is also critical, he says. While there’s no way to cure PPA, there are still ways to make the best of a terrible diagnosis.

“Typically, those are the best outcomes, when you can work with both the patient and family members or other support systems that they may have,” Wilkins says. “That combination makes a big difference.”

Read More: The Man Who Lost His Language Overnight