Pain
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Clinical Trial
Brain activity for spontaneous pain of postherpetic neuralgia and its modulation by lidocaine patch therapy.
Postherpetic neuralgia (PHN) is a debilitating chronic pain condition, yet there is a lack of knowledge regarding underlying brain activity. Here we identify brain regions involved in spontaneous pain of PHN (n=11) and determine its modulation with Lidoderm therapy (patches of 5% lidocaine applied to the PHN affected body part). Continuous ratings of fluctuations of spontaneous pain during fMRI were contrasted to ratings of fluctuations of a bar observed during scanning, at three sessions: (1) pre-treatment baseline, (2) after 6h of Lidoderm treatment, and (3) after 2 weeks of Lidoderm use. ⋯ Pain properties: average magnitude of spontaneous pain, and responses on Neuropathic Pain Scale (NPS), decreased with treatment. The ventral striatal and amygdala activity best reflected changes in NPS, which was modulated only with longer-term treatment. The results show a specific brain activity pattern for PHN spontaneous pain, and implicate areas involved in emotions and reward as best reflecting changes in pain with treatment.
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Randomized Controlled Trial
Lamotrigine for treatment of pain associated with diabetic neuropathy: results of two randomized, double-blind, placebo-controlled studies.
To assess the efficacy and tolerability of lamotrigine in pain associated with diabetic neuropathy, two replicate randomized, double-blind, placebo-controlled studies were conducted. Patients (n=360 per study) with painful diabetic neuropathy were randomized to receive lamotrigine 200, 300, or 400 mg daily or placebo during the 19-week treatment phase, including a 7-week dose-escalation phase and a 12-week, fixed-dose maintenance phase. The mean reduction in pain-intensity score from baseline to week 19 (primary endpoint) was greater (p < or = 0.05) in patients receiving lamotrigine 400 mg than placebo in Study 2 (observed scores, -2.7 versus -1.6 on a 0- to 10-point scale). ⋯ Adverse events were reported in 71-82% of lamotrigine-treated patients compared with 63-70% of placebo-treated patients. The most common adverse events with lamotrigine were headache and rash. Compared with placebo, lamotrigine (300 and 400 mg daily) was inconsistently effective for pain associated with diabetic neuropathy but was generally safe and well tolerated.
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Randomized Controlled Trial Multicenter Study
Randomized controlled trial of exercise for chronic whiplash-associated disorders.
Whiplash-associated disorders are common and incur considerable expense in social and economic terms. There are no known effective treatments for those people whose pain and disability persist beyond 3 months. We conducted a randomized, assessor-blinded, controlled trial at two centres in Australia. ⋯ High levels of baseline pain intensity were associated with greater treatment effects at 6 weeks and high levels of baseline disability were associated with greater treatment effects at 12 months. In the short-term exercise and advice is slightly more effective than advice alone for people with persisting pain and disability following whiplash. Exercise is more effective for subjects with higher baseline pain and disability.
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Randomized Controlled Trial
Classical conditioning and expectancy in placebo hypoalgesia: a randomized controlled study in patients with atopic dermatitis and persons with healthy skin.
The effectiveness of placebos is unchallenged. However, it is still not clear on which mechanisms the placebo effect is based. Besides expectancy theories, classical conditioning is discussed as a major explanatory model. ⋯ However, conditioning processes seem to be necessary for a longer lasting effect. The extent of this effect seemed to be greater in atopics than in healthy controls. Expectancy, achieved through verbal instruction, might also be seen as a conditioned stimulus that reactivates earlier stimulus associations.