Wellness of patients with chronic pain is not only about pain intensity.

OBJECTIVE: Attaining good outcomes in the management of chronic pain remains a clinical challenge. This study aimed to investigate the relationships between - and the contribution of - pain and related conditions to the wellness of these patients. DESIGN: A secondary analysis of database of patients with chronic pain treated with medical cannabis (MC) to carry out a one-year prospective follow-up study was conducted. Questionnaires were completed before (T0 ), six (T6 ), and twelve (T12 ) months after MC initiation. Data included patients' demographics and questionnaires related to three latent factors: pain intensity measures, related conditions (catastrophizing, sleep disturbance, anxiety, and depression), and wellness parameters (quality-of-life, disability, subjective-health-state). Weighted average of the observed variables (WOBs) were calculated for each latent factor. Longitudinal structural equation modeling (SEM) and mediation analyses were performed to identify predictors and interrelations between the WOBs, respectively. RESULTS: Participants included 510 patients. All variables were significantly improved from T0 to T6 and T12 . SEM revealed that related conditions, and to a lesser extent pain, predicted wellness at T0 , T6 , and T12 (related conditions: ß0  = 0.55, p < 0.001; ß6  = 0.54, p < 0.001; and ß12  = 0.51, p < 0.001; pain: ß0  = 0.42, p < 0.001; ß6  = 0.18, p < 0.001; and ß12  = 0.25, p < 0.001). Mediation analyses demonstrated that the effect of WOB-related conditions was greater than WOB-pain on wellness. CONCLUSION: Wellness of patients with chronic pain can be determined not only by pain itself but even more so by the severity of related conditions. Thus, considering a broad spectrum of pain measures and related conditions seems relevant for improving the wellness of patients with chronic pain.

Specific phytocannabinoid compositions are associated with analgesic response and adverse effects in chronic pain patients treated with medical cannabis.

Medical cannabis (MC) treatment for chronic pain is increasing, but evidence regarding short- and long-term efficacy and associated adverse effects (AEs) of the different cannabis plant components is limited. Most reports focus on two phytocannabinoids, (-)-Δ9-trans-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD). This study, aimed to identify patterns of phytocannabinoid compositions associated with MC treatment response and with related AEs. Participants in this multicenter prospective cohort were patients with chronic non-cancer pain that were prescribed MC by physicians. Data was collected before MC treatment, at one month (short-term) and at 12 months (long-term). Simultaneously, liquid chromatography mass spectrometry identification and quantification of phytocannabinoids from the cultivars were performed. The monthly dose of each phytocannabinoid for each patient was z-scaled and clustered into ten groups to assess the difference in analgesic treatment response (≥30%/50% pain intensity reduction) and AEs rates. We identified ten clusters that had similar analgesic treatment response rates. However, there were significant differences in AEs rates both at short- and long-term. We identified specific phytocannabinoid compositions that were associated with overall AEs rates (5% compared to 53% at short-term and 44% at long-term) and with specific AEs rates such as MC related central nervous system, gastrointestinal and psychological AEs. To conclude, Evaluating only Δ9-THC or CBD is insufficient to find associations with MC related AEs. Therefore, comprehensive profiling of phytocannabinoids is needed to discover associations to related AEs and help physicians prescribe safer cannabis with less AEs while still relieving pain.

Additive Analgesic Effect of Transcranial Direct Current Stimulation Together with Mirror Therapy for the Treatment of Phantom Pain.

OBJECTIVE: Current analgesic treatments for phantom pain are not optimal. One well-accepted yet limited nonpharmacological option is mirror therapy, which is thought to counterbalance abnormal plasticity. Transcranial direct current stimulation (tDCS) is an emerging approach believed to affect the membrane potential and activity threshold of cortical neurons. tDCS analgesic effectiveness, however, is mild and short, rendering it a noneffective stand-alone treatment. This study aimed to assess if a combination of mirror therapy with tDCS results in a superior analgesic effect as compared with mirror therapy alone in patients suffering from phantom pain due to recent amputation. DESIGN: Following ethical approval, eligible patients provided informed consent and were randomly assigned to a study treatment group that continued for 2 weeks (once daily): 1) mirror therapy; 2) mirror therapy and sham tDCS; or 3) mirror therapy and tDCS. Assessments were done before treatment; at the end of treatment weeks 1 and 2; and at 1 week, 1 month, and 3 months following treatment. The primary outcome measure was pain intensity. Secondary measures were derived from the Short Form McGill Pain Questionnaire and the Brief Pain Inventory. RESULTS: Thirty patients were recruited, and 29 patients completed the study. Three months following treatment, pain intensity was significantly (P<0.001) reduced in the combined treatment group (reduction of 5.4±3.3 points) compared with the other study arms (mirror therapy, 1.2±1.1; mirror therapy and sham tDCS, 2.7±3.2). All secondary outcome results were in line with these findings. CONCLUSIONS: Combining tDCS with mirror therapy results in a robust long-lasting analgesic effect. These encouraging findings may contribute to the understanding of the underlying mechanisms of phantom pain.

Symptom clusters in hospitalized older adults: Characteristics and outcomes.

Hospital care in medical patients relies mostly on objective measures with limited assessment of subjective symptoms. We subgrouped 331 hospitalized older adults with medical diagnosis (age 75.5 ± 7.1) according to the severity of multiple symptoms to explore if these subgroups differed in health-related characteristics on admission and functional outcomes one month post-discharge. Cluster analysis identified three subgroups based on experiences with five highly distressing symptoms (fatigue, dyspnea, dizziness, sleep disturbance, pain): low levels of all symptoms, high levels of all symptoms; moderate levels of four symptoms with high dyspnea. Belonging in different subgroups was accompanied by different levels of cognitive and mental, but not physical or health status. Patients in the subgroup "Moderate Levels with High Dyspnea" had significantly lower risk of decline in post-discharge instrumental activities of daily living than other subgroups. Better understanding of older hospitalized adults' symptom profiles may yield important information on health condition and recovery.

Double whammy: Adverse childhood events and pain reflect symptomology and quality of life in women in substance abuse treatment.

BACKGROUND: This study examined the profiles of symptoms and health-related quality of life (QOL) of women in substance abuse treatment, comparing those with higher versus lower histories of adverse childhood events (ACE), and those with versus without current pain. METHODS: Adult women in outpatient substance abuse treatment (n = 30) completed questionnaires (cross-sectional study) on topics including drug use, adverse childhood events (ACE), QOL, functional ability, current pain, and depression. RESULTS: Women with pain indicated significant differences in emotional (p < 0.05), and functional ability (p < 0.01); but no significant differences were found between women with high versus low levels of ACE. Yet, radar plots of women with both current pain and high levels of ACE, versus those without, portrayed a distinctive profile indicating high levels of anxiety and depression. CONCLUSIONS: Rather than a checklist, visual composites of symptoms experienced by women in substance abuse treatment illustrates areas of concern in the overall status of women in substance abuse treatment.

Pain perception in healthy young men is modified by time-of-day and is modality dependent.

OBJECTIVE: Several physiological processes exhibit 24-hour oscillations termed circadian rhythms. Despite numerous investigations on the circadian dynamics of pain perception, findings related to this issue remain inconsistent. This study aimed to assess the effect of time-of-day on multimodal experimental pain perception in healthy males, including "static" and "dynamic" quantitative sensory tests. DESIGN: A random order tests were performed in the morning, afternoon and evening. SUBJECTS: Forty-eight healthy males (25.9 ± 4.7 years old). METHODS: Three different pain modalities i) mechanical (pain threshold, tolerance, and intensity), ii) heat (pain threshold and intensity), iii) cold (pain threshold measured in °C and in seconds and cold pain tolerance and intensity) utilizing nine "static" pain parameters, and two "dynamic" pain paradigms i) temporal summation and ii) conditioned pain modulation were assessed in each session. RESULTS: Pain scores varied significantly in six pain parameters during the day. Specifically, lower pain scores were found in the morning for cold pain threshold (in seconds and in °C), cold pain intensity, cold pain tolerance, heat pain threshold and intensity. There were no significant diurnal differences in the mechanical evoked pain parameters or in either of the "dynamic" pain paradigms. CONCLUSIONS: Thermal pain scores varies during the day and morning seems to be the time-of-day most insensitive to pain. Also, dynamic tests and the mechanical pain model are not appropriate for detecting diurnal variability in pain. The results of this study may be partially explained by a potential analgesic effect of some hormones known to have diurnal variation (e.g., melatonin and cortisol).

The effect of hydromorphone therapy on psychophysical measurements of the descending inhibitory pain systems in patients with chronic radicular pain.

OBJECTIVE: Conditioned pain modulation (CPM) and offset analgesia (OA) are considered to represent paradigms of descending inhibitory pain modulation in humans. This study tested the effects of hydromorphone therapy on descending inhibitory pain modulation, as measured by changes from baseline in the magnitudes of CPM and OA. DESIGN: Prospective evaluation. SETTING: Institute of Pain Medicine, Rambam Health Care Campus. SUBJECTS: Patients with chronic radicular pain. METHODS: Thirty patients received 4 weeks of oral hydromorphone treatment at an individually titrated dose (mean ± standard deviation dose of 11.6 ± 4.8 mg/day). CPM and OA were assessed before and after hydromorphone treatment. CPM was assessed by subtracting the response to a painful phasic heat stimulus administered simultaneously with a conditioning cold pain stimulus, from the response to the same heat stimulus administered alone. The OA paradigm consisted of a three-temperature stimuli train (T1 = 49°C [5 seconds], T2 = 50°C [5 seconds], and T3 = 49°C [20 seconds]). The magnitude of OA was quantified by subtracting minimal pain scores obtained during T3 from the maximal pain scores obtained during T2. RESULTS: CPM scores changed from a baseline of 17.7 ± 20.6 to 21 ± 20.4 following treatment, and OA scores changed from 7.8 ± 20.5 to 9.7 ± 14.6. Wilcoxon signed rank test indicated that these changes were not significant (CPM: P = 0.22; OA: P = 0.44). McNemar test revealed that the percentage of patients who exhibited a change in the direction of CPM or OA in response to hydromorphone treatment was not significant (CPM: P = 0.37; OA: P = 0.48). CONCLUSIONS: These results suggest that the descending inhibitory pain modulation, as manifested in humans by CPM and OA, is unlikely to be mediated by hydromorphone therapy.

Alterations in pain response are partially reversed by methylphenidate (Ritalin) in adults with attention deficit hyperactivity disorder (ADHD).

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is characterized by dysregulation of sensory processing and neurobiology of dopamine. Although cumulative evidence suggests that dopamine is involved in pain processing, pain perception in ADHD subjects and the effect of dopamine agonists such as methylphenidate (MP, Ritalin) on it have rarely been studied. AIMS: The aims of this study were to (1) psychophysically assess sensitivity to pain in ADHD subjects as compared to controls and (2) examine the effects of MP on pain response in ADHD subjects. METHODS: Thirty subjects with ADHD and 30 age- and gender-matched controls participated in a preliminary trial. Pain threshold, intensity, and tolerance in response to cold pain stimulation were measured for both groups (ADHD with no treatment). In addition, the ADHD group was reassessed following a single dose of MP treatment. RESULTS: The ADHD subjects "without MP" in comparison with controls displayed significantly shorter cold pain threshold (2.8 ± 2.1 vs. 5.8 ± 2.5 seconds, respectively, P < 0.001) and cold tolerance (21.8 ± 22.3 vs. 62.8 ± 59.8 seconds, respectively P < 0.001). No differences in pain intensities between the groups were found. Following MP treatment, both cold threshold and tolerance in the ADHD subjects increased significantly compared to those with no treatment (3.6 ± 2.5 seconds, P = 0.011, and 46.4 ± 53.3 seconds, P < 0.001, respectively). CONCLUSIONS: These results suggest that adults with ADHD are more sensitive to pain compared with controls and that MP may exert antinociceptive properties in these subjects. Randomized, controlled trials are warranted to verify these findings.

Association between variants of 5-hydroxytryptamine receptor 3C (HTR3C) and chemotherapy-induced symptoms in women receiving adjuvant treatment for breast cancer.

Administration of chemotherapy is associated with a wide array of symptoms affecting quality of life. Genetic risk factors for severity of chemotherapy-induced symptoms have not been determined. The present study aimed to explore the associations between polymorphisms in candidate genes and chemotherapy-induced symptoms. Women treated with at least two cycles of adjuvant doxorubicin and cyclophosphamide, with or without paclitaxel for early breast cancer (n = 105) completed the memorial symptom assessment scale and provided blood for genotyping. DNA was extracted from peripheral blood leukocytes and assayed for single nucleotide polymorphisms (SNPs) in GTP cyclohydrolase 1 (GCH1, rs10483639, rs3783641, and rs8007267), catecholamine-o-methyltransferase (COMT, rs4818), and 5-hydroxytryptamine (serotonin) receptor 3C (HTR3C, rs6766410, and rs6807362). Genotyping of HTR3C revealed a significant association between the presence of rs6766410 and rs6807362 SNPs (K163 and G405 variants) and increased severity of symptoms (p = 0.0001 and p = 0.007, respectively). Multiple regressions revealed that rs6766410 and rs6807362, but not age or stage at diagnosis, predicted severity of symptoms (p = 0.001 and p = 0.006, respectively) and explained 12 % of the variance in each regression model. No association was found between the genetic variants of CGH1 or COMT and symptom score. Our study indicates, for the first time, an association between variants of HTR3C and severity of chemotherapy-induced symptoms. Analyzing these genetic variants may identify patients at increased risk for the development of chemotherapy-induced symptoms and targeting the serotonin pathway may serve as a novel treatment strategy for these patients.

Cannabis oil extracts for chronic pain: what else can be learned from another structured prospective cohort?

Introduction: The use of medicinal cannabis for managing pain expands, although its efficacy and safety have not been fully established through randomized controlled trials. Objectives: This structured, prospective questionnaire-based cohort was aimed to assess long-term effectiveness and safety of cannabis oil extracts in patients with chronic pain. Methods: Adult Israeli patients licensed to use cannabis oil extracts for chronic pain were followed prospectively for 6 months. The primary outcome measure was change from baseline in average weekly pain intensity, and secondary outcomes were changes in related symptoms and quality of life, recorded before treatment initiation and 1, 3, and 6 months thereafter. Generalized linear mixed model was used to analyze changes over time. In addition, "responders" (≥30% reduction in weekly pain at any time point) were identified. Results: The study included 218 patients at baseline, and 188, 154, and 131 at 1, 3, and 6 months, respectively. At 6 months, the mean daily doses of cannabidiol and Δ9-tetrahydrocannabinol were 22.4 ± 24.0 mg and 20.8 ± 30.1 mg, respectively. Pain decreased from 7.9 ± 1.7 at baseline to 6.6 ± 2.2 at 6 months (F(3,450) = 26.22, P < 0.0001). Most secondary parameters also significantly improved. Of the 218 participants, 24% were "responders" but could not be identified by baseline parameters. "Responders" exhibited higher improvement in secondary outcomes. Adverse events were common but mostly nonserious. Conclusion: This prospective cohort demonstrated a modest overall long-term improvement in chronic pain and related symptoms and a reasonable safety profile with the use of relatively low doses of individually titrated Δ9-tetrahydrocannabinol and cannabidiol.

Chemotherapy-induced neuropathic pain and its relation to cluster symptoms in breast cancer patients treated with paclitaxel.

UNLABELLED: The majority of patients with breast cancer receiving chemotherapy report multiple symptoms. Compelling evidence has shown that subgroups of patients can be clustered by the severity of symptoms. Recent studies demonstrate that chemotherapy with such substances as paclitaxel can cause neuropathic pain (CINP) and consequently neural damage. OBJECTIVES: the present study examined the relationship between symptom clusters and CINP among 40 patients with breast cancer. The study was based on 2 sessions conducted before and during paclitaxel treatment. In each session, neuropathic pain was assessed by the DN4 Questionnaire. In the second session, the Lee Fatigue Scale, the General Sleep Disturbance Scale, and the Center for Epidemiological Studies-Depression Scale were also administered, and the worst pain intensity was assessed. Using cluster analysis, 2 symptom clusters were identified on the basis of the severity of the 4 symptoms scores. Patients in the High Cluster (37%) experienced a high level of all symptoms, whereas patients in the Low Cluster (63%) experienced a low level of all symptoms. Twenty patients (50%) were diagnosed with CINP. A subgroup of patients (23%) from the High Cluster was identified as having CINP; 35% were in the Low Cluster and free of CINP. In conclusion, there appears to be a specific subgroup of patients with hypersensitive cancer who need greater attention to symptom management. Early detection of symptoms, together with careful dose selection and assessment of early stages in the development of neuropathic pain, are essential for preventing the simultaneous occurrence of severe multiple symptoms and CINP.

Increased functional connectivity between limbic brain areas in healthy individuals with high versus low sensitivity to cold pain: A resting state fMRI study.

BACKGROUND: The representation of variability in sensitivity to pain by differences in neural connectivity patterns and its association with psychological factors needs further investigation. This study assessed differences in resting-state functional connectivity (rsFC) and its association to cognitive-affective aspects of pain in two groups of healthy subjects with low versus high sensitivity to pain (LSP vs. HSP). We hypothesized that HSP will show stronger connectivity in brain regions involved in the affective-motivational processing of pain and that this higher connectivity would be related to negative affective and cognitive evaluations of pain. METHODS: Forty-eight healthy subjects were allocated to two groups according to their tolerability to cold stimulation (cold pressor test, CPT, 1°C). Group LSP (N = 24) reached the cut-off time of 180±0 sec and group HSP tolerated the CPT for an average of 13±4.8 sec. Heat, cold and mechanical evoked pain were measured, as well as pain-catastrophizing (PCS), depression, anxiety and stress (DASS-21). All subjects underwent resting state fMRI. ROI-to-ROI analysis was performed. RESULTS: In comparison to the LSP, the HSP had stronger interhemispheric connectivity of the amygdala (p = 0.01) and between the amygdala and nucleus accumbens (NAc) (p = 0.01). Amygdala connectivity was associated with higher pain catastrophizing in the HSP only (p<0.01). CONCLUSIONS: These findings suggest that high sensitivity to pain may be reflected by neural circuits involved in affective and motivational aspects of pain. To what extent this connectivity within limbic brain structures relates to higher alertness and more profound withdrawal behavior to aversive events needs to be further investigated.

More Insight on the Role of Personality Traits and Sensitivity to Experimental Pain.

PURPOSE: The present study aimed to assess the influence of personality traits on the variability of sensitivity to pain in two distinct groups of healthy subjects with low versus high sensitivity to pain (LSP vs HSP, respectively). METHODS: Healthy subjects (n=156) were allocated to two groups according to their tolerability to cold stimulation (cold pressor test, CPT, 1°C). Group LSP (n=76) reached the cut-off time of 180±0 sec, and a size matched group of HSP (n=80) tolerated the CPT for an average of 10.5±3.4 sec only. Subjects from both groups completed the self-reported pain sensitivity questionnaire (PSQ), the Pain Catastrophizing Scale (PCS), and the Neuroticism Extraversion Openness - Five Factor Inventory (NEO-FFI). RESULTS: In comparison to the LSP group, HSP individuals had higher scores of PSQ (p<0.001), catastrophizing (p=0.001), and extraversion (p=0.01). By adjusting for age and gender, mediation analyses revealed that catastrophizing mediated the relationship between neuroticism and pain sensitivity, both in the allocation of subjects to a certain group of sensitivity to pain (LSP or HSP, B=0.02 95% CI: 0.006-0.040) and in the PSQ score (B=0.01 95% CI: 0.001-0.023). CONCLUSION: These results, which were demonstrated by two different prisms (CPT and PSQ), point to the potential of the five-factor inventory and pain catastrophizing scale as tools for identifying specific personality traits associated with a high sensitivity to pain.

Medical cannabis treatment for chronic pain: Outcomes and prediction of response.

BACKGROUND: Although studied in a few randomized controlled trials, the efficacy of medical cannabis (MC) for chronic pain remains controversial. Using an alternative approach, this multicentre, questionnaire-based prospective cohort was aimed to assess the long-term effects of MC on chronic pain of various aetiologies and to identify predictors for MC treatment success. METHODS: Patients with chronic pain, licensed to use MC in Israel, reported weekly average pain intensity (primary outcome) and related symptoms before and at 1, 3, 6, 9 and 12 months following MC treatment initiation. A general linear model was used to assess outcomes and identify predictors for treatment success (≥30% reduction in pain intensity). RESULTS: A total of 1,045 patients completed the baseline questionnaires and initiated MC treatment, and 551 completed the 12-month follow-up. At 1 year, average pain intensity declined from baseline by 20% [-1.97 points (95%CI = -2.13 to -1.81; p < 0.001)]. All other parameters improved by 10%-30% (p < 0.001). A significant decrease of 42% [reduction of 27 mg; (95%CI = -34.89 to 18.56, p < 0.001)] from baseline in morphine equivalent daily dosage of opioids was also observed. Reported adverse effects were common but mostly non-serious. Presence of normal to long sleep duration, lower body mass index and lower depression score predicted relatively higher treatment success, whereas presence of neuropathic pain predicted the opposite. CONCLUSIONS: This prospective study provides further evidence for the effects of MC on chronic pain and related symptoms, demonstrating an overall mild-to-modest long-term improvement of the tested measures and identifying possible predictors for treatment success.

Learning mechanisms to limit medication administration errors.

AIM: This paper is a report of a study conducted to identify and test the effectiveness of learning mechanisms applied by the nursing staff of hospital wards as a means of limiting medication administration errors. BACKGROUND: Since the influential report ;To Err Is Human', research has emphasized the role of team learning in reducing medication administration errors. Nevertheless, little is known about the mechanisms underlying team learning. METHOD: Thirty-two hospital wards were randomly recruited. Data were collected during 2006 in Israel by a multi-method (observations, interviews and administrative data), multi-source (head nurses, bedside nurses) approach. Medication administration error was defined as any deviation from procedures, policies and/or best practices for medication administration, and was identified using semi-structured observations of nurses administering medication. Organizational learning was measured using semi-structured interviews with head nurses, and the previous year's reported medication administration errors were assessed using administrative data. RESULTS: The interview data revealed four learning mechanism patterns employed in an attempt to learn from medication administration errors: integrated, non-integrated, supervisory and patchy learning. Regression analysis results demonstrated that whereas the integrated pattern of learning mechanisms was associated with decreased errors, the non-integrated pattern was associated with increased errors. Supervisory and patchy learning mechanisms were not associated with errors. CONCLUSION: Superior learning mechanisms are those that represent the whole cycle of team learning, are enacted by nurses who administer medications to patients, and emphasize a system approach to data analysis instead of analysis of individual cases.

The relationship between sensitivity to pain and conditioned pain modulation in healthy people.

BACKGROUND: The relationship between sensitivity to pain and conditioned pain modulation (CPM) - a paradigm reflecting the activity of the endogenous descending analgesic system - is still unclear. This study aimed at investigating CPM magnitude in two distinct subgroups of healthy subjects, presenting low vs. high sensitivity to pain (LSP vs. HSP, respectively), by employing two different thermal paradigms of CPM. METHOD: Ninety-five healthy subjects (out of 293 tested) were identified as LSP (n = 48) or HSP (n = 47) according to their tolerance time to noxious cold stimulation (Cold Pressor Test, 1 °C). All subjects were exposed to two different paradigms of CPM: 1) Fixed temperature 'test-pain' (TP) where phasic, fixed painful heat stimuli of 47 °C were administered before and during a prolonged 'conditioning stimulus' (cold water at 12 °C for 30 s); and 2) Individually based 'pain-60' where TP was determined as the temperature that induced pain at a magnitude of 60 on a 0-100 rating scale (with the same conditioning stimulus). RESULT: Using both thermal paradigms, LSP subjects showed decreased CPM magnitudes in comparison to HSP (p < 0.0001 in both paradigms). Within each group, no differences in the magnitudes of CPM were found between the two paradigms. CONCLUSION: These findings show that regardless of the thermal CPM paradigm employed, healthy individuals exhibiting low sensitivity to pain have a low pain inhibition profile and vice-versa. It is suggested that in healthy subjects, pain sensitivity predisposes the magnitude of CPM and not the other way around.

The symptom experience of oncology outpatients has a different impact on quality-of-life outcomes.

The aims of this replication study were to determine if subgroups of oncology outpatients receiving active treatment could be identified based on their experience with the symptoms of fatigue, sleep disturbance, depression, and pain; whether patients in these subgroups differed on selected demographic, disease, and treatment characteristics; and if patients in these subgroups differed on functional status and quality of life (QOL). A convenience sample of 228 oncology outpatients was recruited from seven outpatient settings in Israel. Patients completed a demographic questionnaire, a Karnofsky Performance Status score, the Multidimensional Quality of Life Scale-Cancer, the Lee Fatigue Scale, the General Sleep Disturbance Scale, the Center for Epidemiological Studies-Depression Scale, and a numeric rating scale of worst pain intensity. Cluster analysis was used to identify the patient subgroups based on their symptom experience. Four relatively distinct patient subgroups were identified based on their experiences with the above symptoms (i.e., low levels of all four symptoms (32.9%), low levels of pain and high levels of fatigue (18.0%), high levels of pain and moderate levels of fatigue (42.5%), and high levels of all four symptoms (6.6%). No differences were found among the four subgroups on any demographic, disease, or treatment characteristics. The subgroup of patients who reported high levels of all four symptoms reported the worst functional status and poorest QOL. In conclusion, differences in the symptom experience of oncology outpatients suggest that patients may harbor different phenotypic characteristics (e.g., environmental or physiologic) or genetic determinants for experiencing symptoms that are independent of demographic, disease, and treatment characteristics.

Effects of catastrophizing on pain perception and pain modulation.

The multidimensional experience of pain is thought to be partially influenced by the pain modulation system as well as by individual psychological components. Recent studies demonstrated possible common neural network mediating both domains. The present study examined the relationships between pain perception, pain modulation, and catastrophizing in healthy subjects. Forty-eight participants (29 females and 19 males) completed the pain catastrophizing scale (PCS) and underwent psychophysical tests in order to evaluate the modulation of pain, using the diffuse noxious inhibitory control (DNIC) paradigm. Contact heat pain (47.0 degrees C applied for 1 min), which was used as the "test" stimulation, was applied before and after a physical effort that induces pain (repeated squeezing of a hand grip device), which was used as a "conditioning" stimulus. Numeric pain scale intensities (NPS, 0-10) were evaluated four times during each of two separate consecutive runs of heat stimulation. Results showed a significant positive correlation of PCS with heat pain (r = 0.48, p < 0.0005) and with muscle pain (r = 0.31, p = 0.03). In addition, significant negative correlations were found between PCS and DNIC effect (r = -0.34, p = 0.02). Moreover, once catastrophizing was entered into the regression analysis, the previously significant effect of gender was no longer found. In conclusion, individuals with high catastrophizing levels demonstrated higher pain intensities and lower effects of DNIC indicating that catastrophizing might have a significant impact on pain perception via an association with pain modulation.

Does experimental pain affect auditory processing of speech-relevant signals? A study in healthy young adults.

AIM: To assess the effect of tonic pain stimulation on auditory processing of speech-relevant acoustic signals in healthy pain-free volunteers. METHODS: Sixty university students, randomly assigned to either a thermal pain stimulation (46 degrees C/6 min) group (PS) or no pain stimulation group (NPS), performed a rate change detection task (RCDT) involving sinusoidally frequency-modulated vowel-like signals. Task difficulty was manipulated by changing the rate of the modulated signals (henceforth rate). Perceived pain intensity was evaluated using a visual analog scale (VAS) (0-100). RESULTS: Mean pain rating was approximately 33 in the PS group and approximately 3 in the NPS group. Pain stimulation was associated with poorer performance on the RCDT, but this trend was not statistically significant. Performance worsened with increasing rate of signal modulation in both groups (p < 0.0001), with no pain by rate interaction. CONCLUSIONS: The present findings indicate a trend whereby mild or moderate pain appears to affect auditory processing of speech-relevant acoustic signals. This trend, however, was not statistically significant. It is possible that more intense pain would yield more pronounced (deleterious) effects on auditory processing, but this needs to be verified empirically.