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Allochiria (from the Greek meaning "other hand") 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.〔 It is associated with spatial transpositions, usually symmetrical, of stimuli from one side of the body (or of the space) to the opposite one. Thus a touch to the left side of the body will be reported as a touch to the right side, which is also known as somatosensory allochiria.〔 If the auditory or visual senses are affected, sounds (a person's voice for instance) will be reported as being heard on the opposite side to that on which they occur and objects presented visually will be reported as having been presented on the opposite side. Often patients may express allochiria in their drawing while copying an image. Allochiria often co-occurs with unilateral neglect and, like hemispatial neglect, the disorder arises commonly from damage to the right parietal lobe.〔 Allochiria is often confused with alloesthesia, also known as false allochiria.〔 True allochiria is a symptom of dyschiria and unilateral neglect.〔 Dyschiria is a disorder in the localization of sensation due to various degrees of dissociation and cause impairment in one side causing the inability to tell which side of the body was touched. ==Definitional criteria== Allochiria has been observed mainly in the context of neglect which is usually due to a lesion that affects the right parietal lobe.〔 In patients with allochiria, their sensibility is retained completely but the patient is not clear as to which side of the body has been touched. Their power of localization is retained but error exists to the side touched and they often refer the irritation to the corresponding part of the limb.〔 In the patients’ mind there is doubt or error as to which side of the body is touched. There are multiple definitions of allochiria. According to Musser, allochiria is the reference of a sensory stimulus to the corresponding location on the opposite location on the opposite side of the body.〔 Judson Bury says that a patient may refer to an impression on one side to a corresponding place on the opposite side of the body.〔 Thus, if a patient is pricked on one limb, he may say that he feels it on the other. Overall, even though different author’s definition differs on points such as the type of stimulus, and the symmetry between the site of the stimulus and the seat of its localization, they all agree that an essential feature of allochiria is the deflection of a sensation to the wrong side of the body, which is true allochiria. In none of these definitions is any stress laid on the state of the patient’s knowledge of a right or left side and the symptoms are seen as an error in localization. Obsersteiner laid stress that there is in allochiria no defect in vertical localization but merely confusion in the patient’s mind between the opposite sides of the body and come to look upon the symptom as simply any form of bad mistake in localization.〔 There is in the patient’s mind doubt or error as to the side touched while sensibility including the power of localization is otherwise retained. Allochiria has been described as occurring in nerve lesions, Hemiplegia, disseminated sclerosis Multiple sclerosis, tabes dorsalis, unilateral injury to the spinal cord, Ménière's disease, hysteria, symmetrical gangrene,〔http://medical.yourdictionary.com/symmetrical-gangrene〕 and in connection with touch, pain, the "muscle sense," the temperature sense, sight, smell, taste, hearing, and the electrical reactions.〔 Allochiria can occur in relation to any or every segment of the body. In some cases allochiria may be bilateral, and in others it may be restricted to certain regions of the body, or even only to one part of the body. Allochiria is marked to have connections with a variety of senses and sometimes only certain kinds of stimuli can arouse the appropriate feeling of one sidedness.〔 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「allochiria」の詳細全文を読む スポンサード リンク
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