Pain
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Clinical Trial Controlled Clinical Trial
Analgesic effect of amitriptyline in chronic tension-type headache is not directly related to serotonin reuptake inhibition.
The tricyclic antidepressant amitriptyline is the only documented and most widely used prophylactic drug for chronic tension-type headache (CTTH). However, it is not fully clarified whether the serotonin (5-HT) reuptake inhibition plays a major role for the analgesic effect of amitriptyline. To explore the importance of 5-HT reuptake inhibition for mechanism of action of the analgesic effect of amitriptyline we investigated platelet 5-HT levels during preventive treatment of CTTH with amitriptyline, the selective serotonin reuptake inhibitor citalopram, and placebo. ⋯ The lower platelet 5-HT during treatment with citalopram than amitriptyline indicates that 5-HT reuptake was most effectively inhibited by citalopram. In contrast, amitriptyline was most effective in reduction of headache. This suggests that the analgesic effect of amitriptyline in CTTH is not solely due to 5-HT reuptake inhibition and that other mechanisms such as norepinephrine reuptake inhibition, NMDA receptor antagonism, blockade of muscarinic receptors and ion channels should be addressed in the future research.
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Randomized Controlled Trial Clinical Trial
Safety and efficacy of intranasal ketamine for the treatment of breakthrough pain in patients with chronic pain: a randomized, double-blind, placebo-controlled, crossover study.
Few placebo-controlled trials have investigated the treatment of breakthrough pain (BTP) in patients with chronic pain. We evaluated the efficacy and safety of intranasal ketamine for BTP in a randomized, double-blind, placebo-controlled, crossover trial. Twenty patients with chronic pain and at least two spontaneous BTP episodes daily self-administered up to five doses of intranasal ketamine or placebo at the onset of a spontaneous BTP episode (pain intensity > or =5 on a 0-10 scale). ⋯ After ketamine administration, four patients reported a transient change in taste, one patient reported rhinorrhea, one patient reported nasal passage irritation, and two patients experienced transient elevation in blood pressure. A side effect questionnaire administered 60 min and 24 h after drug or placebo administration elicited no reports of auditory or visual hallucinations. These data suggest that intranasal administration of ketamine provides rapid, safe and effective relief for BTP.
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Randomized Controlled Trial Clinical Trial
Graded motor imagery is effective for long-standing complex regional pain syndrome: a randomised controlled trial.
Complex regional pain syndrome type 1 (CRPS1) involves cortical abnormalities similar to those observed in phantom pain and after stroke. In those groups, treatment is aimed at activation of cortical networks that subserve the affected limb, for example mirror therapy. However, mirror therapy is not effective for chronic CRPS1, possibly because movement of the limb evokes intolerable pain. ⋯ The effect of treatment was replicated in the crossed-over control subjects. The results uphold the hypothesis that a MIP initially not involving limb movement is effective for CRPS1 and support the involvement of cortical abnormalities in the development of this disorder. Although the mechanisms of effect of the MIP are not clear, possible explanations are sequential activation of cortical pre-motor and motor networks, or sustained and focussed attention on the affected limb, or both.
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Comparative Study
Psychological factors in pelvic/urogenital pain: the influence of site of pain versus sex.
Chronic pelvic pain (CPP), a fairly common gynecological complaint in women, has been associated with multiple psychological sequelae, including depression and somatization. Previous work has compared these patients to gynecological controls and women with headache, but has failed to include male comparison groups with a comparable site of chronic pain. In order to test possible sex and pain site differences, the present study compared 22 women with CPP, 22 men with either penile or testicular pain, 22 women with low back pain and 28 men with low back pain referred for a psychological evaluation as part of multidisciplinary pain treatment. ⋯ Similar findings were demonstrated for coping. A variety of pain-coping strategies, including catastrophizing, were more frequently utilized by low back pain patients, regardless of sex. In the present study, pain severity and pain site explained more variance in depressive symptoms, physical functioning, and pain-coping than sex.
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Chronic pain can result in anxiety, depression and reduced quality of life. However, its effects on cognitive abilities have remained unclear although many studies attempted to psychologically profile chronic pain. We hypothesized that performance on an emotional decision-making task may be impaired in chronic pain since human brain imaging studies show that brain regions critical for this ability are also involved in chronic pain. ⋯ Only pain intensity assessed during the gambling task was correlated with task outcome and only in CBP patients (r = -0.75, P < 0.003). Other cognitive abilities, such as attention, short-term memory, and general intelligence tested normal in the chronic pain patients. Our evidence indicates that chronic pain is associated with a specific cognitive deficit, which may impact everyday behavior especially in risky, emotionally laden, situations.