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Hemispatial neglect, also called hemiagnosia, hemineglect, unilateral neglect, spatial neglect, contralateral neglect, unilateral visual inattention,〔Unsworth, C. A. (2007). Cognitive and Perceptual Dysfunction. In T. J. Schmitz & S. B. O’Sullivan (Eds.), Physical Rehabilitation (pp. 1149-1185). Philadelphia, F.A: Davis Company.〕 hemi-inattention,〔 neglect syndrome or contralateral hemispatialagnosia is a neuropsychological condition in which, after damage to one hemisphere of the brain is sustained, a deficit in attention to and awareness of one side of space is observed. It is defined by the inability of a person to process and perceive stimuli on one side of the body or environment, where that inability is not due to a lack of sensation.〔 Hemispatial neglect is very commonly contralateral to the damaged hemisphere, but instances of ipsilesional neglect (on the same side as the lesion) have been reported. ==Presentation== Hemispatial neglect results most commonly from strokes and brain unilateral injury to the right cerebral hemisphere, with rates in the critical stage of up to 80% causing visual neglect of the left-hand side of space. Neglect is often produced by massive strokes in the medial cerebral artery region and is variegated, so that most sufferers do not exhibit all of the syndrome's traits. Right-sided spatial neglect is rare because there is redundant processing of the right space by both the left and right cerebral hemispheres, whereas in most left-dominant brains the left space is only processed by the right cerebral hemisphere. Although it most strikingly affects visual perception ('visual neglect'), neglect in other forms of perception can also be found, either alone or in combination with visual neglect. For example, a stroke affecting the right parietal lobe of the brain can lead to neglect for the left side of the visual field, causing a patient with neglect to behave as if the left side of sensory space is nonexistent (although they can still turn left). In an extreme case, a patient with neglect might fail to eat the food on the left half of their plate, even though they complain of being hungry. If someone with neglect is asked to draw a clock, their drawing might show only the numbers 12 to 6, or all 12 numbers might be on one half of the clock face with the other half distorted or blank. Neglect patients may also ignore the contralesional side of their body; for instance, they might shave or apply make-up only to the non-neglected side. These patients may frequently collide with objects or structures such as door frames on the side being neglected.〔 Neglect may also present as a delusional form, where the patient denies ownership of a limb or an entire side of the body. Since this delusion often occurs alone, without the accompaniment of other delusions, it is often labeled as a monothematic delusion. Neglect not only affects present sensation but memory and recall perception as well. A patient suffering from neglect may also, when asked to recall a memory of a certain object and then draw said object, draw only half of the object. It is unclear, however, if this is due to a perceptive deficit of the memory (to the patient having lost pieces of spatial information of the memory) or whether the information within the memory is whole and intact but simply being ignored, the same way portions of a physical object in the patient's presence would be ignored. Some forms of neglect may also be very mild—for example, in a condition called extinction where competition from the ipsilesional stimulus impedes perception of the contralesional stimulus. These patients, when asked to fixate on the examiner's nose, can detect fingers being wiggled on the affected side. If the examiner were to wiggle his or her fingers on both the affected and unaffected sides of the patient, the patient will report seeing movement only on the ipsilesional side. 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「Hemispatial neglect」の詳細全文を読む スポンサード リンク
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