Aphasia After a Stroke

A stroke often makes it difficult to communicate. That is because several regions in the brain work together to allow us to speak and to understand speech. A stroke that damages any of these important regions or the neural pathways between them can impair speech.

Speech problems are called aphasia or dysarthria. Dysarthria is when it is difficult to make speech sounds because of face, mouth, tongue or jaw weakness. Aphasia is a language problem. The most common types of aphasia are called Wernicke’s aphasia and Broca's aphasia.

What Kind of Stroke Causes Dysarthria?

Any stroke that makes the face, mouth, tongue or jaw weak or uncoordinated can cause dysarthria. Large cortical strokes, small white matter strokes, brainstem strokes and cerebellar strokes can all cause dysarthria if they weaken the muscles that control the mouth. People with dysarthria usually do not have a problem understanding speech or reading or writing.

Dysarthria often improves with speech therapy and can get much better with exercise. Stroke survivors with dysarthria may also have dysphagia, which is trouble swallowing, because speech and swallowing are controlled by many of the same muscles.

What Kind of Stroke Causes Aphasia?

One side of the brain, often referred to as the dominant side, controls speech. The dominant side of your brain is the side opposite your dominant hand. So, if you are left handed, your dominant side is the right side of your brain and if you are right handed, your dominant side is on the left side of your brain.

Usually, a stroke affecting either the Broca's or the Wernicke’s area - the two major speech centers on the dominant side of your brain, impairs speech. The Broca's area is at the top middle section of your brain and the Wernicke’s area is located lower down, closer to your ear. Both of these areas are part of the cerebral cortex, which is the region of the brain often associated with high level thinking skills generally injured in a 'big stroke.'

Broca's area allows you to speak smoothly and fluently. A stroke in Broca's area can make you struggle with sounds, as if stuttering irregularly and with an abnormal rhythm.

Wernicke’s area allows you to understand language. A stroke in Wernicke’s area makes your speech full of nonsense words that flow nicely- almost as if you were speaking another language. A stroke in Wernicke’s area also makes it hard to understand other people's spoken and written language.


Speech deficits can improve after a stroke. Rehabilitation and speech therapy are usually more successful for people with Broca's aphasia (the problem with rhythm) than with Wernicke’s aphasia (the problem with language.)

Most right-handed people who have aphasia after a stroke also have some weakness on the right arm or right leg. Most left-handed people who have aphasia after a stroke have some weakness of the left arm or left leg.

Living with Aphasia

Aphasia can certainly make life difficult. Sometimes, bilingual stroke survivors with aphasia can communicate better with the language they learned in childhood than a second language. Some stroke survivors who suffer from aphasia can learn to communicate through sign language or art.


If you are a caregiver of a stroke survivor with aphasia or dysarthria, it can be challenging. Keep in mind that your loved one is often holding in so much that he doesn't know how to get out. Facial expressions and gestures can help supplement communication problems for people with aphasia or dysarthria. Usually, stroke survivors who suffer from aphasia or dysarthria can communicate best with the person they spend the most time with than with others. If that person is you, it makes your job that much more challenging to be the voice of your loved one who can't express herself to anyone but you.


Aphasia and dysarthria can lead to depression and isolation. Use your available resources for speech therapy and try to maximize communication through sign language, facial gestures, body language and drawing to reduce the sense of isolation as much as possible.


Factors predicting post-stroke aphasia recovery, M M W, S A B, Journal of Neurological Sciences, May 2015

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