Apraxia
Encyclopedia
Apraxia is a disorder caused by damage to specific areas of the cerebrum. Apraxia is characterized by loss of the ability to execute or carry out learned purposeful movements, despite having the desire and the physical ability to perform the movements. It is a disorder of motor planning, which may be acquired or developmental, but may not be caused by incoordination, sensory loss, or failure to comprehend simple commands (which can be tested by asking the person to recognize the correct movement from a series). Apraxia should not be confused with ataxia
Ataxia
Ataxia is a neurological sign and symptom that consists of gross lack of coordination of muscle movements. Ataxia is a non-specific clinical manifestation implying dysfunction of the parts of the nervous system that coordinate movement, such as the cerebellum...

, a lack of coordination of movements, aphasia
Aphasia
Aphasia is an impairment of language ability. This class of language disorder ranges from having difficulty remembering words to being completely unable to speak, read, or write....

, an inability to produce and/or comprehend language; abulia, the lack of desire to carry out an action; or allochiria
Allochiria
Allochiria is associated to spatial transpositions, usually symmetrical, of stimuli from one side of the body to the opposite one. It is a neurological disorder in which the patient responds to stimuli presented to one side of their body as if the stimuli had been presented at the opposite side...

, in which patients perceive stimuli to one side of the body as occurring on the other.

There are many different forms of apraxia. Some are listed below:
  • Buccofacial or orofacial apraxia. Difficulty carrying out movements of the face on demand. For example, an inability to lick one's lips or whistle.
  • Ideational apraxia. Loss of ability to carry out learned complex tasks in the proper order, such as putting on socks before putting on shoes.
  • Ideomotor apraxia. Loss of ability to voluntarily perform a learned task when given the necessary objects. For instance, if given a screwdriver, the patient may try to write with it as if it were a pen, or try to comb one's hair with a toothbrush.
  • Limb-kinetic apraxia. Difficulty making precise movements with an arm or leg.
  • Verbal apraxia. Trouble coordinating mouth movements and speech.

The root word of apraxia is praxis, Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 for an act, work, or deed. It is preceded by a privative a
Privative a
In Ancient Greek grammar, privative a is the prefix a-  that expresses negation or absence . It is derived from a Proto-Indo-European syllabic nasal *, the zero ablaut grade of the negation *ne, i.e. /n/ used as a vowel...

, meaning without.

Types

There are several types of apraxia including:
  • Buccofacial or orofacial apraxia. nonverbal-oral or buccofacial (inability to carry out facial movements on command; e.g., lick lips, whistle, cough, or wink);
  • constructional (inability to draw or construct simple configurations), such as intersecting pentagons;
  • gait apraxia
  • Ideational apraxia. Loss of ability to carry out learned complex tasks in the proper order, such as putting on socks before putting on shoes.
  • limb-kinetic apraxia. Difficulty making precise movements with an arm or leg.
  • oculomotor (difficulty moving the eye, especially with saccade movements). This is one of the 3 major components of Balint's syndrome
    Balint's syndrome
    Bálint's syndrome is an uncommon and incompletely understood triad of severe neuropsychological impairments: inability to perceive the visual field as a whole , difficulty in fixating the eyes , and inability to move the hand to a specific object by using vision...

    .
  • verbal (difficulty planning the movements necessary for speech), also known as Apraxia of Speech (see below);


Each type may be tested at decreasing levels of complexity; if the person tested fails to execute the commands, you can make the movement yourself and ask that the person mimic it, or you can even give them a real object (like a toothbrush) and ask them to use it.

Verbal apraxia of speech

Apraxia may be accompanied by a language disorder
Language disorder
Language disorders or language impairments are disorders that involve the processing of linguistic information. Problems that may be experienced can involve grammar , semantics , or other aspects of language...

 called aphasia
Aphasia
Aphasia is an impairment of language ability. This class of language disorder ranges from having difficulty remembering words to being completely unable to speak, read, or write....

. Because this is such a frequently encountered type of apraxia, an entire section is devoted to it:

Symptoms of Acquired Apraxia of speech
Apraxia of speech
Apraxia of Speech is a motor speech disorder affecting an individual's ability to translate conscious speech plans into motor plans and is caused by illness or injury in adults. Like other apraxias, it only affects volitional movement patterns...

 (AOS) and Childhood Apraxia of Speech (CAS) include inconsistent articulatory errors, groping oral movements to locate the correct articulatory position, and increasing errors with increasing word and phrase length. AOS often co-occurs with Oral Apraxia (during both speech and non-speech movements) and Limb Apraxia.

Childhood Apraxia of Speech (CAS) presents in children who have no evidence of difficulty with strength or range of motion of the articulators, but are unable to execute speech movements because of motor planning and coordination problems. This is not to be confused with phonological impairments in children with normal coordination of the articulators during speech.

Acquired apraxia of speech involves the loss of previously acquired speech levels. It occurs in both children and adults who have (prior to the onset of apraxia) acquired some level of speaking ability. Unlike Childhood Apraxia of Speech, AOS is typically the result of a stroke, tumor, or other known neurological illness or injury.

Causes

Ideomotor apraxia is almost always caused by lesions in the language-dominant (usually left) hemisphere of the brain
Human brain
The human brain has the same general structure as the brains of other mammals, but is over three times larger than the brain of a typical mammal with an equivalent body size. Estimates for the number of neurons in the human brain range from 80 to 120 billion...

; and, as such, these patients often have concomitant aphasia
Aphasia
Aphasia is an impairment of language ability. This class of language disorder ranges from having difficulty remembering words to being completely unable to speak, read, or write....

, especially of the Broca
Expressive aphasia
Expressive aphasia , also known as Broca's aphasia in clinical neuropsychology and agrammatic aphasia in cognitive neuropsychology, is caused by damage to or developmental issues in anterior regions of the brain, including the left posterior inferior frontal gyrus known as Broca's area...

 or conduction
Conduction aphasia
Conduction aphasia, also called associative aphasia, is a relatively rare form of aphasia. An acquired language disorder, it is characterized by intact auditory comprehension, fluent speech production, but poor speech repetition. Patients will display frequent errors during spontaneous speech,...

 type. Left-side ideomotor apraxia may be caused by a lesion of the anterior corpus callosum
Corpus callosum
The corpus callosum , also known as the colossal commissure, is a wide, flat bundle of neural fibers beneath the cortex in the eutherian brain at the longitudinal fissure. It connects the left and right cerebral hemispheres and facilitates interhemispheric communication...

.

Ideational apraxia is commonly associated with confusion states and dementia.

Constructional apraxia is associated with hepatic encephalopathy due to cerebral edema.

Treatment

Recommended treatment for individuals with apraxia includes physical therapy
Physical therapy
Physical therapy , often abbreviated PT, is a health care profession. Physical therapy is concerned with identifying and maximizing quality of life and movement potential within the spheres of promotion, prevention, diagnosis, treatment/intervention,and rehabilitation...

, occupational therapy
Occupational therapy
Occupational therapy is a discipline that aims to promote health by enabling people to perform meaningful and purposeful activities. Occupational therapists work with individuals who suffer from a mentally, physically, developmentally, and/or emotionally disabling condition by utilizing treatments...

, play therapy, music therapy, and/or speech therapy.

Prognosis

The prognosis for individuals with apraxia varies. With therapy, some patients improve significantly, while others may show very little improvement. Some individuals with apraxia may benefit from the use of a communication aid
Augmentative and alternative communication
Augmentative and alternative communication is an umbrella term that encompasses the communication methods used to supplement or replace speech or writing for those with impairments in the production or comprehension of spoken or written language...

.
However, many people with apraxia are no longer able to be independent. They should avoid activities in which they might injure themselves or others.

Occupational therapy and counseling and play therapy may help both patients and their caregivers learn ways to deal with the apraxia. However, because people with apraxia have trouble following instructions, occupational therapy for stroke or other brain injury is difficult.

No drug has been shown useful for treating apraxia.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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