Pain
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This review is a critical summary of research examining gender variations in clinical pain experience. Gender-comparative pain research was identified through Medline and Psychlit searches and references obtained from bibliographies of pertinent papers and books. Review of this research demonstrates that women are more likely than men to experience a variety of recurrent pains. ⋯ Women may be at greater risk for pain-related disability than men but women also respond more aggressively to pain through health related activities. Women may be more vulnerable than men to unwarranted psychogenic attributions by health care providers for pain. Underlying biological mechanisms of pain and the contribution of psychological and social factors as they contribute to the meaning of pain for women and men warrant greater attention in pain research.
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One of the physiological changes accompanying neuropathic pain from nerve injury is the spontaneous firing of primary afferent fibers. At least some of this activity is thought to arise from the dorsal root ganglion. We have investigated whether this activity is resident in the cell bodies of dorsal root ganglion neurons and if it is retained in vitro. ⋯ Spontaneous resting potential fluctuations (up to 10 m V peak-to-peak) occurred in both control and CCI neurons, and triggered the spontaneous, random action potentials in neurons from CCI rats. Spontaneously firing neurons exhibited more negative action potential threshold (-34.8 mV) when compared to quiescent neurons from ganglia either after CCI (-18.7 mV) or controls (-20.5 mV). These findings show that spontaneous action potential activity after CCI is a property residing in the cell bodies of dorsal root ganglion neurons and is amenable to more detailed analysis using such an in vitro system, allowing better understanding of the cellular changes underlying neuropathic pain from nerve injury.
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Randomized Controlled Trial Clinical Trial
Specificity of diagnostic nerve blocks: a prospective, randomized study of sciatica due to lumbosacral spine disease.
Temporary nerve blocks using local anesthetic are employed extensively in the evaluation of pain problems, particularly lumbosacral spine disease. Their specificity and sensitivity in localizing anatomic sources of pain have never been studied formally, however, and so their diagnostic and prognostic value is questionable. There have been anecdotal reports of relief of pain by temporary blocks directed to areas of pain referral, as opposed to areas of documented underlying pathology; but there has been no study to define the frequency or magnitude of this effect. ⋯ Our findings indicate a limited role for uncontrolled local anesthetic blocks in the diagnostic evaluation of sciatica and referred pain syndromes in general. Negative blocks or a pattern of responses may have some predictive value, but isolated, positive blocks are non-specific. This lack of specificity may, however, be advantageous in therapeutic applications.
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Randomized Controlled Trial Clinical Trial
Lidocaine patch: double-blind controlled study of a new treatment method for post-herpetic neuralgia.
Post-herpetic neuralgia (PHN) is a common and often intractable neuropathic pain syndrome predominantly affecting the elderly. Topical local anesthetics have shown promise in both uncontrolled and controlled studies. Thirty-five subjects with established PHN affecting the torso or extremities completed a four-session, random order, double-blind, vehicle-controlled study of the analgesic effects of topically applied 5% lidocaine in the form of a non-woven polyethylene adhesive patch. ⋯ The highest blood lidocaine level measured was 0.1 micrograms/ml, indicating minimal systemic absorption of lidocaine. Patch application was without systemic side effect and well tolerated when applied on allodynic skin for 12 h. This study demonstrates that topical 5% lidocaine in patch form is easy to use and relieves post-herpetic neuralgia.