Temporal preparation and inhibitory deficit in fibromyalgia syndrome

Executive functions and functioning in women with fibromyalgia

BACKGROUND

 Fibromyalgia (FM) is a chronic condition characterized by widespread pain that is associated with sleep, emotional, and cognitive disturbances, including in executive functions (EFs).

OBJECTIVE

 To investigate the relationship between EFs and functionality in women with FM.

METHODS

 The study included 17 women with FM, aged between 30 and 59 years, with no history of neurological disease. The EFs were assessed using the Digit Span Subtest (DS), Five Digit Test, Trail Making Test (TMT), Corsi Block-Tapping Task, Hayling Test (HT), and Verbal Fluency Task. Functionality was evaluated through the Fibromyalgia Impact Questionnaire. The Beck Depression Inventory, Hamilton Anxiety Rating Scale, and Brief Pain Inventory were used to measure depression, anxiety, and pain, which were controlled in the statistical analyses.

RESULTS

 The FM patients showed longer response latency on the HT and TMT. They made fewer errors on part B of the HT, and they performed worse on the DS backward and on the Corsi Block-Tapping Task forward and backward. There were moderate correlations in the expected direction between performance on the Corsi Block-Tapping Task backward and interference at work, as well as between the time to complete part B of the Trail Making Test - B (TMT-B) and fatigue. An unexpected relationship was found between errors on part B of the HT and interference at work.

CONCLUSION

 The results suggest lower efficiency in processes such as inhibitory control and cognitive flexibility, difficulties in working memory and non-executive processes such as processing speed. Even with pain, anxiety, and depression controlled, some relationships between EFs and functionality were observed, indicating that these symptoms do not fully explain this relationship. We suggest that cognition, particularly EFs, and broader measures of functionality be considered in the evaluation of FM.

Memory complaints and cognitive performance in fibromyalgia and chronic pain: The key role of depression

To explore the relationship between perceived cognitive problems and cognitive performance in three different samples, taking into account the possible influence of depression, catastrophizing, pain intensity, or medication. Seventy individuals with fibromyalgia, 74 with non-malignant chronic pain and 40 pain-free controls, completed measures of verbal episodic memory, sustained attention, response inhibition, depression, catastrophizing, and pain intensity. Fibromyalgia and chronic pain patients performed worse than controls in verbal memory and sustained attention, but these differences disappeared when depressed participants were excluded from the analyses. Memory complaints were related with depression in all pain patients. However, in the case of fibromyalgia, memory complaints were also related by pain intensity and inversely related by short-term episodic memory. This case-control study shows the importance of jointly assessing cognitive performance and memory complaints and of controlling for variables such as depression, catastrophizing, pain intensity and medication in the studied samples. Accordingly, this study highlights the differences in memory complaints, between the patients with fibromyalgia and the patients with other chronic pain conditions. Finally, it has highlighted the important role played by depression in cognitive performance and memory complaints considering the Neurocognitive Model of Attention to pain.

Executive Functions and Pain

Abstract. A growing body of literature suggests that chronic-pain patients suffer from problems in various neuropsychological domains, including executive functioning. In order to better understand which components of executive functioning (inhibition, shifting and/or updating) might be especially affected by pain and which mechanisms might underlie this association, we conducted a systematic review, including both chronic-pain studies as well as experimental-pain studies. The chronic-pain studies (N = 57) show that pain is associated with poorer executive functioning. The findings of experimental-pain studies (N = 28) suggest that this might be a bidirectional relationship: Pain can disrupt executive functioning, but poorer executive functioning might also be a risk factor for higher vulnerability to pain.

Brain Electrical Activity Associated With Visual Attention and Reactive Motor Inhibition in Patients With Fibromyalgia

OBJECTIVE

Fibromyalgia (FM) is a generalized chronic pain condition associated with multiple cognitive impairments, including altered inhibitory processes. Inhibition is a key component of human executive functions and shares neural substrate with pain processing, which may explain the inhibitory deficits in FM. Here, we investigated the integrity of brain inhibitory mechanisms in these patients.

METHODS

We recorded the electroencephalographic activity of 27 patients with FM and 27 healthy controls (HCs) (all women) while they performed a reactive motor inhibition task (the stop-signal paradigm). We analyzed task-induced modulations in electrophysiological markers related to inhibition (N2, P3, and midfrontal theta oscillations) and visual attention (posterior alpha oscillations).

RESULTS

The FM group performed the task correctly, with no differences relative to HCs at the behavioral level. We did not find any between-group differences in N2 amplitude (F(1,52) = 0.01, p = .93), P3 amplitude (F(1,52) = 3.46; p = .068), or theta power (F(1,52) = 0.05; p = .82). However, modulation of posterior alpha power after presentation of either the go or stop stimuli was lower in patients than in HCs (F(1,52) = 7.98; p = .007).

CONCLUSIONS

N2, P3, theta power, and behavioral results indicate that the mechanisms of motor inhibition are sufficiently preserved to enable correct performance of the stop-signal task in patients with FM. Nevertheless, the lower modulation of alpha suggests greater difficulty in mobilizing and maintaining visual attentional resources, a result that may explain the cognitive dysfunction observed in FM.

Pain Expressions and Inhibitory Control in Patients With Fibromyalgia: Behavioral and Neural Correlates

Fibromyalgia (FM) is a generalized chronic pain condition associated with a variety of symptoms, including altered cognitive and emotional processing. It has been proposed that FM patients show a preferential allocation of attention to information related to the symptoms of the disease, particularly to pain cues. However, the existing literature does not provide conclusive evidence on the presence of this attentional bias, and its effect on cognitive functions such as inhibitory control. To clarify this issue, we recorded the electroencephalographic activity of 31 women diagnosed with FM and 28 healthy women, while performing an emotional Go/NoGo task with micro-videos of pain, happy, and neutral facial expressions. We analyzed behavioral data, performed EEG time-frequency analyses, and obtained the event-related potentials (ERPs) N2 and P3 components in NoGo trials. A series of self-reports was also administered to evaluate catastrophic thinking and the main symptoms of fibromyalgia. Pain expressions were associated with longer reaction times and more errors, as well as with higher theta and delta power, and P3 amplitude to NoGo stimuli. Thus, behavioral and psychophysiological data suggest that increased attention to pain expressions impairs the performance of an inhibitory task, although this effect was similar in FM patients and healthy controls. N2 amplitude was modulated by type of facial expression (larger to pain faces), but only for the control group. This finding suggests that the presentation of pain faces might represent a smaller conflict for the patients, more used to encounter pain stimuli. No main group effects were found significant for N2 or P3 amplitudes, nor for time-frequency data. Using stimuli with greater ecological validity than in previous studies, we could not confirm a greater effect of attentional bias toward negative stimuli over inhibitory performance in patients with FM. Studying these effects allow us to better understand the mechanisms that maintain pain and develop intervention strategies to modify them.

Cognitive deficits in fibromyalgia syndrome are associated with pain responses to low intensity pressure stimulation

Background

Fibromyalgia syndrome (FMS) is a chronic disorder characterized by widespread musculoskeletal pain and diffuse tenderness, accompanied by complaints including morning stiffness, fatigue, insomnia and affective symptoms. In addition, affected patients frequently experience cognitive impairments such as concentration difficulties, forgetfulness or problems in planning and decision-making. These deficits are commonly ascribed to interference between nociceptive and cognitive processing.

Method

The present study investigated the association of cognitive performance with (a) pain responses to low intensity pressure stimulation (0.45–2.25 kg/cm²), (b) responses to stronger (above-threshold) stimulation (2.70 kg/cm²), and (c) pain threshold and tolerance in 42 women with FMS. Tests of attention, memory, processing speed, and executive functions were applied.

Results

While no significant correlations were seen for pain threshold and pain tolerance, inverse associations arose between pain intensity ratings during pressure stimulation and performance in all evaluated cognitive domains. The magnitude of the correlations increased with decreasing stimulus intensity.

Conclusions

It may be concluded that pain experience during somatosensory stimulation of low intensity is more closely related to attention, memory and executive functions in FMS than the traditional measures of pain threshold and pain tolerance. Considering that pain responses to low intensity stimulation reflect the hyperalgesia and allodynia phenomena characterizing FMS, it may be hypothesized that central nervous pain sensitization is involved in cognitive impairments in the disorder.

A Pilot Randomized Controlled Trial to Explore Cognitive and Emotional Effects of Probiotics in Fibromyalgia

It has recently been found that microbes in the gut may regulate brain processes through the gut microbiota–brain axis, which modulates affection, motivation and higher cognitive functions. According to this finding, the use of probiotics may be a potential treatment to improve physical, psychological and cognitive status in clinical populations with altered microbiota balance such as those with fibromyalgia (FMS). Thus, the aim of the present pilot study with a double-blind, placebo-controlled, randomised design was to test whether a multispecies probiotic may improve cognition, emotional symptoms and functional state in a sample of patients diagnosed with FMS. Pain, impact of FMS, quality of life, anxiety and depressive symptoms were measured during the pre- and post-intervention phases; participants also completed two computerised cognitive tasks to assess impulsive choice and decision-making. Finally, urinary cortisol concentration was determined. To our knowledge, this is the first study that explore the effect of a multispecies probiotic in FMS patients. Our results indicated that probiotics improved impulsivity and decision-making in these patients. However, more research is needed to further explore the potential effects of probiotics on other cognitive functions affected in FMS as well as in other clinical populations.

Meta-analysis of cognitive performance in fibromyalgia

INTRODUCTION

Fibromyalgia is a condition with symptoms of pain, physical function difficulties, and emotional problems, but is also characterized by complaints of poor cognition (often called "FibroFog"). Over the last two decades, a number of studies have examined cognitive differences between individuals with and without fibromyalgia. The purpose of the current study was to conduct a quantitative synthesis of these differences across multiple cognitive domains.

METHOD

Following Cochrane guidelines, we identified 37 eligible studies for analysis where persons with fibromyalgia (total n = 964) were compared to participants from age-matched control groups without fibromyalgia (total n = 1025) on a range of neuropsychological measures. Group differences between persons with fibromyalgia and healthy controls were examined for cognitive domains including processing speed, long- and short-term memory, and executive functions (inhibitory control, set shifting, updating, and accessing). Random-effect meta-analyses were conducted to determine effect sizes for these differences in cognitive performance.

RESULTS

Fibromyalgia was significantly and negatively associated with performance on all domains of cognitive function. The largest effect size was found for inhibitory control (g = 0.61), followed by memory (g = 0.51 for short-term, 0.50 for long-term memory). The smallest cognitive difference between those with fibromyalgia and controls was for set shifting (g = 0.30).

CONCLUSION

These findings support the hypothesis that the self-reported cognitive impact of fibromyalgia is also found in objective neuropsychological measures. Routine screening for cognitive dysfunction in those with fibromyalgia may be warranted in addition to assessment of the traditional fibromyalgia symptoms.

Vigilance behaviors and EEG activity in sustained attention may affect acute pain

During Sustained Attention to stimuli across many modalities neural activity often decreases over time on task, while Errors in task performance increase (Vigilance Decrement). Sustained Attention to pain has rarely been investigated experimentally despite its clinical significance. We have employed a Sustained Attention protocol (Continuous Performance Task, CPT) in which the subject counts painful laser stimuli (targets) when they occur randomly in a prolonged train of nonpainful nontargets. We hypothesize that the magnitude of the poststimulus oscillatory power divided by baseline power (Event-Related Spectral Perturbation, ERSP - scalp EEG) over Frontoparietal structures will decrease at all frequencies with time on task, while Beta ERSP (14-30Hz) will be correlated with Error Rates in performance of the CPT. During the CPT with a painful target ERSP was found in four separate Windows, as defined by both their frequency band and the time after the stimulus. A Vigilance Decrement was found which confirms that Sustained Attention to pain was produced by this CPT. In addition, Error Rates was correlated inversely with laser energy, and with ratings of pain unpleasantness and salience. Error Rates also were related directly to the Beta ERSP Window at scalp EEG electrodes over the central sulcus. Over time on task, the ERSP magnitude decreased in Alpha (8-14Hz) Window, was unchanged in early and late Delta/Theta Windows (0-8Hz), and increased in the Beta Window. The increase in Beta ERSP and a decrease in the Alpha ERSP occurred at the same EEG electrode over the parietal lobe to a significant degree across subjects. Overall, Beta activity increases with time on task, and with higher Error Rates as in the case of other modalities. In the case of pain increased Errors correspond to misidentification of painful and nonpainful stimuli and so modulate the sensation of pain under the influence of Sustained Attention.

The Specificity of Health-Related Autobiographical Memories in Patients With Somatic Symptom Disorder

OBJECTIVE

Patients with somatic symptom disorder (SSD) have persistent distressing somatic symptoms that are associated with excessive thoughts, feelings, and behaviors. Reduced autobiographical memory specificity (rAMS) is related to a range of emotional disorders and is considered a vulnerability factor for an unfavorable course of pathology. The present study investigated whether the specificity of health-related autobiographical memories is reduced in patients with SSD with medically unexplained dyspnea complaints, compared with healthy controls.

METHODS

Female patients with SSD (n = 30) and matched healthy controls (n = 24) completed a health-related Autobiographical Memory Test, the Beck Depression Inventory, the Ruminative Response Scale, and rumination scales concerning bodily reactions. Depressive symptoms and rumination were assessed because both variables previously showed associations with rAMS.

RESULTS

Patients with SSD recalled fewer specific (F(1,52) = 13.63, p = .001) and more categoric (F(1,52) = 7.62, p = .008) autobiographical memories to health-related cue words than healthy controls. Patients also reported higher levels of depressive symptoms and rumination (all t > 3.00, p < .01). Importantly, the differences in memory specificity were independent of depressive symptoms and trait rumination.

CONCLUSIONS

The present study extends findings on rAMS to a previously unstudied sample of patients with SSD. Importantly, the presence of rAMS could not be explained by increased levels of depressive symptoms and rumination. We submit that rAMS in this group reflects how health-related episodes and associated symptoms are encoded in memory.

Neuroimaging of Central Sensitivity Syndromes: Key Insights from the Scientific Literature

Central sensitivity syndromes are characterized by distressing symptoms, such as pain and fatigue, in the absence of clinically obvious pathology. The scientific underpinnings of these disorders are not currently known. Modern neuroimaging techniques promise new insights into mechanisms mediating these postulated syndromes. We review the results of neuroimaging applied to five central sensitivity syndromes: fibromyalgia, chronic fatigue syndrome, irritable bowel syndrome, temporomandibular joint disorder, and vulvodynia syndrome. Neuroimaging studies of basal metabolism, anatomic constitution, molecular constituents, evoked neural activity, and treatment effect are compared across all of these syndromes. Evoked sensory paradigms reveal sensory augmentation to both painful and nonpainful stimulation. This is a transformative observation for these syndromes, which were historically considered to be completely of hysterical or feigned in origin. However, whether sensory augmentation represents the cause of these syndromes, a predisposing factor, an endophenotype, or an epiphenomenon cannot be discerned from the current literature. Further, the result from cross-sectional neuroimaging studies of basal activity, anatomy, and molecular constituency are extremely heterogeneous within and between the syndromes. A defining neuroimaging "signature" cannot be discerned for any of the particular syndromes or for an over-arching central sensitization mechanism common to all of the syndromes. Several issues confound initial attempts to meaningfully measure treatment effects in these syndromes. At this time, the existence of "central sensitivity syndromes" is based more soundly on clinical and epidemiological evidence. A coherent picture of a "central sensitization" mechanism that bridges across all of these syndromes does not emerge from the existing scientific evidence.

Fibromyalgia: A Critical and Comprehensive Review

Fibromyalgia is a disorder that is part of a spectrum of syndromes that lack precise classification. It is often considered as part of the global overview of functional somatic syndromes that are otherwise medically unexplained or part of a somatization disorder. Patients with fibromyalgia share symptoms with other functional somatic problems, including issues of myalgias, arthralgias, fatigue and sleep disturbances. Indeed, there is often diagnostic and classification overlap for the case definitions of a variety of somatization disorders. Fibromyalgia, however, is a critically important syndrome for physicians and scientists to be aware of. Patients should be taken very seriously and provided optimal care. Although inflammatory, infectious, and autoimmune disorders have all been ascribed to be etiological events in the development of fibromyalgia, there is very little data to support such a thesis. Many of these disorders are associated with depression and anxiety and may even be part of what has been sometimes called affected spectrum disorders. There is no evidence that physical trauma, i.e., automobile accidents, is associated with the development or exacerbation of fibromyalgia. Treatment should be placed on education, patient support, physical therapy, nutrition, and exercise, including the use of drugs that are approved for the treatment of fibromyalgia. Treatment should not include opiates and patients should not become poly pharmacies in which the treatment itself can lead to significant morbidities. Patients with fibromyalgia are living and not dying of this disorder and positive outlooks and family support are key elements in the management of patients.

Cognitive performance in women with fibromyalgia: A case-control study

BACKGROUND/AIM

This study aimed to evaluate the differences in cognitive skills between women with fibromyalgia and healthy women, and the correlations between functional independence and cognitive limitations.

METHODS

A cross-sectional study was performed. Twenty women with fibromyalgia and 20 matched controls participated. Outcomes included the Numerical Pain Rating Scale, the Functional Independence Measure, the Fibromyalgia Impact Questionnaire and Gradior^© software. The Student's t-test and the Spearman's rho test were applied to the data.

RESULTS

Women affected required a greater mean time (P < 0.020) and maximum time (P < 0.015) during the attention test than the healthy controls. In the memory test they displayed greater execution errors (P < 0.001), minimal time (P < 0.001) and mean time (P < 0.001) whereas, in the perception tests, they displayed a greater mean time (P < 0.009) and maximum time (P < 0.048). Correlations were found between the domains of the functional independence measure and the cognitive abilities assessed.

CONCLUSIONS

Women with fibromyalgia exhibited a decreased cognitive ability compared to healthy controls, which negatively affected the performance of daily activities, such as upper limb dressing, feeding and personal hygiene. Patients required more time to perform activities requiring both attention and perception, decreasing their functional independence. Also, they displayed greater errors when performing activities requiring the use of memory.

SIGNIFICANCE OF THE STUDY

Occupational therapists treating women with fibromyalgia should consider the negative impact of possible cognitive deficits on the performance of daily activities and offer targeted support strategies.

Unraveling the relationship between trait negative affectivity and habitual symptom reporting

Objective

In two studies, we aimed at further elucidating the relationship between trait negative affectivity (NA) and habitual symptom reporting (HSR) by relating these variables to measures of executive function, trait questionnaires, and effects of emotion induction.

Methods

Healthy female participants (N = 75) were selected on their scores for trait NA and for the Checklist for Symptoms in Daily Life. Three groups were compared: (1) low NA-low HSR; (2) high NA-low HSR; and (3) high NA-high HSR (low NA-high HSR did not occur). In study 1, participants underwent a Parametric Go/No-go Task and a Stroop Color-Word test, and trait questionnaires measured alexithymia and absorption. Forty-five participants (N = 15 in each group) were further engaged in study 2 to induce state NA using an affective picture paradigm.

Results

Impaired inhibition on the Stroop and Go/No go Task characterized high trait NA, but not high HSR, whereas alexithymia and absorption were elevated in HSR, regardless of trait NA. Negative picture viewing induced elevated state NA in all groups, but only high HSR also reported more bodily symptoms. This effect was moderated, but not mediated by state NA.

Conclusion

High trait NA is a vulnerability factor but not a sufficient condition to develop HSR. Deficient inhibition is related to the broad trait of NA, whereas the moderating effect of state NA on symptom reporting is specific for high HSR. Understanding processes related to alexithymia and absorption may specifically help to explain elevated HSR.

Neuropsychological function, anxiety, depression and pain impact in fibromyalgia patients

Cognitive deficits have a significant impact on the daily performance of fibromyalgia patients. This paper analyzes executive functioning and decision-making performance, and the relationships between these functions and pain, anxiety, depression and medication in fibromyalgia patients. A group of fibromyalgia patients (FG) (n = 85) was compared with a healthy control group (CG) (n = 85) in their performance in the Wisconsin Card Sorting Test (WCST) and the Iowa Gambling Task (IGT). In the WCST, results showed a percentage of non-perseverative errors significantly higher in the CG than in the FG (p = .026), the other variables (percentage of perseverative errors, number of categories and failures to maintain set) showed no significant differences. In relation to decision-making (IGT), once the rules had been learnt, the FG made fewer advantageous choices than the CG, but these differences were not statistically significant (p = .325). In the FG, pain severity (p = .010) and impact on daily activities (p = .016) interfered with decision-making, unlike anxiety, depression or medication, which did no relate to it. In executive function, pain and impact on daily activities were associated with the percentage of perseverative errors (p = .051) and the number of categories (p = .031), whereas pain severity was related to failures to maintain set (p = .039), indicative of increased distractibility and poor attentional ability. In conclusion, FG showed normal performance in executive functioning and decision-making. Moreover, pain was associated with neuropsychological functioning whereas anxiety, depression and medication were not.

Cognitive performance in women aged 50 years and older with and without fibromyalgia

OBJECTIVES

Persons with fibromyalgia (FM) report having cognitive dysfunction. Neuropsychological performance was compared across a variety of domains in 43 women with FM (Mage = 63 years) and in 44 women without FM (Mage = 65 years).

METHOD

Measures included explicit memory (Consortium to Establish a Registry for Alzheimer's Disease [CERAD] immediate/delayed recall, delayed recognition), aspects of executive function including interference/inhibition (Stroop Color/Word test), working memory (Digit Span Forward/Backward), set-shifting/complex sequencing (Trails B), monitoring (verbal fluency: naming animals), processing speed (Trails A, Digit Symbol Substitution Coding), and problem solving (Everyday Problems Test).

RESULTS

Women with FM performed more poorly than controls on executive function (Stroop Color/Word) and one processing speed measure (Digit Symbol Substitution Coding).

DISCUSSION

Results partly support altered cognitive function in FM. Mixed findings across cognitive domains among individuals with or without FM is consistent with the literature and suggest that factors beyond those typically controlled for (e.g., heterogeneity in FM) may be influencing findings. Future research is warranted.

Neurobiology underlying fibromyalgia symptoms

Fibromyalgia is characterized by chronic widespread pain, clinical symptoms that include cognitive and sleep disturbances, and other abnormalities such as increased sensitivity to painful stimuli, increased sensitivity to multiple sensory modalities, and altered pain modulatory mechanisms. Here we relate experimental findings of fibromyalgia symptoms to anatomical and functional brain changes. Neuroimaging studies show augmented sensory processing in pain-related areas, which, together with gray matter decreases and neurochemical abnormalities in areas related to pain modulation, supports the psychophysical evidence of altered pain perception and inhibition. Gray matter decreases in areas related to emotional decision making and working memory suggest that cognitive disturbances could be related to brain alterations. Altered levels of neurotransmitters involved in sleep regulation link disordered sleep to neurochemical abnormalities. Thus, current evidence supports the view that at least some fibromyalgia symptoms are associated with brain dysfunctions or alterations, giving the long-held “it is all in your head” view of the disorder a new meaning.

Rhythms can overcome temporal orienting deficit after right frontal damage

The main aim of this study was to test whether the use of rhythmic information to induce temporal expectations can overcome the deficit in controlled temporal preparation shown by patients with frontal damage (i.e. temporal orienting and foreperiod effects). Two tasks were administered to a group of 15 patients with a frontal brain lesion and a group of 15 matched control subjects: a Symbolic Cued Task where the predictive information regarding the time of target appearance was provided by a symbolic cue (short line-early vs. long line-late interval) and a Rhythm Cued Task where the predictive temporal information was provided by a rhythm (fast rhythm-early vs. slow rhythm-late interval). The results of the Symbolic Cued Task replicated both the temporal orienting deficit in right frontal patients and the absence of foreperiod effects in both right and left frontal patients, reported in our previous study (Triviño, Correa, Arnedo, & Lupiañez, 2010). However, in the Rhythm Cued Task, the right frontal group showed normal temporal orienting and foreperiod effects, while the left frontal group showed a significant deficit of both effects. These findings show that automatic temporal preparation, as induced by a rhythm, can help frontal patients to make effective use of implicit temporal information to respond at the optimum time. Our neuropsychological findings also provide a novel suggestion for a neural model, in which automatic temporal preparation is left-lateralized and controlled temporal preparation is right-lateralized in the frontal lobes.