Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, Division of Physiotherapy, School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, Australia.
Clin J Pain. 2012 Sep;28(7):615-22. doi: 10.1097/AJP.0b013e31823e16b9.
Impaired left/right judgment of the affected body part is regarded as a disruption of the body's representation in cortical and subcortical somatosensory and motor areas and has previously been demonstrated in patients with severe neuropathic pain states. It remains unknown whether persistent but less severe pain states are sufficient to induce a similar impairment.
Twenty-seven patients with unilateral carpal tunnel syndrome (CTS) and 27 healthy matched subjects performed 4 visual left/right judgment tasks. Series of pictures of hands, feet, and necks from 4 different views were presented at 6 rotation angles. Participants had to decide as accurately and quickly as possible whether a right or left body part was presented (for hands and feet) or whether the pictured neck was rotated toward the right or left. To control for a generalized impairment in mental rotation, a recognition task for Shepard-Metzler figures was included.
Recognition time for all tasks was comparable between participants with CTS and healthy participants (P>0.47). However, participants with CTS were ∼10% less accurate in recognizing their affected hand (P=0.008). Recognition accuracy was also reduced for necks (P=0.019) but not for feet or Shepard-Metzler figures (P>0.69).
This study demonstrates that individuals with CTS present with a selective impairment in left/right judgment that is restricted to the affected quadrant. This indicates that left/right judgment is impaired in much less severe pain states than previously demonstrated. The findings are in line with previous reports, which suggested the presence of central mechanisms in patients with CTS.
受影响身体部位的左右判断受损被认为是皮质和皮质下体感和运动区域身体代表的破坏，先前已在严重神经病理性疼痛状态的患者中得到证实。目前尚不清楚持续但较轻的疼痛状态是否足以引起类似的损伤。
27 名单侧腕管综合征（CTS）患者和 27 名健康匹配的受试者进行了 4 项视觉左右判断任务。从 4 个不同视角呈现一系列手、脚和颈部的图片，旋转角度为 6 个。参与者必须尽可能准确和快速地判断是呈现了右侧还是左侧身体部位（手和脚），或者所画的颈部向右侧还是左侧旋转。为了控制心理旋转的一般性损伤，包括 Shepard-Metzler 图形的识别任务。
CTS 患者和健康参与者在所有任务的识别时间上无差异（P>0.47）。然而，CTS 患者识别其受影响手的准确性降低了约 10%（P=0.008）。对颈部的识别准确性也降低（P=0.019），但对脚部或 Shepard-Metzler 图形则没有（P>0.69）。
本研究表明，CTS 患者存在左右判断的选择性损伤，仅限于受影响的象限。这表明，左右判断在比以前显示的疼痛状态轻得多的情况下受到损害。研究结果与先前的报告一致，表明 CTS 患者存在中枢机制。
