Dysarthria happens when you’re unable to coordinate or control the muscles required for proper speech. It is a motor-speech disorder that can affect the muscles in your face, mouth, and respiratory tract that allow you to have a clear speech. The people affected by this condition are unable to pronounce words correctly and often have slurred speech which is difficult to understand by other people. The severity of dysarthria depends on the underlying cause. Treatment is done by addressing the root cause along with speech therapy.
Dysarthria can be caused by multiple factors, but the most common cause is neurological injury. Damage to the brain, spinal cord, or nerves that control the activity of speech muscles can result in dysarthria. The muscles in your face, mouth, and throat are responsible for production of speech. When the motor signals of these muscles are uncoordinated, it is difficult to speak clear words. Traumatic brain injury, stroke, cerebral palsy, brain tumor, Guillain-Barre syndrome, etc., can result in dysarthria. Degenerative diseases that can cause motor-speech incoordination include Parkinsonism, multiple sclerosis, amytrophic lateral sclerosis, and Huntington’s disease.
Dysarthria can also be caused by certain toxins or metabolic conditions that affect your nervous system. These include hypoxic encephalopathy, Wilson’s disease, and central pontine myelinolysis. Certain medications that affect your nervous system can also cause dysarthria, including tranquilizers, sedatives, and anti-seizure drugs.
Dysarthria can occur in people who have a positive family history of neurological diseases, especially genetic diseases that can be passed on to the next generation. People with hypertension, deep vein thrombosis, clotting disorders, etc., are at high risk of stroke, which can lead to dysarthria. Frequent use of medications that affect your nervous system can also put your health at risk. In rare cases, alcohol or drug abuse may affect your motor coordination.
Dysarthria can be found in both children and adults, depending on the cause. Stroke or cerebral palsy is usually present among older adults. Other causes of dysarthria can also impair speech from an early age. There is no gender or racial predilection for this disease.
The severity of the signs and symptoms of dysarthria depends on the extent of the underlying disease. The disease can present with mild to severe symptoms. The predominant symptoms include slurred speech, difficulty forming words, slow speech, abnormal rhythm of speech, rapid speech at times, difficulty adjusting the volume of speech, reduced quality of voice, nasal or hoarse voice, and difficulty in moving facial muscles. Many people with dysarthria also have dysphagia which is difficulty in swallowing food. This is because the throat and upper respiratory tract muscles are affected. People with dysarthria can have altered volume or speed of speech because they are unable to control these factors while talking. This makes it difficult for others to understand their speech.
If you have dysarthria, your doctor will likely refer you to a speech-language pathologist who will figure out the extent of dysarthria. Multiple speech examinations and tests are used to understand the possible cause. The movement of your tongue, quality of speech, voice, and other factors are observed. Imaging tests can be done to visualize the underlying cause. These tests include CT scans or MRI. Electroencephalogram, electromyogram, and nerve conduction study are other tests that can be performed to assess the functioning of your brain and motor activity. If an infection, brain tumor, or other metabolic diseases are suspected, your doctor will require blood tests, urinalysis, or lumbar puncture tests to identify the cause.
Dysarthria should be differentiated from other speech disorders that might present with similar symptoms. These include apraxia and developmental verbal dyspraxia. Differentiation between these disorders can be done by a speech-language pathologist on the basis of symptoms, speech examination, and necessary tests.
In many cases, the treatment of dysarthria focuses on treating the root cause. If the root cause is identified and treated to completion, there is a high chance that your speech will get better as well. Your doctor may recommend medications, therapy, or surgery, depending on the severity of your disease. If the symptoms are related to certain medicines, alternative prescriptions will be provided to relieve them. A speech-language pathologist can also guide you to improve your speech. They may develop a plan which will include exercises to improve the movement of your tongue and lips, have control over speed and volume of voice, and pronounce words correctly. Once your individual skills have improved, they may suggest group therapy or exposure to practical life situations to test your communication skills.
Medications are only recommended to treat the cause of dysarthria. The dosage and frequency of prescribed medicines depend on the type of your disease. The symptoms of dysarthria itself cannot be managed with medications alone.
According to research, approximately two-thirds of people with dysarthria due to central nervous system diseases can improve their speech with the help of treatment and speech-language pathologists. The definitive prognosis depends on the cause of dysarthria.
There are no established measures to prevent dysarthria. The causes can occur at any time or may be inherited in genes. If you develop difficulty forming speech or cannot control the movement of your tongue and speech muscles, it is better to consult a specialist at an early stage.
Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 17, 2023.
Dysarthria (difficulty speaking) - NHS (www.nhs.uk)