A New Spinal Cord Stimulation System Effectively Relieves Chronic,Intractable Pain: A Multicenter Prospective Clinical Study

Objectives. A prospective, open label, multicenter clinical trial confirmed the functionality of a new spinal cord stimulation (SCS) system for the treatment of chronic, intractable pain of the trunk and/or limbs. Materials and Methods. Sixty‐five subjects tested a rechargeable 16‐channel SCS system with individual current control of each contact on one or two percutaneous eight‐contact epidural leads. After baseline measurements, subjects were tracked on pain ratings and complication rates for up to 18 months. Results. After a trial period, 75% of subjects underwent permanent implantation of the entire SCS system. More than one‐half the implanted subjects experienced 50% or greater relief of pain after permanent implantation; some subjects reported relief of 90% or more of their pain. The most common complications after permanent implantation were lead migration, uncomfortable stimulation, and component failure; most resolved after reprogramming or device replacement. Conclusions. The new SCS system provided good pain relief to a majority of subjects, and the results confirm a favorable safety and efficacy profile for the SCS system.     

A Prospective Multicenter Case Series Utilizing Intraoperative Neuromonitoring With Evoked Compound Action Potentials to Confirm Spinal Cord Stimulation Lead Placement

ObjectivesThe use of intraoperative neuromonitoring (IONM) has been adapted to address issues of safety and proper lead positioning in spinal cord stimulation. This multicenter case series seeks to incorporate the use of evoked compound action potential (ECAP) and late response (LR) recording and compare it with the results obtained with IONM, specifically electromyography (EMG), for the confirmation of lead placement. This study aimed to establish a correlation between ECAPs, LR, and EMG and publish human recordings of ECAPs and LR during their use with IONM.Materials and MethodsStandard neuromonitoring protocols were followed at two institutions, with two separate physicians and with seven patients, as part of a larger ongoing study registered with ClinicalTrials.gov (NCT02924129). Stimulation and recording were performed, top and bottom, on each percutaneous lead. Stimulation amplitude was increased considering ECAP, LR, and EMG thresholds.ResultsECAPs, LRs, and EMG signals were observed in all patients. The onset of LR signals on implanted electrodes and EMG signal on subdermal electrodes was well correlated (rs = 0.94, p < 0.001), with a median LR:EMG value of 1.06 (N = 21). LR:EMG for the top (mean = 0.97, N = 8) vs bottom (mean = 1.15, N = 13) of the lead was compared using a paired Wilcoxon signed rank test and an independent samples Mann-Whitney test, revealing a marginally significant and a statistically significant difference (p = 0.078 and p = 0.015, respectively). Mean LR:ECAP was >2 in all locations and approximately 3.5 overall. LR:ECAP between the top and bottom of the lead was significantly different (Wilcoxon test, p < 0.01, N = 12).ConclusionsLR correlated with EMG; leads with bilateral (not necessarily symmetric) EMG activity showed LR:ECAP > 1.5. An LR:ECAP of <1, with LR/EMG generated before the ECAP, indicated that the lead is too lateral. The use of ECAP and LR has the potential of maintaining objective lead placement, without the need for needle placement with IONM.     

Transcutaneous electrical nerve stimulator trial may be used as a screening tool prior to spinal cord stimulator implantation

This is a prospective pilot study looking at the utility of Transcutaneous Electrical Nerve Stimulator (TENS) trial as a screening tool prior to spinal cord stimulator (SCS) implant to identify patients who may fail a SCS trial. The accepted screening test prior to a permanent SCS implant is a SCS trial. Patients may fail the SCS trial due to several causes of which one is the inability to tolerate stimulation induced paresthesias. Twenty five patients scheduled for a SCS trial for the treatment of refractory pain secondary to Failed Back surgery syndrome underwent a TENS trial and psychological evaluation by personnel uninvolved in the SCS trial. Data was collected by personnel not involved in the SCS trial or permanent placement. Twenty patients completed the study. Data collected included area of coverage, paresthesia tolerance, pain and anxiety measured on a VAS scale. Comparability between the groups were analyzed using Pearson’s correlation, Fisher Exact test and simple regression analysis. We noted a significant correlation between ability to tolerate TENS and SCS induced paresthesias. Statistically significant correlation was also noted between pre SCS trial anxiety score and high pain score during SCS trial. We conclude that there is potential applicability of a TENS trial as a non invasive screening tool which may promote cost effectiveness and decrease unnecessary procedural risks to the patient by avoiding SCS trial in select patients.     

Effect of polar day on plasma profiles of melatonin, testosterone, and estradiol in high-Arctic Lapland Longspurs

In polar habitats, continuous daylight (polar day) can prevail for many weeks or months around the summer solstice. In the laboratory, continuous light conditions impair or disrupt circadian rhythms in many animals. To determine whether circadian rhythms are disrupted under natural polar day conditions in a species that is only a summer resident in polar regions we analyzed diel rhythms in plasma concentrations of melatonin, testosterone (T), and 17-beta estradiol (E(2)) during the summer solstice in Arctic-breeding Lapland Longspurs (Calcarius lapponicus). We compared these profiles to those of conspecifics housed in outdoor aviaries at a mid-latitude site in Seattle, Washington, during spring, summer, fall, and winter. Under polar day conditions plasma melatonin concentrations of Lapland Longspurs were strongly suppressed, but still showed a significant diel rhythm. Likewise, plasma T in males, and E(2) in females, showed significant diel changes in Arctic birds. Lapland Longspurs housed at mid-latitude in Seattle showed high-amplitude melatonin cycles at all times of the year, and the duration of the nightly melatonin secretion was positively correlated with the duration of the dark phase. We found no diel changes in plasma T in Seattle males in May, but Seattle females showed significant day/night differences in plasma E(2) in May. The data suggest that even under polar day conditions diel rhythms can persist. The maintenance of hormone rhythms could provide a physiological basis to reports of rhythmic behavior in many birds during the Arctic summer.     

West African monsoon dynamics inferred from abrupt fluctuations of Lake Mega-Chad

From the deglacial period to the mid-Holocene, North Africa was characterized by much wetter conditions than today. The broad timing of this period, termed the African Humid Period, is well known. However, the rapidity of the onset and termination of the African Humid Period are contested, with strong evidence for both abrupt and gradual change. We use optically stimulated luminescence dating of dunes, shorelines, and fluviolacustrine deposits to reconstruct the fluctuations of Lake Mega-Chad, which was the largest pluvial lake in Africa. Humid conditions first occur at ∼15 ka, and by 11.5 ka, Lake Mega-Chad had reached a highstand, which persisted until 5.0 ka. Lake levels fell rapidly at ∼5 ka, indicating abrupt aridification across the entire Lake Mega-Chad Basin. This record provides strong terrestrial evidence that the African Humid Period ended abruptly, supporting the hypothesis that the African monsoon responds to insolation forcing in a markedly nonlinear manner. In addition, Lake Mega-Chad exerts strong control on global biogeochemical cycles because the northern (Bodélé) basin is currently the world’s greatest single dust source and possibly an important source of limiting nutrients for both the Amazon Basin and equatorial Atlantic. However, we demonstrate that the final desiccation of the Bodélé Basin occurred around 1 ka. Consequently, the present-day mode and scale of dust production from the Bodélé Basin cannot have occurred before 1 ka, suggesting that its role in fertilizing marine and terrestrial ecosystems is either overstated or geologically recent.The West African monsoon (WAM) is key to our understanding of the African climate system and the impacts of future climate change upon its population. Climatically, the WAM is a major component of the global monsoon belt, which regulates moisture availability in the low latitudes and is sensitive to climate dynamics in both the high latitudes and the tropics. From a human perspective, the WAM represents the dominant control upon agricultural productivity in a densely populated region that is heavily reliant on subsistence agriculture (1). The broad pattern of WAM dynamics since the Last Glacial Maximum (LGM) is well known, with initially arid conditions being replaced by a more humid phase, sometimes termed the African Humid Period (AHP), which lasted from the deglacial period to the mid-Holocene. However, paleoclimate proxy data from North Africa and adjacent areas of the Atlantic provide contrasting evidence for the rate and timing of these changes, leading to uncertainty over the controls upon WAM dynamics.     

冬病夏治穴位贴敷理论及临床应用

冬病夏治是我国传统中医药疗法中的特色疗法,是根据古代医书中“春夏养阳”和“长夏胜冬”等理论发展而来.穴位贴敷是冬病夏治法中的典型代表,现代医学研究阐释了穴位贴敷疗法的作用机制,通过药物透皮吸收和经络穴位共同作用,主要调节免疫功能,对于代谢、神经、抗肿瘤等方面也有调节作用,为冬病夏治穴位贴敷治疗疾病提供了理论依据,在临床应用中也有很好的疗效,尤其对于呼吸系统疾病如过敏性鼻炎、咳嗽等效果显著.