Dysarthria is a communication impairment that affects the ability to produce normal sounding, intelligible speech. Although it can co-exist with other communication disorders, dysarthria only affects speech intelligibility. Language processing, intellectual abilities and social skills are not affected by dysarthria.
Dysarthria is caused by damage to areas of the brain that control the muscles needed for speech or by direct damage to the nerves leading to the speech muscles. The person will know how to speak and what words to use, but cannot produce them clearly. There are changes to the muscle tone, strength and coordination. Often, one side of the face is more affected than the other.
Speech characteristics of dysarthria:
- Movements of muscles needed to articulate speech may lack strength, have a reduced range of movement and reduced accuracy.
- Articulatory movements may be slowed.
- Speech may sound imprecise, slurred, nasal, too quiet or loud and may lack normal intonation patterns.
- Speech may be difficult to understand.
- Sentences may be shortened to make the speech clearer.
- Speech can sound hesitant.
- Speech syllables can be slowed and/or separated.
- Speech may sound breathy or there may be changes to voice quality, speech sounding harsh, hoarse or whispery (dysphonia).
- Intelligibility can vary between being nearly normal to being very difficult to understand.
- The person may no longer able to usefully produce any intelligible speech and may require augmentative and alternative communication
Dysarthria can also affect the person’s non-verbal communication in different ways. Changes to non-verbal communication can include:
- The person’s ability to use facial expression and voice intonation may be impaired. This can make it difficult for their communication partners to accurately interpret the person’s emotions and potentially affects interpretation of the meaning of the words the person with dysarthria uses.
- Dysarthria can cause facial expression to be fixed or slow to respond. This can lead to other people erroneously thinking they are bored, uninterested, uncaring, angry, not understanding or lacking in empathy etc.
Trying to speak may be frustrating, tiring and upsetting for the person affected by dysarthria. It can also be very distressing for family and friends. In some social situations, dysarthria has caused people to be wrongly labelled as ‘drunk’ or intellectually impaired. Dysarthria can also significantly alter other people’s interpretation of the person’s personality.