Department of Pain Management, BG Universitätsklinikum Bergmannsheil GmbH, Ruhr University Bochum, Bochum, Germany Department of Neurology, BG Universitätsklinikum Bergmannsheil GmbH, Ruhr University Bochum, Bochum, Germany.
Pain. 2012 Jul;153(7):1484-1494. doi: 10.1016/j.pain.2012.04.005. Epub 2012 May 30.
Tactile acuity measured by 2-point discrimination performance is impaired in patients with complex regional pain syndrome type I (CRPS-I). This is mirrored by pain-associated shrinkage of the cortical representation of the affected limb. We investigated whether, also, more complex tactile performance assessed by a dynamic 2D-form perception task is disturbed in CRPS-I patients. Therefore, we developed a Braille-like recognition task (BT) for geometrical dot pattern identification by dynamic touch. We studied 47 healthy volunteers (Study I) and compared them to 16 CRPS-I patients (Study II). Besides recognition time and error quote of the BT, we assessed static 2-point discrimination thresholds (TPDT). In healthy subjects, the performance in the BT correlated significantly with age and TPDT. In CRPS patients, TPDT was significantly increased on the affected side compared to sex- and age-matched controls from study I (2.98 ± 0.84 mm vs 2.05 ± 0.82 mm, P<0.01). The performance in the BT was not impaired in CRPS-I patients (compared to sex- and age-matched controls from study I) and was not correlated to the TPDT. The intact 2D-form recognition ability in CRPS-I patients might be explained by intact dynamic tactile and proprioceptive functions, which appear to be uncompromised by the impaired static tactile perception, provided that the spacing of the dot pattern is above the individual tactile acuity. These intact 2D-form perception capacities may also be related to higher sensory integration functions like the visual system and intact semantic understanding, which may be spared by the cortical reorganization phenomena in CRPS-I.
两点辨别觉测量的触觉敏锐度在复杂性区域疼痛综合征 I 型（CRPS-I）患者中受损。这与受影响肢体皮质代表区域的疼痛相关收缩相吻合。我们研究了通过动态 2D 形态感知任务评估的更复杂的触觉性能是否也在 CRPS-I 患者中受到干扰。因此，我们开发了一种用于通过动态触觉识别几何点模式的盲文识别任务（BT）。我们研究了 47 名健康志愿者（研究 I），并将其与 16 名 CRPS-I 患者（研究 II）进行了比较。除了 BT 的识别时间和错误率外，我们还评估了静态两点辨别阈值（TPDT）。在健康受试者中，BT 的表现与年龄和 TPDT 呈显著相关。在 CRPS 患者中，与来自研究 I 的年龄和性别匹配的对照组相比，受影响侧的 TPDT 显著增加（2.98 ± 0.84 mm 比 2.05 ± 0.82 mm，P<0.01）。CRPS-I 患者的 BT 表现未受损（与来自研究 I 的年龄和性别匹配的对照组相比），且与 TPDT 无关。CRPS-I 患者中未受损的 2D 形态识别能力可能归因于未受损的动态触觉和本体感觉功能，这些功能似乎不受受损的静态触觉感知的影响，前提是点模式的间距高于个体的触觉敏锐度。这些完整的 2D 形态感知能力也可能与更高的感觉整合功能（如视觉系统）和完整的语义理解有关，这些功能可能在 CRPS-I 中的皮质重组现象中得以保留。
