Pain
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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.
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Randomized Controlled Trial Comparative Study Clinical Trial
Responsiveness of functional status in low back pain: a comparison of different instruments.
This study compares the responsiveness of three instruments of functional status: two disease-specific questionnaires (Oswestry and Roland Disability Questionnaires), and a patient-specific method (severity of the main complaint). We compared changes over time of functional status instruments with pain rated on a visual analog scale. Two strategies for evaluating the responsiveness in terms of sensitivity to change and specificity to change were used: effect size statistics and receiver-operating characteristic method. ⋯ The sensitivity to change of the rating of Oswestry Questionnaire was lower than that of the other instruments. The main complaint was not very specific to change. The two strategies for evaluating the responsiveness were very useful and appeared to complement each other.
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Randomized Controlled Trial Clinical Trial
Correlates of depression in chronic pain patients: a comprehensive examination.
This study examined the relations between depression and demographic, pain-related, and work-related variables in 254 chronic pain patients. Regression analyses were conducted, initially by category (i.e., demographic, pain-related, and work-related), and finally a comprehensive regression analysis was performed, containing the significant independent variables from each category. Among the demographic variables, education level and marital status were related to depression, and an interaction between age and gender was associated with depression, with younger women and older men reporting more depression. ⋯ Among the work-related variables, unemployment was associated with depression, and there was an interaction between work status and litigation status, with working and litigating being associated with depression and not working and not litigating being associated with depression. In the comprehensive analysis, work status, education level, and marital status accounted for a significant amount of the variance in depression scores. These findings, together with future research directions, are discussed.
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Randomized Controlled Trial Clinical Trial Controlled Clinical Trial
Modulation of pressure pain thresholds during and following isometric contraction in patients with fibromyalgia and in healthy controls.
This study aimed at evaluating the influence of submaximal isometric contraction on pressure pain thresholds (PPTs) in 14 fibromyalgia (FM) patients and 14 healthy volunteers, before and after skin hypoesthesia. PPTs were determined with pressure algometry over m. quadriceps femoris before, during and following an isometric contraction. Maximum voluntary contraction (MVC) was assessed using a computerized dynamometer. ⋯ Anesthetic cream raised PPTs at rest in controls (P < 0.01) but not in FM patients, and did not influence contraction or post-contraction PPTs in either group. Therefore, the increased pressure pain sensibility in FM patients is more pronounced deep to the skin. The observed decrease of PPTs during isometric contraction in FM patients could be due to sensitization of mechanonociceptors caused by muscle ischemia and/or dysfunction in pain modulation during muscle contraction.