What Is Apraxia?
Apraxia is a poorly understood neurological condition. People who have it find it difficult or impossible to make certain motor movements, even though their muscles are normal. Milder forms of apraxia are known as dyspraxia.
Apraxia can occur in a number of different forms. One form is orofacial apraxia. People with orofacial apraxia are unable to voluntarily perform certain movements involving facial muscles. For instance, they may not be able to lick their lips or wink. Another form of apraxia affects a person's ability to intentionally move arms and legs.
With apraxia of speech a person finds it difficult or impossible to move his or her mouth and tongue to speak. This happens, even though the person has the desire to speak and the mouth and tongue muscles are physically able to form words.
Are There Different Types of Apraxia of Speech?
There are two forms of apraxia of speech -- acquired apraxia and developmental apraxia. Acquired apraxia can occur in people of all ages. Typically, though, it is found in adults. This condition causes people to lose the speech-making abilities they once possessed.
Developmental apraxia of speech is also known as childhood apraxia of speech. This condition is present from birth, and it affects a child's ability to form sounds and words. Children with speech apraxia often have far greater abilities to understand speech than to express themselves with spoken words.
The majority of children with developmental apraxia will experience significant improvement, if not complete recovery, with the correct treatment.
What Is the Difference Between Apraxia of Speech and Aphasia?
Apraxia is sometimes confused with aphasia, another communication disorder. That confusion can be complicated by the fact that the two conditions can occur together.
People with apraxia and aphasia might both have difficulty expressing themselves with words. There are, though, distinct differences between the two. Aphasia describes a problem in a person's ability to understand or use words in and of themselves. This may make it hard for someone with the condition to speak, read, or write. But apraxia does not describe a problem with language comprehension. Apraxia refers to the difficulty someone has initiating and performing the movements needed to make speech. This difficulty arises despite the fact that there is no weakness in the necessary muscles.
What Are the Symptoms of Apraxia of Speech?
There are a variety of speech-related symptoms that can be associated with apraxia, including:
- Difficulty stringing syllables together in the appropriate order to make words, or inability to do so
- Minimal babbling during infancy
- Difficulty saying long or complex words
- Repeated attempts at pronunciation of words
- Speech inconsistencies, such as being able to say a sound or word properly at certain times but not others
- Incorrect inflections or stresses on certain sounds or words
- Excessive use of nonverbal forms of communication
- Distorting of vowel sounds
- Omitting consonants at the beginnings and ends of words
- Seeming to grope or struggle to make words
Childhood apraxia of speech rarely occurs alone. It is often accompanied by other language or cognitive deficits, which may cause:
- Limited vocabulary
- Grammatical problems
- Problems with coordination and fine motor skills
- Difficulties chewing and swallowing
What Causes Apraxia of Speech?
Experts do not yet understand what causes childhood apraxia of speech. Some scientists believe that it results from signaling problems between the brain and the muscles used for speaking.
Ongoing research is focusing on whether brain abnormalities that cause apraxia of speech can be identified. Other research is looking for genetic causes of apraxia. Some studies are trying to determine exactly which parts of the brain are linked to the condition.
Are There Tests to Diagnose Apraxia of Speech?
There is not a single test or procedure that is used to diagnose apraxia of speech. Diagnosis is complicated by the fact that speech-language pathologists have different opinions about which symptoms indicate developmental apraxia.
Most experts, though, look for the presence of multiple, common apraxia symptoms. They may assess a patient's ability to repeat a word multiple times. Or they may assess whether a person can recite a list of words that are increasingly more difficult, such as "play, playful, playfully."
A speech-language pathologist may interact with a child to assess which sounds, syllables, and words the child is able to make and understand. The pathologist will also examine the child's mouth, tongue, and face for any structural problems that might be causing apraxia symptoms.
When diagnosing apraxia, experts may look for the presence of other symptoms. For instance, they may look for weakness or difficulties with language comprehension. Both of these are indicative of other conditions and their presence would help rule out apraxia. For people with possible acquired apraxia, an MRI of the brain may be useful to determine the extent and location of any brain damage.
Typically, a diagnosis of childhood apraxia of speech cannot be made before a child's second birthday. Before this time, most children are unable to understand or perform the tasks needed to determine the presence of apraxia.
Are There Treatments for Apraxia of Speech?
In some cases of acquired apraxia, the condition resolves spontaneously. This is not the case with developmental apraxia of speech, which does not go away without treatment.
There are various treatment approaches used for apraxia. How effective they are can vary from person to person. For the best results, apraxia treatment must be developed to meet a given individual's needs. Most children with apraxia of speech benefit from meeting one on one with a speech-language pathologist three to five times a week. They may also need to work with their parents or guardians to practice the skills they are developing.
Therapy for childhood apraxia of speech aims to improve speech coordination. Exercises may include:
- Repeatedly practicing the formation and pronunciation of sounds and words
- Practicing stringing together sounds to make speech
- Working with rhythms or melodies
- Using multisensory approaches, such as watching in a mirror while trying to form words or touching the face while talking
Many therapists believe that sign language is beneficial for children who have difficulty being understood. They often recommend that children attempt to say the words they are signing to practice making the necessary movements with their mouths.
People with more extreme cases of acquired apraxia may also benefit from sign language. Or they may use assistive electronic devices, including computers that can be used to produce words and sentences.
Very few studies have been done to determine the relative effectiveness of various treatment approaches for childhood apraxia of speech. This may be due, in part, to ongoing debate among experts as to which symptoms and characteristics merit a diagnosis of apraxia.