There is limited evidence to date of the effectiveness of minimally-invasive brain stimulation in controlling postoperative pain. Two studies have provided preliminary evidence that transcranial magnetic stimulation (TMS) can significantly reduce post-operative pain, and no studies have been published on the effects of transcranial direct current stimulation (tDCS) on postoperative pain. The evidence supporting the role of brain stimulation in producing general anesthetic effects is also limited but there is a possibility that appropriately targeted electrical stimulation might have a role in the future if the technology permits such stimulation in a non-invasive manner. The present article provides a brief overview of the available evidence supporting the role of minimally invasive brain stimulation technology in perioperative medicine. More studies and well-controlled trials are needed to establish a clear role for minimally-invasive brain stimulation technologies in the perioperative arena.
Transcranial magnetic stimulation; pain; direct current stimulation; postoperative; perioperative
Fibromyalgia is a poorly understood disorder that likely involves central nervous system sensory hypersensitivity. There are a host of genetic, neuroendocrine and environmental abnormalities associated with the disease, and recent research findings suggest enhanced sensory processing, and abnormalities in central monoamines and cytokines expression in patients with fibromyalgia. The morbidity and financial costs associated with fibromyalgia are quite high despite conventional treatments with antidepressants, anticonvulsants, low-impact aerobic exercise and psychotherapy. Noninvasive brain stimulation techniques, such as transcranial direct current stimulation, transcranial magnetic stimulation, and electroconvulsive therapy are beginning to be studied as possible treatments for fibromyalgia pain. Early studies appear promising but more work is needed. Future directions in clinical care may include innovative combinations of noninvasive brain stimulation, pharmacological augmentation, and behavior therapies.
Fibromyalgia; transcranial magnetic stimulation; transcranial direct current stimulation; noninvasive brain stimulation; chronic pain; electroconvulsive therapy; prefrontal cortex; primary motor cortex
Little is known about how sociodemographic factors relate to children’s chronic pain. This paper describes the pain, health, and sociodemographic characteristics of a cohort of children presenting to an urban tertiary chronic pain clinic and documents the role of age, sex and minority status on pain-related characteristics. A multidisciplinary, tertiary clinic specializing in pediatric chronic pain. Two hundred and nineteen patients and their parents were given questionnaire packets to fill out prior to their intake appointment which included demographic information, clinical information, Child Health Questionnaire – Parent Report, Functional Disability Index – Parent Report, Child Somatization Index – Parent Report, and a Pain Intensity Scale. Additional clinical information was obtained from patients’ medical records via chart review. This clinical sample exhibited compromised functioning in a number of domains, including school attendance, bodily pain, and health compared to normative data. Patients also exhibited high levels of functional disability. Minority children evidenced decreased sleep, increased somatization, higher levels of functional disability, and increased pain intensity compared to Caucasians. Caucasians were more likely to endorse headaches than minorities, and girls were more likely than boys to present with fibromyalgia. Younger children reported better functioning than did teens. The results indicate that sociodemographic factors are significantly associated with several pain-related characteristics in children with chronic pain. Further research must address potential mechanisms of these relationships and applications for treatment.
Chronic pain; pediatric; clinical cohort; ethnic differences
To determine which of the previously proposed functional interference cluster models is most appropriate in patients with bone metastases and to determine if the cluster structures identified at baseline differed between responders and non-responders following palliative radiotherapy.
The confirmatory test data set consists of breast and prostate cancer patients treated with palliative radiotherapy between May 2003 to January 2007. Worst pain and functional interference scores were assessed using Brief Pain Inventory at baseline, 4, 8 and 12 weeks post radiation treatment. The baseline cluster structure of the confirmatory dataset was compared to each of the previously proposed baseline cluster models. Maximum likelihood CFA was used to account for possible correlation amongst the factor components. A MIMIC model was used to determine the invariance of the cluster models between responders and non-responders during follow-up.
A total of 169 eligible patients were analysed. There were 91 male and 78 female patients with a median age of 68 years. The median KPS was 70. A single 8 Gy and 20 Gy in 5 fractions were used in 97% of all analysed patients. The RTOG model, in which relationships with others and sleep comprised the mood-related interference cluster and walking ability and normal work comprised the physical-interference cluster, provides the best fit for the sample data. The follow-up cluster structure is not similar across the responder groups indicating that cluster structures shift following radiation treatment, as evidenced by pain response.
Although differing slightly this analysis confirms pretreatment symptom clusters exist for patients with bone metastases from breast or prostate cancer based on the RTOG 9714 data. This could help formulate symptom management interventions at initial diagnosis. Symptom clusters dissolve or change after treatment which may be a function of the treatment or population and requires further study.
Bone metastases; palliative radiotherapy; functional interference clusters
Although sex differences in anxiety sensitivity or the specific tendency to fear anxiety-related sensations have been reported in adults with clinical pain, there is a dearth of relevant research among children. This study examined sex differences in anxiety sensitivity across unselected samples of 187 children with chronic pain (71.7% girls; mean age = 14.5) and 202 non-clinical children (52% girls; mean age = 13.6). Girls in the chronic pain and non-clinical samples reported elevated anxiety sensitivity relative to boys irrespective of clinical status. Girls with chronic pain also reported heightened fears of the physical consequences of anxiety compared to non-clinical girls but there were no such differences for psychological or social concerns. Among boys, anxiety sensitivity did not differ between the chronic pain and non-clinical groups. Future longitudinal research may examine whether specific fears of anxiety-related somatic sensations constitutes a sex-based vulnerability factor in the development of chronic pain.
chronic pain; children; anxiety sensitivity; anxiety; sex differences
Fibromyalgia has been recognized as a central pain disorder with evidence of neuroanatomic and neurophysiologic alterations. Previous studies with techniques of noninvasive brain stimulation--transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS)--have shown that these methods are associated with a significant alleviation of fibromyalgia-associated pain and sleep dysfunction. Here we sought to determine whether a longer treatment protocol involving 10 sessions of 2 mA, 20 min tDCS of the left primary motor (M1) or dorsolateral prefrontal cortex (DLPFC) could offer additional, more long-lasting clinical benefits in the management of pain from fibromyalgia. Methods: Forty-one women with chronic, medically refractory fibromyalgia were randomized to receive 10 daily sessions of M1, DLPFC, or sham tDCS. Results: Our results show that M1 and DLPFC stimulation both display improvements in pain scores (VAS) and quality of life (FIQ) at the end of the treatment protocol, but only M1 stimulation resulted in long-lasting clinical benefits as assessed at 30 and 60 days after the end of treatment. Conclusions: This study demonstrates the importance of the duration of the treatment period, suggesting that 10 daily sessions of tDCS result in more long lasting outcomes than only five sessions. Furthermore, this study supports the findings of a similarly designed rTMS trial as both induce pain reductions that are equally long-lasting.
Transcranial direct current stimulation; brain polarization; healthy subjects; fibromyalgia; pain
Methods of cortical stimulation including epidural motor cortex stimulation (MCS), repetitive transcranial magnetic stimulation (rTMS), and transcranial direct current stimulation (tDCS) are emerging as alternatives in the management of pain in patients with chronic medically-refractory pain disorders. Here we consider the three methods of brain stimulation that have been investigated for the treatment of central pain: MCS, rTMS, and tDCS. While all three treatment modalities appear to induce significant clinical gains in patients with chronic pain, tDCS is revealed as the most cost-effective approach (compared to rTMS and MCS) when considering a single year of treatment. However, if a 5-year treatment is considered, MCS is revealed as the most cost-effective modality (as compared to rTMS and tDCS) for the neuromodulatory treatment of chronic pain. We discuss the theory behind the application of each modality as well as efficacy, cost, safety, and practical considerations.
Chronic pain; brain stimulation; cost-effect analysis; motor cortex stimulation; repetitive transcranial magnetic stimulation; transcranial direct current stimulation; brain polarization
This study examined the relationship between race, laboratory-based coping strategies and anticipatory anxiety and pain intensity for cold, thermal (heat) and pressure experimental pain tasks. Participants were 123 healthy children and adolescents, including 33 African Americans (51% female; mean age =13.9 years) and 90 Caucasians (50% female; mean age = 12.6 years). Coping in response to the cold task was assessed with the Lab Coping Style interview; based on their interview responses, participants were categorized as ‘attenders’ (i.e., those who focused on the task) vs. ‘distractors’ (i.e., those who distracted themselves during the task). Analysis of covariance (ANCOVA) revealed significant interactions between race (African-American vs. Caucasian) and lab-based coping style after controlling for sex, age and socioeconomic status. African-American children classified as attenders reported less anticipatory anxiety for the cold task and lower pain intensity for the cold, heat and pressure tasks compared to those categorized as distractors. For these pain outcomes, Caucasian children classified as distractors reported less anticipatory anxiety and lower pain intensity relative to those categorized as attenders. The findings point to the moderating effect of coping in the relationship between race and experimental pain sensitivity.
pain; coping; race; children
Morphine given by Patient Controlled Analgesia (PCA) is widely used in hospital settings to manage severe pain during acute painful episodes. Wide variations in prescription patterns occur and some patients are often self-administering sub- or low- therapeutic doses. In this preliminary study, a descriptive design with repeated measures was used to examine the effects of different PCA morphine regimens on the intensity, location and quality of pain as well as on the perceived amount of relief and side effects in patients with sickle cell disease (N=13; mean age 13.7 years; eight males; five females). The preliminary data showed that a regimen with a high background infusion rate and low intermittent push dose (Regimen B) may provide better response to PCA morphine. The difference in trends between the worst and least pain intensity ratings were narrower in this regimen, suggesting that pain peaks and troughs were not occurring as in a regimen with an around the clock nurse administered dosing schedule (Regimen C). The amount of morphine that was administered per day was not significantly different (p > 0.05) among the three morphine regimens. The combination of a high background infusion rate and low intermittent push dose (as in Regimen B) within the first 24 hours of admission, may provide improved response and possibly shorter recovery from the painful episode than the regimen that would routinely be prescribed with lower background infusion rate and high intermittent push dose (as in regimen A).
Patient Controlled Analgesia (PCA) morphine; acute painful episodes; sickle cell disease
Chronic or recurrent pain is a widespread health issue that affects a large proportion of the population, including adults and children. Family factors in the development of pain have received increasing attention of late as research has shown that pain tends to run in families, A burgeoning literature has also demonstrated the influence of parental factors in children’s responses to chronic and laboratory pain. This review attempts to integrate: first,) the literature documenting an association between parent and child pain both within the clinical chronic pain and laboratory pain literatures; and second,) research accounting for likely mechanisms explaining the parent-child pain association. To this end, we present a conceptual model that incorporates a number of parent and child specific characteristics, such as parental responses, coping and gender role socialization as well as broader socio-demographic factors such as parent and child age and sex, family functioning, socioeconomic status, and race/ethnicity. It is anticipated that consideration of such variables will lead to needed research exploring the mechanisms of parent-child pain relationships, and to interventions designed to prevent and ameliorate child pain sensitivity when it correlates with poor adaptation to pain.
children; pain; family; parents
The use of hydromorphone is increasing but little is known about its effects during painful episodes in adolescents with sickle cell disease. This pilot study examined the intensity, location, and quality of pain and evaluated the amount of relief and side effects from PCA hydromorphone during acute painful episodes in five adolescents with sickle cell disease. Data suggest that hydromorphone may provide a better alternative than morphine, the most commonly prescribed opioid in patients with sickle cell disease. Hydromorphone may provide improved pain control and recovery from acute painful episodes in patients with sickle cell disease.
Hydromorphone (Dilaudid); sickle cell disease; patient controlled analgesia; acute painful episodes
This paper uses a mixed-methods approach to examine the impact of pain-associated functioning limitations on children's lives and the strategies they develop to try to continue functioning. Forty-five children ages 10-18 completed standardized questionnaires and participated in semistructured interviews prior to intake at a university-based tertiary clinic specializing in the treatment of pediatric chronic pain. All the children reported that pain limited their functioning in everyday activities and that these limitations caused them frustration and distress. Qualitative analysis identified three distinct functioning patterns or groups, which were designated as Adaptive, Passive, and Stressed. The groups did not differ significantly in demographics or clinical pain characteristics. Adaptive children continued to participate in many activities and were more likely to realize that focusing on pain would heighten their perception of pain. Children in this group reported more effective use of distraction and of other independently developed strategies to continue functioning. Passive children had given up most activities, tended to use passive distraction when in pain, and were more likely to feel isolated and different from peers. Stressed children described themselves as continuing to function, but were highly focused on their pain and the difficulties of living with it. The qualitative groupings were supported by quantitative findings that Stressed children reported a higher degree of social anxiety than did Passive children and were more likely than the other groups to report experiencing pain throughout the day. Finally, Adaptive children were rated by their parents as having better overall health compared to Passive children.
children; chronic pain; functioning; United States