Pain sensitisation in patients with sickle cell disease: A preliminary study.

BACKGROUND: Responses to experimental pain have suggested central and peripheral sensitisation in adult patients with sickle cell disease (SCD). Recent studies have proposed an algometry-derived dynamic measure of pain sensitisation, slowly repeated evoked pain (SREP), which is useful in the discrimination of painful conditions related to central sensitisation. Pain and fatigue are two symptoms that affect the general functioning of patients with SCD most significantly, however, research about experimental dynamic pain measures and their relation to the main symptoms of SCD (pain and fatigue) is still scarce. OBJECTIVE: This preliminary study aimed to test the utility of the SREP protocol for detecting pain sensitisation in patients with SCD, and to evaluate the associations of pain sensitisation, pain threshold, and pain tolerance with the main clinical symptoms of SCD, pain and fatigue. METHODS: Twenty-two female outpatients with SCD and 20 healthy women participated. Pain threshold, pain tolerance, and pain sensitisation were assessed by algometry in the fingernail. Clinical pain, fatigue, anxiety, depression and pain catastrophizing were evaluated. RESULTS: No group differences were found in pain threshold and tolerance. However, using the SREP protocol, pain sensitisation was greater in patients than in healthy participants, even after controlling for psychological variables and body mass index. Pain threshold and tolerance were inversely associated with fatigue levels in the SCD group, with pain tolerance being the main predictor. CONCLUSIONS: Pain threshold and tolerance did not discriminate between patients and healthy individuals, but were useful for predicting fatigue severity in SCD. The SREP protocol provides a useful dynamic measure of pain for the discrimination and detection of enhanced pain sensitisation in patients with SCD, which could contribute to more personalised pain evaluations and treatment for these patients.

Long-term stress exposure, cortisol level and cardiovascular activity and reactivity: Observations in patients with fibromyalgia.

Previous research suggested that exposure to long-lasting or repeated laboratory stressors may lead to rearrangement of cardiovascular control, with a shift of regulation mechanisms from dominant cardiac to dominant vascular influences between the early and late response phases, respectively. This study investigated whether similar rearrangement occurs during life stress accompanying chronic disease by analyzing also associations between cortisol level and cardiovascular variables in patients with fibromyalgia (FM). In 47 women with FM and 36 healthy women (HW), cardiovascular recordings were taken during active body posture changes (sitting, lying down, and standing). Moreover, hair cortisol concentration (HCC) was obtained. During standing, which involved orthostatic challenge, FM patients showed higher total peripheral resistance (TPR) but lower stroke volume (SV), cardiac output (CO), and baroreflex sensitivity than HW. During sitting and lying down, TPR was more closely associated with blood pressure (BP) than CO in FM patients; in contrast, CO was more closely associated with BP than TPR in HW. HCC correlated positively with TPR and BP in FM patients, but negatively with TPR and BP and positively with SV and CO in HW. Results suggest that chronic disease-related stress is associated with alterations in cardiovascular regulation toward greater involvement of vascular than cardiac mechanisms in BP control. Stress-related cortisol release may contribute to the long-term rearrangement of autonomic regulation. At the behavioral level, the dominance of vascular over cardiovascular control may relate to reduced somatic mobilization during an active fight-flight response in favor of passive and behaviorally immobile coping.

Racial differences in baroreflex function: Implications for the cardiovascular conundrum.

Study objective: African Americans (AAs) show early signs of vascular dysfunction paired with elevated blood pressure (BP) and total peripheral resistance (TPR), which is thought to underlie their increased rates of cardiovascular health complications relative to European Americans (EAs). AAs paradoxically have higher cardiac vagal tone, indexed by heart rate variability (HRV), which is cardio-protective. This paradox has been termed the Cardiovascular Conundrum. The physiological mechanism underlying this phenomenon is not well understood. We examined race differences in baroreflex function, which might be an important mechanism underlying the Cardiovascular Conundrum. Design: Participants completed a 5-minute baseline period where resting cardiac metrics were assessed. Setting: Laboratory. Participants: 130 college-aged individuals (54 women, 57 AAs). Main outcome measures: Baroreflex function was indexed as baroreflex sensitivity (BRS; the magnitude of changes in cardiovascular activity in accordance with BP changes) and effectiveness (BEI; the ratio of BP changes that elicit changes in cardiovascular activity) in the cardiac, vascular, and myocardial limbs. Results and conclusions: Results showed AAs to have higher HRV and cardiac BRS in comparison to EAs, suggesting the baroreflex is more sensitive to correcting the heart period for changes in BP among AAs compared to EAs. However, AAs showed lower vascular BEI relative to EAs, suggesting less effective control of TPR. In sum, lower BEI in the vascular branch might be an important mechanism underlying the Cardiovascular Conundrum (i.e., higher HRV and BP) and by extension, health disparities in cardiovascular diseases between AAs and EAs.

A Comparative Analysis of Cognitive Deficits in Rheumatoid Arthritis and Fibromyalgia: Impact of Symptoms Severity and Its Clinical Implications.

Purpose: Fibromyalgia syndrome (FMS) and rheumatoid arthritis (RA) are chronic pain disorders, with clearly distinct pathogenetic mechanisms, frequently accompanied by symptoms like depression, fatigue, insomnia and cognitive problems. This study compared performance in various cognitive domains between patients with FMS and RA. The role of clinical symptoms severity in determine the differences in cognitive performance was also investigated. Patients and Methods: A cross-sectional study was conducted according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement. In total, 64 FMS patients, 34 RA patients and 32 healthy controls participated, all women. Using factor analysis, questionnaire scores were combined to yield a symptom severity factor, which was used as a control variable in the group comparisons. Results: Without controlling for symptom severity, both patient groups performed worse than controls in all the cognitive domains assessed (visuospatial memory; verbal memory; strategic planning and self-regulation; processing speed, attention and cognitive flexibility; and planning and organizational abilities); overall deficits were greater in FMS than in RA patients. FMS patients reported more severe clinical symptoms (current pain intensity, total pain, state anxiety, depression, fatigue and insomnia) than RA patients. After controlling for symptom severity, a large proportion of the cognitive test parameters no longer differed between FMS and RA patients. Conclusion: The study confirmed significant impairments in attention, memory, and higher cognitive functions in both FMS and RA. The greater deficits seen in FMS patients may at least partly be explained by more severe pain and secondary symptoms. Cognitive screening may facilitate the development of personalized treatment plans to optimize the quality of life of FMS and RA patients.

The investigation substantiated noteworthy impairments in attention, memory, and executive functions among individuals diagnosed with Fibromyalgia Syndrome (FMS) and Rheumatoid Arthritis (RA).The heightened cognitive deficits observed in FMS patients compared to those with RA could be attributed in part to the heightened severity of pain and secondary symptoms characteristic of FMS.Semantic clustering, by leveraging cognitive resources optimally, may serve as a compensatory mechanism for memory deficits and thus warrants inclusion in interventions aimed at assisting patients in coping with cognitive impairments.Incorporating cognitive deficit screenings into routine diagnostic protocols for FMS and RA is recommended, as it may facilitate the development of personalized treatment strategies aimed at enhancing the overall quality of life for affected individuals.

Blunted sudomotor reactivity in fibromyalgia is associated with levels of depression.

OBJECTIVES: Assessment of sudomotor function by distal electrochemical skin conductance (ESC) can provide an index of peripheral neuropathy. This study explored ESC in fibromyalgia (FM) patients, controlling for tricyclic antidepressant use and body mass index, and its association with the clinical severity of the disease. METHODS: ESC, clinical symptoms and an index of central pain sensitisation derived from pressure algometry were explored in thirty-three fibromyalgia patients and 33 healthy women. RESULTS: ESC was significantly lower in fibromyalgia patients than healthy participants. About 51% of patients exhibited moderate-to-severe ESC dysfunction, indicative of possible neuropathy. However, ESC was not related to any indicators of clinical severity, nor to algometry. ESC only correlated with depression levels; the group differences in ESC disappeared after controlling for depression. Finally, ESC was asymmetric in the overall sample, with lower values seen in the right hand relative to the left one. CONCLUSIONS: The greater prevalence of sudomotor dysfunction in fibromyalgia patients is consistent with the presence of neuropathy in subgroups of patients, and with the basic heterogeneity of the disorder. However, neuropathy does not appear helpful for determining the clinical features of the disorders, or the level of central sensitisation measured by pressure algometry. Future studies including patients with fibromyalgia suffering and not suffering from depression as well as patients with depression but free from chronic pain, are required to identify the role of depression in the observed low ESC levels.

Impact of homeostatic body hydration status, evaluated by hemodynamic measures, on different pain sensitization paths to a chronic pain syndrome.

Contrasting findings on the mechanisms of chronic pain and hypertension development render the current conventional evidence of a negative relationship between blood pressure (BP) and pain severity insufficient for developing personalized treatments. In this interdisciplinary study, patients with fibromyalgia (FM) exhibiting clinically normal or elevated BP, alongside healthy participants were assessed. Different pain sensitization responses were evaluated using a dynamic 'slowly repeated evoked pain' (SREP) measure, as well as static pain pressure threshold and tolerance measures. Cardiovascular responses to clino-orthostatic (lying-standing) challenges were also examined as acute re- and de-hydration events, challenging cardiovascular and cerebrovascular homeostasis. These challenges involve compensating effects from various cardiac preload or afterload mechanisms associated with different homeostatic body hydration statuses. Additionally, hair cortisol concentration was considered as a factor with an impact on chronic hydration statuses. Pain windup (SREP) and lower pain threshold in FM patients were found to be related to BP rise during clinostatic (lying) rehydration or orthostatic (standing) dehydration events, respectively. These events were determined by acute systemic vasoconstriction (i.e., cardiac afterload response) overcompensating for clinostatic or orthostatic cardiac preload under-responses (low cardiac output or stroke volume). Lower pain tolerance was associated with tonic blood pressure reduction, determined by permanent hypovolemia (low stroke volume) decompensated by permanent systemic vasodilation. In conclusion, the body hydration status profiles assessed by (re)activity of systemic vascular resistance and effective blood volume-related measures can help predict the risk and intensity of different pain sensitization components in chronic pain syndrome, facilitating a more personalized management approach.

[Neuropsychological impairments in patients undergoing peritoneal dialysis treatment]. / Alteraciones neuropsicológicas en pacientes en tratamiento con diálisis peritoneal.

BACKGROUND: Patients with chronic kidney disease on hemodialysis (HD) often have cognitive deficits. However, there are few studies that have examined the neuropsychological impairments of patients receiving peritoneal dialysis (PD). METHODS: Executive functions, processing speed and verbal memory were assessed in 27 PD patients, 42 HD patients, and 42 healthy participants (HP). Systolic blood pressure and total time on renal replacement therapy (RRT) were controlled statistically. Associations between performance and clinical factors were analyzed using correlations and multiple regression. RESULTS: The DP group showed better performance compared to the HD group in verbal fluency, working memory, cognitive flexibility, planning and decision making. The DP group showed worse execution than the HP group in verbal inhibition and memory. Executive function scores were positively associated with total months on PD, total months on RRT, total months on HD, albumin, total cholesterol, and phosphorus, and negatively with ferritin. CONCLUSION: Global executive functioning was more optimal in PD patients than in HD patients. The results show the positive effect of PD on executive functions, which must be taken into account when choosing the TRS. The associations observed between biochemical factors and performance show the importance of maintaining an adequate nutritional status in these patients.

A Case-Control Study of Cognitive Function in Patients with End-Stage Renal Disease Before and After Hemodialysis in Southern Spain.

BACKGROUND Cognitive problems are frequent in patients with end-stage renal disease (ESRD) treated with hemodialysis. However, previous studies used only a single cognitive screening test or a small number of cognitive indices, which is inadequate for an exhaustive evaluation of cognitive deficits. This case-control study aimed to evaluate cognitive function in patients with ESRD before and after hemodialysis at centers in southern Spain, and included analysis of associations between cognitive function and duration of hemodialysis, biochemistry, body composition, and treatment variables. MATERIAL AND METHODS Cognitive performance was evaluated in 42 healthy participants (HPs) and in 43 ESRD patients, before and after hemodialysis. The tests measured verbal and visual memory, sustained/selective attention, and processing speed. The diagnostic criterion for ESRD was a glomerular filtration rate.

Experimental carotid baroreceptor stimulation reduces blood flow velocities in the anterior and middle cerebral arteries of healthy individuals.

This study investigated effects of experimental baroreceptor stimulation on bilateral blood flow velocities in the anterior and middle cerebral arteries (ACA and MCA) using functional transcranial Doppler sonography. Carotid baroreceptors were stimulated by neck suction in 33 healthy participants. Therefore, negative pressure (- 50 mmHg) was applied; neck pressure (+ 10 mmHg) was used as a control condition. Heart rate (HR) and blood pressure (BP) were also continuously recorded. Neck suction led to reductions in bilateral ACA and MCA blood flow velocities, which accompanied the expected HR and BP decreases; HR and BP decreases correlated positively with the ACA flow velocity decline. The observations suggest reduction of blood flow in the perfusion territories of the ACA and MCA during baroreceptor stimulation. Baroreceptor-related HR and BP decreases may contribute to the cerebral blood flow decline. The findings underline the interaction between peripheral and cerebral hemodynamic regulation in autoregulatory control of cerebral perfusion.

Did you get the joke? Physiological, subjective and behavioral responses to mirth.

Mirth is elicited by the perception of humor, which requires the resolution of an incongruity in an unexpected and playful manner. Previous psychophysiological research using affective pictures is scarce, and did not elucidate the cognitive and affective components of the humor process. In this study, the passive viewing paradigm is applied to mirthful, incongruent, neutral and erotic pictures to characterize the emotional response of mirth. Physiological (zygomaticus major [ZM] activity, skin conductance response [SCR] and heart rate [HR]), behavioral (free viewing time) and subjective responses (mirthful ratings) were recorded from 63 participants. The presence of an inflection change in the ZM response and mirthfulness ratings were used as markers of humor comprehension. Participants showed the greatest ZM and HR in response to mirthful compared to incongruent, erotic and neutral pictures, as well as a stronger SCR response to mirthful compared to incongruent and neutral pictures. The overall results shed light on the temporal course of the humor process, suggesting that humor comprehension (cognitive component) occurred around 1000-1500 ms after picture onset, according to the ZM and SCR responses; and the humor appreciation stage (emotional component) occurred at around 3500 ms after stimulus onset, according to the HR and SCR changes. Moreover, marked interindividual variability was observed in the number of smiles, and in the pictures that provoked them. This points to the complexity of the humor process, and suggests the need to develop methods to elicit mirth and elucidate the factors potentially underlying individual differences in humor.

Blood Pressure Prediction Using Ensemble Rules during Isometric Sustained Weight Test.

BACKGROUND: Predicting beat-to-beat blood pressure has several clinical applications. While most machine learning models focus on accuracy, it is necessary to build models that explain the relationships of hemodynamical parameters with blood pressure without sacrificing accuracy, especially during exercise. OBJECTIVE: The aim of this study is to use the RuleFit model to measure the importance, interactions, and relationships among several parameters extracted from photoplethysmography (PPG) and electrocardiography (ECG) signals during a dynamic weight-bearing test (WBT) and to assess the accuracy and interpretability of the model results. METHODS: RuleFit was applied to hemodynamical ECG and PPG parameters during rest and WBT in six healthy young subjects. The WBT involves holding a 500 g weight in the left hand for 2 min. Blood pressure is taken in the opposite arm before and during exercise thereof. RESULTS: The root mean square error of the model residuals was 4.72 and 2.68 mmHg for systolic blood pressure and diastolic blood pressure, respectively, during rest and 4.59 and 4.01 mmHg, respectively, during the WBT. Furthermore, the blood pressure measurements appeared to be nonlinear, and interaction effects were observed. Moreover, blood pressure predictions based on PPG parameters showed a strong correlation with individual characteristics and responses to exercise. CONCLUSION: The RuleFit model is an excellent tool to study interactions among variables for predicting blood pressure. Compared to other models, the RuleFit model showed superior performance. RuleFit can be used for predicting and interpreting relationships among predictors extracted from PPG and ECG signals.

Revealing the Role of Social Support on Cognitive Deficits in Fibromyalgia Syndrome.

Despite the relevance of cognitive deficits in fibromyalgia syndrome (FMS) and the attempts to elucidate the influence of the disorder symptoms in the cognitive decline reported by patients, no studies have explored the specific role of social support on cognition in FMS. Social support has been shown to be an essential modulator factor on cognitive performance in other diseases. Sixty-four women with FMS and 32 healthy women participated in the study and completed questionnaires pertaining to anxiety, depression, fatigue, insomnia, clinical pain, and social support, along with a neuropsychological battery assessing verbal memory, organization, strategic and planning abilities, self-regulation, processing speed, attention, and cognitive flexibility. Results showed that FMS patients exhibited lower values in all social support dimensions in comparison with healthy individuals, especially in the socializing dimension. Despite the lower social support observed in FMS, all social support dimensions showed a positive impact on verbal memory, organization and planning abilities, strategic planning, self-regulation, processing speed, attention, and cognitive flexibility in these patients. In fact, social support was associated with greater correct responses and processing speed and minor number of errors in all the neuropsychological battery tests. Socializing was the main predictor of organization and planning abilities, strategic planning, and self-regulation. In sum, results suggest that social support may be a key factor in buffering the cognitive decline observed in FMS. Designing psychoeducation programs and intervention programs directed not only to FMS patients but also relatives, health care workers, and the general population might be essential to improve the social support of FMS patients and positively impact on patient's cognitive status.

The Role of Depressive Disorders in Autonomic Cardiovascular Dysregulation in Fibromyalgia.

OBJECTIVE: Previous research revealed aberrances in autonomic cardiovascular regulation in fibromyalgia, which may be relevant to symptoms genesis and the increased risk of cardiovascular disorders in individuals with fibromyalgia. This study investigated the role of comorbid depression in autonomic cardiovascular dysregulations in fibromyalgia. METHODS: Cardiovascular recordings were obtained in 53 participants with fibromyalgia who also had depression ( n = 27), in participants with fibromyalgia without depression ( n = 26), and in 29 healthy controls, at rest and during a cold pressor test and an arithmetic task. Assessed parameters included interbeat interval, blood pressure, heart rate variability, baroreflex sensitivity, stroke volume, preejection period, left ventricular ejection time, Heather index, and total peripheral resistance. RESULTS: Participants with both fibromyalgia and depression displayed lower tonic interbeat interval, baroreflex sensitivity, and heart rate variability compared with participants with fibromyalgia without depression and controls ( p values < .012, d values = 0.71-1.06). Participants with fibromyalgia but without depression did not differ from controls in these variables. Moreover, participants with fibromyalgia who also had depression, but not those without depression, exhibited lower Heather index, stroke volume, and left ventricular ejection time compared with controls ( p values < .013, d values = 0.62-0.78). No group differences arose for preejection period or total peripheral resistance. Stress reactivity was reduced in participants with fibromyalgia, independently of depression, for diastolic blood pressure, interbeat interval, left ventricular ejection time, and heart rate variability, than in controls. CONCLUSIONS: The role of depression in the autonomic dysregulation in fibromyalgia involves chronotropic cardiac control rather than adrenergic influences on contractility and vascular tone. Blunted cardiovascular reactivity may be ascribable to pathological factors inherent to fibromyalgia. These results underline the importance of diagnostics and treatment of comorbid depressive disorders in the management of fibromyalgia.

Variability of Reaction Time as a Marker of Executive Function Impairments in Fibromyalgia.

In addition to chronic widespread pain and depression and anxiety symptoms, patients with fibromyalgia frequently experience cognitive problems. This study investigated executive functions in fibromyalgia via a Go/No-Go task. To obtain comprehensive information about performance, traditional and ex-Gaussian parameters of reaction time (RT) variability were used, in addition to speed and accuracy indices. Ex-Gaussian parameters show an excellent fit to empirical RT distributions. Fifty-two female fibromyalgia patients and twenty-eight healthy controls participated. The task included 60 visual stimuli, which participants had to respond to (Go stimuli) or withhold the response to (No-Go stimuli). After 30 trials, the task rule changed, such that previous No-Go stimuli had to be responded to. Performance was indexed by the hit rate, false alarm rate, and mean (M) and intraindividual standard deviation (SD) of RT and the ex-Gaussian parameters mu, sigma, and tau. Mu and sigma indicate the M and SD of the Gaussian distribution; tau reflects the M and SD of the exponential function. Patients exhibited a lower hit rate, higher M RT, and higher tau than controls. Moreover, patients showed greater decrease of the hit rate after the change of task rule. In the entire sample, SD, sigma, and tau were inversely associated with the hit rate and positively associated with the false alarm rate. While the greater decline in hit rate after the change in task rule indicates deficient cognitive flexibility, the lack of any difference in false alarm rate suggests intact response inhibition. Higher M RT reflects reduced cognitive or motor speed. Increased tau in fibromyalgia indicates greater fluctuations in executive control and more frequent temporary lapses of attention. For the first time, this study demonstrated that indices of RT variability, in particular those derived from the ex-Gaussian function, may complement speed and accuracy parameters in the assessment of executive function impairments in fibromyalgia. Optimized assessment may facilitate the personalization of therapies aimed at improving the cognitive function of those with the disorder.

Fibromyalgia Syndrome and Cognitive Decline: The Role of Body Mass Index and Clinical Symptoms.

The high prevalence of obesity and overweight in fibromyalgia (FM) may be an important factor in the well-known cognitive deficits seen in the disorder. This study analyzed the influence of body mass index (BMI) and primary clinical symptoms of FM (pain, fatigue, insomnia, anxiety, and depression) on attention, memory, and processing speed in FM. Fifty-two FM patients and thirty-two healthy participants completed cognitive tasks assessing selective, sustained, and divided attention; visuospatial and verbal memory; and information processing speed. Furthermore, they were evaluated in terms of the main clinical symptoms of the disorder. FM patients showed a marked reduction of cognitive performance in terms of selective, sustained, and divided attention; visuospatial memory; and processing speed, but no group differences were observed in verbal memory. BMI negatively affects sustained and selective attention, verbal memory, and processing speed and is the main predictor of performance in these basic cognitive domains. Our findings confirm the presence of cognitive deficits with respect to attention and visual memory, as well as slower processing speed, in FM. Moreover, the results support a role of BMI in the observed cognitive deficits. Interventions increasing physical activity and promoting cognitive stimulation could be useful for strengthening cognitive function in FM patients.

Central sensitisation pain and autonomic deficiencies in fibromyalgia.

OBJECTIVES: Fibromyalgia (FM) is associated with central pain sensitisation, autonomic alterations and neuropathy in small nerve fibres. This study aimed to analyse the association between tonic sweating and central pain sensitisation in FM. METHODS: Fifty-eight FM patients and thirty healthy women were assessed in terms of slowly repeated evoked pain (SREP), as a measure of central sensitisation. Sweating was evaluated by skin conductance (SC), as a sympathetic autonomic measure secondarily indexing possible small nerve fibre peripheral neuropathy. Clinical and psychological factors were evaluated through questionnaire measures. RESULTS: FM patients displayed smaller SC values than healthy controls, and SREP sensitisation was only observed in FM patients. Pain threshold and tolerance were also lower in the patient sample. Clinical symptoms (pain, fatigue, insomnia) only correlated significantly with SREP sensitisation. SC was inversely related to SREP sensitisation, and this association persisted after statistically controlling for levels of catastrophising and antidepressant use. CONCLUSIONS: These results suggest that central pain sensitisation, proposed as a main pathophysiological mechanism of FM, may depend on sympathetic autonomic deficiencies, suggestive of small nerve fibres neuropathy. Future studies should aim to replicate these results using other central pain sensitisation measures and direct measures of neuropathy or small nerve fibre density.

Algometry for the assessment of central sensitisation to pain in fibromyalgia patients: a systematic review.

INTRODUCTION: The pathophysiology of fibromyalgia (FM) is related to central sensitisation (CS) to pain. Algometry allows assessing CS based on dynamic evoked pain. However, current algometrýs protocols require optimising, unifying and updating. OBJECTIVES: 1) identify the dynamic pain measures used most frequently to effectively assess CS processes in FM, and 2) consider the future of the algometry assessing CS in these patients. METHODS: Cochrane Collaboration guidelines and PRISMA statements were followed. The protocol was registered in PROSPERO database (ID: CRD42021270135). The selected articles were evaluated using the Cochrane risk of bias (ROB) assessment tool. The PubMed, Scopus, and Web of Science databases were searched. RESULTS: Thirty-four studies were selected, including measures such as temporal summation of pain (TSP), aftersensations (AS), spatial summation of pain (SSP), the noxious flexion reflex (NFR) threshold, conditioned pain modulation (CPM), cutaneous silent period (CuSP), and slowly repeated evoked pain (SREP); and evoked pain combined with neuroimaging. Each measure offered various advantages and limitations. According to ROB, 28 studies were of low quality, 3 of moderate quality, and 3 of high quality. CONCLUSIONS: Several pain indicators have been demonstrated to successfully examine CS involvement in FM in the last years. Algometry, especially when it involves diverse body sites and tissues, might provide further insight into (1) the evaluation of psychological factors known to influence pain experience, (2) new dynamic pain indicators, and (3) the simultaneous use of certain neuroimaging techniques. Further research clarifying the mechanisms underlying some of these measures, and homogenisation and optimisation of the algometrýs protocols, are needed. KEY MESSAGESAlgometry allows for assessing Central Sensitisation by applying dynamic evoked pain.The future of algometry could relapse in its combination with neuroimaging.Recently-emerged pain indicators should be considered for algometrýs new protocols.

Parasympathetic cardiac control during attentional focus and worry in major depressive disorder.

Worry, which refers to uncontrollable chains of thoughts and images with negative affective load, is a transdiagnostic symptom of various mental disorders including major depressive disorder (MDD). Current theories relate excessive worry to deficient top-down control of automatically occurring perseverative thinking. This study investigated parasympathetic cardiac control in MDD in the context of worry and cognitive control. Heart rate variability (HRV) was recorded, in the high frequency (HF) and low frequency (LF) bands, in 36 MDD patients and 36 healthy controls while they performed a breathing focus task. The task included two phases during which participants' ability to concentrate on their breathing was assessed before and after an instructed worry phase. In addition to higher self-reported worry, MDD patients exhibited lower HF and LF HRV at rest, and lower LF HRV during the task than controls. MDD was also associated with impaired breathing concentration ability, more negative and neutral thought intrusions, more negative mood during breathing focus and increased stress during instructed worry. In the total sample, LF HRV correlated negatively with self-reported worry and negative thought intrusions, and positively with mood ratings. The reduction of HRV confirms the notion of low parasympathetic cardiac control in MDD. Moreover, low HRV represents a correlate of blunted prefrontal activity and impaired cognitive control that characterize the disorder. Impaired cognitive control may exacerbate worry, which is in turn involved in the genesis of aversive emotional states and maintenance of MDD.

Blunted short-term autonomic cardiovascular reactivity to orthostatic and clinostatic challenges in fibromyalgia as an indicator of the severity of chronic pain.

Fibromyalgia is a long-term pain disorder that has been related to autonomic dysfunctions and reduced cardiovascular reactivity. We aimed to assess the dynamic short-term cardiovascular responses to postural changes in fibromyalgia. Thirty-eight women with fibromyalgia and thirty-six healthy women underwent the "Chronic Pain Autonomic Stress Test". Electrocardiogram, blood pressure and impedance cardiography were continuously recorded during active standing and lying down. Second-by-second values were derived over the first 30 s of each posture. Lower reactivity during the beginning of each position was observed in fibromyalgia sufferers compared to healthy women, with smaller responses seen during stand up in heart rate, blood pressure, cardiac output, total peripheral resistance, and pre-ejection period, and smaller changes during lying down in heart rate, cardiac output and total peripheral resistance. The magnitude of the autonomic adjustments to postural changes was inversely associated with the severity of clinical pain. These findings indicate an early impaired autonomic cardiovascular response to orthostatic and clinostatic challenges in fibromyalgia, suggesting less autonomic flexibility and adaptability to situational demands and challenges. Short-term second-by-second cardiovascular measures may be useful in the clinical assessment of fibromyalgia.

The Link between Fibromyalgia Syndrome and Anger: A Systematic Review Revealing Research Gaps.

Anger has been associated with increased pain perception, but its specific connection with Fibromyalgia Syndrome (FMS) has not yet been established in an integrated approach. Therefore, the present systematic review focuses on exploring this connection, and based on this connection, delimiting possible gaps in the research, altogether aimed at improving FMS clinical intervention and guiding future research lines. Anger is considered a basic negative emotion that can be divided into two dimensions: anger-in (the tendency to repress anger when it is experienced) and anger-out (the leaning to express anger through verbal or physical means). The current systematic review was performed based on the guidelines of the PRISMA and Cochrane Collaborations. The Prospective Register of Systematic Reviews (PROSPERO) international database was forehand used to register the review protocol. The quality of chosen articles was assessed and the main limitations and research gaps resulting from each scientific article were discussed. The search included PubMed, Scopus, and Web of Science databases. The literature search identified 13 studies eligible for the systematic review. Levels of anger-in have been shown to be higher in FMS patients compared to healthy participants, as well as patients suffering from other pain conditions (e.g., rheumatoid arthritis). FMS patients had also showed higher levels of state and trait anxiety, worry and angry rumination than other chronic pain patients. Anger seems to amplify pain especially in women regardless FMS condition but with a particularly greater health-related quality of life´s impact in FMS patients. In spite of the relevance of emotions in the treatment of chronic pain, including FMS, only two studies have proposed intervention programs focus on anger treatment. These two studies have observed a positive reduction in anger levels through mindfulness and a strength training program. In conclusion, anger might be a meaningful therapeutic target in the attenuation of pain sensitivity, and the improvement of the general treatment effects and health-related quality of life in FMS patients. More intervention programs directed to reduce anger and contribute to improve well-being in FMS patients are needed.