Motor Speech Disorders
What are motor speech disorders?
Motor speech disorders are the inability to speak properly when constructing sentences or saying single words. The coordination, timing and strength needed to speak words is affected.
Types of motor speech disorders
The two main types of motor speech disorders are Dysarthria and Apraxia. Dysarthria is produced from a disruption of muscular control from either the central or peripheral nervous systems. Dysarthria is classified as a neuromotor disorder because it is caused by the interruption of information from the nervous system to the muscles. Muscles of the face and mouth can become weak to the point of moving slowly or can stop moving all together. Some causes of dysarthria can be stroke, cerebral palsy, muscular dystrophy and head injuries. Symptoms of dysarthria include: talking very quietly, slurred speech, poor quality of speech, drooling, etc.
Apraxia, also known as “Apraxia of speech” and “verbal Apraxia” is caused by parts brain damage, damage to parts of the brain associated with speech. Subjects with Apraxia of speech know the words they wish to speak, however their brain has problems coordinating the facial muscles used to sound the words properly. As with all motor speech disorders there are different levels of severity with people suffering Apraxia of speech. People suffering Apraxia of speech can display inconsistent errors in speech, difficulty imitating sounds and a slow rate of speech.
Dysarthria vs Apraxia
Dysarthria shows consistant errors in speech. The subject with Dysarthria will exhibit the same amount and types of errors in speech no matter which type of speaking task or materials that are used. Apraxia of speech on the other hand is inconsistent and very unpredictable. Well rehearsed or automatic (learned) speech is easiest to produce, however spontaneous speech more difficult. The number of errors increases as length of the word or phrase increases.
How are Motor Speech Disorders treated?
Treatments vary depending on the patient and severity of the speech disorder. The speech and language pathologists may use many different treatment methods that are specific to each patient. Treatment programs are formulated to focus on the strengths and weaknesses of the patient.