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. Dysarthrias are characterized by weakness and/or abnormal muscle tone of the speech musculature that moves the articulators such as the lips and tongue.
What causes Dysarthria?
Dysarthria is caused by damage to areas in the brain that are important for more motor aspects of speech (as opposed to linguistic). There are several types of dysarthria: 1) flaccid dysarthria due to damage of cranial nerves and/or regions in the brain stem and midbrain; 2) spastic dysarthria due to damage of motor regions in the cortex, on both sides of the brain; 3) ataxic dysarthria due to damage of pathways that connect the cerebellum with other regions in the brain; 4) hypokinetic dysarthria due to Parkinson’s disease, and 5) hyperkinetic dysarthria due to damage of the basal ganglia.
How does Dysarthria relate to Aphasia?
Both aphasia and dysarthria affect production of speech. However, dysarthria is different from aphasia in that it is not a language disorder per se. A person with aphasia may have a limited ability to understand speech, to find the right words, use the correct grammatical structures, etc. A person with dysarthria has mostly problems with motor execution of language, i.e. with movement of the articulators, although sometimes other aspects of language production might be affected, such as working memory.
More Dysarthria Resources
- Coping and support (Mayo Clinic)
- Tests and diagnosis (Mayo Clinic)
- Treatment efficacy – ASHA summary
- Duffy, JR (2005). Motor speech disorders: substrates, differential diagnosis, and management (2nd edition). St. Louis, MO: Mosby-Year Book, Inc.
- Guenther, FH, (2016). Neural Control of Speech. MIT Press pp: 239-252