Neuropathic pain in the acute pain service: a prospective survey

Traditionally the focus of Acute Pain Services (APSs) has been in the management of nociceptive pain. The recognition and management of neuropathic pain has been neglected. The aim of this study was to define the incidence of neuropathic pain in an Acute Pain Service population and to assess the risk of progression of these patients to persistent pain states.We report an incidence of acute neuropathic pain as 1–3% in patients seen by our APS. At follow up 78% of the patients had ongoing pain at 6 months and 56% at 12 months. Although numerically small in terms of overall APS activity the acute neuropathic pain group is significant in terms of the high risk of progression to chronicity. Early recognition of patients with acute neuropathic pain is an important component of APS activity. Further work is needed to clarify the role of pre-emptive strategies and early intervention in modulating progression to chronicity.     

Trajectories of pain in adolescents: a prospective cohort study

Identification of different patterns of change in pain over time - trajectories - has the potential to provide new information on the course of pain. Describing trajectories among adolescents would improve understanding of how pain conditions can develop. This prospective cohort study identified distinct trajectories of pain among adolescents (11-14 years) in the general population (n = 1336). Latent class growth analysis was carried out on the self-reported frequency of back pain, headache, stomach pain and facial pain, which was collected every 3 months for 3 years. Forty four percent of adolescents had a ‘painful’ trajectory for at least one pain site, and 12% reported persistent pain at one or more pain site. Headache was the most common; 25% of subjects were in a ‘painful’ trajectory and 5% reported persistent pain. Back pain and stomach pain were also common, with 22% and 21% of subjects in painful trajectories, respectively. Facial pain was the least common, with only 10% in a painful trajectory, and 1% reporting persistent pain. Trajectory characteristics were similar at baseline across pain sites, with the more painful trajectories having significantly higher levels of depression and somatization, lower life satisfaction and more females. Trajectories did not differ significantly at baseline in physical activity levels or BMI. Agreement of trajectory membership among pain sites was moderate. In summary, reporting a painful trajectory was common among adolescents, but persistent pain was reported by a small minority, and was usually experienced at a single pain site.     

Childhood headache, stress in adolescence, and primary headache in young adulthood: a longitudinal cohort study

OBJECTIVES: To determine the association between childhood history of headache, adolescent stress, and headache syndromes (determined by International Headache Society criteria) in young adulthood. BACKGROUND: The association between stress and tension-type headache has recently been challenged. Little is known about stress and other headache subtypes, particularly among young people from the general population. DESIGN: Members of the longitudinal Dunedin Multidisciplinary Health and Development Study participated in this study. Study members were asked about headache characteristics/symptoms at aged 26 (96% of the living cohort), and historical records were examined to ascertain headache history (younger than 12 years) and the reporting of stressful life events at aged 15 years. RESULTS: Study members with childhood headache were significantly more likely to report adolescent stress than those without headache. High-intensity stress during mid adolescence increased the likelihood of migraine diagnosis. In those with combined headache (migraine as well as tension-type headache), this relation held only for those with a history of headache. Stress associated with bodily changes during mid adolescence was the only significant predictor of tension-type headache. CONCLUSIONS: Childhood headaches are related to the appraisal of life events reported during mid adolescence. Childhood headaches also appear to confer a specific risk for the development of combined headache. There was little evidence for a prospective relation between stress in mid adolescence and tension-type headache in young adulthood, supporting claims that proximal (rather than distal) stress is associated with this disorder.     

Childhood pain: the school-aged child's viewpoint

This interview study was designed to obtain a substantial body of information about childhood pain from a large cohort (n = 994) of Northern Californian school children between the ages of 5 and 12 years. The primary criteria for assignment to groups were extent of hospitalization experience, recency of hospitalization, presence of a painful chronic condition, and chronic iatrogenic pain. Open-ended questions were used to determine the extent of the children's knowledge and understanding of pain, their ability to describe pain, specific pain experiences, use of coping strategies, preferences concerning the timing of information about impending pain, and maladaptive pain usage. There was unequivocal evidence of the children's ability to communicate effectively concerning their pain, however, knowledge and understanding of pain for most of the sample was at a low developmental level, with no clearly defined age trends and no sex differences. There was relatively low use of coping strategies and the frequency of maladaptive pain usage was disquieting.     

Unpleasant odors increase pain processing in a patient with neuropathic pain: psychophysical and fMRI investigation

A 49-year old man with neuropathic pain in his right elbow, wrist and digits III-V of his hand reported that certain odors increased his pain by superimposing an electric shock-like pain to his already existing pain. Psychophysical testing revealed that the best predictor of pain exacerbation was odor unpleasantness. Functional magnetic resonance imaging (fMRI) showed increased activation following an unpleasant odor in pain related areas, including the thalamus, amygdala, insular and anterior cingulate cortices, with similar trends in primary somatosensory cortex hand/arm area. The increased pain and associated neural activations in response to unpleasant odors may be related to the phenomenon of synesthesia, to a rewiring of olfactory pathways onto pain pathways mimicking synesthesia or, to activation of the sympathetic nervous system.     

Expectancy, fear and pain in the prediction of chronic pain and disability: a prospective analysis.

Studies with (sub) acute back pain patients show that negative expectancies predict pain and disability at a one-year follow up. Yet, it is not clear how expectations relate to other factors in the development of chronic disability such as pain and fear. This study investigates the relationship between expectations, pain-related fear and pain and studies how these variables are related to the development of chronic pain and disability. Subjects (N = 141) with back and/or neck pain (duration <1 year) were recruited via primary care. They completed measures on pain, expectancy, pain-related fear (pain-related negative affect and fear avoidance beliefs) and function. A one-year follow up was conducted with regard to pain and function. It was found that pain, expectancy, pain-related fear and function were strongly interrelated. In the cross-sectional analyses negative expectancies were best explained by frequent pain and a belief in an underlying and serious medical problem. Prospectively, negative expectancy, negative affect and a belief that activity may result in (re) injury or increased pain, explained unique variance in both pain and function at one-year follow up. In conclusion, expectancy, negative affect and fear avoidance beliefs are interrelated constructs that have predictive value for future pain and disability. Clinically, it can be helpful to inquire about beliefs, expectancy and distress as an indication of risk as well as to guide intervention. However, the strong interrelations between the variables call for precaution in treating them as if they were separate entities existing in reality.     

Functional abdominal pain in childhood and adolescence increases risk for chronic pain in adulthood

A few studies of long-term outcomes for pediatric functional abdominal pain (FAP) have assessed acute non-abdominal pain at follow-up, but none has assessed chronic pain. We followed a cohort of pediatric patients with FAP (n = 155) and a well control group (n = 45) prospectively for up to 15 years. Participants ranged in age from 18 to 32 years at a follow-up telephone interview. FAP patients were classified as Resolved (n = 101) versus Unresolved (n = 54) at follow-up, based on whether they reported symptoms consistent with the adult Rome III criteria for a functional gastrointestinal disorder. Headache symptoms and reports of chronic non-abdominal pain also were assessed at follow-up. In the Unresolved group, 48.1% reported one or more sites of chronic non-abdominal pain at follow-up, compared to 24.7% in the Resolved group and 13.3% in the control group, p < 0.01. More than half (57.4%) of the Unresolved group endorsed symptoms consistent with International Headache Society criteria for headache, compared to 44.6% of the Resolved group and 31% of controls, p < 0.05. One-third of the Unresolved group reported both headache and one or more sites of chronic non-abdominal pain at follow-up, compared to 17.8% of the Resolved group and 4.4% of controls. Youth with FAP that persists into adulthood may be at increased risk for chronic pain and headache. Examination of central mechanisms that are common across chronic pain disorders may enhance understanding of this subgroup of FAP.     

Chiropractic treatment of low back pain: a prospective survey

The clinical course of low back pain (LBP) during chiropractic treatment has not previously been reported on the basis of a prospective survey. The prospective survey is based on patient questionnaires filled in before treatment was started, as well as 1, 3, 6 and 12 months later. Clinical examination was performed at entry and also 1 month later. Two hundred ninety-eight patients with acute or chronic LBP from ten different chiropractic clinics were selected sequentially for this study. At the time of first contact between these patients and the clinics, the current episode of LBP had lasted less than 1 wk in 30% of the patients and for more than 4 wk in 51%. Sixty-five percent had radiating pain into the lower extremity, and 38% were unable to work. Fifty-three percent of the patients had consulted a medical doctor or had received other types of treatment due to the current episode. Nineteen percent were referred by a medical doctor to the chiropractor. After each period of registration, approximately 75% of the patients reported being free of symptoms or feeling much better. The present study was designed to be compared to a similar investigation carried out in a general medical practice. A clear indication of a more favorable outcome was found in those patients receiving chiropractic treatment when compared to those receiving medical treatment, especially concerning such factors as ability to work, bedrest and use of medication. Only a randomized controlled clinical trial is suited for a direct comparison of the effect and cost of chiropractic and medical treatment of LBP.     

Surgical management of neuroma pain: a prospective follow-up study

Painful neuromas can cause severe loss of function and have great impact on the daily life of patients. Surgical management remains challenging; despite improving techniques, success rates are low. To accurately study the success of surgical neuroma treatment and factors predictive of outcome, a prospective follow-up study was performed. Between 2006 and 2009, pre- and post-operative questionnaires regarding pain (VAS, McGill), function (DASH), quality of life (SF-36), symptoms of psychopathology (SCL-90), epidemiologic determinants and other outcome factors were sent to patients surgically treated for upper extremity neuroma pain. Pain scores after diagnostic nerve blocks were documented at the outpatient clinic before surgery. Thirty-four patients were included, with an average follow up time of 22 months. The mean VAS score decreased from 6.8 to 4.9 after surgery (p < 0.01), 19 (56%) of patients were satisfied with surgical results. Upper extremity function improved significantly (p = 0.001). Neuroma patients had significantly lower quality of life compared to a normal population. Employment status, duration of pain and CRPS symptoms were found to be prognostic factors. VAS scores after diagnostic nerve block were predictive of post-operative VAS scores (p = 0.001). Furthermore, smoking was significantly related to worse outcome (relative risk: 2.10). The results could lead to improved patient selection and treatment strategies. If a diagnostic nerve block is ineffective in relieving pain, patients will most likely not benefit from surgical treatment. Patients should be encouraged to focus on activity and employment instead of their symptoms. Smoking should be discouraged in patients who will undergo surgical neuroma treatment.     

A rise in pain threshold during labor: a prospective clinical trial

To evaluate changes in pain threshold before, during and after labor in a prospective clinical trial. Forty pregnant women at term were included. Pain threshold in 18 specific pressure points was evaluated using a dolorimeter. Woman underwent pain threshold assessment at term before labor, during the active phase of labor and postpartum. Subjective pain intensity was assessed by the parturient using the Verbal Rating Scale (VRS). Pain threshold was significantly higher during active phase of labor. There was a significant decline in pain threshold after labor as compared to pain threshold during labor (2.507+/-0.947 and 2.608+/-1.023, respectively, p=0.01). Pain intensity using the VRS score was higher during labor than before labor (4.8+/-2.7 and 2.4+/-2.6 p<0.001). We found a significant rise in pain threshold during labor in term pregnancies. This rise may have an intended protective effect during the intense labor pain experience.     

The roles of pain catastrophizing and anxiety in the prediction of postoperative pain intensity: a prospective study

OBJECTIVES: This study was a prospective investigation of the extent to which psychologic variables could be predictive of postoperative pain. Study aims were: 1) to evaluate whether an assessment of pre-operative distress factors could predict the intensity of postoperative pain; and 2) to characterize the unique pattern in which anxiety and pain catastrophizing scores relate to postoperative pain. METHODS: The Pain Catastrophizing Scale and the State-Trait Anxiety Inventory were administered to 38 patients scheduled for elective abdominal surgery. The questionnaires were completed on the day of admission, a day before the operation. On day 1 and day 2 following the operation, perception of pain intensity at the surgical wound was assessed by visual analog scale. RESULTS: The Pain Catastrophizing Scale and State-Trait Anxiety Inventory scores were significantly correlated with the postoperative pain scores. A linear regression analysis showed that Pain Catastrophizing Scale predicted the level of postoperative pain intensity even after controlling for state anxiety and that trait anxiety was not a significant predictor. In addition, analysis of the unique pattern of each predictor related to postoperative pain intensity indicated a linear curve for the Pain Catastrophizing Scale and curvilinear curve for the state anxiety. DISCUSSION: The results are discussed in light of appraisal and coping theories. It is suggested that a simple assessment of preoperative catastrophizing tendency and anxiety scores may assist medical teams in postoperative pain management.     

Childhood mourning: prospective case analysis of multiple losses

Multiple losses within short time periods make one question life and can exponentially influence one's coping skills. But what are the effects on a child and what should be done when the next loss occurs? This case addresses the multiple losses suffered by a child while assessing coping skills of the child and coping strategies used by the parents to assist the child.     

Relationship between mechanical sensitivity and postamputation pain: a prospective study.

Limb amputation is followed by stump and phantom pain in a large proportion of amputees and postamputation pain may be associated with signs of hyperexcitability such as hyperalgesia to mechanical stimulation. The present study examined the possible relationship between mechanical pain threshold of the limb and early (after 1 week) and late (after 6 months) phantom pain. Thirty-five patients scheduled for amputation of the lower limb were examined before, 1 week and 6 months after amputation. On all three examination days pressure-pain thresholds were measured and compared with the simultaneous recording of ongoing pain intensity assessed on a visual analogue scale (VAS). There was a weak but significant inverse relationship between preamputation thresholds and early stump and phantom pain. There was no relationship between preamputation thresholds and late stump and phantom pain. One week after amputation there was a significant and inverse relationship between mechanical thresholds and phantom pain but no relationship was found after 6 months. The findings suggest that although tenderness of the limb before and after amputation is related to early stump and phantom pain, the relationship is weak. Neuronal sensitization peripherally or centrally may play a role in the development of phantom pain.     

Interdisciplinary rehabilitation in fibromyalgia and chronic back pain: a prospective outcome study.

This study aimed to examine short-term and mid-term course of health, biopsychosocial functional ability, and coping performance of patients with fibromyalgia (FM) or chronic back pain (BP) after participation in a standardized 4-week inpatient, interdisciplinary pain rehabilitation program. In a prospective cohort study, assessments were made by using a set of standardized, well-tested self-rating instruments and other parameters before and after the intervention up to the 6-month follow-up with standardized effect sizes (ES) and comparison to population norms. The effects of improvements in health and coping domains on pain reduction were examined by linear regression modeling. The health of the 65 FM and the 60 BP patients at baseline was far worse than expected from the norms. Improvements included ES up to 1.09 for pain, physical role performance, and mental/affective health dimensions and 0.50 in coping at discharge from the clinic. At the 6-month follow-up, all effects were consistently lower but still up to ES = 0.75. Improvements of FM and BP were equal at discharge but slightly better for the FM's mood scales at the 6-month follow-up. Physical and social function, mood, and coping were significantly associated with pain reduction. PERSPECTIVE: Inpatient, structured interdisciplinary rehabilitation covering elements of cognitive and operant behavioral therapy, graded activity exercise, and adapted drug therapy revealed moderate to large short-term and mid-term improvements in physical and mental health and in the major coping dimensions as captured by comprehensive and specific assessment.