Apraxia of Speech is a form of oral motor speech disorder that affects a person’s ability to communicate conscious speech plans into motor plans.
A person may therefore be aware of the words they intend to say, but find their ability to say them is limited by an inability to connect intended words with the movement patterns required from the mouth, tongue, or lips, for example. The condition occurs as a loss of previous speaking ability due to brain damage incurred through stroke or another illness.
Symptoms and manifestations
- Apraxia of speech is typically characterized by repeated sounds or silently voiced attempts at sound, as a person begins the trial and error process of communicating their words. This searching of the mouth for the correct position to articulate a certain sound is referred to as “groping”. Sometimes, people with the condition can produce certain sounds independently but struggle to do so when prompted by others.
- The speech may be interspersed with an irregular pitch or rhythm, which can cause the speech to sound too fast, too slow or too segmented. The voice may also be monotone and syllables may be incorrectly pronounced and the speech is therefore sometimes described as “robotic” sounding. These speech patterns occur even though the affected individual is aware of the intonation and rhythm that should be used.
- As patients are aware of the abnormal speech pattern, they try to correct the speech, which can lead to distortion of vowels and consonants.
- Apraxia of speech is commonly mistaken for Broca’s Aphasia (expressive aphasia), mainly due to the fact that the conditions often occur concomitantly. Although the conditions both stem from damage in the language centre of the brain and present with difficulty producing sounds, the ability to comprehend language differs significantly between the two conditions. Those with apraxia are fully capable of understanding speech, while those with aphasia are not always capable.
Diagnosis and treatment
A speech-language pathologist usually diagnoses and treats apraxia of speech. They examine a patient’s ability to perform oral mechanisms such as pursing the lips, lifting the tongue, blowing and licking the lips. The patient’s reading and writing ability may also be assessed. Apraxia of speech is usually treated using one-to-one speech therapy. One main theme of therapy is the use of repetition to help patients achieve desired sounds and speech patterns.
Reviewed by Sally Robertson, BSc