Dysarthria (Slurred Speech): Symptoms, Causes, & Treatment
Dysarthria is a motor speech disorder that occurs when muscles used for speech are weak. Motor speech disorders are characterized by difficulty moving the muscles that are needed for speech production. Individuals with dysarthria know what they want to say; they just have a hard time saying it due to muscle weakness. This typically causes speech to become slow or slurred and often difficult to understand.
Symptoms of Dysarthria
Symptoms of dysarthria depend on the cause and type of dysarthria. Common symptoms include:
- Slurred Speech
- Speech Speed Problems - Too slow or too fast
- Trouble controlling speech volume - they may speak quieter or louder than they intend to
- Monotonous/robotic Speech
- Hoarse/Breathy Speech
- Speech that sounds nasally/stuffy
- Difficulty moving tongue, lips, and facial muscles
What causes dysarthria?
Dysarthria occurs when damage has occurred to the parts of the nervous system that control the muscles that control speech. It can be developed or acquired. In some cases, dysarthria is due to a condition that was present at birth. An example of this is cerebral palsy. A child with this disorder will possibly have developmental dysarthria. Acquired dysarthria occurs as a result of damage later in life from health issues such as brain damage, Multiple Sclerosis (MS), Parkinson’s disorder, or stroke.
Types of Dysarthria
The various types of dysarthria are classified based on the specific part of the nervous system that is affected.
Ataxic Dysarthria - Ataxic dysarthria results from damage to the cerebellum. The cerebellum is the part of the brain that helps coordinate muscle movement. This type of dysarthria results in struggles with pronouncing various vowels and consonants and, overall, a very uncoordinated pattern of speech.
Flaccid Dysarthria - Flaccid dysarthria is associated with damage to the lower motor neurons. The lower motor neurons are part of the peripheral nervous system. This type of dysarthria results in breathy and nasally sounding speech.
Hyperkinetic Dysarthria - Hyperkinetic dysarthria results from damage to the basal ganglia. The basal ganglia refers to a group of brain structures that help control muscle movement. This type of dysarthria results in fast, hyper, and sometimes unpredictable speech.
Hypokinetic Dysarthria - Hypokinetic dysarthria, like hyperkinetic dysarthria, also results from damage to the basal ganglia; however, this type results in slow, almost robotic/monotone sounding speech.
Spastic Dysarthria - Spastic dysarthria is associated with damage to the upper motor neurons resulting in weakness in the muscles needed for speech. This type of dysarthria results in a slow rate of speech and a strained voice.
Mixed Dysarthria - Mixed dysarthria includes a mix of two or more of the other types of dysarthria. This is the most common type.
Dysarthria vs Aphasia
Dysarthria and aphasia are both disorders that affect speech. Dysarthria affects speech clarity and is the result of weakness in the muscles that are responsible for speech. Aphasia affects a person's ability to both produce and understand language and is the result of damage to the area of the brain where language is processed. Individuals with dysarthria often know what they want to say; they just struggle to say it due to muscle weakness. Individuals with aphasia do not have muscle weakness but have issues speaking and understanding language due to damage in the brain.
How is dysarthria diagnosed?
Dysarthria is diagnosed with a combination of testing, assessments, and a thorough look through the individual's medical history.
- MRI or CT scans of the brain and head may be arranged to check for abnormalities that may be affecting speech
- An electroencephalogram (EEG) can check for abnormalities in the brain that could be related to the dysarthria
- Speech-language Pathologists (SLPs) can complete a thorough assessment for dysarthria and its type.
Can speech therapy improve dysarthria?
Speech therapy can help improve dysarthria. Treatment will depend on the type of dysarthria as well as the severity of the symptoms. The SLP will start with an assessment and develop a treatment plan that fits the needs of the individual.
Speech exercises for dysarthria may include the following:
- Exercises to strengthen lips, jaw, tongue, and other muscles needed for speech
- Breathing exercises
- Exercises to work on speech volume
- Exercises to work on speech speed
- Articulation exercises to improve speech clarity
In some cases, speech therapy is sufficient to fix dysarthria, while in others, it's about improving the clarity of speech. Sometimes speech therapy will include learning alternate means of communication (devices, hand gestures, written communication, etc).
It is always beneficial to include family and caregivers in the treatment plan for speech disorders. Understanding the treatment plan and learning ways to communicate will help them better support their loved ones in their everyday life.
If you or someone you love has symptoms of dysarthria, Schedule a free introductory call.