Auricular transcutaneous electrical nerve stimulation (TENS) reduces phantom limb pain

Phantom bladder sensations: a new concern for stoma care workers

The phenomena of phantom limb pain and sensations are well recognized in the medical literature. However, historically, there has been little more than passing reference to phantom pain and sensations of visceral organs. In particular, phantom bladder pain has been barely recognized. This article describes the result of a small survey of urostomists (n=50) who experienced bladder pain and sensations that were described by the respondents as being a perpetuation of the pain and sensations that they experienced before cystectomy or urinary bladder diversion surgery. Respondents reported a varied frequency of sensations, unhelpful healthcare professional responses and a range of strategies that they employed to deal successfully with the pain and sensations. The findings of this study are important because they have identified significant issues for stoma care patients that need to be addressed by those involved in stoma care and which could lead to significant quality of life improvements. This research has shown that stoma care workers need to include the possibility of the occurrence of phantom bladder sensations in preoperative counselling, acknowledge and support postoperative patients by confirming the validity of their experience and by using interventions, identified in this study, that can minimize the effects.

The effect of varying frequency and intensity of transcutaneous electrical nerve stimulation on secondary mechanical hyperalgesia in an animal model of inflammation

For years, transcutaneous electrical nerve stimulation (TENS) has been used clinically for the treatment of many types of pain. Although there have been many studies conducted on the efficacy of TENS in the clinical setting, the results are conflicting. The purpose of our investigation was to determine the effect of varying frequency and intensity of TENS on secondary mechanical hyperalgesia induced by acute joint inflammation. Male Sprague-Dawley rats were injected with a mixture of 3% carrageenan and 3% kaolin (100 microL in 0.9% sterile saline) into the joint cavity of one knee. The response threshold to mechanical stimuli was determined before inflammation of the knee joint; 4 hours after inflammation; immediately after the administration of TENS (approximately 5 hours after inflammation); and at 8, 12, and 24 hours after inflammation. TENS was applied to the inflamed knee joint at either high (100 Hz) or low (4 Hz) frequency and at either sensory or motor intensity. Sensory intensity was just below the threshold for motor contraction, and motor intensity was 2 x threshold for motor contraction. Either low- or high-frequency TENS is equally successful in reducing secondary mechanical hyperalgesia. Similarly, either sensory- or motor-intensity TENS equally reduces secondary mechanical hyperalgesia. Thus, selection of TENS should be based on patient comfort and symptoms for relief of secondary mechanical hyperalgesia.

Measurement of pain

Pain is a personal, subjective experience influenced by cultural learning, the meaning of the situation, attention, and other psychologic variables. Approaches to the measurement of pain include verbal and numeric self-rating scales, behavioral observation scales, and physiologic responses. The complex nature of the experience of pain suggests that measurements from these domains may not always show high concordance. Because pain is subjective, patients' self-reports provide the most valid measure of the experience. The VAS and the MPQ are probably the most frequently used self-rating instruments for the measurement of pain in clinical and research settings. The MPQ is designed to assess the multidimensional nature of pain experience and has been demonstrated to be a reliable, valid, and consistent measurement tool. A short-form MPQ is available for use in specific research settings when the time to obtain information from patients is limited and when more information than simply the intensity of pain is desired. The DDS was developed using sophisticated psychophysical techniques and was designed to measure separately the sensory and unpleasantness dimensions of pain. It has been shown to be a valid and reliable measurement of pain with ratio-scaling properties and has recently been used in a clinical setting. Behavioral approaches to the measurement of pain also provide valuable data. Further development and refinement of pain measurement techniques will lead to increasingly accurate tools with greater predictive powers.

Phantom limb pain: a review of the literature on attributes and potential mechanisms

This study presents a review of the literature on the attributes and potential mechanisms involved in phantom limb pain, encompassing studies describing pain in the residual limb, phantom sensation and phantom limb pain, and the difficulties that may arise when making these distinctions. A variety of theories have been proposed to explain causal mechanisms for phantom limb pain. Conceptually, research into phantom limb pain is informed by the particular theory of chronic pain that is dominant at the time the research is undertaken. For example, early physiological theories on the etiology of phantom limb pain were grounded in specificity or pattern theories of pain. Later physiological research was based on the framework provided by Gate Control Theory and focused on identifying peripheral, spinal, and central neural mechanisms. Psychological explanations were grounded in psychoanalytic or personality theories of chronic pain which propose that phantom limb pain results from pre-amputation psychological disturbance. Despite numerous studies examining phantom limb pain, much of this research has both conceptual and methodological shortcomings. As such, the application of these research findings to clinical practice has limited utility.

Phantom limb pain and related disorders

Postamputation phenomena, including painful and nonpainful phantom sensations occur following loss of limbs and other body parts. Peripheral and central nervous system mechanisms play a role in persistent phantom pain. Understanding the pathophysiology of this syndrome has improved in recent years. Comprehensive evaluation and a multimodality treatment approach comprise the current standard of care of the patient with phantom pain.

Responses of the nervous system to low frequency stimulation and EEG rhythms: clinical implications

The present paper reviews literature data on the role of the non-specific central nervous system response mechanisms on the therapeutic effects of relatively weak external stimulations used in clinical practice. The factors affecting the stimulation efficiency and increased sensitiveness of living things to extra-low-frequency periodic stimulations (in the range of from less than 1 Hz to tens of Hz) are discussed. Among the factors determining such effects, the non-specific response mechanisms of the nervous system, the resonance phenomena in different organism systems, and the interaction of external stimulation with endogenous rhythmic processes are analyzed. Most attention is given to endogenous rhythms of the electrical brain activity reflected in the EEG rhythms. A high resolution EEG processing approach that is used to reveal the intrinsic oscillators in the individual EEG spectrum is described. Synchronization of sensory stimulation parameters with the frequencies of intrinsic EEG oscillators is supposed to be an appropriate way to enhance the therapeutic effects of various sensory stimulation treatments. Specific methods for utilizing resonance therapy via sensory stimulation with intrinsic EEG frequencies, and for automatic modulation of stimulation parameters by endogenous organism rhythms are delineated; some preliminary results are described.

Phantom limb pain: elusive, yet real

Phantom limb pain is reported by almost all people who have had an amputation and by others who have dysfunction of their afferent nervous system pathways. Those who experience it indicate that the pain is real and that it is the body part that is "phantom." Although this phenomenon is widely recognized, it is not well understood. The seeming incongruence of pain in a missing body part, combined with the difficulty of successfully treating this pain, result in severe chronic pain in a majority of people who have had an amputation. Treatment with drugs that reduce the number of functional sodium channels has been tried with success, as have various neurophysiological manipulations. This article addresses issues related to sensory experiences associated with phantom body parts and the treatment of pain associated with those experiences.

Rogerian science, phantoms, and therapeutic touch: exploring potentials

Traditional medical approaches to the treatment of potentially distressing phantom pain and sensations have been inconsistent in their success. In this article, the subject of phantom pain and sensations is explored and reconceptualized according to Martha Rogers' science of unitary human beings. Emergent perspectives, illustrated by a series of short case studies, suggest that such a reconceptualization and particularly the use of therapeutic touch may have a significant impact on positive human field image patterning.

The prevalence of phantom sensation and pain in pediatric amputees

Phantom sensations and pain occur with an unknown frequency in children. We hypothesized that such experiences are common among children, and occur more often than is recognized by health-care personnel. Children and adolescents, ages 5-19 years, who had undergone limb amputation in the past 10 years, served as subjects for this retrospective study. Subjects were divided into three major groups depending upon the indication for amputation: congenital deformity (CD), trauma/infection (TI), and cancer (Ca). Surveys assessing phantom sensations and phantom pain were mailed to children and their parents/guardians. The incidence of phantom sensations was 100% in each group, and phantom pain occurred in the overwhelming majority. Both types of phantom phenomena began within days of surgery for almost all patients. Seventy-five percent of children and adolescents who had experienced phantom pain also had preoperative limb pain. At the time of the study, phantom pain had resolved in only 35% of the subjects. Phantom pain was documented in the medical records of only 40% of those answering positively to questions regarding phantom pain on the questionnaire. We conclude that phantom pain occurs commonly in children and adolescents. The association of preoperative pain in the diseased extremity and the later occurrence of phantom pain suggests that preoperative regional anesthesia may prevent phantom pain.

Psychophysical correlates of phantom limb experience

Phantom limb phenomena were correlated with psychophysiological measures of peripheral sympathetic nervous system activity measured at the amputation stump and contralateral limb. Amputees were assigned to one of three groups depending on whether they reported phantom limb pain, non-painful phantom limb sensations, or no phantom limb at all. Skin conductance and skin temperature were recorded continuously during two 30 minute sessions while subjects continuously monitored and rated the intensity of any phantom limb sensation or pain they experienced. The results from both sessions showed that mean skin temperature was significantly lower at the stump than the contralateral limb in the groups with phantom limb pain and non-painful phantom limb sensations, but not among subjects with no phantom limb at all. In addition, stump skin conductance responses correlated significantly with the intensity of non-painful phantom limb paresthesiae but not other qualities of sensation or pain. Between-limb measures of pressure sensitivity were not significantly different in any group. The results suggest that the presence of a phantom limb, whether painful or painless, is related to the sympathetic-efferent outflow of cutaneous vasoconstrictor fibres in the stump and stump neuromas. The hypothesis of a sympathetic-efferent somatic-afferent mechanism involving both sudomotor and vasoconstrictor fibres is proposed to explain the relationship between stump skin conductance responses and non-painful phantom limb paresthesiae. It is suggested that increases in the intensity of phantom limb paresthesiae follow bursts of sympathetic activity due to neurotransmitter release onto apposing sprouts of large diameter primary afferents located in stump neuromas, and decreases correspond to periods of relative sympathetic inactivity. The results of the study agree with recent suggestions that phantom limb pain is not a unitary syndrome, but a symptom class with each class subserved by different aetiological mechanisms.

Psychophysiological contributions to phantom limbs

Recent studies of amputees reveal a remarkable diversity in the qualities of experiences that define the phantom limb, whether painless or painful. This paper selectively reviews evidence of peripheral, central and psychological processes that trigger or modulate a variety of phantom limb experiences. The data show that pain experienced prior to amputation may persist in the form of a somatosensory memory in the phantom limb. It is suggested that the length and size of the phantom limb may be a perceptual marker of the extent to which sensory input from the amputation stump have re-occupied deprived cortical regions originally subserving the amputated limb. A peripheral mechanism involving a sympathetic-efferent somatic-afferent cycle is presented to explain fluctuations in the intensity of paresthesias referred to the phantom limb. While phantom pain and other sensations are frequently triggered by thoughts and feelings, there is no evidence that the painful or painless phantom limb is a symptom of a psychological disorder. It is concluded that the experience of a phantom limb is determined by a complex interaction of inputs from the periphery and widespread regions of the brain subserving sensory, cognitive, and emotional processes.