Brodtmann Amy, Puce Aina, Darby David, Donnan Geoffrey
Behavioural Neuroscience, Florey Institute for Neuroscience and Mental Health, University of Melbourne Melbourne, VIC, Australia.
Department of Psychological and Brain Sciences, Indiana University Bloomington, IN, USA.
Front Hum Neurosci. 2015 Apr 28;9:224. doi: 10.3389/fnhum.2015.00224. eCollection 2015.
The extent of visual cortex reorganization following injury remains controversial. We report serial functional magnetic resonance imaging (fMRI) data from a patient with sequential posterior circulation strokes occurring 3 weeks apart, compared with data from an age-matched healthy control subject. At 8 days following a left occipital stroke, contralesional visual cortical activation was within expected striate and extrastriate sites, comparable to that seen in controls. Despite a further infarct in the right (previously unaffected hemisphere), there was evolution of visual cortical reorganization progressed. In this patient, there was evidence of utilization of peri-infarct sites (right-sided) and recruitment of new activation sites in extrastriate cortices, including in the lateral middle and inferior temporal lobes. The changes over time corresponded topographically with the patient's lesion site and its connections. Reorganization of the surviving visual cortex was demonstrated 8 days after the first stroke. Ongoing reorganization in extant cortex was demonstrated at the 6 month scan. We present a summary of mechanisms of recovery following stroke relevant to the visual system. We conclude that mature primary visual cortex displays considerable plasticity and capacity to reorganize, associated with evolution of visual field deficits. We discuss these findings and their implications for therapy within the context of current concepts in visual compensatory and restorative therapies.
损伤后视觉皮层重组的程度仍存在争议。我们报告了一名间隔3周先后发生后循环卒中的患者的系列功能磁共振成像（fMRI）数据，并与一名年龄匹配的健康对照受试者的数据进行了比较。在左侧枕叶卒中8天后，对侧视觉皮层激活位于预期的纹状和纹外区域，与对照组所见相当。尽管右侧（先前未受影响的半球）进一步发生梗死，但视觉皮层重组仍在进展。在该患者中，有证据表明梗死灶周围区域（右侧）被利用，并且在纹外皮层包括外侧颞中回和颞下回募集了新的激活位点。随时间的变化在地形上与患者的病变部位及其连接相对应。首次卒中8天后显示存活视觉皮层发生重组。在6个月扫描时显示现存皮层持续重组。我们总结了与视觉系统相关的卒中后恢复机制。我们得出结论，成熟的初级视觉皮层表现出相当大的可塑性和重组能力，这与视野缺损的演变有关。我们在视觉代偿和恢复性治疗的当前概念背景下讨论这些发现及其对治疗的意义。
