Nitrini Ricardo, Lucato Leandro T, Sitta Maria C, Oliveira Maíra O, de Andrade Daniel Ciampi, Silva Valquiria A, Carneiro Camila G, Buchpiguel Carlos A
Department of Neurology, University of São Paulo Medical School, São Paulo, SP, Brazil.
Department of Radiology, University of São Paulo Medical School, São Paulo, SP, Brazil.
Dement Neuropsychol. 2019 Apr-Jun;13(2):244-249. doi: 10.1590/1980-57642018dn13-020015.
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.
丘脑性失语症患者几乎总能保留重复词语的能力。丘脑性失语症及其重复能力保留的病理生理学机制尚未完全明确。在一例左侧丘脑出血后出现严重失语但保留重复能力的病例中，磁共振成像（MRI）显示左侧丘脑病变以及左侧半卵圆中心各向异性分数降低。氟代脱氧葡萄糖正电子发射断层扫描（FDG-PET）显示左侧大脑半球严重代谢减退，但颞上回、颞横回、距状裂和额极区除外。与丘脑的几个核团有联系的异模态和边缘旁区域相比，初级感觉功能在功能上对丘脑连接的依赖性可能较小。由于远隔性机能障碍导致的广泛皮质代谢减退可能是造成失语症严重程度的原因，而颞上回和颞横回以及布罗卡区代谢减退程度较轻（尽管不太明显），这可能解释了重复能力的保留。
