Key Laboratory of Brain Functional Genomics (MOE and Shanghai), Institute of Cognitive Neuroscience, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China.
Department of Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
J Int Med Res. 2024 Sep;52(9):3000605241265338. doi: 10.1177/03000605241265338.
Functional MRI (fMRI) is gaining importance in the preoperative assessment of language for presurgical planning. However, inconsistencies with the Wada test might arise. This current case report describes a very rare case of an epileptic patient who exhibited bilateral distribution (right > left) in the inferior frontal gyrus (laterality index [LI] = -0.433) and completely right dominance in the superior temporal gyrus (LI = -1). However, the Wada test revealed a dissociation: his motor speech was located in the left hemisphere, while he could understand vocal instructions with his right hemisphere. A clinical implication is that the LIs obtained by fMRI should be cautiously used to determine Broca's area in atypical patients; for example, even when complete right dominance is found in the temporal cortex in right-handed patients. Theoretically, as the spatially separated functions of motor speech and language comprehension (by the combined results of fMRI and Wada) can be further temporally separated (by the intracarotid amobarbital procedure) in this case report, these findings might provide direct support to Broca's initial conclusions that Broca's area is associated with acquired motor speech impairment, but not language comprehension . Moreover, this current finding supports the idea that once produced, motor speech can be independent from language comprehension.
功能磁共振成像（fMRI）在术前语言评估中对于手术规划越来越重要。然而，它与瓦达试验可能存在不一致性。本病例报告描述了一例非常罕见的癫痫患者，其下额前回呈双侧分布（右侧>左侧）（侧化指数[LI]=-0.433），而上颞回完全右侧优势（LI=-1）。然而，瓦达试验显示存在分离：他的运动言语位于左半球，而他可以用右半球理解口头指令。这一临床发现表明，fMRI 获得的 LI 应谨慎用于确定非典型患者的布罗卡区；例如，即使在右利手患者中颞叶皮质完全右侧优势也如此。从理论上讲，由于在本病例报告中，运动言语和语言理解的空间分离功能（通过 fMRI 和瓦达试验的综合结果）可以进一步时间分离（通过颈动脉内安替比林程序），这些发现可能直接支持布罗卡最初的结论，即布罗卡区与后天性运动言语障碍有关，而与语言理解无关。此外，本研究发现支持这样一种观点，即运动言语一旦产生，就可以独立于语言理解。
