Rosén Birgitta, Chemnitz Anette, Weibull Andreas, Andersson Gert, Dahlin Lars B, Björkman Anders
Department of Hand Surgery. Lund University, Malmö, Sweden.
J Plast Surg Hand Surg. 2012 Apr;46(2):106-12. doi: 10.3109/2000656X.2011.653257.
Injury to the peripheral nerves in the upper extremity results in changes in the nerve, and at multiple sites throughout the central nervous system (CNS). We studied the long-term effects of an injury to the median nerve in the forearm with a focus on changes in the CNS. Four patients with isolated injuries of the median nerve in their 20s were examined a mean of 14 years after the injury. Cortical activation was monitored during tactile stimulation of the fingers of the injured and healthy hand using functional magnetic resonance imaging at 3 Tesla. The neurophysiological state and clinical outcome were also examined. Activation in the primary somatosensory cortex was substantially larger during tactile stimulation of the injured hand than with stimulation of the uninjured hand. We also saw a redistribution of hemispheric dominance. Stimulation of the injured median nerve resulted in a substantially increased dominance of the contralateral hemisphere. However, stimulation of the healthy ulnar nerve resulted in a decreased dominance of the contralateral hemisphere. Neurophysiology showed low sensory amplitudes, velocity, and increased motor latency in the injured nerve. Clinically there were abnormalities predominately in the sensory domain. However, there was an overall improved mean result compared with a five year follow-up in the same subjects. The cortical changes could be the result of cortical reorganisation after a changed afferent signal pattern from the injured nerve. Even though the clinical function improved over time it did not return to normal, and neither did the cortical response.
上肢周围神经损伤会导致神经以及中枢神经系统（CNS）多个部位发生变化。我们研究了前臂正中神经损伤的长期影响，重点关注中枢神经系统的变化。对4名20多岁的孤立性正中神经损伤患者在损伤后平均14年进行了检查。使用3特斯拉的功能磁共振成像在对手指进行触觉刺激时监测皮层激活情况，同时也检查了神经生理状态和临床结果。在对受伤手的手指进行触觉刺激时，初级体感皮层的激活明显大于对未受伤手的刺激。我们还观察到半球优势的重新分布。刺激受伤的正中神经会导致对侧半球的优势明显增加。然而，刺激健康的尺神经会导致对侧半球的优势降低。神经生理学显示受伤神经的感觉振幅、速度降低，运动潜伏期增加。临床上主要在感觉领域存在异常。然而，与对同一受试者进行的五年随访相比，总体平均结果有所改善。皮层变化可能是受伤神经传入信号模式改变后皮层重组的结果。尽管临床功能随时间有所改善，但并未恢复正常，皮层反应也未恢复正常。
