Updated: Jul 6, 2020
What is Dysarthria?
Dysarthria is a speech disorder that is characterized by poor articulation, respiration, and/or phonation. This includes slurred, slow, effortful, and prosodically abnormal speech. Dysarthria(s) are characterized by weakness and/or abnormal muscle tone of the speech musculature that moves the articulators such as the lips and tongue.
According to the American Speech Language Hearing Association (ASHA), dysarthria can affect one or more of the following five systems that speech involves:
Respiration: Respiration moves air across the vocal cords, creating sounds that the mouth and nose shape into words.
Phonation: This system uses airflow from the lungs plus vocal cord vibrations to produce speech sounds.
Resonance: Resonance refers to the quality of speech sounds that the vocal tract produces.
Articulation: This term means shaping sounds into recognizable words, which involves forming precise and accurate vowels and consonants.
Prosody: The rhythm and intonation of speech that give words and phrases their meaning.
The five speech systems work together, meaning that impairment in one system can affect the others.
People who have dysarthria may experience one or more of the following symptoms:
abnormally quiet or loud speaking voice
rough, scratchy, or hoarse voice
stuffy or nasal-sounding voice
speech that is too fast or too slow
distorted consonant and vowel sounds
As conditions that cause dysarthria also affect the nerves that control muscles, people with dysarthria may experience physical symptoms, such as:
tremors or involuntary movements of the jaw, tongue, or lip
overly sensitive or under-sensitive gag reflex
The neurological damage that causes dysarthria can occur due to:
neurological conditions, such as epilepsy, amyotrophic lateral sclerosis (ALS), and Parkinson's disease
trauma from injuries to the head or neck, as well as repeated blunt force impacts to the skull
inflammatory conditions, such as autoimmune diseases, encephalitis, and meningitis
vascular conditions, such as stroke or Moyamoya disease
exposure to toxic substances, such as alcohol, heavy metals, or carbon monoxide