Secondary Logo

Journal Logo

Article

Exploring the Phantom Phenomenon from a Psychophysiological Perspective

Price, James B. Jr PhD, CPO

Author Information
JPO Journal of Prosthetics and Orthotics: July 2005 - Volume 17 - Issue 3 - p 87-95
  • Free

When limb amputation becomes necessary it is reasonable to expect that the victim of limb loss will have significant and complex issues to resolve. The pain associated with disease or trauma has been replaced by, or is sometimes coupled with, the pain of surgery, and the psychological implications of the affliction have become psychological implications of body image and body damage.1 The phantom limb sensation2 and the degenerative effect that pain can have on the immune system3 compromise personal well-being and can affect physical, social, and emotional experiences. If proportions of influence among major categories of experience, general well-being, and pain phenomena can be determined, causal mechanisms of phantom pain might be more easily identified and managed.

THE PHANTOM PHENOMENON

Phantom limb pain is one of the most fascinating and complex clinical pain syndromes. The experience of the phantom limb is not always described as painful, yet the sensation of the missing limb being intact after amputation is extremely prevalent. Phantom limb sensation has been shown to be present in 65% of persons with limb amputation 6 months after amputation, and in 60% at 2-year and 7-year intervals.2 Most of these amputees report phantom limb sensation immediately after surgery. It is typically described as a tingling feeling in which the original shape of the amputated extremity is perceived. The phantom limb reacts the same when moving, sitting, and lying down, and the missing extremity’s “presence” has caused some amputees to step out of bed expecting their missing foot to touch the floor, or to reach out to grasp an object with a missing hand. With time, the shape of the phantom extremity changes and there is sometimes a “telescoping” effect, in which the foot or hand recedes into the body. In some cases the phantom foot or hand subsequently disappears. It has been suggested that the central nervous system produces the phantom in response to lack of normal input and that it manifests as a neural substrate in the perception of body position.2

About 50% of amputees experience phantom pain classified as chronic or severe.4 Phantom limb pain is periodically to frequently described as cramping, shooting, burning, or crushing. The pain may vary in quality and intensity. Rather than simply feeling the shape of the absent extremity, those who experience phantom limb pain sometimes report feeling that the appendage is contorted. Phantom pain can be triggered by emotional upsets and bodily functions.2 Phantom pain may endure long after the tissue damaged from disease and surgery has healed, and “trigger zones” may spread to healthy areas of the body.2

PHANTOM PAIN AND THE BRAIN

The experience of the phantom limb is realistic to the person with limb loss because the same brain processes that are present when the body is intact remain present after amputation.5 Melzack5 describes the body as being unitary with an integrated quality that includes the “self” and the incorporation of a neural network that can be changed by sensory experience, although the “body-self” is genetically determined. He describes experiences of the body as having a quality of self, thereby influencing the individual’s perception and response to pain.

Historically, there has been controversy in determining the causal mechanisms of the phantom limb. The major problem is the attempt to identify a single problem as the entire explanation when it is more likely there are a variety of contributing factors. Recent research in psychological science emphasizes a progression from the periphery to the central nervous system as a means of explaining the phantom limb phenomenon.2 However, more than 40 types of therapy to address phantom limb pain have been described, with a success rate of only about 15%,2 indicative of predominant confusion regarding the mechanisms that underlie phantom limb pain.

Psychological evidence suggests that perceptual experience is influenced by history and current state of mind.5 In other words, state of mind, or emotion, under certain circumstances may determine responses to pain or pain sensation thresholds. Phantom limb pain perplexes the investigation by beginning as signals of serious body damage and may persist, spread, and increase in intensity to the point that it becomes a malady in its own right. Evidence reveals that prolonged pain can have deleterious effects resulting in immunosuppression caused by extended periods of stress, anxiety, or depression.3

PAIN, STRESS, AND IMMUNOLOGIC COMPROMISE

Consequences of stress on the immune system can be delineated and measured. Individual patterns of affective, behavioral, and cognitive responses significantly influence reaction to stress and physiologic consequences.6,7 Whether the stress is classified as major or minor may play an important role in the immune response.

The stress-pain connection may be a reciprocal event, as supported by research investigating the stress responses of individuals experiencing temporomandibular pain, fibromyalgia, and unrestorative sleep.8–10 Stress has been identified as a predictor of pain and depression, and life-stress and depression have been associated with experiences of chronic pain.11,12 Specific to the phantom phenomenon, there is evidence that the impact of stress on pain intensity suggests a connection between the long-term emotional memory of amputation and the occurrence of phantom pain.13

Other examples of stress producing pain with physiological consequences include work-related stress and musculoskeletal pain with catecholamine compromises, elevated blood pressure, increased heart rate, and psychosomatic symptoms14; chronic psychoemotional stress and reduced pain thresholds15; stress producing injury and resulting in prolonged chronic pain16; posttraumatic stress disorder, alterations of hypothalamic-pituitary-adrenal (HPA) axis, and chronic pain17; and the development of pain in pain-free subjects after prolonged mental stress.18

Degenerative disease processes along with major stress-producing constructs such as bereavement have been shown to have significant influences on immunologic responses.19 Increments in CD4 cell counts of patients with human immunodeficiency virus in a controlled bereavement support group were associated with lower levels of stressors, whereas higher levels of grief were associated with negative physiologic response.19

DEPRESSION AND DISABILITY

Depression is defined as a state of low mental vitality or dejection and is a generic term that has been used to explain a variety of disorders. Situational and biological depression may present interactively or exclusively in related or unrelated phenomena. Depression in the elderly generally is reported differently than depression in middle-aged or younger counterparts, specifically with increased somatic concerns and less guilt. Hypochondriasis, psychotic depression, and pseudodementia are more prevalent with age. Physical illnesses, sociological considerations, and other psychological concerns may also play an interactive role. Many times depression is used as a barometer to determine personal well-being.

The following themes are consistent in many individuals with a diagnosis of depression:20

  1. Depressed mood most of the day nearly every day.
  2. Markedly diminished interest or pleasure in all or almost all activities most of the day.
  3. Significant weight loss or weight gain.
  4. Insomnia or hypersomnia nearly every day.
  5. Psychomotor agitation or retardation nearly every day.
  6. Fatigue or loss of energy nearly every day.
  7. Feelings of worthlessness or excessive or inappropriate guilt.
  8. Diminished ability to think or concentrate.
  9. Recurrent thoughts of death, suicidal ideation, or a suicide attempt.

These characteristics have remained static over time for determining depression and were used as a basis for diagnosis in the Diagnostic and Statistical Manual of Mental Disorders,3rd edition, (DSM-III). The newer version, DSM-IV-TR, no longer states a requirement of the presence of five of these characteristics; however, the same qualities remain inherent in determining higher and lower levels of depression and depressive symptoms as defined by the more recent manual.

Depression may vary in depth from neurosis to psychosis. Many variables can result in the affliction of a depressive state, and various circumstances of life situations may determine how depression is handled and how it should be treated. For instance, sexual abuse early in life may set the stage for the predisposition to a depressed state caused by low self-esteem. Likewise, attachment styles that are developed in infancy and early childhood may influence the method by which individuals cope with depressive symptoms. Major depression might also be genetically determined.

Individuals with a diagnosis of depression may exhibit depression in any or all stages of life. Furthermore, depression may be manifested before, during, or just after major life events. Onset of disability is a salient example of major life events that produce depression.

AMPUTATION AND WELL-BEING

Among individuals with various types of disabilities, those who experience limb amputation display more indecisiveness, thoughts of death, and thoughts of self-harm.21 Restriction of activity is interrelated with public self-consciousness, depression, and feelings of vulnerability.21,22 Perceived social stigma has been found to contribute significantly to depression.23 Those who experience amputation exhibit a broad spectrum of psychological responses that range from extreme despair to feelings of relief after eliminating the source of pain.

Perceptual changes after amputation are a potential source of emotional despair. Magnetic resonance imaging has revealed that organizational and perceptual changes correlate with the number of sites from which painful stimuli can evoke referred sensation. Phantom limb pain can mediate depressive symptoms, especially when the phantom limb is evoked by unrelated body functions.24

Modification of the sense of self, sense of loss, awareness of mortality, loss of confidence, disfigurement, loss of balance, guilt, and phantom limb sensations are among the traumatic effects of amputation that can cause this population to have a bleak outlook for the future.25

The connection among physical experience, physiological response, and psychological outcome is well established. Physical identity is a construct in which appearance, competence, and limitations combine to develop a sense of self and depend heavily on the individual’s capability to function physically.26 Pain processing in the brain, the role of pain and stress in immunological decrement, and depressive tendencies are considered as catalysts for disturbing physical identity and evoking the phantom limb. This study investigated physical, social, and emotional life experiences as a continuum that when disrupted contributed to a relationship between distress and phantom pain. Specifically, each category in the life experience continuum was measured against the criterion variables of distress and phantom pain to determine the relative predicting power of each category.

METHOD

SAMPLE AND SELECTION

Study participants included 50 individuals (37 males, 13 females) who had experienced surgical removal of a lower extremity, had received prosthetic management, and were capable of ambulation with their prostheses. Forty participants had transtibial amputations, and 10 participants had transfemoral amputations. Thirty-five participants had amputations because of disease, 12 because of trauma, and 3 for congenital conditions. The age range of participants was 32 years to 80 years (mean, 56.6 years). The qualifying criteria were that each patient had a lower-extremity amputation, was 21 years of age or older, had received and had been using a prosthesis, was capable of ambulating with his or her prosthesis, and had been ambulating with his or her prosthesis for at least 3 months. Each participant completed four instruments: the Trinity Amputation and Prosthetic Experience Scales (TAPES),27 the TAPES demographic survey, The Beck Depression Inventory II (BDI-II),28 and the TAPES phantom pain survey.

TAPES

The TAPES instrument was developed to better understand from a multidimensional perspective the experiences of those who suffer limb loss. The occurrence of limb loss produces many challenges, the most obvious being that of learning to use a prosthetic limb. This obvious physical challenge leads to social and psychological adjustments as well. TAPES allows in-depth examination of physical, social, and emotional functioning by asking questions directly related to issues of postamputation experience and specific issues regarding prosthesis use. TAPES is a 54-item multidimensional self-report instrument that investigates psychosocial issues, activity restriction, and qualitative satisfaction with a prosthetic device. Factor analysis regarding psychometric evaluation of TAPES was used by its developers to reveal subscales, including adjustment, restriction, and satisfaction, in each of the domains of inquiry. Each subscale crossed the boundaries of the major continuum and provided the impetus for this study. Specifically, extraneous influences represented by the various subscales and measured as psychosocial, activity, and satisfaction issues are purported to be influences affecting depression measures after rehabilitation. Furthermore, studies regarding clinical depression after amputation have revealed a range of 21% to 35% of all persons with limb loss,27 providing incentive for investigation into the postamputation-rehabilitation-depression continuum.

DEMOGRAPHIC SURVEY

The demographic survey included a variety of questions regarding personal information about the participants and was provided as a means of assessing variances among demographic variables as they pertained to amputation experiences and relationships with well-being and phantom pain. Information included but was not limited to age, gender, months elapsed since amputation, amputation level, and diagnostic category. For the purpose of this study, nominal variables were not included in the primary analysis. The interval variables of age and months elapsed since amputation were included in the primary analysis to maintain no less than a 10:1 ratio between participants and variables examined.

BDI-II

The BDI-II was developed to identify depressive disorders based on the criteria of the DSM-IV. The BDI-II was appropriate for this study because it addresses four items pertinent to the mental processes of those who experience amputation: agitation, feelings of worthlessness, concentration difficulty, and loss of energy. It is a survey designed to indicate the presence and degree of depressive symptoms rather than an instrument for clinical diagnosis. Appropriateness of the BDI-II was further supported because the intent was to investigate relationships among multidimensional postamputation experiences, depressive symptoms, and phantom pain, not diagnose for the purpose of clinical treatment. The BDI-II is a 21-item self-report instrument designed for individuals at least 13 years of age.

PHANTOM PAIN SURVEY

Two specific questions from the TAPES phantom pain inventory were used to analyze phantom pain in the 50 participants: 1) To what extent do you experience phantom limb pain? and 2) How much did phantom limb pain interfere with your normal lifestyle during the last week?

The questions were scored on a Lichert scale and entered into a regression analysis with the TAPES, BDI-II, and demographic variables.

DATA ANALYSIS

Data analysis was performed using SPSS 11.029 for Windows. Frequency distributions, descriptive statistics characterizing distribution, dispersion, and central tendency values, as well as parametric and nonparametric tests, were used to analyze the data.

Pearson r correlation analyses, which determined the significance of bivariate relationships among the interval level data, were used to examine the relationships between each predictor variable represented by the subscale scores on the TAPES instrument, the interval level demographic variables, the BDI-II scores, and the phantom pain scores. Each of the primary predictor variables, represented by the subscale measures on the TAPES instrument, along with the continuous demographic variables of age and months elapsed since amputation, were entered into a regression analysis. The TAPES scores, BDI-II scores, and phantom pain scores were entered into a multiple regression analysis. Backward regression analysis provided a determination of the individual values of the significant variables. An analysis of variance (ANOVA) was a product of the regression analysis that measured significant differences, not attributed to chance, between the means of the variables. Other products of the regression analysis, the independent t tests, determined the proportion each predictor variable contributed to the criterion variables and produced beta values that measured the proportions of statistical significance for the primary variables.

RESULTS

Raw data distributions for scores on each subscale of the TAPES instrument revealed a symmetrical distribution for each category (Figure 1). The distribution of scores on the BDI-II was positively skewed with a mean of the combined scores of 9.56, a median score of 7, and a skewness value of 0.901 (Figure 2). Thirty-four participants (68%) reported some degree of phantom pain.

Figure 1.
Figure 1.:
Raw data distributions for sum of the TAPES scores. Normal curve overlay is shown and implies a representative sample for the study exists based on expected frequencies. (COUNT = Number of participants; TAPESSUM = Sum of the three TAPES subscale scores.)
Figure 2.
Figure 2.:
Raw data distributions for scores on the BDI-II. Normal curve overlay is shown and implies a representative sample for the study exists based on expected frequency of those who experience depression. (COUNT = Number of participants; BDI = BDI-II depression scores.)

The Pearson r correlation analysis revealed significant values for each bivariate relationship among the primary predictor variables and the criterion variables of depression and phantom pain for which p < 0.05 (Table 1). The regression analysis determined that significant degrees of common variance existed between each primary predictor variable and the depression variable. Age and “months elapsed since amputation” were revealed not to be statistically significant and were eliminated from the regression analysis. Stepwise regression analysis automatically eliminated the continuous demographic variables and revealed substantial common variances between the primary predictor variables measured by the TAPES instrument and the criterion variable of depression. Multiple regression analysis revealed substantial common variance between the TAPES and phantom pain scores and the BDI-II scores.

Table 1
Table 1:
Pearson r bivariate correlation analysis of all primary variables (n = 50).

The social experience variable was revealed as the variable sharing the majority of common variance with depression at 55%. The emotional experience variable explained 8% of common variance with depression, and the physical experience variable contributed the least common variance of the predictor variables to depression at 5%. Clustered together, the TAPES predictors and the depression variable shared 68% common variance. Table 2 provides the model summary for the stepwise regression analysis of the primary predictors and the depression criterion. Figure 3 provides a visual illustration of the linearity among the primary predictors and the depression criterion.

Table 2
Table 2:
Model summary of stepwise regression of primary predictor (independent) and depression (dependent) variables.
Figure 3.
Figure 3.:
Scatterplot of sum of TAPES and BDI-II scores. Relative close clustering of scores along the descending plane reveals linearity and suggests a close relationship between the two sets of scores. (TAPESSUM = Sum of the three TAPES subscale scores. BDI-II = BDI-II depression scores.)

The regression analysis for the TAPES, BDI-II, and phantom pain scores revealed 75% common variance between TAPES and phantom pain and BDI-II. Significant F ratios produced by the ANOVA indicated that the hypothesis of a correlation among physical, social, and emotional experience, phantom pain, and depression should be accepted (Table 3). Figure 4 provides a three-dimensional visual representation of the scores for each variable. Independent t tests produced beta values that revealed proportions of significance of the TAPES variables and phantom pain variable to be similar as statistically significant predictors of personal well-being, as defined by the BDI-II scores (Table 4). When the physical, social, and emotional experience variables were entered into a multiple regression analysis with phantom pain as the dependent variable, social experience was the only variable retained as a significant predictor of phantom pain (p = 0.01).

Table 3
Table 3:
Analysis of variance (ANOVA) from regression analysis of significant predictor variables.
Figure 4.
Figure 4.:
Three-dimensional scatterplot of TAPES, BDI-II, and phantom pain scores. Relative close clustering of scores along the descending plane reveals linearity and suggests significant correlations among the variables. (X axis = Phantom pain scores; Y axis = BDI-II scores; Z axis = Clustered TAPES scores.)
Table 4
Table 4:
Proportions of significance from independent t tests.

DISCUSSION

The research hypothesis for this study was: Individuals who suffer limb loss will report relationships among postamputation experience as measured by the TAPES instrument, distress as measured by the BDI-II, and phantom pain.

The research hypothesis was directional in that depression and phantom pain scores were expected to decline as predictor variable scores increased. The null hypothesis assumed that there would be no statistically significant relationships among self-reported measures of unsatisfactory postamputation experience, depression, and phantom pain. Beta and t values supported the rejection of the null hypothesis with 95% certainty that a Type II error, rejection of the null hypothesis when it was in fact true, had not occurred.

The literature supports the concept of physical, social, and emotional experience contributing to the whole of well-being. Support between the literature and this study was reciprocal. The study confirmed inferences in the literature pertaining to the importance of an undisrupted continuum of positive experiences in the physical, social, and emotional realms, and the literature anticipated the findings of this study; the “whole” of well-being was best predicted by an undisrupted continuum that includes the three aforementioned domains of experience. The literature overwhelmingly supports that multidimensional approaches to health care are beneficial, and the results of this study confirmed the claims of the literature.

Statistical analysis determined that the physical, social, and emotional realms were overlapping and intermingling. Each domain of experience shared common variance with the others, yet values supported the ideology that although all are important, under specific circumstances, each domain is not equally important. This became apparent when the depression and phantom pain variables were entered into the regression equations with the primary predictor variables. The social component emerged as the category most likely to predict predisposition to depressive symptoms and was the only significant predictor of phantom pain in the absence of depression. Furthermore, the results demonstrated that individuals were more predisposed to phantom pain as severity of depressive symptoms increased.

The presence of disease, amputation surgery, and disability in general represents disruptions of the physical domain. At face value, it would be reasonable to conclude that isolation of the experiences in the physical domain would preclude psychological disturbance. Because psychological disturbance has been shown to increase risk for pain syndromes, it would appear that drug treatment would effectively manage most occurrences of phantom pain. However, results of the study indicate that upon occurrence of disease and physical detriments that follow, disruption spreads from the physical realm into social and emotional realms of experience. Disease and amputation are physical processes that invade the social and emotional realms. Not only are a disease cause and psychological effect implied, but interaction between physical and mental processes have been substantiated to the following extent. Disease and pain cause psychological disturbance, psychological disturbance can cause pain and disease, and stress-producing pain can result in physiological compromises. Those who experience disease are at risk for stress-produced physiological decrements, and those who experience psychological detriments in the social or emotional realms are at risk for deleterious physical effects. The results of this study indicate that as phantom pain begins to assume a social and emotional identity in addition to a physical identity, treatment success begins to decline.

The concept of a physical, social, and emotional continuum that is overlapping and mutually contingent has been statistically tested and revealed to be a dynamic force that significantly influences personal well-being. Microcomponents of the primary categories have been established by previous studies and in many cases have been shown to originate in a primary domain and influence other domains, or exist simultaneously in multiple domains. The results of this study have revealed another continuum that includes personal experience, well-being, and phantom pain, and suggest that traditional drug therapies for the treatment of phantom pain might be less successful when depressive symptoms are not present.

CONCLUSIONS

The purpose of this study was to investigate relationships among physical, social, and emotional experiences of amputation, personal well-being, and phantom pain. A significant negative correlation was revealed between physical, social, and emotional experiences of amputation and well-being. A significant negative correlation was revealed between well-being and phantom pain. Finally, a significant negative correlation was revealed between social experience and phantom pain. Although the relationships between variables could not within the chosen design be confirmed as causal, the overwhelming significance indicators support the need for consideration of nontraditional approaches in the treatment of those who experience amputation and specifically those predisposed to phantom pain.

REFERENCES

1.Breakey JW. Body image: the lower limb amputee. J Prosthet Orthot 1997;9:58–66.
2.Melzack R, Wall P. The Challenge of Pain. London: Penguin Books; 1988.
3.Kludt CJ. Effects of disease activity, neuroticism, and minor stress on pain perception in two immunologically distinct subgroups of patients with rheumatoid arthritis [dissertation]. Chicago: The Chicago Medical School, 2000.
4.Pinel JPJ. Biopsychology, 4th ed. Boston: Allyn and Bacon; 2000.
5.Melzack R. Phantom limbs, the self, and the brain. Can Psychol 1989;30(1):1–16.
6.Vedhara K, Fox JD, Wang ECY. The measurement of stress-related immune dysfunction in psychoneuroimmunology. Neurosci Biobehav Rev 1999;23(5):699–715.
7.Kemeny ME, Laudenslager ML. Beyond stress: The role of individual difference factors in psychoneuroimmunology. Brain Behav Immun 1999;13(2):73–75.
8.Tracey DJ, Walker JS, Carmody JJ. Chronic pain: neural basis and interactions with stress. In: Kenny DT, Carlson JG, eds. Stress and Health: Research and Clinical Applications. Amsterdam, Netherlands: Harwood Academic Publishers; 2000:105–125.
9.Bragdon EE. Cardiovascular and pain responses to stress in healthy adults and temporomandibular disorder patients [dissertation]. Chapel Hill: University of North Carolina, 2000.
10.Moxham EG. The Contribution of Pain, Nonrestorative Sleep, Depression, and Stress to Fatigue in Fibromyalgia Patients. San Francisco: California School of Professional Psychology, 1999.
11.Kim JY. A longitudinal study of interpersonal stress, major life events, and weekly stressors as predictors of pain and depression in fibromyalgia patients [dissertation]. San Francisco: California School of Professional Psychology, 2000.
12.Catley D. Psychological distress in chronic pain: examination of integrative models of stress, and a cognitive-behavioral mediation model of depression [dissertation]. Stony Brook: New York University, 2000.
13.Angrilli A, Koester U. Psychophysiological stress responses in amputees with and without phantom limb pain. Physiol Behav 2000;68(5):699–706.
14.Lundberg U, Dohns IE, Melin B, et al. Psychophysiological stress responses, muscle tension, and neck and shoulder pain among supermarket cashiers. J Occup Health Psychol 1999;4(3):245–255.
15.Ashkinazi IY, Vershinia EA. Pain sensitivity in chronic psychoemotional stress in humans. Neurosci Behav Physiol 1999;29(3):333–337.
16.Melzack R. Pain and stress: clues toward understanding chronic pain. In: Sabourin M, Craik F, eds. Advances in Psychological Science, Vol. 2: Biological and Cognitive Aspects. Hove, England: Psychology Press/Erlbaum;1998:63–85.
17.Heim C, Ehlert U, Hanker JP, Hellhammer DH. Abuse-related posttraumatic stress disorder and alterations of the hypothalamic-pituitary- adrenal axis in women with chronic pelvic pain. Psychosomatic Medicine 1998;60(3):309–318.
18.Bansevicius D, Westgaard RH, Jensen C. Mental stress of long duration: EMG activity, perceived tension, fatigue, and pain development in pain-free subjects. Headache 1997;37(8):499–510.
19.Burkhalter JE. A bereavement support group intervention: effects on bereavement-specific situational coping and associations of dispositional coping style and situational coping with psychological distress and immune function in bereaved HIV seronegative gay men [dissertation]. Miami: University of Miami; 1998.
20.Hay DP, Hay L, Sperry L. Depression and anxiety in the elderly. In: Greenspan SI, Pollock GH, eds. The Course of Life, Vol. VII. Madison, CT: International Universities Press, Inc.; 1998:249–263.
21.Langer KG. Depression in disabling illness: severity and patterns of self-reported symptoms in three groups. J Geriatr Psychiatr Nurs 1994;7(2):121–128.
22.Rybarczyk B, Szymanski L, Nicholas JJ. Limb amputation. In: Frank R, Elliott TR, eds. Handbook of Rehabilitation Psychology. Washington, DC: American Psychological Association; 2000:29–47.
23.Williamson GM, Schulz R, Bridges MW, Behan AM. Social and psychological factors in adjustment to limb amputation. J Soc Behav Personal 1994;9(5):249–268.
24.Rybarczyk B, Nyenhuis DL, Nicholas JJ, Cash SM. Body image, perceived social stigma, and the prediction of psychosocial adjustment to leg amputation. Rehabil Psychol 1995;40(2):95–110.
25.Knecht S, Henningsen H, Elbert T, et al. Reorganizational and perceptual changes after amputation. Brain 1996;119(4):1213–1219.
26.McGarry J. Hypnotic interventions in psychological and physiological aspects of amputation. Austral J Clin Hypnother Hypn 1993;14(1):7–12.
27.Gallagher P, MacLachlan M. Development and psychometric evaluation of the Trinity Amputation and Prosthetic Experience Scales (TAPES). Rehabil Psychol 2000;45(2):130–154.
28.Beck AT, Steer RA, Brown GK. Beck Depression Inventory manual, 2nd ed. San Antonio, TX: Psychological Corporation; 1996.
29.SPSS [computer program]. Release 11.0. Chicago: SPSS Inc.; 2001.
Keywords:

phantom pain; psychophysiological; psychoprosthetic

© 2005 American Academy of Orthotists & Prosthetists