Discipline of Psychology, College of Science, Health, Engineering and Education, Murdoch University, South Street, Murdoch, WA, Australia.
Pain. 2021 Apr 1;162(4):1233-1240. doi: 10.1097/j.pain.0000000000002118.
In complex regional pain syndrome (CRPS), hyperalgesia encompasses uninjured sites on the ipsilateral side of the body and may also include the special senses because auditory discomfort often is greater on the CRPS-affected side. To determine whether this hemilateral hyperalgesia involves the visual system, the discomfort threshold to a light-source that increased in intensity at 100 lux/second from 500 to 3600 lux was investigated for each eye, and the nasal and temporal half of each visual field, in 33 patients with CRPS and 21 pain-free controls. Recent headache history was reviewed and, in patients with CRPS, sensitivity to mechanical and thermal stimuli was assessed in all 4 limbs and on each side of the forehead. In addition, the pupils were photographed in dim and bright light. The visual discomfort threshold was lower in patients than controls and was lower on the CRPS-affected than unaffected side (P < 0.001), indicating photophobia. Visual discomfort was unrelated to pupil diameter. Headache frequency was greater in CRPS patients than controls, and unilateral headaches were more likely to be on the CRPS-affected than contralateral side. Similarly, mechanical and thermal hyperalgesia was greater in the CRPS-affected than contralateral limb and was greater ipsilateral than contralateral to CRPS in the forehead and nonsymptomatic limbs. Ipsilateral photophobia was associated with mechanical and thermal hyperalgesia in the ipsilateral forehead but not the CRPS-affected limb. Together, these findings suggest that aberrant processing of nociceptive input in the ipsilateral trigeminal-medullary region of the brainstem contributes to visual discomfort in CRPS.
在复杂性区域疼痛综合征 (CRPS) 中，超敏反应包括身体同侧的未受伤部位，并且可能还包括特殊感觉，因为听觉不适通常在 CRPS 受影响的一侧更为严重。为了确定这种偏侧性超敏反应是否涉及视觉系统，我们研究了 33 名 CRPS 患者和 21 名无痛对照者的每只眼睛和每个视野的鼻侧和颞侧，以确定对光源的不适感阈值，该光源的强度从 500 勒克斯/秒增加到 100 勒克斯/秒，增加到 3600 勒克斯。回顾了最近的头痛病史，并在所有 4 肢和前额的每一侧评估了 CRPS 患者的机械和热刺激敏感性。此外，在弱光和强光下拍摄了瞳孔照片。患者的视觉不适阈值低于对照组，CRPS 受累侧低于未受累侧（P <0.001），表明畏光。视觉不适与瞳孔直径无关。CRPS 患者的头痛频率高于对照组，单侧头痛更可能发生在 CRPS 受累侧而不是对侧。同样，CRPS 受累侧的机械和热超敏反应大于对侧，前额和无症状肢体的同侧大于对侧。同侧畏光与同侧前额的机械和热超敏反应有关，但与 CRPS 受累侧无关。这些发现表明，脑干同侧三叉神经-髓质区域对伤害性输入的异常处理导致 CRPS 中的视觉不适。
