Oelschläger M, Pfannmöller J, Langner I, Lotze M
Functional Imaging Unit, Center for Diagnostic Radiology, University of Greifswald, Greifswald, Germany.
Department of Trauma and Orthopaedic Surgery, University of Greifswald, Greifswald, Germany.
Restor Neurol Neurosci. 2014;32(4):507-15. doi: 10.3233/RNN-130380.
The primary somatosensory cortex (S1) is somatotopically reorganized after limb amputation. The duration of the amputation, the intensity of phantom limb pain but also a multifactoral model of altered cerebral input have been discussed to be associated with cortical changes. Patients with finger amputation rarely show phantom limb pain, the deafferented cortical area is small but other fingers might well overtake function.
We selected a group of index finger amputated patients and performed a high resolution (in plane: 1.5 mm2) S1-mapping during tactile stimulation of finger tips.
We found an interhemispheric imbalance of the distance between the thumb and middle finger only for the patient-group. When patients used their middle finger more they showed less interhemispheric imbalance, increased spatial tactile discrimination and increased fMRI-activation in response to stimulation. Phantom limb pain was not associated with somatotopic representation parameters in S1.
Overall, our fMRI-data point to a usage dependent plasticity of Brodmann's area 3b in man.
肢体截肢后，主要体感皮层（S1）会发生躯体感觉重组。截肢持续时间、幻肢痛强度以及大脑输入改变的多因素模型都被认为与皮层变化有关。手指截肢患者很少出现幻肢痛，去传入皮层区域较小，但其他手指可能会很好地接管功能。
我们选择了一组食指截肢患者，并在指尖触觉刺激期间进行了高分辨率（平面内：1.5平方毫米）的S1映射。
我们发现仅在患者组中，拇指与中指之间的距离存在半球间不平衡。当患者更多地使用中指时，他们表现出的半球间不平衡减少，空间触觉辨别能力增强，并且对刺激的功能磁共振成像激活增加。幻肢痛与S1中的躯体感觉代表参数无关。
总体而言，我们的功能磁共振成像数据表明人类布罗德曼3b区存在使用依赖性可塑性。
