There are approximately 4 million amputees in the United States, with at least 70% experiencing phantom pain. Unfortunately, the loss of a limb will continue to be a medical condition.1 Phantom sensation, the phenomenon of feeling the presence of a missing limb, has been well documented dating to 1551 by Ambroise Pare.2 It has generally been accepted that phantom sensation poses the amputee no discomfort or distress, but phantom pain is highly undesirable and warrants treatment; however, there has been no successful cure to date. Approximately 60% of women who undergo a mastectomy also experience phantom pain in their missing breast.3 Zuckweiler underwent a bilateral mastectomy with silicone implants at age 30 years.
Zuckweiler made the connection between body image and phantom pain and sensation when she had her ruptured silicone implants explanted with no reconstruction at age 43 years. Zuckweiler experienced phantom breast pain/sensation and found it to be extremely distressing and a hindrance to completing the grief process because the phantom pain and sensation were constant reminders of her loss. The phantom sensation was also a mental distraction that interfered with daily task efficiency because it required Zuckweiler to make a cognitive reality statement to reduce the discomfort of experiencing a sensation that did not match with reality. She developed Zuckweiler’s Image Imprinting (ZIPS) for phantom pain and sensation to treat her own and three other women’s phantom breast pain and sensation.4 The purpose of this study was to determine if ZIPS is effective in reducing phantom pain and sensation in adults after amputation.
In 1551, Ambroise Pare first described the phenomenon of phantom limb sensation. After the American Civil War, Siles Weir Mitchell wrote a classic essay about his work with 15,000 war victims who had undergone amputation of a limb. He found that phantom sensation was remarkably constant and almost universally experienced after a major amputation.5
The term “phantom sensation” has been reserved for individuals who have an awareness of the missing body part and describe it as painless and not distressing so that the medical profession has taken the position the condition does not require treatment. Phantom sensation is commonly described as numbness, pressure, tingling, and a feeling that the limb is still present. It can be activated with a simple thought or muscle movement, and for some, it is present much of their waking hours. In contrast to phantom sensation, phantom pain is described as extremely distressing and painful. Phantom pain is commonly described as cramping, burning, and sharp shooting pains.2,6
Despite the extensive research done on phantom pain and phantom sensation, the cause remains a mystery. Explanations have tended to focus on irritation to nerve endings in the residual tissue, the part of the brain that allows us to experience sensations, and psychological factors. Dr. Andres Lozano, an associate professor of surgery at the Toronto Hospital, along with a team of researchers, has discovered that the hiding place of phantom pain is in the cells that represent the missing part of the brain.7 These cells remember their old job and if they are stimulated in certain ways, they will continue to indicate that the absent part is feeling pain. Edward Taub, a psychologist at the University of Alabama, and his colleagues have found that when a limb is amputated, the sensory cortex in the brain gets rewired, and sensations from the intact body parts seem to be coming from the missing limb.1
It has been widely accepted that people who have congenital limb deficiency or have undergone amputation of a limb as a young child, do not experience phantom pain or phantom sensation. However, there is considerable research to show that this is not the case. To rule out the concern that children are not reliable reporters, one study described four cases of adult subjects who had congenital limb deficiency, in which three had phantom limb experiences after minor surgery of the residual limb and one after an accident that involved the residual limb.6 One study showed that of 125 people who had congenital limb deficiency or underwent amputation of a limb before the age of 6 years, 20% of those with congenital limb deficiency and 50% of those who underwent amputation before age 6 years experienced phantom limb.8
Most treatments for phantom pain and phantom sensation focus on producing a physiological change in the residual limb. Short-term treatment for phantom pain has been the use of drugs that increase blood flow to the limb to alleviate chronic pain or a sympathectomy, which increases blood flow to the remaining portion of the limb to decrease the burning sensation. Less invasive forms of treatment that cause physiological changes include gentle manipulation of the residual limb with massage or a vibrator, wrapping, baths, and applications of hot packs or ultrasound. Certain “trigger points” on or near the point of amputation may be injected with local anesthetics for temporary relief, so the treatment has to be repeated.9 Transcutaneous electrical nerve stimulation (TENS) has also been somewhat successful in treating phantom pain.7,10,11 Wearing an artificial limb can decrease phantom pain but may also initiate phantom pain.13
It is reasonable to assume that all physiological treatments that focus on the residual limb can offer only partial and temporary relief. Other practitioners offer alternative treatments. David L. Katz,12 a doctor of Oriental medicine and licensed acupuncturist who has a private practice in North Hollywood, California, says that after six to eight treatments of acupuncture, he can reduce a patient’s phantom pain by 80%. Neves et al.,13 at the American Institute of Hypnotherapy in Irvine, California, have been using hypnotherapy to treat phantom pain. They are using imagery and visualization through a hypnotic state to work on the subconscious mind to get control of and direct the pain. They report their approach is showing longer term success. Stemming from Taub’s discovery that the mind needs to be rewired, Vilayanur Ramachandran, a neurologist at Scripps Research Institute and the University of California at San Diego, has been able to offer relief to amputees by using a mirror box that allows the patient to “see” his or her phantom limb.14,15 Amputees slip their intact limb into a specialized box, and mirrors make it appear as if the amputated limb has appeared. This produces phantom pain relief but only while the limb is in the box.
It has been an accepted fact that phantom pain/sensation exists but cannot be treated. Many amputees are told their phantom pain and phantom sensation will go away after they have grieved their loss and reached the stage of acceptance. Patients quickly learn there is no purpose in discussing their phantom pain and phantom sensation because there is no treatment. Medical caregivers who care for amputees are in a prime position to be able to assess the level of phantom pain and phantom sensation, inform the patient that it can be treated, and make an appropriate referral for treatment. But new, less invasive treatments are needed.
A novel, noninvasive intervention for phantom pain could not be more timely in light of the new climate that is developing to make pain assessment the “fifth vital sign” and the treatment of pain essential, as a result of the 1999 Joint Commission on Accreditation of Healthcare Organizations (JCAHO) guidelines15 for pain management. The medical profession is being expected to accept that it is the right of all patients to receive the appropriate assessment and management of pain. The JCAHO guidelines have heightened the medical profession’s awareness for the need for better assessment, allowing practitioners to reject and clarify misunderstandings and myths about pain management. Internationally, the United Nations and Red Cross seek a treatment for phantom pain, as they address the needs of the children of the African diamond mines and those who come to be amputees because of natural disasters, war, or terrorism. This report describes ZIPS and reports the findings of a preliminary, pretest, and post-test intervention study.
The development of this treatment is based on a combination of cognitive behavioral16 and psychosynthesis17 theories. The theoretical framework from which this intervention was developed is based on a systems framework, in which no single part can be understood except in its relation to the whole. Symptoms are looked at as only a part of a complete imbalance in the body/mind. Individuals experience human, earthly life through their minds, emotions, and bodies. Symptoms such as pain are experienced cognitively, emotionally, spiritually, and physically. The experience of pain can be altered both by manipulating or changing the conditions in the area of the body where the person says he/she is having pain, such as the spinal nerves, and manipulating thoughts and images in the brain.
ZIPS assumes that phantom pain and phantom sensation exist because of a discrepancy between the body image held in the mind and the actual state of the body. The amputee’s physiological reaction is a response to an old body image that does not reflect the changed body. The mind needs to be reprogrammed so the body image reflects the changed body that is missing a part. Regardless of the origin of body image (whether from prolonged sensory input or partially genetically determined), mental imagery can alter the body image to influence the experience of phantom pain and phantom sensation.
ZIPS was developed and used as the treatment intervention for phantom pain/sensation for patients with an amputated limb. ZIPS is a therapeutic process that leads the patient through several steps (Table 1) in which the patient creates an accurate body image, so the mind and body sensory messaging system can return to normal functioning.
AIMS OF STUDY
After developing the ZIPS intervention, a study was conducted to determine the effectiveness of this intervention for adult amputees using a single group, pretest, and post-test design. The research question was “Does ZIPS reduce phantom pain/phantom sensation in adults post amputation?” The specific aims of this preliminary study were to:
- Determine the change in frequency of phantom pain and phantom sensation and the level of distress over phantom pain and phantom sensation from pre- to post-intervention and 3 and 6 months after intervention.
- Determine the change in perceived control over life and level of disability from pre- to post-intervention.
- Determine the association of age, time since amputation, and cause of amputation with phantom pain and phantom sensation at pre-intervention and 6 months after intervention.
- Determine the association among the number of treatments, daily practice of ZIPS, and duration of ZIPS and phantom pain/phantom sensation at 6 months post-intervention.
- Determine the association between the pre- and post-intervention perceived control over life and disability to phantom pain and phantom sensation at pre-intervention and 6 months post-intervention.
Subjects were mostly male, older than 50 years, with a leg amputation because of illness or accident. One female subject had two amputations: a leg and breast. All subjects were white and most were not employed. There was a wide range of time between amputation and the initiation of ZIPS (Table 2).
Subjects were volunteers from Winkley Orthotics & Prosthetics clientele and an amputee support group. Subjects were verbally given information about the study by the researcher. The researcher developed an informational flyer that included a telephone number to call if the individual was interested in participating. Inclusive criteria for subject selection included age older than 18 years, English speaking, absence of a portion of a limb, experiencing phantom pain and phantom sensation, desire for treatment for the phantom pain and sensation, and willingness to try a new intervention.
Subjects were interviewed and treated in the researcher’s psychotherapy office or one of the Winkley Orthotics & Prosthetics clinics. The treatment setting was the subjects’ choice.
The study was designed and conducted solely by the researcher. A pre- and post-interview questionnaire was developed by the researcher for this preliminary study (Table 3). A confidential medical file was kept on each subject, and a progress note was made after each session. Intervention sessions were tape recorded and transcribed to redirect ongoing treatment sessions, assure for accuracy, and allow for pattern identification during data summarization. Subjects were given recording logs to summarize their experiences, including the frequency with which they practiced the ZIPS outside their therapy sessions.
Each subject was seen for two 1-hour sessions and then half-hour sessions thereafter. The frequency and total number of half-hour sessions was individualized to meet the needs of the subject. Termination was mutually decided by the subject and researcher based on when the subject wished to stop or when the patient thought he/she had reached maximum benefit from the treatment. A follow-up assessment was done by telephone 3 and 6 months after the ZIPS intervention. This follow-up telephone call assessed the frequency of phantom pain and sensation and the level of distress over phantom pain and sensation.
Data were analyzed using the SPSS statistical program and interpreted by both authors and a biostatistical consultant. Coding of the phantom pain and phantom sensation frequency (Question 10 of the phantom pain assessment questionnaire) was reversed (from 1 = always and 7 = never to 0 = never and 6 = always) to facilitate interpretation of the data. Data were not normally distributed, so nonparametric statistics were used. Associations between variables of interest were assessed using Spearman’s correlations for ranked data. Friedman’s repeated measures ANOVA was used to assess change over time for ranked data. Measures with only pre- and post-intervention values were compared using Wilcoxon signed ranks test. Comparisons between independent groups were accomplished using a Mann-Whitney U test. All statistical tests of significance were two-tailed, and the confidence interval was set at 95%.
Determine the change in frequency of phantom pain and phantom sensation and level of distress over phantom pain and phantom sensation from pre-intervention to post-intervention and 3 and 6 months post-intervention.
Table 4 depicts the individual and mean pre- and post-ZIPS scores and 3- and 6-month follow-up scores of phantom pain and phantom sensation. Subjects were asked to report the frequency with which they experienced phantom pain and sensation on a 7-point scale. There was a statistically significant reduction in the frequency of both phantom pain and sensation. Subjects reported less frequent pain at the end of the ZIPS intervention compared with pain at the beginning of the intervention (Friedman’s test χ2 = 19.18, df = 3, p < 0.00), and this reduced pain continued at 6 months. There was a corresponding reduction in phantom sensation scores (Friedman’s test χ2 = 15.51, df = 3, p = 0.001) from the time of ZIPS initiation to termination, and these scores continued to drop at 3 months, with a slight increase at 6 months. Subjects were also asked to rate their level of distress about the phantom pain and sensation using a 10-point scale (0 = not at all distressed; 10 = extremely distressed). Table 5 summarizes these ratings for pre- and post-ZIPS. Subject ratings of distress about phantom pain dropped significantly from pre-ZIPS to post-ZIPS (Friedman’s test χ2 = 17.26, df = 3, p = 0.001), and distress about phantom sensation also was significantly reduced from pre- to post-ZIPS (Friedman’s test χ2 = 15.31, df = 3, p = 0.002) and continued to be less at 6 months post-ZIPS.
Determine the change in the perceived level of control over life and the level of disability from pre- to post-intervention.
There was no statistically significant difference between the pre- and post-ZIPS scores of perceived control over life (Wilcoxon signed rank test, z = −1.8, p = 0.07) and subjects’ perception of being disabled (z = −0.69, p = 0.49) (Table 6). At post-ZIPS, seven subjects reported feeling they had more control over their lives, two perceived less control, and five reported feeling the same. In terms of considering oneself disabled, at the end of ZIPS, three subjects reported feeling more disabled, four less disabled, and seven had no change.
Determine the association of age, time since amputation, and cause of amputation with phantom pain and phantom sensation at pre-intervention and 6 months post-intervention.
Table 7 shows the lack of correlation between the subjects’ age and the frequency of phantom pain and phantom sensation at post-intervention (rho = −0.39, p = 0.17, and rho = −0.31, p = 0.29, respectively) and 6 months after intervention (rho = −0.29, p = 0.32, and rho = −0.30, p = 0.30, respectively). The association between the number of years since the amputation and the frequency of phantom pain and phantom sensation was not statistically significant. However, there was a statistically significant difference between the frequency of phantom pain at 6 months and the cause of the amputation (Mann-Whitney U, z = −2.6, p = 0.02). Subjects who underwent amputation because of illness experienced less pain at 6 months than did subjects who did so because of an accident.
Determine the association among the number of treatments, duration of ZIPS intervention, and daily practicing of ZIPS, and phantom pain and phantom sensation at 6 months post-intervention.
Table 7 shows no significant correlation between the number of treatments or the duration (weeks) of ZIPS and the frequency of phantom pain or phantom sensation at 6 months post-intervention. However, for those who practiced ZIPS on a daily basis, there was a reduction in phantom sensation at 6 months that was statistically different from that of subjects who did not practice daily (Mann-Whitney U, z = −2.1, p = 0.03), but there was no correlation between daily practicing and the frequency of phantom pain.
Determine the association between pre- and post-intervention perceived control over life and level of disability at pre-intervention and 6 months post-intervention.
There was a significant correlation between subjects’ pre-intervention perception of their disability and the frequency of phantom pain (rho = 0.61, p = 0.02) at 6 months post-intervention, but not with phantom sensation (rho = 0.51, p = 0.06) as seen in Table 7. There also was a significant correlation between the subjects’ pre-intervention perception of the control they thought they had over their lives and the frequency of phantom sensation at 6 months post-intervention (rho = 0.61, p = 0.02). Subjects’ post-intervention ratings of disability and level of control showed no correlation with their 6 months post-intervention frequency of phantom pain or phantom sensation.
These findings support what was observed throughout the study, which is that phantom pain was fairly quickly treated, but phantom sensation was more difficult to influence. It took more ZIPS sessions with many changes in the images before the phantom sensation lessened in intensity and was eradicated. How the subject rated his/her level of disability before treatment proved to be an influencing factor in reducing or eliminating phantom pain but not phantom sensation, and how the subject rated his/her level of control influenced the reduction or elimination of phantom sensation, not phantom pain. Amputees who perceived themselves as less disabled and in more control were more successful in managing their phantom pain and sensation.
Although the number of treatment sessions and number of weeks during which ZIPS treatment occurred did not prove to be a factor in reducing phantom pain or sensation, letting the subjects determine their own process of mentally defining their mind/body connection and restructuring their body image seemed to be an important factor in helping them succeed. Daily practicing of ZIPS between treatments was not necessary to produce a reduction in phantom pain, but it helped to reduce phantom sensation. Working with phantom sensation involved many attempts of trying-on new ideas of images to make the mind accept that there was no longer a body part with which to communicate sensation messages. Often the subjects took away from a treatment session a new idea to “play with” on their own between sessions. This required that they practice between sessions.
The amount of time between the subject’s amputation and treatment did not matter, so ZIPS could be expected to produce a positive change in frequency of phantom pain and phantom sensation whether it is done immediately after the amputation or many years later. Findings from this study suggest that those who underwent amputation because of illness had a better outcome than did those who underwent amputation as a result of an accident. The influence of the type and cause of amputation needs additional study given the small sample size and limited types of amputations.
The length of treatment and the number of sessions proved to be insignificant factors, but daily practicing of ZIPS improved pain sensation. The key to the success of this treatment seems to be in reprogramming the mind so it has an accurate body image from which it responds to pain signals. The Scripps Research Institute’s limb mirroring box does not sustain relief of phantom pain and phantom sensation when the box is removed because the solution is being achieved by giving the mind a whole body to respond to, instead of correcting the body image to match with the altered body. All the subjects who continued sessions until they thought they had reached maximum benefit and practiced daily between sessions showed improvement in being able to eliminate phantom sensation, which is the hardest form of phantom phenomenon to treat. Initially, the successful subjects practiced between 2 and 25 times per day. Most of them practiced about 3 to 4 times a day. As the frequency of their phantom pain and phantom sensation decreased, they shifted to using ZIPS primarily when they were experiencing phantom pain or phantom sensation. Subjects did not complete and return the recording sheets of how often they practiced between sessions. Sending the forms home with them seemed to serve as a way to reinforce the importance of their homework assignment, but it was not a reliable indicator of how often they practiced. Their subjective recall indicated that frequent practice kept their motivation up and produced good results in a short period.
The content of each person’s treatment sessions was reviewed to see if there were unique features involved in the outcomes. The conclusion was that each treatment session was unique in that the subjects’ creativity with the ZIPS was essential for progress to be made. Certain types of severe pain were unique circumstances that seemed to affect the outcome of the treatment. Severe residual limb pain that occurred during the fitting period for a prosthetic limb or other forms of severe pain involving nerves to the missing body part seemed to make it very difficult for the subject to make progress in eliminating or reducing the phantom pain and phantom sensation. One elderly woman’s progress stopped when she experienced severe bladder pain that radiated down her legs, both of which were amputated just below the knees. After bladder surgery, she continued her ZIPS sessions and was able to be free of phantom pain and phantom sensation. That could suggest that the treatment for phantom pain and phantom sensation should be done before and after the fitting times and not at the same time the patient is experiencing another form of severe pain.
Clearly the results of this pilot study are limited because of the small sample size and the one-group, pre-/post-test design without a control group for comparison. However, the results clearly show that Zuckweiler’s Image Imprinting for phantom pain and sensation is an effective intervention for phantom pain and phantom sensation.
Subjects were asked about the content of their dreams to help assess their psychological state with regard to their loss. Dreams were also used to see if they were operating from the old or the new body image. Most subjects did not have or did not remember having dreams in which they saw an image of their body, and they did not have dreams about their loss. Dream activity proved to be an inconsistent, unreliable assessment tool for changes in body image.
Unresolved grief has often been the explanation for phantom pain and phantom sensation. This study did not use a standardized rating scale to address whether or not there is a correlation between unresolved grief and the effectiveness of ZIPS. Regardless of whether the amputation occurred weeks or many years ago, most subjects considered themselves in Kübler-Ross’s grief stage19 of acceptance at the beginning and at the end of treatment, but during the treatment sessions, many amputees showed signs of further grief processing. One woman stated that she believed she had resolved the loss of her breast and leg, but when she started to do the ZIPS, she found she became quite sad. To complete her ZIPS assignment, she first had to take some time out to grieve; otherwise, she would be crying at work when she was trying to do the imaging. The grief work did not get rid of the phantom pain and sensation. In her case, she needed to deal with some additional grief before she could start to treat her phantom pain and phantom sensation. Several other subjects exhibited some grieving behaviors in the course of treating the phantom pain and sensation. Additional resolution of the loss of the body part was sometimes an added benefit that occurred while the phantom pain and phantom sensation were being treated.
Conclusions regarding the relevance of post-traumatic stress disorder (PTSD) and acute stress reaction to the success of using ZIPS were also limited to clinical observations. Several subjects showed signs of PTSD or acute stress reaction when they explored the images they held in their minds and were able to move beyond those intrusive thoughts as they worked to correct their body image. Just working on grief and specific PTSD symptoms did not seem to treat the phantom pain or sensation, but in treating phantom pain and phantom sensation, some subjects made progress in managing the symptoms of PTSD.
RECOMMENDATIONS FOR FUTURE STUDY
Recently, it has been well documented that many children born with a missing limb or who lose a limb experience phantom pain or phantom sensation. A question to be addressed is what happens when a teenager loses a limb during the developmental time when body image is significantly changing. Could the age when an amputee loses a limb play a part in the ability to eliminate phantom pain and phantom sensation? Subject 1 had a leg amputated when she was 13 years old, and she was the only subject who practiced ZIPS but was not able to permanently influence her phantom pain and phantom sensation. All other subjects underwent amputation during their adulthood and were able to change phantom pain/sensation. This could mean that when the amputation occurs during adolescence, it may be especially important to use ZIPS at the time of the amputation and throughout the remaining teen years, while body image is being shaped to match with the maturing body.
There are still many unanswered questions about the origin of phantom pain and phantom sensation. According to Poeck,19 an 11-year-old girl who was born without her forearms and hands could use her hands to count, like the other children. Was she able to do that because she was born with a full body image, or is it possible that she was able to use the role modeling of the other children and create a body image that included the hands she wished to have. In this preliminary study, ZIPS was an effective intervention for phantom pain and phantom sensation. The question that needs exploring is under what conditions is the intervention most successful?
The best time to use ZIPS warrants additional study. The case cited in Living in the Postmastectomy Body,4 in which a woman practiced visualizing her body without a breast before surgery and then reported having phantom pain and phantom sensation for only hours, suggests that preoperative preventive treatment may be most effective. Because subjects in the current study who underwent amputation because of illness had a better outcome than did those who did so as a result of an accident, it would be interesting to study the effectiveness of ZIPS administered before surgery for those who will undergo amputation because of an illness. Most illness amputees have a significant amount of time before the actual loss. Are they more successful with correcting their body image because they naturally start to imagine themselves without the limb while the decision is being made?
The Zuckweiler’s Image Imprinting for phantom pain and sensation intervention for treating phantom pain and phantom sensation could be an effective, economical, noninvasive, self-empowering approach to reducing and eliminating phantom pain and sensation. It is a tool that can be administered by psychiatric nurses, clinical social workers, psychologists, and psychiatrists on an inpatient or outpatient basis. The biggest obstacle to offering this treatment will be getting the medical profession to believe that phantom pain and phantom sensation are distressing and treatable so that clinicians will educate their patients and make referrals.
Greg Gruman, CP, President of Winkley Orthotics & Prosthetics, compassionately understood the importance of this research to his patients, generously funded the project, trusted the authors with his patients, and allowed the use of his facility. Two other Winkley staff members, Jill Marshall, CP, and Al Ingersoll, CP, identified subjects and provided many hours of case consultation. Kay Savik, MS, University of Minnesota, Graduate School of Nursing, biostatistician, provided the statistical analysis and data layout. The authors thank the subjects for their participation.