The Japanese journal of neuropsychology

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ArticleTitle	A reason for unawareness in symptoms of motor neglect
Language	J
AuthorList	Yoshitsugu Nakagawa MD, PhD
Affiliation	Graduate School of Nursing and Social Services, Health Sciences University of Hokkaido
Publication	Japanese Journal of Neuropsychology: 19 (2), 87-95, 2003
Received
Accepted
Abstract	In this study, the symptom of motor neglect is investigated to disclose a reason for unawareness of under-utilization of contra-lesional limb. In two cases with the lesion in the right supplementary motor area, the left hand was under-used in daily life tasks, with no apparent defect of muscle strength or sensory impairments. During daily life in general they were hardly aware of the decreased use. Only when they had some trouble in accomplishing a task did they notice the imbalance, and once they noticed the decreased use of the left hand, they could then normally perform the movements. In contrast on examination, the patients knew how to use each hand effectively, and showed a fundamentally preserved ability to monitor the condition of their hands; they normally performed most of voluntary movements examined. This symptom can be regarded as a deficiency of left hand movement only when the patients diverted attention from their hands. This symptom can be explained by that there is a strategy wherein according to a content of ﾔintent' set up at the target level, an appropriate hand movement can be unconsciously selected and evoked without paying attention to the hands. A reason for unawareness of motor neglect can be caused by diversion of attention from hand condition under-used. We further investigated one case with a lesion in the left parietal lobe, showing mild unilateral spatial neglect as well as motor neglect. We pointed out that the symptom of motor neglect caused by parietal lesion had a similar aspect to that of unilateral spatial neglect in terms of "occurred" behavioral problem and its awareness of the case itself.
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