Limb Pain Patients Research Articles

Psychophysiological stress responses in amputees with and without phantom limb pain

The present experiment tested the hypothesis that phantom limb pain amputees show a different pattern of psychophysiological reactivity to stress compared with painfree amputees. Six phantom limb pain (PLP) and five painfree upper-extremity amputees were administered two groups of tasks: stressful and relaxing. The measured dependent variables were skin temperature recorded at both stump and intact site, heart rate, blood pressure, subjective pain and stress ratings. Phantom limb pain patients were characterized by higher stump temperature compared with phantom limb painfree patients. This effect was observed during the whole recording. Consistently with the between-subjects effect, when PLP patients exhibited higher skin temperature (during relaxation, compared with during stressful tasks), they perceived more pain. The experiment showed higher cardiovascular reactivity in PLP patients, specifically to the stressful free-speech task, which focused on recollection of the amputation event. As compared with the painfree patients, during the personal stressor, PLP patients' heart rate and systolic blood pressure increased, indicating a greater sympathetic response. Results indicate that peripheral factors, such as stump temperature reliably differentiate PLP from painfree patients. Moreover, the clear cardiovascular hyperreactivity observed in PLP patients during their report of amputation suggests that PLP is associated with a long-term emotional memory for the painful experience of that event. These results are consistent with most reports in the literature relating phantom pain development to the experience of preamputation pain.

Successful Therapy Of Phantom Pain In The Upper Limb By Blocking The Brachial Plexus

Early treatment of phantom limb pain in patients after amputation reduces the incidence of chronic pain sensations from 60 85 % to 10 20 % [1]. A 33 year old patient with osteosarcoma of proximal humerus developed a burning pain VAS 7-8 (Visual analog scale 0-10) of the left hand and fingers three days after amputation of the left arm in the shoulder joint. Treatment with calcitonin, amitriptyline, naproxen, piritramide and carbamazepine did not influence the pain. On the seventh day an interscalene block was done with the use of a nerve stimulator. After a bolus of 30 ml ropivacaine 0.2 % was infused with a rate of 6 ml/h for ten days. Within a time period of ten minutes the phantom limb pain was relieved (VAS 0). After four hours phantom limb sensations developed, but were not classified as pain by the patient. With the option of a patient controlled bolus of 5 ml (2x /h) it was possible to reduce the additional pain therapy to carbamazepine and amitriptyline. During the ropivacaine treatment no motor blockade or other side effects were observed. After ten days the catheter site showed minor signs of inflammation and the catheter was removed. In an early follow-up (5 month) the patient reported mild phantom limb sensations and infrequent phantom pain (VAS 1-2), no analgesic medication was necessary. Interscalene block provided comfortable and safe analgesia for this patient and helped to avoid development of chronic phantom limb pain. A comparable therapy using bupivacaine would have led to toxic plasma concentrations. Ropivacaine is not only less toxic (16), it also provides the advantage of a less intensive motor blockade (17), limiting the danger of phrenic nerve block.

Treatment of childhood hypophosphatasia with nonsteroidal antiinflammatory drugs

Hypophosphatasia (HP) is an inborn error of metabolism that is characterized by reduced bone mineralization. The aim of this investigation was to evaluate treatment of incapacitating lower limb pain in patients with childhood HP using nonsteroidal antiinflammatory drugs (NSAID). All patients (seven boys; age 32 months to 16 years) presented with delayed walking, the typical waddling gait, muscular weakness of the lower limbs, and a limited walking distance. Six patients had severe diffuse lower limb pain following physical activity and were therefore treated with NSAID. The benefit of this treatment was evaluated clinically and by measurement of renally (PGE 2) and systemically (PGE-M) derived prostaglandins (PG) in urine before and during therapy. After treatment with NSAID all six patients showed marked clinical improvement with reduced pain, increased muscle strength, and a normalized walking distance. Levels of PGE-M, which had been elevated in four patients prior to therapy, returned to normal. The use of NSAID in childhood HP should be considered as a possible therapeutic approach because the quality of life in these patients is markedly impaired by pain of the limbs. Elevated PG might play a role in the bone metabolism of HP patients.

551 Relationship of phantom phenomena and somatosensory cortical reorganization in amputees

The present study was designed to investigate differences in neural processing of pain-related semantic information in amputees with and without chronic phantom limb pain and healthy controls. One-hundred-and-twenty words (40 neutral, 40 body-related, 40 pain-related) were presented in pseudorandom order to probe group differences in the perception of pain-related information. Visual evoked potentials (VEP) to the words were recorded from 11 scalp locations, EMG was measured at the stump and the contralateral side and bilaterally from the M. corrugator. In addition, heart rate and skin conductance responses were obtained. Both early and late VEP components were altered. Pain-free amputees showed a reduced N100 amplitude compared to phantom limb pain patients and healthy controls whereas the phantom limb pain patients displayed a significantly enhanced late positivity (500–800 msec after word onset). VEP components were unaffected by word type. The peripheral EMG responses were significantly different among the groups: phantom limb pain patients showed larger EMG reactions on the stump than on the contralateral side, whereas pain-free amputees showed the opposite effect. The data suggest an enhanced central and peripheral processing of visual stimuli in phantom limb pain patients.

136 Sensory feedback for phantom limb pain

Using functional magnetic resonance imaging and single slice FLASH technique, we investigated reorganization of the hand representation of the primary sensorimotor cortex (SMC) in 16 patients with upper extremity amputation. Patients were asked to perform finger tapping with the intact hand, repetitive eye closing and anteflexion of the amputation stump or intact shoulder. Six normal volunteers served as control. In the normal volunteers activations during shoulder anteflexion, finger tapping and eye closure were located within the central sulcus in a medio-lateral fashion. Patients demonstrated invasion of the face or shoulder representation into the hand representation of the amputated limb. Eight phantom limb pain patients showed significantly greater activation in SMC and supplementary motor area (SMA) in contrast to eight patients without phantom limb pain. We conclude, that different parts of the motor system are affected in patients with phantom limb pain – possibly in the sense of an up-regulation of excitability.

Effects of Regional Anesthesia on Phantom Limb Pain Are Mirrored in Changes in Cortical Reorganization

The causes underlying phantom limb pain are still unknown. Recent studies on the consequences of nervous system damage in animals and humans reported substantial reorganization of primary somatosensory cortex subsequent to amputation, and one study showed that cortical reorganization is positively correlated with phantom limb pain. This paper examined the hypothesis of a functional relationship between cortical reorganization and phantom limb pain. Neuroelectric source imaging was used to determine changes in cortical reorganization in somatosensory cortex after anesthesia of an amputation stump produced by brachial plexus blockade in six phantom limb pain patients and four pain-free amputees. Three of six phantom limb subjects experienced a virtual elimination of current phantom pain attributable to anesthesia (mean change: 3.8 on an 11-point scale; Z = -1.83; p < 0.05) that was mirrored by a very rapid elimination of cortical reorganization in somatosensory cortex (change = 19.8 mm; t(2) = 5.60; p < 0.05). Cortical reorganization remained unchanged (mean change = 1.6 mm) in three phantom limb pain amputees whose pain was not reduced by brachial plexus blockade and in the phantom pain-free amputation controls. These findings suggest that cortical reorganization and phantom limb pain might have a causal relationship. Methods designed to alter cortical reorganization should be examined for their efficacy in the treatment of phantom limb pain.

Evidence for a change in neural processing in phantom limb pain patients

The present study was designed to investigate differences in neural processing of pain-related semantic information in amputees with and without chronic phantom limb pain and healthy controls. One-hundred-and-twenty words (40 neutral, 40 body-related, 40 pain-related) were presented in pseudorandom order to probe group differences in the perception of pain-related information. Visual evoked potentials (VEP) to the words were recorded from 11 scalp locations, EMG was measured at the stump and the contralateral side and bilaterally from the M. corrugator. In addition, heart rate and skin conductance responses were obtained. Both early and late VEP components were altered. Pain-free amputees showed a reduced N100 amplitude compared to phantom limb pain patients and healthy controls whereas the phantom limb pain patients displayed a significantly enhanced late positivity (500–800 msec after word onset). VEP components were unaffected by word type. The peripheral EMG responses were significantly different among the groups: phantom limb pain patients showed larger EMG reactions on the stump than on the contralateral side, whereas pain-free amputees showed the opposite effect. The data suggest an enhanced central and peripheral processing of visual stimuli in phantom limb pain patients.

Psychological differences between reflex sympathetic dystrophy and non-RSD chronic pain patients

This study examined possible psychological differences between Reflex Sympathetic Dystrophy (RSD) and non-RSD chronic pain patients. Unlike the few previous studies in this area, this study controlled statistically for age and pain duration differences across diagnostic groups, and included a non-RSD limb pain control group. Subjects were a consecutive series of 34 RSD, 50 non-RSD limb pain (Limb), and 165 low back pain (LBP) patients presenting for treatment at the Rush Pain Center. Analyses revealed that RSD patients reported more somatization and phobic anxiety on the Brief Symptom Inventory than LBP patients. RSD patients also reported greater coping with pain through diverting attention than LBP patients did on the Coping Strategies Questionnaire. Comparisons between the RSD and Limb groups revealed no significant differences with the exception of somatization scores. The relationship between distress and pain severity was found to be stronger in RSD and Limb patients than in LBP patients. These results provide partial support for clinical assumptions that RSD patients are more psychologically dysfunctional than other chronic pain patients. However, these conclusions do not generalize across all comparison groups. The fact that RSD and non-RSD limb pain patients were quite similar on nearly all measures suggests that sympathetic mediation of pain is not the source of these psychological differences.

Pain Complaints and Psychological Distress among Soldiers in Specialty Military Medical Clinics

This paper explores: (1) the relationship of pain complaints and psychological distress among orthopedic, dermatology, ophthalmology, and neurology outpatients, (2) the ability of patients with pain complaints and their physicians to detect patients' psychological distress, and (3) the connection between type of pain, prognosis as rated by physician, and patient's use of military primary health care and mental health treatment. Five hundred fifty-six soldiers in compulsory service in the Israel Defence Forces, ages 18 to 21, responded to the PERI-D (Psychiatric Epidemiological Research Interview Demoralization Scale), a measure of psychological distress, and questions about presenting medical complaint and use of mental health and primary health services. Military specialist physicians, who were blind to patients' responses, were asked the extent to which they thought that the cause of the patients' complaints were physical or psychological and to prognosticate. Almost 47% of soldiers attended clinics due to pain. In descending order were limb pain (42.5%), headache (29.1%), lower-back pain (24.5%), and right arm pain (3.8%). Right arm complainers were the most distressed and the heaviest users of primary health care and got the lowest prognosis, yet the physicians did not detect any psychological distress in this group. The least distressed and lowest users of medical services were patients with limb pain. There was a positive linear relationship between psychological distress and use of primary health care. There was a negative linear relationship between distress and prognosis. The patients' ability to detect psychological distress was better than that of the physicians. Physicians tended to find more cases of psychological distress than did the PERI-D in lower-back pain and limb pain patients. Psychologically distressed headache and limb pain patients reported using significantly more primary health care than non-distressed patients with similar pain complaints. Special attention to psychological distress among pain complainers in military secondary health care clinics is needed. Such attention may reduce the use of primary health care and may have implications for improving prognoses.

The Use of Pain Coping Strategies by Patients with Phantom Limb Pain

Previous research has demonstrated a relationship between the use of pain coping strategies and the level of pain and psychological distress experienced by patients suffering from a variety of chronic pain syndromes. The present study assessed coping strategy use in patients suffering from phantom limb pain by means of the Coping Strategies Questionnaire (CSQ). Sixty phantom limb pain patients completed the CSQ and measures of pain and psychological distress. The factor structure of the CSQ was found to be broadly similar to that obtained in other studies of chronic pain. Three factors reflecting 'Cognitive Coping', 'Helplessness' and 'Pain Denial' were found. Both pain report and psychological distress were found to be related to use of strategies within factor 2 (Helplessness), the number of different drugs patients used, and the time they had experienced phantom limb pain. Twenty percent of the variance in pain scores and 19% of the variance in psychological distress were significantly explained by coping strategies included in the 3 factors on the CSQ. Patient history variables significantly explained a further 14% of the variance in pain scores and 14% of the variance in psychological distress. Examination of regression analyses of the subscales of the CSQ revealed that catastrophising explained the largest proportion of the variance in pain report and psychological distress.

The use of pain coping strategies by patients with phantom limb pain

Previous research has demonstrated a relationship between the use of pain coping strategies and the level of pain and psychological distress experienced by patients suffering from a variety of chronic pain syndromes. The present study assessed coping strategy use in patients suffering from phantom limb pain by means of the Coping Strategies Questionnaire (CSQ). Sixty phantom limb pain patients completed the CSQ and measures of pain and psychological distress. The factor structure of the CSQ was found to be broadly similar to that obtained in other studies of chronic pain. Three factors reflecting ‘Cognitive Coping’, ‘Helplessness’ and ‘Pain Denial’ were found. Both pain report and psychological distress were found to be related to use of strategies within factor 2 (Helplessness), the number of different drugs patients used, and the time they had experienced phantom limb pain. Twenty percent of the variance in pain scores and 19% of the variance in psychological distress were significantly explained by coping strategies included in the 3 factors on the CSQ. Patient history variables significantly explained a further 14% of the variance in pain scores and 14% of the variance in psychological distress. Examination of regression analyses of the subscales of the CSQ revealed that catastrophising explained the largest proportion of the variance in pain report and psychological distress.

Psychopathology amongst acute and chronic patients with occupationally related upper limb pain versus accident injuries of the upper limbs

: Subjects included five groups of women: (a) acute patients with occupational upper limb pain, (b) chronic patients with occupational upper limb pain, (c) acute patients with accident injuries of the upper limbs, (d) chronic patients with accident injuries of the upper limbs, and (e) non-injured keyboard operators. Psychopathology, as measured by the Beck Depression Inventory; Spielberger State-Trait Anxiety Inventory; and the personality characteristics of introversion-extroversion, neuroticism, and psychoticism on the Eysenck Personality Questionnaire, was assessed for each group. Groups were equivalent in terms of age and occupational status. The results provided no evidence of greater psychopathology amongst occupational upper limb pain patients compared with those with upper limb accident injuries. Anxiety levels were found to be higher for acute and chronic cases of both diagnostic categories compared to non-injured controls. Depression levels were found to be higher for chronic cases of both diagnostic types compared with acute cases and non-injured controls. There was no evidence of differences in personality characteristics between acute or chronic occupational, upper limb pain subjects compared to accident-injured or non-injured controls other than significantly lower extraversion scores for the chronic, accident-injured patients compared to the chronic, occupational upper limb group.

Treatment of phantom limb pain with muscular relaxation training to disrupt the pain-anxiety-tension cycle

Sixteen phantom limb pain patients were treated with a combination of (1) progressive muscle relaxation exercise, (2) feedback of stump and forehead muscle tension, and (3) reassurance about normal phantom sensations and the relationship between anxiety and pain. Fourteen of the patients had chronic pain (average of 12 years) and two were recent amputees (5- and 1- week). At the end of treatment, 8 of the chronic pateints showed virtually complete relief from pain, 4 showed significant decreases to a point at which they no longer desired treatment and 2 showed no significant change. Both recent amputees showed complete relief from pain. These changes have been sustained for follow-up periods of 6 months to 3 years. The unsuccessful patients did not learn to relax and had strong psychological needs for their pain. s