A stroke occurs when blood flow to part of the brain is interrupted, damaging or killing brain cells. This can be due to a blocked artery (ischemic stroke) or a ruptured blood vessel (hemorrhagic stroke). Such damage often impacts speech and language, with communication difficulties affecting about one-third of stroke survivors.
Types of Speech Changes After Stroke
Speech and language challenges following a stroke vary based on the specific brain areas affected. Three primary communication disorders often arise: aphasia, dysarthria, and apraxia of speech. Each impacts distinct aspects of communication, from language processing to muscle control.
Aphasia
Aphasia is a language disorder impairing a person’s ability to understand or express language, affecting speech, writing, and comprehension. Individuals might speak in short or incomplete sentences, substitute words, or struggle to find the right words. While it affects language, aphasia does not diminish intelligence. Severity varies from mild word-finding difficulties to a near-total inability to communicate.
Dysarthria
Dysarthria involves difficulty speaking due to weakness or poor coordination of speech muscles. This can result in slurred, slow, or mumbled speech, making it challenging to understand. Affected muscles may include the tongue, lips, face, and vocal cords, leading to changes in speech volume, pitch, or rhythm. Unlike aphasia, dysarthria is a motor speech disorder; the person understands language but struggles to produce sounds.
Apraxia of speech
Apraxia of speech is a disorder where the brain struggles to plan and coordinate speech movements, even though the muscles are not weak. Individuals know what they want to say but struggle to move their tongue, lips, and jaw correctly. This can lead to inconsistent errors, slow and effortful articulation, and difficulty with longer words or specific sounds. It is less common than aphasia or dysarthria, though it can occur alongside them.
How Stroke Affects the Brain’s Speech Centers
The brain has specialized regions that produce and understand language. A stroke damages these areas by disrupting blood flow, leading to cell death or injury. The location and extent of this damage determine the communication difficulties that arise.
Broca’s area
Broca’s area, typically in the left frontal lobe, is involved in speech production and forming words and sentences. Damage here can result in slow, effortful speech, often with simplified grammatical structures, though comprehension may remain relatively intact.
Wernicke’s area
Wernicke’s area, found in the left temporal lobe, is crucial for language comprehension. When affected by a stroke, a person might speak fluently but use nonsensical words or sentences, and have difficulty understanding what others say.
Motor cortex
The motor cortex, in the frontal lobe, sends signals to the muscles of the face, mouth, tongue, and throat to coordinate articulation. Damage here can impair the physical ability to move these muscles, contributing to dysarthria. These brain regions are interconnected; a stroke impacting any part of this network can disrupt communication.
Pathways to Speech Recovery
Speech-language pathologists (SLPs) assess, diagnose, and rehabilitate communication impairments after a stroke. They create individualized treatment plans to help survivors regain communication skills. Therapy often begins early, as intensive intervention can lead to better long-term outcomes.
Therapeutic approaches include exercises to improve articulation, language comprehension, and word retrieval. This might involve tongue and lip strengthening for clearer speech, or language activities like naming objects and forming sentences. Singing therapy can also be beneficial, as it may activate different brain pathways, aiding speech recovery.
Neuroplasticity, the brain’s ability to reorganize and form new connections, guides speech therapy. Consistent practice and repetition strengthen these new neural pathways. For severe communication challenges, SLPs may introduce assistive communication devices, such as visual cues, gesture use, alphabet boards, or computer-based technology.
Practical Communication Strategies
Effective communication after a stroke involves adjustments from both the survivor and their communication partners. Survivors can facilitate clearer expression by speaking slowly and loudly, exaggerating pronunciation. Using gestures, pointing, or writing key words can also help convey messages when verbal communication is difficult. Taking breaks and avoiding important conversations when tired is beneficial, as fatigue can worsen speech difficulties.
Communication partners can adopt specific techniques to better understand and support stroke survivors. Reducing background noise, such as turning off the television, creates a quieter environment for conversation. Sitting face-to-face and allowing ample time for responses demonstrates patience. Avoid finishing sentences or correcting errors; instead, repeat what was understood and ask for clarification on unclear parts. Using simple sentences and asking yes or no questions can also make comprehension easier.