Modern concepts of treatment of phantom limb pain

Abstract

Phantom limb pain is a specific entity of neuropathic pain that develops in 30%85% of patients with amputated limbs and leads to considerable worsening of the quality of life. The number of such cases increases during military conflicts. It can be caused by a traumatic amputation due to mine blast injury, peculiarities of provided medical assistance, and the special psychological state of casualties being in extremely stressful situations at the moment of wounding. Phantom limb pain development is accompanied by multiple functional and structural changes at different levels of the peripheral and central nervous systems. As a result, different theories of pathogenesis are proposed. However, at present, no final opinion concerns mechanisms of phantom limb pain development. Although different versions of drug and non-drug therapy have been suggested, none of them turned out to be universal and fully effective. Many medications were found to be linked to phantom limb pain pathogenesis; however, even first-line therapy drugs (non-steroidal anti-inflammatory drugs, tricyclic antidepressants, narcotic analgesics, and anticonvulsants) often fail to provide adequate analgesia. Long-term prescription of narcotic analgesics is at risk of the development of addictive disorders. Surgical interventions have not demonstrated their effectiveness as well. Thus, their use is justified only in the case of ineffective conservative treatment. Poor efficacy of conventional concepts of phantom limb pain treatment led to the use of new means such as botulinum toxin therapy, non-drug methods (psychotherapy, mirror therapy, biological feedback, virtual reality, acupuncture, massage, hypnosis, etc.). Thus, the search for original methods based on the development and introduction of new drug therapy schemes is imperative. A possible solution to this problem is not only creating absolutely new non-opioid analgesics but also using adjuvant therapeutic means in the multimodality schemes of analgesia. The latter promotes neurotransmission in the antinociceptive system and potentiates the effect of traditional analgesics.