Phantom limb pain.
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Electric Stimulation↗
Biomedical subjects
E Huse
Publications and source records attributed to E Huse.
The effect of opioids on phantom limb pain and cortical reorganization.
The efficacy of oral retarded morphine sulphate (MST) was tested against placebo in a double-blind crossover design in 12 patients with phantom limb pain after unilateral leg or arm amputation. Two counterbalanced treatment phases of 4 weeks each were initiated with an intravenous test infusion of MST or Placebo. The titration phase was 2 weeks. The dose of MST was titrated to at least 70 mg/day and at highest 300 mg/day. Pain intensity was assessed hourly on visual analog scales during a 4-week treatment-free phase, both treatment phases and at two follow-ups (6 and 12 months). Reorganization of somatosensory cortex, electric perception and pain thresholds as well as selective attention were measured pre- and post-treatment. A significant pain reduction was found during MST but not during placebo. A clinically relevant response to MST (pain reduction of more than 50%) was evident in 42%, a partial response (pain reduction of 25-50%) in 8% of the patients. Neuromagnetic source imaging of three patients showed initial evidence for reduced cortical reorganization under MST concurrent with the reduction in pain intensity. Perception and pain thresholds were not significantly altered whereas attention was significantly lower under MST. Thus, opioids show efficacy in the treatment of phantom limb pain and may potentially influence also cortical reorganization. These data need to be replicated in larger patient samples.
Adult↗
[The phantom and stump phenomena interview (PSPI)].
RESEARCH QUESTION: A structured German-language interview was developed for the assessment of painful and non-painful phantom and stump phenomena after amputation. The aim was a thorough assessment of the quality, quantity and time course of these phenomena, which is of scientific as well as therapeutic relevance. METHODS: Each phenomenon was assessed using visual analogue scales as well as qualitative descriptors adapted from the McGill Pain Inventory and from literature reports. The factor structure and psychometric properties of the interview were evaluated in a sample of 139 upper and lower limb amputees. Test-retest coefficients were obtained in a subset of 20 amputees. RESULTS: As expected, all pain-related scales showed a two-dimensional internal structure with the factors "affective pain" and "sensory pain". For the non-painful phantom sensations, three factors "general/kinesthetic phantom sensations", "phantom movements" and "paresthesias" were obtained, while for non-painful stump sensations only one general factor emerged. The internal consistency was high with respect to the pain-related scales and was still satisfying for the scales that cover nonpainful phantom and stump phenomena. All scales have sufficient validity. Test-retest coefficients suggest a satisfactory stability of all scales that assess present phenomena, while the stability of the retrospective scales is markedly lower and in some cases insufficient. CONCLUSIONS: The phantom and stump phenomena interview is a highly reliable and valid instrument to assess present perceptual phenomena after amputation. Only the included retrospective scales apparently show low stability scores over time. This raises the more general question of the validity of retrospective pain reports.
Adult↗
[Cortical reorganization and pain. Empirical findings and therapeutic implication using the example of phantom pain].
The neuroscientific research of the past years has shown that extensive plastic change occurs in the adult human brain. The functional reorganization of the somatosensory and motor maps related to phantom limb pain is described. Subsequent to deafferentation amputees with phantom limb pain show a shift of neighbouring representation zones into the deafferented zone of the somatosensory and motor cortex that can be detected with noninvasive neuroimaging methods. This reorganization of the sensory and motor maps is not found in painfree amputees and persons with congenital loss of a limb. We discuss a model of the development of phantom limb pain that incorporates both peripheral and central factors and assigns an important role to chronic pain before the amputation. The modulation of plasticity and phantom limb pain by anesthesiological interventions is described and the results of preemptive analgesia for the prevention of phantom limb pain are discussed. Opioid treatment and behaviorally relevant stimulation are effective means to eliminate phantom limb pain and cortical somatosensory pain memories.
Humans↗
Does use of a myoelectric prosthesis prevent cortical reorganization and phantom limb pain?
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Adult↗
The cortical somatotopic map and phantom phenomena in subjects with congenital limb atrophy and traumatic amputees with phantom limb pain.
The extent of the cortical somatotopic map and its relationship to phantom phenomena was tested in five subjects with congenital absence of an upper limb, four traumatic amputees with phantom limb pain and five healthy controls. Cortical maps of the first and fifth digit of the intact hand, the lower lip and the first toe (bilaterally) were obtained using neuroelectric source imaging. The subjects with congenital upper limb atrophy showed symmetric positions of the left and right side of the lower lip and the first toe, whereas the traumatic amputees with pain showed a significant shift (about 2.4 cm) of the cortical representation of the lower lip towards the hand region contralateral to the amputation side but no shift for the toe representation. In healthy controls, no significant hemispheric differences between the cortical representation of the digits, lower lip or first toe were found. Phantom phenomena were absent in the congenital but extensive in the traumatic amputees. These data confirm the assumption that congenital absence of a limb does not lead to cortical reorganization or phantom limbs whereas traumatic amputations that are accompanied by phantom limb pain show shifts of the cortical areas adjacent to the amputation zone towards the representation of the deafferented body part.
Adult↗