Pain: past, present and future

Alternative medicine and common errors of reasoning

Why do so many otherwise intelligent patients and therapists pay considerable sums for products and therapies of alternative medicine, even though most of these either are known to be useless or dangerous or have not been subjected to rigorous scientific testing? The author proposes a number of reasons this occurs: (1) Social and cultural reasons (e.g., many citizens' inability to make an informed choice about a health care product; anti-scientific attitudes meshed with New Age mysticism; vigorous marketing and extravagant claims; dislike of the delivery of scientific biomedicine; belief in the superiority of "natural" products); (2) psychological reasons (e.g., the will to believe; logical errors of judgment; wishful thinking, and "demand characteristics"); (3) the illusion that an ineffective therapy works, when actually other factors were at work (e.g., the natural course or cyclic nature of the disease; the placebo effect; spontaneous remission; misdiagnosis). The author concludes by acknowledging that when people become sick, any promise of a cure is beguiling. But he cautions potential clients of alternative treatments to be suspicious if those treatments are not supported by reliable scientific research (criteria are listed), if the "evidence" for a treatment's worth consists of anecdotes, testimonials, or self-published literature, and if the practitioner has a pseudoscientific or conspiracy-laden approach, or promotes cures that sound "too good to be true."

Catastrophizing, depression and expectancies for pain and emotional distress

The present research addressed the relation between catastrophizing, depression and response expectancies in anticipation of an experimental pain procedure. One hundred and twenty undergraduates (48 men, 72 women) participated in exchange for course credit. Prior to immersing one arm in a container of ice water, participants were asked to complete measures of catastrophizing and depression, and to estimate the degree of pain and emotional distress they expected to experience. After a 1-min immersion, participants rated their actual experience. Pain expectancies partially mediated the relation between catastrophizing and pain experience. Pain expectancies also mediated the relation between depression and pain experience. Catastrophizing, but not depression, was associated with a tendency to underestimate pain and emotional distress. The implications of these findings for the conceptual distinctiveness of catastrophizing and depression are discussed. Discussion also examines the potential implications of the present findings for pain management interventions.

Korrelate der kortikalen Schmerzverarbeitung - eine Übersicht

Zusammenfassung: Schmerz ist ein kompliziertes Resultat verschiedener neuronaler Aktivitäten unseres Gehirns und nicht nur das einfache Ergebnis der Tätigkeit des peripheren nozizeptiven Systems. Schmerz resultiert aus dem Zusammenspiel verschiedener Module im Gehirn, die sich in verschiedenen Hirnarealen befinden. Er wird durch Erwartungen, Lernprozesse, Erfahrungen und Coping modifiziert. Elektrophysiologische Begleiterscheinungen, die mit der zentralnervösen Schmerzverarbeitung assoziiert sind, erlauben dabei eine Charakterisierung der ablaufenden Informationsverarbeitungsprozesse. Neben der grundlagentheoretischen Bedeutung spielt hier die Evaluation verschiedener Therapieansätze eine herausragende Rolle. Darüber hinaus konnte mit Hilfe der Hirnelektrizität nachgewiesen werden, daß auch die kortikalen Module des nozizeptiven Systems im Zusammenhang mit Schmerzverarbeitung funktionell reorganisiert werden. Die relativ neuen quellenanalytischen Ansätze lassen einen weiteren, deutlichen Erkenntnisgewinn über die Rolle einzelner Hirnstrukturen bei der Verarbeitung und Behandlung von Schmerz erwarten.

Hypnotic analgesia: 1. Somatosensory event-related potential changes to noxious stimuli and 2. Transfer learning to reduce chronic low back pain

Fifteen adults with chronic low back pain (M = 4 years), age 18 to 43 years (M = 29 years), participated. All but one were moderately to highly hypnotizable (M = 7.87; modified 11-point Stanford Hypnotic Susceptibility Scale, Form C [Weitzenhoffer & Hilgard, 1962]), and significantly reduced pain perception following hypnotic analgesia instructions during cold-pressor pain training. In Part 1, somatosensory event-related potential correlates of noxious electrical stimulation were evaluated during attend and hypnotic analgesia (HA) conditions at anterior frontal (Fp1, Fp2), midfrontal (F3, F4), central (C3, C4), and parietal (P3, P4) regions. During HA, hypothesized inhibitory processing was evidenced by enhanced N140 in the anterior frontal region and by a prestimulus positive-ongoing contingent cortical potential at Fp1 only. During HA, decreased spatiotemporal perception was evidenced by reduced amplitudes of P200 (bilateral midfrontal and central, and left parietal) and P300 (right midfrontal and central). HA led to highly significant mean reductions in perceived sensory pain and distress. HA is an active process that requires inhibitory effort, dissociated from conscious awareness, where the anterior frontal cortex participates in a topographically specific inhibitory feedback circuit that cooperates in the allocation of thalamocortical activities. In Part 2, the authors document the development of self-efficacy through the successful transfer by participants of newly learned skills of experimental pain reduction to reduction of their own chronic pain. Over three experimental sessions, participants reported chronic pain reduction, increased psychological well-being, and increased sleep quality. The development of "neurosignatures of pain" can influence subsequent pain experiences (Coderre, Katz, Vaccarino, & Melzack, 1993; Melzack, 1993) and may be expanded in size and easily reactivated (Flor & Birbaumer, 1994; Melzack, 1991, 1993). Therefore, hypnosis and other psychological interventions need to be introduced early as adjuncts in medical treatments for onset pain before the development of chronic pain.

Cognitive-behavioral therapy for clinical pain control: a 15-year update and its relationship to hypnosis

Since Tan's (1982) review of cognitive and cognitive-behavioral methods for pain control was published 15 years ago, significant advances have been made in cognitive-behavioral therapy for pain. The scientific evidence for its efficacy for clinical pain attenuation is now much more substantial and is briefly reviewed. In particular, cognitive-behavioral therapy for chronic pain was recently listed as one of 25 empirically validated or supported psychological treatments available for various disorders. A number of emerging issues are further discussed in light of recent developments and research findings. The relationship of cognitive-behavioral therapy to hypnosis for pain control is briefly addressed, with suggestions for integrating hypnotic and cognitive-behavioral techniques.

Phantom limb imaginary fingertapping causes primary motor cortex activation: an fMRI study

A conventional 1.0 T MR-scanner was used to detect signal intensity changes in blood oxygenation level dependent-sensitive acquisitions of motor cortex during real (left hand) and imaginary (right hand) fingertapping in a man who had his right arm amputated. The subject was instructed alternately to move the intact left hand fingers and to imagine tapping his 'fingers' on the amputated right hand. Activated areas were detected using a cross-correlation technique with superimposition of highly correlated voxels on to a corresponding high resolution, anatomical 3D image. Activation was observed in the right motor cortex during fingertapping with the intact left hand, and a corresponding activation in the left motor cortex for imaginary movements of the amputated right hand fingers.

Orofacial phantom pain: theory and phenomenology

Developing a treatment strategy for patients who are in chronic pain can be challenging for any health care professional, particularly when traditional measures to relieve pain are ineffective. Pain treatment can be further complicated by phenomena known as phantom pain--most often associated with limb amputation. The author describes three phantom syndromes experienced in the orofacial region: phantom tooth pain, phantom bite syndrome and intraoral stump pain.

PSYCHOLOGY IN CANADA

▪ Abstract  This chapter reviews how psychology in Canada evolved over half a century to become the most popular discipline in universities and a respected health-care and helping profession. The organization, journals, and funding of the scientific discipline are described. The importance of DO Hebb's research as the stimulus and foundation for discipline growth and significant research contributions to basic processes is identified. The multicultural mosaic of Canadian society and early research on second-language learning are shown to have influenced cross-cultural and social research. Canadian research contributions to basic processes and to the social and health sciences are reviewed. Although late to begin in Canada, clinical research and the profession of psychology are shown to have substantially developed over the past two decades. With large numbers of quality researchers and practitioners, psychology has a bright future in Canada.

Hypnosis treatment of clinical pain: understanding why hypnosis is useful

Clinical and experimental research literature indicates hypnosis is very useful for severe and persistent pain, yet reviews suggest hypnosis is not widely used. To encourage more widespread clinical application, the author reviews recent controlled clinical studies in which hypnosis compares favorably with other interventions; links advances in understanding endogenous pain modulation to a neurophysiologic view of hypnosis and hypnoanalgesia; relates the neurophysiology of hypnoanalgesia to management of chronic pain; challenges the view that hypnotic pain control is only for the highly hypnotizable patient; and raises issues about how people learn to control pain with hypnosis. Training in hypnotic analgesia may usefully enhance nervous system inhibitory processes that attenuate pain.