One-Year Results of Prospective Research Study Using 10 kHz Spinal Cord Stimulation in Persistent Nonoperated Low Back Pain of Neuropathic Origin: Maiden Back Study.

PURPOSE: Spinal cord stimulation (SCS) is a recommended treatment for chronic neuropathic pain. Persistent nonoperative low back pain of neuropathic origin has profound negative impacts on patient's lives. This prospective, open label, research study aimed to explore the use of SCS in patients with associated features of central sensitisation such as allodynia and hyperalgesia. MATERIALS AND METHODS: Twenty-one patients with back pain and hyperalgesia or allodynia who had not had prior spinal surgery underwent a SCS trial followed by full implantation. SCS comprised administering electrical impulses epidurally at a frequency of 10 kHz and pulse width of 30 µsec. Patients attended follow-up visits after 6 and 12 months of SCS. Repeated measure ANOVAs/Friedman tests explored change after 6 and 12 months of 10 kHz SCS. Independent sample t-tests/Mann-Whitney U tests examined differences in response after 12 months of 10 kHz SCS. RESULTS: Back and leg pain, quality of life (QoL), pain-related disability, and morphine equivalence significantly improved compared with baseline following 6 and 12 months of 10 kHz SCS. There were no increases in the consumption of opioids, amitriptyline, gabapentin or pregabalin in any patient. After 12 months of treatment, 52% encountered ≥50% improvement in back pain, 44% achieved remission (0-3 cm back pain VAS), 40% reported ODI scores between 0 and 40 and 60% experienced a reduction of at least 10 ODI points. Patients reporting ≥10-point improvement in ODI had significantly longer pain history durations and experienced significantly greater improvements in back pain, leg pain and QoL than those reporting <10-point improvement in ODI. CONCLUSION: The 10 kHz SCS improved back and leg pain, QoL, pain-related disability and medication consumption in patients with nonoperative back pain of neuropathic origin. With further research incorporating a sham control arm, the efficacy of 10 kHz SCS in this patient cohort will become more established.

Psychosocial vulnerability from adolescence to adulthood: a prospective study of attachment style differences in relationship functioning and partner choice.

Using a prospective research design, this study explored whether attachment style during adolescence forecasts the nature and quality of romantic relationships in early adulthood and investigated two general pathways for explaining these effects. Black and White community residents were first interviewed in adolescence at which time they completed a self-report measure of attachment style. Approximately 6 years later, they participated in a follow-up interview along with their current romantic partners (N = 224 couples). Results revealed that insecure attachment in adolescence was a risk factor for adverse relationship outcomes in adulthood, although the effects were most consistent for avoidant attachment. Avoidant adolescents were involved in relationships that they (and their partners) rated as less satisfying overall; they also engaged in fewer pro-relationship behaviors, and perceived that their partners engaged in fewer pro-relationship behaviors. In addition, avoidant adolescents were involved with partners who had less healthy personality profiles. Results for anxious-ambivalent and secure attachment were weaker, more complex, and moderated by gender. This study provides the first prospective evidence that avoidant attachment places individuals at risk for adverse relationship outcomes and highlights potential pathways through which this occurs.

Host responses to Renibacterium salmoninarum and specific components of the pathogen reveal the mechanisms of immune suppression and activation.

During infection, Renibacterium salmoninarum survives within the pronephric macrophages of salmonid fish. Therefore, to study the initial phases of the interaction we infected macrophages with live bacteria and analysed the responses of host and pathogen. It was found that the expression of msa encoding the p57 antigen of R. salmoninarum, was constitutive, while the expression of hly and rsh, encoding haemolysins, and lysB and grp was reduced after infection. Macrophages showed a rapid inflammatory response in which the expression of interleukin-1beta (IL-1beta), major histocompatibility complex class II (MHC II), inducible cyclo-oxygenase (Cox-2), and inducible nitric oxide synthase (iNOS) was enhanced, but tumour necrosis factor-alpha (TNF-alpha) expression was greatly reduced initially and then increased. After 5 days, except for TNF-alpha and MHC II, expression returned to levels approaching those of uninfected macrophages. We propose that R. salmoninarum survives initial contact with macrophages by avoiding and/or interfering with TNF-alpha-dependent killing pathways. The effects of specific R. salmoninarum components were studied in vivo by injecting fish with DNA vaccine constructs expressing msa, hly, rsh, lysB, or grp. We found that msa reduced the expression of IL-1beta, Cox-2, and MHC II but stimulated TNF-alpha while hly, rsh and grp stimulated MHC II but down-regulated TNF-alpha. Constructs expressing hly or lysB stimulated iNOS expression and additionally, lysB stimulated TNF-alpha. The results show how p57 suppresses the host immune system and suggest that the immune mechanisms for the containment of R. salmoninarum infections rely on MHC II- and TNF-alpha-dependent pathways. Moreover, prolonged stimulation of TNF-alpha may contribute to the chronic inflammatory pathology of bacterial kidney disease.

Illness experience, depression, and anxiety in chronic fatigue syndrome.

OBJECTIVE: Given the high rate of psychiatric comorbidity with chronic fatigue syndrome (CFS), we considered two possible correlates of anxiety and depression: lack of illness legitimization and beliefs about limiting physical activity. METHOD: A total of 105 people diagnosed with CFS reported on their experiences with medical professionals and their beliefs about recovery and completed the depression and anxiety subscales of the Brief Symptom Inventory. RESULTS: Those who said that their physician did not legitimize their illness (36%) had higher depression and anxiety scores (P's<.05) than their counterparts. Those who believed that limiting their physical exertion was the path to recovery (55%) had lower depression and anxiety scores (P's<.01) than their counterparts. CONCLUSION: Lack of illness legitimization ranked high as a source of dissatisfaction for CFS patients, and it may aggravate psychiatric morbidity. Many CFS patients believed that staying within what they felt to be their physical limits would improve their condition. This belief, and possibly an accompanying sense of control over their symptoms, may alleviate psychiatric morbidity.