Dysarthria vs. Aphasia: How They Affect Communication

Our ability to speak and understand language is something we can take for granted. From toddlerhood on, our words just flow — day in and day out, often without thinking too much about them.

So, when something gets in the way of communicating, it can throw a big wrench in your life.

Neurological diseases, stroke, head injuries and other events can affect your speech and language abilities. Dysarthria and aphasia are two common neurological disorders that affect how you communicate.

What’s the difference between them? Speech-language pathologist Martin Brodsky, PhD, ScM, explains.

The differences between dysarthria vs. aphasia

Dysarthria is a condition that affects your ability to physically produce words and sounds. Aphasia affects your ability to use the words you mean to.

“It’s the difference between a speech disorder and a language disorder,” Dr. Brodsky clarifies. “Dysarthria affects speech — how you form and produce words. Aphasia affects language, which is your ability to express your thoughts and understand others’ words.”

Damage to your brain or central nervous system causes dysarthria and aphasia. The location of the damage affects whether your speech or language centers (or both) are affected.

Both conditions can result from brain or nervous system damage, such as:

• Severe head injury
• Stroke
• ALS
• Brain tumors
• Dementia and Alzheimer’s disease
• Multiple sclerosis (MS)

Importantly, neither dysarthria nor aphasia is a sign that there’s a problem with your thinking. And they’re not a reflection of your intelligence.

“Dysarthria and aphasia usually have no impact on cognition,” Dr. Brodsky confirms. “They limit your ability to respond — not your ability to think.”

Understanding dysarthria

People with dysarthria have damage to their brain or nervous system that keeps them from speaking clearly.

Speech takes coordination. Your tongue, lips, teeth, vocal cords, airflow and even rhythm all work together to form words and sentences. Any disruptions along the way can keep you from properly forming and pronouncing words. That means your speech may sound:

• Slurred
• Too fast or too slow
• Too quiet or too loud
• Hoarse, strained or breathy
• Choppy

Dr. Brodsky points out that the speech patterns associated with dysarthria can be mistaken for drunkenness, which can be a real problem.

“Imagine you get pulled over, and when you speak, you’re slurring,” he illustrates. “So, the officer asks you to walk a straight line. If you’ve had a stroke or another condition that affects your balance, too, they can easily assume you’re intoxicated.”

Understanding aphasia

People with aphasia speak clearly, with crisp sounds and well-paced sentences. But they may use the wrong words.

It’s not that your thinking is flawed, though. Your brain is still forming cohesive and complex thoughts. But there’s a break in the bridge that connects the words you plan to use and the words that come out of your mouth.

For example, you may mean to say, “Can you pass me the salt?” But what comes out is “Can you eat the table?” Or you might want to say, “I’m tired,” but instead say, “I’m water.” Or you may say words that aren’t words at all — “Where are my gleets?” instead of “keys.”

People with aphasia can find it tough to understand other people’s speech, too. And it can cause trouble reading or writing words.

“Aphasia affects communication across multiple modes of language — spoken, written, heard and read,” Dr. Brodsky says. “That’s part of the difference between speech disorders like dysarthria and language disorders like aphasia. Speech disorders only affect your spoken words.”

Bottom line

Living with a speech or communication disorder can be frustrating. When you can’t give voice to your thoughts in ways that others understand, it can affect your confidence, your relationships and your well-being.

If you or a loved one is experiencing speech or language difficulties, talk with a healthcare provider. Depending on your needs, they may recommend exercises and assistive technologies to help.