Pharmacotherapies for Central Post-Stroke Pain: A Systematic Review and Network Meta-Analysis.

Background: Central post-stroke pain (CPSP) is a common condition. Several pharmacotherapies have been applied in practice. However, the comparative effectiveness among these pharmacotherapies is unknown. Aim: The aim of this study is to study the comparative effectiveness among differential pharmacotherapies for CPSP through a network meta-analysis. Methods: We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science from inception to 30 March 2022, without any language restriction. Two reviewers independently screened the retrieved articles, extracted data, and evaluated the risk of bias (RoB). The outcome of interest of the study was the change in the scores of pain intensity scales. We estimated standard mean differences (SMDs) between treatments and calculated corresponding 95% CIs. Results: Thirteen randomized controlled trials (529 participants) were included after a screen of 1774 articles. Compared with placebo, pamidronate (SMD -2.43, 95% CI -3.54 to -1.31; P - score = 0.93), prednisone (SMD -2.38, 95% CI -3.09 to -1.67; P - score = 0.92), levetiracetam (SMD -2.11, 95% CI -2.97 to -1.26; P - score = 0.87), lamotrigine (SMD -1.39, 95% CI -2.21 to -0.58; P - score = 0.73), etanercept (SMD -0.92, 95% CI -1.8 to -0.03; P - score = 0.59), and pregabalin (SMD -0.46, 95% CI -0.71 to -0.22; P - score = 0.41) had significantly better treatment effect. Pamidronate, prednisone, and levetiracetam ranked as the first three most effective treatments. In subgroup analyses, prednisone, levetiracetam, lamotrigine, and pregabalin were more effective than placebo as oral pharmacotherapies, while etanercept was more effective than placebo as injectable pharmacotherapy. Conclusions: Our study confirmed that pamidronate, prednisone, and guideline-recommended anticonvulsants were effective for reducing pain intensity for CPSP. Pamidronate and prednisone showed better effect than other pharmacotherapies, which warrants further investigation.

Social crowding sensitizes high-responding rats to psychomotor-stimulant effects of morphine.

Large individual differences have been identified toward varied addictive effects as evidenced in self-administration, place conditioning, and psychomotor stimulation paradigms, which have been primarily attributed to the role of congenital factors. However, it remains unknown whether environmental factors, like extraneous social stress events, could distinctively modulate animals with differentiated biobehavioral traits, such as rats with higher motor activity (high responder, HR) developed in a novel environment and their counterparts, LR (low responder) rats. In the present study, the influence of social crowding procedure upon morphine psychomotor effect was investigated. Moreover, the roles social stress played, respectively, on HRs and LRs were explored based on previous observation that HRs not only responded more to drugs but also to stress. Our results revealed that social crowding procedure could sensitize morphine psychomotor effect as a whole, and this effect was only evident for HR but not LR rats. The individual differences toward morphine psychomotor effects was indiscernible in rats housed in normal social conditions and only turned out to be significant under stress conditions. Given the fact that the occurrence of human addictive behavior usually happens within social environment permeated with various stress factors, the genetic and environmental elements may collaboratively contribute to the ultimate susceptibility of drug-prone individuals.