Thulborn K R, Carpenter P A, Just M A
MR Research Center, University of Pittsburgh Medical Center, PA 15213, USA.
Stroke. 1999 Apr;30(4):749-54. doi: 10.1161/01.str.30.4.749.
This study was undertaken to correlate functional recovery from aphasia after acute stroke with the temporal evolution of the anatomic, physiological, and functional changes as measured by MRI.
Blood oxygenation level-dependent contrast and echo-planar MRI were used to map language comprehension in 6 normal adults and in 2 adult patients during recovery from acute stroke presenting with aphasia. Perfusion, diffusion, sodium, and conventional anatomic MRI were used to follow physiological and structural changes.
The normal activation pattern for language comprehension showed activation predominately in left-sided Wernicke's and Broca's areas, with laterality ratios of 0.8 and 0.3, respectively. Recovery of the patient confirmed as having a completed stroke affecting Broca's area occurred rapidly with a shift of activation to the homologous region in the right hemisphere within 3 days, with continued rightward lateralization over 6 months. In the second patient, in whom mapping was performed fortuitously before stroke, recovery of a Wernicke's aphasia showed a similar increasing rightward shift in activation recruitment over 9 months after the event.
Recovery of aphasia in adults can occur rapidly and is concomitant with an activation pattern that changes from left to a homologous right hemispheric pattern. Such recovery occurs even when the stroke evolves to completion. Such plasticity must be considered when evaluating stroke interventions based on behavioral and neurological measurements.
本研究旨在将急性卒中后失语症的功能恢复与通过MRI测量的解剖、生理和功能变化的时间演变相关联。
使用血氧水平依赖对比和回波平面MRI对6名正常成年人和2名急性卒中后出现失语症正在恢复的成年患者的语言理解能力进行映射。使用灌注、扩散、钠和传统解剖MRI来跟踪生理和结构变化。
语言理解的正常激活模式显示主要在左侧韦尼克区和布洛卡区激活，偏侧化比率分别为0.8和0.3。被确认为影响布洛卡区的完全性卒中患者的恢复迅速，在3天内激活转移到右半球的同源区域，并在6个月内持续向右偏侧化。在第二名患者中，在卒中前偶然进行了映射，韦尼克失语症的恢复在事件发生后9个月内显示出类似的激活募集向右增加的偏移。
成人失语症的恢复可能迅速发生，并且伴随着激活模式从左侧向右侧同源模式的变化。即使卒中发展为完全性卒中，这种恢复也会发生。在基于行为和神经学测量评估卒中干预措施时，必须考虑这种可塑性。
