[Referred pain from amputation stump trigger points into the phantom limb]. / Auslösung von Phantomschmerzen und -sensationen durch muskuläre Stumpftriggerpunkte nach Beinamputationen.

OBJECTIVES: The aim of the study was to examine whether/how myofascial stump trigger points (TPs) after lower leg amputations are able to produce stump pain (SP), phantom pain (PP), and sensations (PS) in the phantom limb. METHODS: Palpation of the 5 most striking stump TPs of 30 leg amputees (12 transfemoral, 18 transtibial) was documented in a standardized manner. Patients were asked to localize SP, PP, and PS. RESULTS: Of 150 TPs, 14 produced involuntary stump movements and 10 stump fasciculations. Dorsal PP after ventral TP palpation occurred as well as PP in the toes from TPs near the hip. Of 30 patients, 20 reported PS and 8 PP; 60 of 150 TPs produced PS and 17 PP. Phantom phenomena were localized in 62.8% in the toes (1st toe 19.8%, toes 2-5 about 10% each), 17.9% midfoot, and the rest were more proximal. TPs were localized more in the lateral/dorsal stump than medial/ventral. About 70% of the TPs were found between 3 and 7 cm from the stump end, those with toe projections more distal than those with tibial projections. CONCLUSIONS: Myofascial TPs in amputation stumps are common and able to produce sensations and pain in the phantom limb. Most reported experiences were localized in the toes, as phantom pain usually is. There seems to be a "stump representation" and it seems possible that "referred TP pain" and "phantom pain" may develop from similar origin.

[Long-term treatment of phantom- and stump pain with Botulinum toxin type A over 12 months. A first clinical observation]. / Langszeitbehandlung von Phantom- und Stumpfschmerzen mit Botulinumtoxin Typ A über 12 Monate. Eine erste klinische Beobachtung.

Recently we were able to describe the successful treatment of phantom pain and stump pain with botulinum toxin A in a first pilot study. This case report over a 1-year period now demonstrates that long-term treatment for this indication is possible. We injected 4 x 25 IU of botulinum toxin A (Botox) into trigger points of the stump muscles of a lower limb amputee who suffered from severe phantom and stump pain. With four injections performed every 3 months, the patient became almost completely pain-free, and his intrathecal morphine therapy could be reduced to 40% of the initial dose. Intrathecal clonidine was eliminated completely, as were the oral analgesics. A surgical treatment suggested for the stump pain was no longer necessary, and we suppose that botulinum toxin can also improve the tolerance of artificial limbs in cases of stump pain.

[Treatment of phantom pain with botulinum-toxin A. A pilot study]. / Botulinum-Toxin-A in der Behandlung von Phantomschmerzen. Eine Pilotstudie.

BACKGROUND: Therapy of phantom pain following amputation is still difficult, since pathophysiological mechanisms are not clarified. Botulinum-toxin A never has been used for this issue. We report four successfully treated cases with chronic phantom pain longer than 3 years. METHODS: We injected 100 IU botulinum-toxin A (4x25 IU in 0,5 ml preservative-free saline 0.9%) in four muscle-triggerpoints of the amputation stump of each patient. All triggerpoints were painful to compression before injection, all patients reported referred sensations in the phantom-foot from at least one of them. Controls were performed by questioning and pain-diaries after 1,2 and 5 weeks. RESULTS: In all cases phantom pain was reduced about 60-80%. The three patients, who had pain attacks, reported a dramatically reduction of the number of attacks (about 90%). In two of them duration of attacks shortened from 120 to 5-10 min and a reduction of pain intensity from VAS 9 to VAS 1 and VAS 9 to VAS 2 was reported. Disorder of sleep disappeared in both affected patients within 2-3 weeks. Three patients,who could move the phantom foot (mental), had a subjective weakness a few days after botulinum-toxin A injection; in one case although injection was performed in the muscles of the femur! CONCLUSIONS: This is the first report of the use of botulinum-toxin A in the treatment of phantom pain. The contribution of the muscles in the cause of phantom pain is unclear and may be local, as a trigger of spinal reflexes or by modulation of "cortical reorganisation" after amputation. Botulinum-toxin A could work analgesic by the relaxation of the stump muscles or by modulation of neuronal transmitters, for example substance P, with an indirect influence of the CNS.