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Apraxia is a motor disorder caused by damage to the brain (specifically the posterior parietal cortex), in which someone has difficulty with the motor planning to perform tasks or movements when asked, provided that the request or command is understood and he/she is willing to perform the task. A person with apraxia cannot move his or her lips or tongue to the right place to say sounds correctly because, even though the muscles are not weak, the message from the brain to the mouth are disrupted. The nature of the brain damage determines the severity.〔(ASHA )〕 Apraxia is an acquired disorder of motor planning, but is not 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). It is caused by damage to specific areas of the cerebrum. Apraxia should not be confused with ataxia, a lack of coordination of movements; aphasia, an inability to produce and/or comprehend language; abulia, the lack of desire to carry out an action; or allochiria, in which patients perceive stimuli to one side of the body as occurring on the other. Developmental coordination disorder is the developmental disorder of motor planning. ==Types== There are several types of apraxia including: *Ideomotor apraxia: These patients have deficits in their ability to plan or complete motor actions that rely on semantic memory. They are able to explain how to perform an action, but unable to "imagine" or act out a movement such as "pretend to brush your teeth" or "pucker as though you bit into a sour lemon." The ability to perform an action automatically when cued, however, remains intact. This is known as automatic-voluntary dissociation. For example, they may not be able to pick up a phone when asked to do so, but can perform the action without thinking when the phone rings. *Ideational/conceptual apraxia: Patients have an inability to conceptualize a task and impaired ability to complete multistep actions. Consists of an inability to select and carry out an appropriate motor program. For example, the patient may complete actions in incorrect orders, such as buttering bread before putting it in the toaster, or putting on shoes before putting on socks. There is also a loss of ability to voluntarily perform a learned task when given the necessary objects or tools. For instance, if given a screwdriver, the patient may try to write with it as if it were a pen, or try to comb his hair with a toothbrush.〔〔 *Buccofacial or orofacial apraxia: Non-verbal oral or buccofacial ideomotor apraxia resulting in difficulty carrying out movements of the face on demand. For example, an inability to lick one's lips or whistle. This is an ability to carry out any volitional movements of the tongue, cheeks, lips, pharynx, or larynx on command. *Constructional apraxia: The inability to draw or construct simple configurations, such as intersecting shapes. *Gait apraxia: The loss of ability to have normal function of the lower limbs such as walking. This is not due to loss of motor or sensory functions. *Limb-kinetic apraxia: Difficulty making precise movements with an arm or leg. *Oculomotor apraxia: Difficulty moving the eye, especially with saccade movements that direct the gaze to targets. This is one of the 3 major components of Balint's syndrome. *Apraxia of speech (AOS): Difficulty planning and coordinating the movements necessary for speech (e.g. Potato=Totapo,Topato.)〔Heilman KM, Watson RT, Gonzalez-Rothi LJ. Praxis. In: Goetz CG. Goetz: Textbook of Clinical Neurology. 3rd ed. Philadelphia, PA: Saunders Elsevier; 2007:chap 4.〕 AOS can independently occur without issues in areas such as verbal comprehension, reading comprehension, writing, articulation or prosody. 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. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「apraxia」の詳細全文を読む スポンサード リンク
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