Preserved repetition in thalamic afasia. A pathophysiological hypothesis

Autor: Ricardo Nitrini, Leandro T. Lucato, Maria C. Sitta, Maíra O. Oliveira, Daniel Ciampi de Andrade, Valquiria A. Silva, Camila G. Carneiro, Carlos A. Buchpiguel
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Dementia & Neuropsychologia, Vol 13, Iss 2, Pp 244-249 (2019)
Druh dokumentu: article
ISSN: 1980-5764
DOI: 10.1590/1980-57642018dn13-020015
Popis: ABSTRACT. The ability to repeat words is almost always preserved in thalamic aphasia. The pathophysiology of both thalamic aphasia and preservation of repetition are not fully understood. In a case of severe aphasia with preserved repetition after a left thalamic hemorrhage, MRI disclosed left thalamic lesion and loss of fractional anisotropy in the left centrum semiovale. FDG-PET showed severe hypometabolism in the left cerebral hemisphere, except for superior and transverse temporal gyri, calcarine fissure and frontopolar regions. Primary sensory function may be less functionally dependent on thalamic connections than heteromodal and paralimbic areas, which have connections with several thalamic nuclei. The extensive cortical hypometabolism due to diaschisis may have been responsible for the severity of the aphasia, whereas the less severe reduction of metabolism in the superior and transverse temporal gyri, and also, albeit less evident, in Broca’s area, might explain the preservation of repetition.
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