Speech Apraxia

Clinic

• Apraxia of speech (AOS) also known as acquired apraxia of speech, verbal apraxia, or childhood apraxia of speech (CAS)
• It is a speech sound disorder.
• AOS has trouble saying what he or she wants to say correctly and consistently.
• AOS is a neurological disorder that affects the brain pathways involved in planning the sequence of movements involved in producing speech.
• The brain knows what it wants to say, but cannot properly plan and sequence the required speech sound movements.
• AOS is not caused by weakness or paralysis of the speech muscles (Jaw, tongue, or lips).
• Weakness or paralysis of the speech muscles results in a separate speech disorder, known as dysarthria.
• Some people have both dysarthria and AOS
• AOS can be so mild that it causes trouble with only a few speech sounds or with pronunciation of words that have many syllables. In the most severe cases, someone with AOS might not be able to communicate effectively by speaking, and may need the help of alternative communication methods.

Types

• Acquired AOS :Stroke, Head injury, Tumor, or other illness affecting the brain. Acquired AOS may occur together with dysarthria or aphasia
• Childhood AOS: Also known as developmental apraxia of speech, developmental verbal apraxia, or articulatory apraxia. Childhood AOS is not the same as developmental delays in speech, in which a child follows the typical path of speech development but does so more slowly than is typical. The causes of childhood AOS are not well understood. Imaging and other studies have not been able to find evidence of brain damage or differences in the brain structure of children with AOS. Children with AOS often have family members who have a history of a communication disorder or a learning disability. This observation and recent research findings suggest that genetic factors may play a role in the disorder. Childhood AOS appears to affect more boys than girls.

Symptoms

• Distorting sounds.
  • Difficulty pronouncing words correctly.
  • Sounds, esp vowels are often distorted. Because the speaker may not place the speech structures (e.g., tongue, jaw) quite in the right place, the sound comes out wrong.
  • Longer or more complex words are usually harder to say than shorter or simpler words.
  • Sound substitutions might also occur when AOS is accompanied by aphasia.

• Making inconsistent errors in speech. For example, someone with AOS may say a difficult word correctly but then have trouble repeating it, or may be able to say a particular sound one day and have trouble with the same sound the next day.

• Groping for sounds. People with AOS often appear to be groping for the right sound or word, and may try saying a word several times before they say it correctly.

• Making errors in tone, stress, or rhythm. Another common characteristic of AOS is the incorrect use of prosody. Prosody is the rhythm and inflection of speech that we use to help express meaning. Someone who has trouble with prosody might use equal stress, segment syllables in a word, omit syllables in words and phrases, or pause inappropriately while speaking.

Children with AOS generally understand language much better than they are able to use it. Some children with the disorder may also have other speech problems, expressive language problems, or motor-skill problems.

How is apraxia of speech diagnosed?

Professionals known as speech-language pathologists play a key role in diagnosing and treating AOS. Because there is no single symptom or test that can be used to diagnose AOS, the person making the diagnosis generally looks for the presence of several of a group of symptoms, including those described earlier. Ruling out other conditions, such as muscle weakness or language production problems (e.g., aphasia), can help with the diagnostic process. In formal testing for both acquired and childhood AOS, a speech-language pathologist may ask the patient to perform speech tasks such as repeating a particular word several times or repeating a list of words of increasing length (for example, love, loving, lovingly). For acquired AOS, a speech-language pathologist may also examine the patient’s ability to converse, read, write, and perform nonspeech movements. To diagnose childhood AOS, parents and professionals may need to observe a child’s speech over a period of time.