Hozumi Jun, Sumitani Masahiko, Yozu Arito, Tomioka Toshiya, Sekiyama Hiroshi, Miyauchi Satoru, Yamada Yoshitsugu
Department of Anesthesiology and Pain Relief Center, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Anesthesiol Res Pract. 2011;2011:984281. doi: 10.1155/2011/984281. Epub 2011 May 22.
Neural blockades are considered an alternative to pharmacotherapy for neuropathic pain although these blockades elicit limited effects. We encountered a patient with postbrachial plexus avulsion injury pain, which was refractory to conventional treatments but disappeared temporarily with the administration of the local anesthetic lidocaine around the left mandibular molar tooth during dental treatments. This analgesic effect on neuropathic pain by oral local anesthesia was reproducible. Under conditions of neuropathic pain, cerebral somatotopic reorganization in the sensorimotor cortices of the brain has been observed. Either expansion or shrinkage of the somatotopic representation of a deafferentated body part correlates with the degree of neuropathic pain. In our case, administration of an oral local anesthetic shrank the somatotopic representation of the mouth, which is next to the upper limb representation and thereby expanded the upper limb representation in a normal manner. Consequently, oral local anesthesia improved the pain in the upper limb. This case suggests that pain alleviation through neural plasticity within the brain is related to neural blockade.
神经阻滞被认为是治疗神经性疼痛的药物治疗的替代方法，尽管这些阻滞的效果有限。我们遇到一名臂丛神经撕脱伤后疼痛的患者，这种疼痛对传统治疗无效，但在牙科治疗期间，在左下颌磨牙周围注射局部麻醉剂利多卡因后疼痛暂时消失。口服局部麻醉对神经性疼痛的这种镇痛作用是可重复的。在神经性疼痛的情况下，已观察到大脑感觉运动皮层的脑躯体感觉定位重组。去传入身体部位的躯体感觉表征的扩大或缩小与神经性疼痛的程度相关。在我们的病例中，口服局部麻醉剂使紧邻上肢表征的口腔的躯体感觉表征缩小，从而以正常方式扩大了上肢表征。因此，口服局部麻醉改善了上肢疼痛。该病例表明，通过大脑内神经可塑性实现的疼痛缓解与神经阻滞有关。
