- Email: [email protected]
Phantom limb pain
CORRESPONDENCE
has shifted from hospital to home care, greater emphasis needs to be placed on patients’ education and active participation in overcoming their misconceptions. More attention must be paid to the role of patients themselves in managing their own pain. Several paineducation programmes have been started in which pain patients are taught about basic principles of pain management, instructed how to report pain, and how to communicate about pain. The beneficial effects of these programmes have been characterised by means of improved pain knowledge, decreased non-adherence, reduced pain intensity, and increased adequacy of pain treatment. As long as half the terminally ill patients have moderate to severe pain, there remains sufficient reason to continue to concentrate on pain. It should become the norm that patients have access to the best level of pain relief and inadequate pain treatment should no longer be accepted.
were willing to tolerate pain even when it was substantial, to avoid troublesome side-effects. We agree that the intensity of pain for dying patients is too high and advocate the development of better pain treatments. However, these data also suggest that in trying to improve care at the end of life, we should not focus only on pain and the intensity of pain. Other things matter, and according to our data these things matter more than pain intensity to dying patients. Assessment of the quality of end-of-life care on pain intensity is a less relevant outcome measure than that of side-effects and other symptoms, such as depression, confusion, and incontinence. We agree that patients’ education about pain management needs to be a priority. Patients’ opinions of overmedication and inevitable addiction are counterproductive to achieving satisfactory treatment. Indeed, patients need to be informed that pain relief can be achieved and in a way that does not result in many of the feared side-effects.
Rianne de Wit
*Stefan C Weiss, Linda L Emanuel, Diane L Fairclough, Ezekiel J Emanuel
University Hospital Rotterdam, Pain Expertise Center-Dijkzigt Hospital; Molewaterplein 40, 3015 GD Rotterdam, The Netherlands (e-mail: [email protected]) 1
2
3
4
5
Weiss SC, Emanuel LL, Fairclough DL, Emanuel EJ. Understanding the experience of pain in terminally ill patients. Lancet 2001; 357: 1311–15. Ahmedzai SM. Window of opportunity for pain control in the terminally ill. Lancet 2001; 357: 1304–05. De Wit R, Van Dam F, Huijer Abu-Saad H, et al. Empirical comparison of frequently used measures to evaluate pain treatment in cancer patients with chronic pain. J Clin Oncol 1999; 17: 1280–87. De Wit R, Van Dam F, Loonstra S, et al. The Amsterdam pain management index compared to eight frequently used outcome measures to evaluate the adequacy of pain treatment in cancer patients with chronic pain. Pain 2001; 91: 339–49. De Wit R, Van Dam F, Zandbelt L, et al. A pain education program for chronic cancer patients: follow-up results from a randomized controlled trial. Pain 1997; 73: 55–69.
Authors’ reply Sir—Rianne de Wit suggests that objective measures rather than patients’ satisfaction should be used to assess pain. The most important outcome at the end of life is the actual measure of patients’ experiences, because that is what must be at the optimum in the last days of life. Objective measures that do not correlate with experiences patients deem important are distracting; they frequently make physicians focus on making the numbers better rather than improving the lives of patients. Contrary to the prevailing emphasis on pain as the key outcome for end-oflife care, we noted that most patients
THE LANCET • Vol 358 • September 22, 2001
*Department of Clinical Bioethics, Warren G Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA; Northwestern University School of Medicine, Chicago, IL; and Center for Research Methodology and Biometrics, AMC Cancer Research Center, Denver, CO
Phantom limb pain Sir—Herta Flor and colleagues (June 2, p 1763)1 report that sensory discrimination training applied to the stump of upper-limb amputees effectively reduces phantom limb pain and cortical reorganisation. Data from an experimental study from our laboratory supports the beneficial effect of somatosensory training in the treatment of phantom limb pain. As noted by Flor and colleagues, phantom limb pain is closely associated with neuroplastic changes in the primary somatosensory cortex. In upper-extremity amputees, the region adjacent to the deafferented region invades the region formerly representing the amputated limb. Based on the assumption that the adjacent face and residual limb region invade the zone that formerly represented the amputated limb, we constructed a device that provides continuous innocuous tactile stimulation to the stump and lip. Stimulation was applied asynchronously at 1–10 Hz to support a segregation of the representation of both regions.2 Six patients with unilateral upperlimb amputation self-monitored their phantom limb pain intensity for 4 weeks before treatment. Pain ratings
were done hourly—by use of a 10 cm visual analogue scale. Patients then participated in an intensive 2-week treatment programme of asynchronous tactile stimulation of the residual limb and lip. Three daily treatment sessions of 60 min were scheduled. Before and after the stimulation, tactile v-Frey-Hair and two-point discrimination perception thresholds were measured. We analysed cortical reorganisation of the lip representation in the somatosensory cortex by recording cortical magnetic evoked fields with a 151-channel wholehead magnetoencephalographic system, during passive pneumatic stimulation of the lower lip of both sides.3 For each early magnetic field, a single equivalent current dipole was fitted for the latency with the highest amplitude (latency range 70–90 ms). We noted a significant reduction in phantom limb pain after treatment. Sensory perception improved at the stimulated sites compared with the contralateral side after treatment. We observed an increase of the lip dipole moment in five of six patients after the 2week training, which is consistent with a functional enlargement of the cortical representation.4 The expansion of the lip representation was significantly positively correlated with the reduction in a combined measure of the intensity, frequency, and duration of pain attacks. Unlike Flor and colleagues, we used asynchronous residual limb and lip stimulation and therefore expected a segregation of the cortical representations of both stimulated body parts, a hypothesis confirmed by the neuroimaging results. Thus, the application of long-term asynchronous tactile stimulation to the cortical zones adjacent to the deafferented representation might be effective for alteration of cortical reorganisation and phantom limb pain. Ellena Huse, *Hubert Preissl, Wolfgang Larbig, Niels Birbaumer Institute of Medical Psychology and Behavioral Neurobiology, and *MEG-Center, University of Tübingen, 72076 Tübingen, Germany; and Dipartimento di Psicologia Generale, Università di Padova, Padova, Italy (e-mail: [email protected]) 1
2
3
4
Flor H, Denke C, Schaefer M, Grüsser S. Effect of sensory discrimination training on cortical reorganisation and phantom limb pain. Lancet 2001; 357: 1763. Wang X, Merzenich MM, Sameshima K, Jenkins WM. Remodelling of hand representation in adult cortex determined by timing of tactile stimulation. Nature 1995; 378: 71–75. Huse E, Larbig W, Flor H, Birbaumer N. The effects of opioids on phantom limb pain and cortical reorganization. Pain 2001; 90: 47–55. Elbert T, Pantev C, Wienbruch C, Rockstroh B, Taub E. Increased cortical representations of the fingers of the left hand in string players. Science 1995; 270: 305–07.
1015
For personal use. Only reproduce with permission from The Lancet Publishing Group.
has shifted from hospital to home care, greater emphasis needs to be placed on patients’ education and active participation in overcoming their misconceptions. More attention must be paid to the role of patients themselves in managing their own pain. Several paineducation programmes have been started in which pain patients are taught about basic principles of pain management, instructed how to report pain, and how to communicate about pain. The beneficial effects of these programmes have been characterised by means of improved pain knowledge, decreased non-adherence, reduced pain intensity, and increased adequacy of pain treatment. As long as half the terminally ill patients have moderate to severe pain, there remains sufficient reason to continue to concentrate on pain. It should become the norm that patients have access to the best level of pain relief and inadequate pain treatment should no longer be accepted.
were willing to tolerate pain even when it was substantial, to avoid troublesome side-effects. We agree that the intensity of pain for dying patients is too high and advocate the development of better pain treatments. However, these data also suggest that in trying to improve care at the end of life, we should not focus only on pain and the intensity of pain. Other things matter, and according to our data these things matter more than pain intensity to dying patients. Assessment of the quality of end-of-life care on pain intensity is a less relevant outcome measure than that of side-effects and other symptoms, such as depression, confusion, and incontinence. We agree that patients’ education about pain management needs to be a priority. Patients’ opinions of overmedication and inevitable addiction are counterproductive to achieving satisfactory treatment. Indeed, patients need to be informed that pain relief can be achieved and in a way that does not result in many of the feared side-effects.
Rianne de Wit
*Stefan C Weiss, Linda L Emanuel, Diane L Fairclough, Ezekiel J Emanuel
University Hospital Rotterdam, Pain Expertise Center-Dijkzigt Hospital; Molewaterplein 40, 3015 GD Rotterdam, The Netherlands (e-mail: [email protected]) 1
2
3
4
5
Weiss SC, Emanuel LL, Fairclough DL, Emanuel EJ. Understanding the experience of pain in terminally ill patients. Lancet 2001; 357: 1311–15. Ahmedzai SM. Window of opportunity for pain control in the terminally ill. Lancet 2001; 357: 1304–05. De Wit R, Van Dam F, Huijer Abu-Saad H, et al. Empirical comparison of frequently used measures to evaluate pain treatment in cancer patients with chronic pain. J Clin Oncol 1999; 17: 1280–87. De Wit R, Van Dam F, Loonstra S, et al. The Amsterdam pain management index compared to eight frequently used outcome measures to evaluate the adequacy of pain treatment in cancer patients with chronic pain. Pain 2001; 91: 339–49. De Wit R, Van Dam F, Zandbelt L, et al. A pain education program for chronic cancer patients: follow-up results from a randomized controlled trial. Pain 1997; 73: 55–69.
Authors’ reply Sir—Rianne de Wit suggests that objective measures rather than patients’ satisfaction should be used to assess pain. The most important outcome at the end of life is the actual measure of patients’ experiences, because that is what must be at the optimum in the last days of life. Objective measures that do not correlate with experiences patients deem important are distracting; they frequently make physicians focus on making the numbers better rather than improving the lives of patients. Contrary to the prevailing emphasis on pain as the key outcome for end-oflife care, we noted that most patients
THE LANCET • Vol 358 • September 22, 2001
*Department of Clinical Bioethics, Warren G Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA; Northwestern University School of Medicine, Chicago, IL; and Center for Research Methodology and Biometrics, AMC Cancer Research Center, Denver, CO
Phantom limb pain Sir—Herta Flor and colleagues (June 2, p 1763)1 report that sensory discrimination training applied to the stump of upper-limb amputees effectively reduces phantom limb pain and cortical reorganisation. Data from an experimental study from our laboratory supports the beneficial effect of somatosensory training in the treatment of phantom limb pain. As noted by Flor and colleagues, phantom limb pain is closely associated with neuroplastic changes in the primary somatosensory cortex. In upper-extremity amputees, the region adjacent to the deafferented region invades the region formerly representing the amputated limb. Based on the assumption that the adjacent face and residual limb region invade the zone that formerly represented the amputated limb, we constructed a device that provides continuous innocuous tactile stimulation to the stump and lip. Stimulation was applied asynchronously at 1–10 Hz to support a segregation of the representation of both regions.2 Six patients with unilateral upperlimb amputation self-monitored their phantom limb pain intensity for 4 weeks before treatment. Pain ratings
were done hourly—by use of a 10 cm visual analogue scale. Patients then participated in an intensive 2-week treatment programme of asynchronous tactile stimulation of the residual limb and lip. Three daily treatment sessions of 60 min were scheduled. Before and after the stimulation, tactile v-Frey-Hair and two-point discrimination perception thresholds were measured. We analysed cortical reorganisation of the lip representation in the somatosensory cortex by recording cortical magnetic evoked fields with a 151-channel wholehead magnetoencephalographic system, during passive pneumatic stimulation of the lower lip of both sides.3 For each early magnetic field, a single equivalent current dipole was fitted for the latency with the highest amplitude (latency range 70–90 ms). We noted a significant reduction in phantom limb pain after treatment. Sensory perception improved at the stimulated sites compared with the contralateral side after treatment. We observed an increase of the lip dipole moment in five of six patients after the 2week training, which is consistent with a functional enlargement of the cortical representation.4 The expansion of the lip representation was significantly positively correlated with the reduction in a combined measure of the intensity, frequency, and duration of pain attacks. Unlike Flor and colleagues, we used asynchronous residual limb and lip stimulation and therefore expected a segregation of the cortical representations of both stimulated body parts, a hypothesis confirmed by the neuroimaging results. Thus, the application of long-term asynchronous tactile stimulation to the cortical zones adjacent to the deafferented representation might be effective for alteration of cortical reorganisation and phantom limb pain. Ellena Huse, *Hubert Preissl, Wolfgang Larbig, Niels Birbaumer Institute of Medical Psychology and Behavioral Neurobiology, and *MEG-Center, University of Tübingen, 72076 Tübingen, Germany; and Dipartimento di Psicologia Generale, Università di Padova, Padova, Italy (e-mail: [email protected]) 1
2
3
4
Flor H, Denke C, Schaefer M, Grüsser S. Effect of sensory discrimination training on cortical reorganisation and phantom limb pain. Lancet 2001; 357: 1763. Wang X, Merzenich MM, Sameshima K, Jenkins WM. Remodelling of hand representation in adult cortex determined by timing of tactile stimulation. Nature 1995; 378: 71–75. Huse E, Larbig W, Flor H, Birbaumer N. The effects of opioids on phantom limb pain and cortical reorganization. Pain 2001; 90: 47–55. Elbert T, Pantev C, Wienbruch C, Rockstroh B, Taub E. Increased cortical representations of the fingers of the left hand in string players. Science 1995; 270: 305–07.
1015
For personal use. Only reproduce with permission from The Lancet Publishing Group.