截肢者幻肢感覺探討與新型幻肢疼痛治療之研究

Abstract

截肢病人在截掉肢體後，60%~80%的人會發生幻肢疼痛或幻肢感覺的現象，但目前真正的機轉仍然不清楚。目前解釋幻肢疼痛的主要理論認為幻肢疼痛是由於中樞神經調適不良所引起，但這個理論仍然無法解釋有關幻肢感覺與許多幻肢現象，且沒有一個標準有效的方法來治療幻肢痛，許多病人仍然被幻肢痛所困擾。 在本論文研究中，我們在病人的”幻肢處”，即已經截掉肢體的地方，使用遠紅外線照射，發現可以使截肢病人產生幻肢感覺。由此，我們提出一個新的幻肢痛治療方法，即使用遠紅外線直接照射截肢者的幻肢疼痛處。經由16個截肢病人的臨床試驗，看出此一新的治療方法對於幻肢疼痛有很好的止痛效果。在不到8次的治療，幻肢疼痛的強度VAS(Visual Analogue Pain Scale) 下降了50%~100%， 幻肢痛的時間縮短了80%~100%。同時我們發現幻肢痛的強度與時間均隨著治療次數的增加而下降。整體幻肢痛的強度VAS從未治療前的5.6 ± 3.1降至治療後的0.9 ± 0.8。另外，經由6年的追蹤調查，此一新療法並未出現任何副作用。 為了探索背後可能的機制，我們使用遠紅外線照射截肢病人的幻肢腳底處與一般健康受試者的腳底。結果顯示，當截肢病人的幻肢照射遠紅外線(FIR)時可引起脾經、腎經與膀胱經的經絡反應，但在假照射時(sham FIR)則無此經絡反應。同時，健康受試者也在脾經、腎經與膀胱經上有顯著的經絡反應，顯示不論肢體的存在與否，照射遠紅外線於”腳底”的經絡反應都是一樣的。此一結果暗示經絡系統可能還存在於幻肢處，並扮演著與身體溝通的可能角色之一。 此外，截肢病人在照射遠紅外線前，其幻肢通常有緊繃、麻痺的不舒服感覺。而在遠紅外線治療後，其幻肢會有舒緩放鬆的感覺。此一放鬆的感覺，在初步的靜息態的功能性磁振造影中得到印證，我們發現在受試者的後中央廻（即大腦皮質感覺區）與整個大腦功能性的連結數明顯減少。此一結果顯示，於幻肢處照射遠紅線，也可以引起中樞神經的反應。 本研究與以往治療幻肢痛的方法最大的不同在於我們直接於”幻肢處”探索幻肢感覺與幻肢疼痛，此一地方正是幾百年來截肢者宣稱幻肢痛真正產生的地方。我們創新的遠紅外線療法在臨床上證實了它能有效的舒緩截肢者的幻肢疼痛，為治療幻肢痛帶來新的曙光。同時，研究的結果與發現，也可以對人體結構的研究帶來新的啟發。

About 60%~80% of amputees experience phantom limb pain or phantom limb sensation, but the real mechanism is still unclear. One of the theories for phantom limb pain argues that the phantom limb pain is due to the maladaptive plasticity in the central nervous system. However, many phantom limb phenomena including phantom limb sensation still can not be clarified. At present, there is no effective therapy to treat phantom limb pain. Many amputees are still suffering from the phantom limb pain. In this study, we discovered that phantom limb sensation could be induced by applying far infrared ray (FIR) at the phantom limb site, i.e., the location of the amputated absent limb. Accordingly, we proposed a new therapy for phantom limb pain. We applied FIR directly to the phantom pain site specified by the amputee. The results showed that this novel therapy was very effective for phantom pain relief through clinical trials of 16 patients. This therapy quickly reduced the phantom pain for all patients, with 50%-100% decrease of VAS (Visual Analogue Pain Scale) after less than eight treatments while the phantom pain duration shortened 80%-100%. In addition, we also found the dose-response between the analgesic effect and the number of treatments. The VAS dropped from 5.6 ± 3.1 to 0.9 ± 0.8 for all subjects following this new therapy. Further, the side effects have not been observed or reported for patients up to six-year post-treatment follow-ups. We also applied FIR to the ‘phantom sole’ in amputee group and the corresponding ‘intact sole’ in healthy group. By comparing the responses to FIR and sham FIR in patients, we found that meridian responses could be induced by applying FIR at the phantom limb site. In addition, significant responses of 3 meridians that were spleen, kidney and urinary-bladder meridians running through the lower limb in the healthy group were also observed for the corresponding meridians in patient group, implying that the meridian system might be present in the ‘phantom limb’ and help communicate between the ‘phantom limb’ and the intact body. The preliminary resting fMRI result showed a significant decrease of the functional connectivity in the amputee’s postcentral gyrus, indicating a reduction of phantom sensation, in agreement with the amputee’s perception, from a tight and numb to relaxed state after the FIR treatment at the phantom limb site. This result showed that the central nervous system could be activated by applying FIR at the phantom limb site. What really makes this study differ from all current treatments for phantom limb pain is that we reconsider the role of the ‘phantom limb’ at the absent limb site that have been claimed as the origin of the phantom limb pain for hundreds of years by amputees. The results showed that this innovative FIR therapy was very effective for treating the phantom limb pain. Meanwhile, the discovery in this study might inspire researchers to explore the unknown communication system for the 'invisible, amputated part’of human body.