Background and Purpose-Generally it is accepted that spatial neglect occurs predominantly after stroke of the human right hemisphere. In contrast, it remained controversial whether extinction follows the same hemispheric asymmetry. The opinion prevails that the laterality of visual extinction is not as pronounced as it is for spatial neglect. Methods-To directly compare the incidence of the 2 disorders within the same sample, spatial neglect and visual extinction were investigated during a 1-year period in 83 consecutively admitted patients with unilateral right or left hemisphere stroke. Results-The incidence of visual extinction and of spatial neglect was not significantly different, neither after left hemisphere (2.4% neglect; 4.9% extinction) nor after right hemisphere (26.2% neglect; 24.3% extinction) stroke. Conclusions-Visual extinction seems to be as asymmetrically associated with the human right hemisphere as is spatial neglect. (Stroke. 2007;38:3172-3174.)Key Words: brain damage Ⅲ clinical neurology Ⅲ cognitive impairment Ⅲ human Ⅲ neuropsychology Ⅲ spatial neglect Ⅲ visual extinction S patial neglect is a lateralized disorder with a characteristic failure to explore or react to stimuli presented in contralesional space. 1 Visual extinction, however, is a failure to detect a contralesional target in the presence of a competing ipsilesional stimulus. In contrast to neglect, extinction is apparent only when 2 stimuli compete for the subject's attention.Generally it is accepted that spatial neglect occurs predominantly after disruption of the human right hemisphere. [2][3][4][5][6][7][8][9] The disorder seems to be as asymmetrically represented in the right hemisphere, as are language functions in the human left hemisphere. In contrast, it remained controversial whether extinction follows the same hemispheric asymmetry as spatial neglect. In the literature, the opinion prevails that the laterality of visual extinction is not as pronounced as it is for spatial neglect. It has been suggested that the association with damage of the right hemisphere is much weaker in visual extinction than in spatial neglect. 10 -14 However, the empirical basis underlying this assumption is weak. Whereas the asymmetrical representation has been frequently demonstrated for spatial neglect, to our knowledge only very few studies investigated hemispheric lateralization for visual extinction by comparing directly right-side and left-side stroke patients. 4,15 Moreover, their results remained controversial. Although Odgen 15 found a preponderance of extinction after left brain damage (16% with left versus 6% with right brain damage), Stone et al 4 reported the opposite pattern (2% after left versus 23% after right brain damage).The controversial results could be attributable to the fact that the studies included patients with different etiologies (tumor/ stroke) or used different clinical methods/cut-off scores for evaluation.The present study aimed to reinvestigate the question whether visual extinction follows the same hemisph...
Conjugate eye deviation describes the tonic horizontal deviation of the eyes in acute stroke patients. Here we investigate whether measuring patients' eye-in-head position in clinical magnetic resonance imaging or computed tomography scans obtained at admission shows a specific relationship to spatial neglect. We investigated 124 continuously admitted subjects with unilateral, first-ever left- or right-sided stroke. To control for the possibility that the degree of eye deviation is related to lesion size rather than spatial neglect, overall lesion volume was used as a covariate in the statistical analysis. Horizontal eye-in-head deviation on clinical brain scans appeared to be associated with spatial neglect rather than with brain damage per se. In contrast to the subject groups without the disorder, the patients with spatial neglect showed an eye-in-head position that was significantly deviated towards the ipsilesional right. Evaluation of eye-in-head position on clinical scans thus may be an additional helpful tool for diagnosing spatial neglect, particularly in the very early period of the stroke.
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