Visual extinction in relation to visuospatial neglect after right-hemispheric stroke: quantitative assessment and statistical lesion-symptom mapping.
J Neurol Neurosurg Psychiatry
; 82(8): 862-8, 2011 Aug.
Article
em En
| MEDLINE
| ID: mdl-21242287
ABSTRACT
BACKGROUND:
Visual neglect and extinction are two common neurological syndromes in patients with right-hemispheric brain damage. Whether and how these two syndromes are associated or share common neural substrates is still a matter of debate.METHODS:
To address these issues, the authors investigated 56 patients with right-hemispheric stroke with a novel diagnostic test to detect extinction and neglect. In this computerised task, subjects had to respond to target stimuli in uni- and bilateral stimulation conditions with detection probabilities being assessed. A cluster-analytical approach identified 18 patients with neglect and 13 patients with extinction. Statistical lesion-symptom mapping analyses with measures for extinction and neglect were performed.RESULTS:
Extinction and neglect co-occurred in a subset of patients but were also observed independently from each other, thereby constituting a double dissociation. Lesions within the right inferior parietal cortex were significantly associated with the severity of visual extinction. Visuospatial neglect was related to damage of fronto-parietal brain regions, with parieto-occipital areas affecting line bisection and dorsal fronto-parietal areas affecting cancellation task performance, respectively.CONCLUSION:
Quantifying lesion-induced symptoms with this novel paradigm shows that extinction and neglect are dissociable syndromes in patients with right-hemispheric stroke. Furthermore, extinction and neglect can be related to differential neural substrates, with extinction being related to focal brain damage within the right inferior parietal cortex.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Reconhecimento Visual de Modelos
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Transtornos da Percepção
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Percepção Espacial
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Acidente Vascular Cerebral
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Testes Neuropsicológicos
Tipo de estudo:
Diagnostic_studies
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Etiology_studies
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Evaluation_studies
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Prognostic_studies
Limite:
Female
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Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article