Current review of pain最新文献

Visceral pain, although different from somatic pain in several important features, is not as widely researched and consequently our knowledge of neurophysiologic mechanisms as well as clinical management of visceral pain states remains unsatisfactory. Several recent studies have employed different visceral pain animal models to provide insight into the peripheral and central nervous system mechanisms underlying pain originating from the urinary bladder, ureter, and gastrointestinal tract. The effects of opioid and nonopioid drugs in these models have also been evaluated and are reviewed in this article. The importance of anatomic pathways relaying pain sensation in the central nervous system, particularly the newly described dorsal column pathway, is also discussed. In human subjects, new techniques like positron emission tomography are now being used to better understand visceral pain perception. Such findings deriving from basic animal research and human studies summarized in the present overview lead to a better understanding of visceral pain states and may be helpful in developing better treatment strategies to combat visceral pain states in the clinical setting.

Fibromyalgia and other chronic pain and fatigue syndromes constitute an increasingly greater societal burden that currently is not being approached effectively by traditional Western medicine. Although the hallmarks of fibromyalgia--chronic widespread pain, fatigue, and multiple other somatic symptoms--have neurophysiologic and endocrinologic underpinnings, these biological aspects derive primarily from psychological variables. Female gender, adverse experiences during childhood, psychological vulnerability to stress, and a stressful, often frightening environment and culture are important antecedents of fibromyalgia. To understand fibromyalgia and related syndromes and to provide optimum care requires a biopsychosocial, not a biomedical, viewpoint.

Physicians and other clinicians who treat patients with chronic pain have doubtless recognized the interplay of various psychological and somatic variables in their patients' pain. Notwithstanding, there continues to be primary emphasis on the somatic factors, and continued neglect of the psychological. This article asserts that pain disorder and somatization disorder are indeed valid diagnostic entities, and that their respective incidence and prevalence are quite high both in patients with chronic pain and in the primary care setting. These diagnoses are compared and contrasted, along with the related diagnosis of the psychological factors affecting physical condition. Guidelines for assessment of these conditions are provided, as are recommendations as to when to refer patients for further psychological and psychiatric assessment and treatment.

In the last decade there has been significant controversy about the appropriateness, efficacy, safety, and wisdom of treating chronic pain patients (CPPs) with opioids. Arguments against their use have included concerns about tolerance, dependence, addiction, persistent side effects, and interference with physical or psychosocial functioning. However, considerable experience and research with long-term cancer pain treatment suggests that in appropriately selected patients, opioids have a low morbidity, and a low addiction potential, and in addition to the primary analgesic action, can facilitate reduction in suffering, enhance functional activity level, and improve quality of life without significant risk of addictive behaviors. Some patients, however, are at risk. Risk factors for addiction are discussed in this article.

Neurolytic celiac plexus block (NCPB) is commonly performed to relieve pancreatic cancer pain. Since Kappis described the percutaneous NCPB, a number of variations of this technique have been proposed to improve analgesic results and minimize complications. In this article, we review and discuss techniques, results, and complications of NCPB.

Postherpetic neuralgia (PHN) is the most common complication of herpes zoster, and as such has been an area of extensive medical research for the past three decades. The patients at highest risk for PHN include those older than 50 years, those with severe acute cases of zoster, and those with shingles in a trigeminal distribution. As persons with malignancy are at a high risk for developing zoster itself, PHN is a complication that will be faced by many of these patients and their caregivers. This article reviews the available treatments and preventative measures for this debilitating condition.

The nomenclature, pathophysiology, and treatment modalities of complex regional pain syndrome (CRPS) are controversial. Thus far there are no specific, scientifically valid treatments for the management of CRPS. The numerous modalities of treatment range from sympathetic ganglion blocks, intravenous regional blocks, administration of a multitude of pharmacologic agents and behavioral interventions, to surgical sympathectomy. Minimally invasive radiofrequency lesioning for managing CRPS is a modality in its developmental stages. This article describes radiofrequency lesioning techniques in managing CRPS.

Two approaches to genetic therapy for the management of chronic pain have recently been investigated in animal models of pain. First, transgene-mediated delivery of antinociceptive molecules to the cerebrospinal fluid has been performed with engineered cell lines transplanted to the subarachnoid space and with recombinant adenoviruses that transduce pia mater cells. Second, the phenotype of nociceptive neurons has been altered by recombinant herpes viruses overexpressing antinociceptive peptides or reducing expression of endogenous nociceptive molecules. Both approaches attenuate or reverse persistent nociceptive states, suggesting use in the development of genetic therapy for pain management in humans.

Pharmacologic, electrophysiologic, and immunohistochemical studies have suggested a role of nitric oxide (NO) in nociception processing. Recent studies have indicated that NO may modulate spinal and sensory neuron excitability through multiple mechanisms that may underlie its distinctive roles in different pain states. Differential regulation of a family of NO-producing enzymes, NO synthases, contributes mainly to the complexity underlying the role of NO in nociception. This review summarizes the latest advances in our understanding of the contribution of NO to pain transduction. Possible cellular mechanisms regarding the connection between NO production and the abnormal sensation derived from different stimuli and pathologic conditions are discussed.

Although the feeling or sensation that we call pain is usually uncomfortable and unpleasant, it is actually a great asset in many situations in general medicine, especially when we think of children and older people. Were it not for a persistent complaint or expression of pain, family members or others might not realize that a small child or older person has suffered a significant injury or is ill. Indeed, at any age, the symptom of pain may be an important indication that a disease may be present. For young children, the sensation of pain can also be a learning experience, teaching them to take extra care with such items as hot stoves or broken glass. All those situations in which injury, disease, or something of a physical nature has caused pain are universally understood without any disagreement. We see in them a logical sequence of cause and effect. The focus of this article is on those patients who complain of pain for a long period of time but in whom no physical disease has ever been found.