Dysarthria is a motor-speech disorder. It causes the inability to coordinate or control the muscles in the face, mouth, and respiratory system. It usually occurs when a brain injury causes the muscles to become weak or immobile. Depending on its cause, dysarthria may develop slowly or occur suddenly.
Dysarthria may be the result of brain damage due to brain injury, brain tumor, dementia, disease that causes the brain to lose its function, multiple sclerosis, Parkinson disease, and stroke. Dysarthria may result from damage to the nerves that supply the muscles that help you talk, or to the muscles themselves from face or neck, surgery for head and neck cancer, such as partial or total removal of the tongue or voice box. This may be caused by diseases that affect nerves and muscles (neuromuscular diseases) like cerebral palsy, muscular dystrophy, and myasthenia gravis.
People with dysarthria have trouble making certain sounds or words. Their speech is poorly pronounced (such as slurring), and the rhythm or speed of their speech changes. Other symptoms include sounding as though they are mumbling, speaking softly or in a whisper, speaking in a nasal or stuffy, hoarse, strained, or breathy voice. A person with dysarthria may also drool and have problems chewing or swallowing. It may be difficult to move the lips, tongue, or jaw.
Treatment will depend on the cause and severity of your symptoms and the type of dysarthria. One may need to be referred to a speech and language therapist for testing and treatment. Special skills you may learn include safe chewing or swallowing techniques, if needed. To avoid conversations when you are tired. To repeat sounds over and over again so you can learn mouth movements. Patients with amyotrophic lateral sclerosis (ALS or Lou Gehrig disease) eventually lose the ability to speak. Few people with Parkinson disease or multiple sclerosis lose the ability to speak. Dysarthria caused by medication or poorly fitting dentures can be reversed. Dysarthria caused by a stroke or brain injury will not get worse, and may improve. Dysarthria after surgery to the tongue or voice box should not get worse, and may improve with therapy.