Di Pietro Flavia, Stanton Tasha R, Moseley G Lorimer, Lotze Martin, McAuley James H
Neuroscience Research Australia, Sydney, Australia ; Faculty of Medicine, University of New South Wales, Sydney, Australia; Department of Anatomy and Histology, Sydney Medical School, University of Sydney.
Hum Brain Mapp. 2015 Feb;36(2):508-18. doi: 10.1002/hbm.22643. Epub 2014 Sep 26.
It is widely accepted that complex regional pain syndrome (CRPS) is associated with shrinkage of the primary somatosensory cortex (S1) representation of the affected limb. However, supporting evidence is surprisingly limited and may be compromised by high risk of bias. This study compared the S1 spatial representation of the hand in 17 patients with upper-limb CRPS to 16 healthy controls, using functional MRI. Innocuous vibration was delivered to digits one (D1) and five (D5) in a block-design. Resultant activation maxima were located within a bilateral S1 mask, determined a priori. Distance between D1 and D5 activation maxima, calculated for both hands, was used as a measure of S1 representation. Analyses were blinded to group and hand. In patients, S1 representation was smaller for the affected hand than it was for the healthy hand (t(11) = 2.02, P = 0.03), as predicted. However, S1 representation of the affected hand was no different to that of either hand in controls. Critically, S1 representation of the healthy hand of patients was larger than that of controls' hands. CRPS seems to be associated with an enlarged representation of the healthy hand, not a smaller representation of the affected hand. These findings raise important questions about neuroplasticity in CRPS.
人们普遍认为，复杂性区域疼痛综合征（CRPS）与患肢初级体感皮层（S1）表征的萎缩有关。然而，支持证据出奇地有限，而且可能因高偏倚风险而受到影响。本研究使用功能磁共振成像，比较了17例上肢CRPS患者与16名健康对照者手部的S1空间表征。采用组块设计，将无害振动施加于示指（D1）和小指（D5）。最终激活最大值位于预先确定的双侧S1掩膜内。计算双手D1和D5激活最大值之间的距离，作为S1表征的一种度量。分析对分组和手的情况设盲。正如预期的那样，患者患侧手的S1表征比健侧手小（t(11) = 2.02，P = 0.03）。然而，患者患侧手的S1表征与对照组任一只手的S1表征并无差异。关键的是，患者健侧手的S1表征大于对照组手部的S1表征。CRPS似乎与健侧手表征增大有关，而非患侧手表征减小。这些发现引发了关于CRPS中神经可塑性的重要问题。
