Memory functioning in patients with primary fibromyalgia and major depression and healthy controls

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.

Executive function in chronic pain patients and healthy controls: different cortical activation during response inhibition in fibromyalgia

The primary symptom of fibromyalgia (FM) is chronic, widespread pain; however, patients report additional symptoms including decreased concentration and memory. Performance-based deficits are seen mainly in tests of working memory and executive function. Neural correlates of executive function were investigated in 18 FM patients and 14 age-matched healthy controls during a simple Go/No-Go task (response inhibition) while they underwent functional magnetic resonance imaging (fMRI). Performance was not different between FM and healthy control, in either reaction time or accuracy. However, fMRI revealed that FM patients had lower activation in the right premotor cortex, supplementary motor area, midcingulate cortex, putamen and, after controlling for anxiety, in the right insular cortex and right inferior frontal gyrus. A hyperactivation in FM patients was seen in the right inferior temporal gyrus/fusiform gyrus. Despite the same reaction times and accuracy, FM patients show less brain activation in cortical structures in the inhibition network (specifically in areas involved in response selection/motor preparation) and the attention network along with increased activation in brain areas not normally part of the inhibition network. We hypothesize that response inhibition and pain perception may rely on partially overlapping networks, and that in chronic pain patients, resources taken up by pain processing may not be available for executive functioning tasks such as response inhibition. Compensatory cortical plasticity may be required to achieve performance on a par with control groups.

PERSPECTIVE

Neural activation (fMRI) during response inhibition was measured in fibromyalgia patients and controls. FM patients show lower activation in the inhibition and attention networks and increased activation in other areas. Inhibition and pain perception may use overlapping networks: resources taken up by pain processing may be unavailable for other processes.

The relationship between cognitive functions, somatization and behavioural coping in patients with multiple functional somatic symptoms

BACKGROUND AND AIMS

Patients with multiple functional somatic symptoms (MFS) often express cognitive complaints. The aim of this descriptive study was to investigate whether these patients have cognitive deficits and whether the patients' cognitive functioning relates to their experience of physical and psychological distress and to their use of pain-related coping strategies.

METHODS

Neuropsychological assessment of verbal ability, psychomotor speed, attention, working memory, perceptual organization and memory, was conducted on 22 MFS patients and 27 healthy age- and gender-matched controls. Psychological distress, health anxiety, health status and pain coping were measured with questionnaires [Symptom Checklist 90-Revised (SCL-somatization, SCL-depression, SCL-anxiety), the Whiteley-7 scale, the Short Form (SF-36) and the Coping Strategies Questionnaire (CSQ)].

RESULTS

For patients, a high score on the SCL-somatization subscale was associated with poor performance on tests of attention and psychomotor speed, and with a high score on the coping scale Increasing behavioural activities. A high score on this coping scale was associated with poor performance on tests of verbal ability and executive functioning. After controlling for years of education, controls performed significantly better than patients on verbal as well as performance IQ scales but not on tests of memory.

CONCLUSION

In the present study, we found that physical complaints are related to deficits in attention and psychomotor speed. Moreover, our results suggest that poor verbal skills may play a role in the development of MFS because of an increased tendency to apply behavioural/avoidant coping strategies. We suggest that treatment of MFS should involve training of attention as well as practicing the use of cognitive coping strategies.

Altered associative learning and emotional decision making in fibromyalgia

OBJECTIVE

The present study examines the possibility that a chronic pain condition, such as fibromyalgia, was associated with deficits in decision making and associative learning.

METHODS

Fifteen patients with fibromyalgia (aged 42-59 years) and 15 healthy controls (aged 39-61 years) participated in the experiment. Subjects completed anxiety (STAI) and depression (BDI) questionnaires, as well as standardized neuropsychological tests (Stroop and WAIS subscales). In addition, an emotional decision-making task (Iowa Gambling Task) and a conditional associative learning task (CALT) were administered to all participants.

RESULTS

Results indicated that fibromyalgia had a poorer performance than healthy controls in both tasks, showing more perseveration errors in the learning task, and more disadvantageous decisions, as well as a more random behavior in the gambling task. Moreover, we observed that poor performance on the associative learning task was mediated by depression, whereas performance on the gambling task was not influenced by depression. No group differences were found on the standardized neuropsychological tests.

CONCLUSION

These findings indicate that pain and depressive symptoms in fibromyalgia might lead to significant deficits in emotionally charged cognitive tasks. Furthermore, it suggests that chronic pain might impose a high cost on executive control, undermining mainly affective processes involved in learning, memory, attention, and decision-making.

Spatial versus verbal memory impairments in patients with fibromyalgia

Mounting evidence suggests that individuals with fibromyalgia (FM) have impairments in general cognitive functions. However, few studies have explored the possibility of dissociation between verbal and visuospatial memory impairments in FM. Therefore, the purpose of this study was to investigate the asymmetrical impairment of cognitive functions between verbal and visuospatial memory and between short-term and long-term memory. Neuropsychological assessments were carried out on 23 female patients with FM and 24 healthy female controls. Verbal memory abilities were assessed using the Korean version of the Rey auditory verbal learning test (KAVLT) and digit span task, and visuospatial memory abilities were assessed using the Korean version of the Rey complex figure test (KCFT) and spatial span task. The analysis of covariance was used to assess group differences in performance on cognitive tests after controlling for depression. The two groups did not significantly differ in terms of age, years of education, or in their estimated verbal and performance IQ, but FM patients reported more severe depressive symptoms than did controls on the Beck depression inventory. Significant group differences were found in immediate and delayed recall on the KCFT (F (1,44) = 6.49, p = 0.014 and F (1,44) = 6.96, p = 0.011, respectively), whereas no difference was found in immediate and delayed recall on the KAVLT. In terms of short-term memory, neither the digit span task nor spatial span task showed any difference between groups, regardless of whether repetition was forward or backward. These findings suggest that spatial memory abilities may be more impaired than verbal memory abilities in patients with FM.

[Cognitive impairment in patients suffering from fibromyalgia. An underestimated problem]

The primary symptom of fibromyalgia (FM) is chronic, widespread pain accompanied by diffuse tenderness to light palpation. However, many patients report a multitude of additional complaints and symptoms. Besides fatigue, exhaustibility and stiffness, a decrease in concentration and memory are further complaints that add significantly to the degree of suffering. This complaint, often termed "fibrofog", is increasingly recognised as an independent symptom that has made its way into the medical literature under the term "dyscognition". Nonetheless there are only a few studies that have specifically investigated neuropsychological deficits in FM patients in order to further specify clinical complaints. The studies performed so far have provided increasing evidence that FM patients have attention and working memory deficits, which are most prominent when patients have to cope with an additional source of distraction. With this review we intend to give an overview of the neuropsychological studies in FM performed so far and to assess possible implications for the underlying pathophysiology. In addition, we discuss potential clinical approaches to these symptoms. A systematic literature review up to June 2009 was carried out using the keywords (pairs) "fibromyalgia" and "cognition", "fibromyalgia" and "dyscognition", "fibromyalgia" and "cognitive deficits".

Fibromyalgia syndrome module at OMERACT 9: domain construct

The objective of the module was to (1) establish a core domain set for fibromyalgia (FM) assessment in clinical trials and practice, (2) review outcome measure performance characteristics, (3) discuss development of a responder index for assessment of FM in clinical trials, (4) review objective markers, (5) review the domain of cognitive dysfunction, and (6) establish a research agenda for outcomes research. Presentations at the module included: (1) Results of univariate and multivariate analysis of 10 FM clinical trials of 4 drugs, mapping key domains identified in previous patient focus group: Delphi exercises and a clinician/researcher Delphi exercise, and breakout discussions to vote on possible essential domains and reliable measures; (2) Updates regarding outcome measure status; (3) Update on objective markers to measure FM disease state; and (4) Review of the issue of cognitive dysfunction (dyscognition) in FM. Consensus was reached as follows: (1) Greater than 70% of OMERACT participants agreed that pain, tenderness, fatigue, patient global, multidimensional function and sleep disturbance domains should be measured in all FM clinical trials; dyscognition and depression should be measured in some trials; and stiffness, anxiety, functional imaging, and cerebrospinal fluid biomarkers were identified as domains of research interest. (2) FM domain outcome measures have generally proven to be reliable, discriminative, and feasible. More sophisticated and comprehensive measures are in development, as is a responder index for FM. (3) Increasing numbers of objective markers are being developed for FM assessment. (4) Cognitive dysfunction assessment by self-assessed and applied outcome measures is being developed. In conclusion, a multidimensional symptom core set is proposed for evaluation of FM in clinical trials. Research on improved measures of single domains and composite measures is ongoing.

Cognitive impairment in patients with fibromyalgia syndrome as assessed by the mini-mental state examination

Background

This study evaluated the frequency of cognitive impairment in patients with Fibromyalgia syndrome (FMS) using the Mini Mental State Examination (MMSE).

Methods

We analyzed baseline data from all 46 patients with FMS and 92 age- and sex-matched controls per diagnosis of neuropathic (NeP) or mixed pain (MP) selected from a larger prospective study.

Results

FMS had a slight but statistically significant lower score in the adjusted MMSE score (26.9; 95% CI 26.7-27.1) than either NeP (27.3; 95% CI 27.2-27.4) or MP (27.3; 27.2-27.5). The percentage of patients with congnitive impairment (adjusted MMSE ≤ 26) was numerically higher in FMS (15%; 95% CI 6.3-29) compared with NeP (5%; 95% CI 1.8-12.2) or MP (5%; 95% CI 1.8-12.2) and higher than in the same age stratum of the general population (0.05%).

Conclusions

Compared with the population reference value, patients with FMS showed high frequency of cognitive impairment.

Understanding the ‘miserable minority’: a diasthesis-stress paradigm for post-concussional syndrome

Opinions about persisting post-concussional symptoms after minor traumatic brain injury still reflect a polarization of views around the sterile debate concerning the psychological vs organic origins of symptoms. Reviews of the experimental literature do not always integrate the often diverse perspectives that explain persisting symptoms of concussion. As a result, the disorder is still poorly understood. In this review, a diasthesis-stress paradigm examines the interaction between physiological and psychological factors that generate and maintain post-concussional symptoms. Motivational factors and different coping strategies are considered to explain why some people are at risk of developing a post-concussional syndrome. The early iatrogenic potential of GPs and hospital doctors who may create insecurity or reinforce illness perceptions is considered. Finally, the rationale and effectiveness of interventions that ameliorate the impact of early post-concussional symptoms is reviewed to see if prevention of the post-concussional syndrome is more effective than cure.

Executive functions, self-regulation, and chronic pain: a review

BACKGROUND

Chronic pain conditions are complicated and challenging to live with. Capacity to adjust to such conditions may depend on the ability to self-regulate, that is, the ability to alter thoughts, feelings, and behaviors. Self-regulation appears to rely on executive cognitive functions, and the current review, therefore, sought to draw attention to the impact of self-regulatory capacity and executive functions on chronic pain.

DISCUSSION

Chronic pain conditions present with complex interactions of cognitive, emotional, behavioral, and physiological components for which self-regulatory ability is crucial. The ability to self-regulate varies, and self-regulatory strength appears to be a limited resource that can be fatigued. The many challenges of chronic pain conditions could, therefore, tax self-regulatory strength, leading to self-regulatory deficits.

CONCLUSION

The current review proposes a relationship among pain, self-regulatory capacity, self-regulatory demands, executive functions, and self-regulatory fatigue, suggesting that executive functions and self-regulatory deficits are indeed part of the etiology and maintenance of chronic pain conditions.

Disruption of cognitive function in fibromyalgia syndrome

Accumulating evidence points to significant cognitive disruption in individuals with Fibromyalgia Syndrome (FMS). This study was carried out in order to examine specific cognitive mechanisms involved in this disruption. Standardized experimental paradigms were used to examine attentional function and working memory capacity in 30 women with FMS and 30 matched controls. Cognitive function was examined using performance on these tests and between group results were analysed in the context of important psychological and behavioural measures. Performance of standardized everyday attentional tasks was impaired in the FMS group compared to controls. Working memory was also found to be impaired in this group. Stimulus interference was found to be significantly worse in the FMS group as the demands of the tasks increased. These effects were found to exist independent of the measures of mood and sleep disruption. However, when pain levels were accounted for statistically, no differences existed between groups on cognitive measures. These findings point to disrupted working memory as a specific mechanism that is disrupted in this population. The results of this study suggest that pain in FMS may play an important role in cognitive disruption. It is likely that many factors, including disrupted cognition, play a role in the reduced quality of life reported by individuals with FMS.

The relationship between fibromyalgia and major depressive disorder: a comprehensive review

OBJECTIVE

A large body of evidence suggests that the relationship between major depressive disorder (MDD) and fibromyalgia (FM) is complex. Improved understanding of this relationship promises to provide clinicians with better assessment and treatment options for both disorders.

METHOD

This paper reviews research on the prevalence, etiology and pathogenesis, clinical characterization, and treatment of FM and MDD, as well as studies that examined the relationship between these disorders. Studies were identified via PubMed literature search.

RESULTS

Our findings point to substantial similarities in neuroendocrine abnormalities, psychological characteristics, physical symptoms and treatments between FM and MDD. However, currently available findings do not support the assumption that MDD and FM refer to the same underlying construct or can be seen as subsidiaries of one disease concept.

CONCLUSION

New methodological and theoretical approaches may lead to a better understanding of the link between FM and MDD, and to more effective psychological and psychopharmacological therapies for FM patients. In the meantime, clinicians should carefully screen for a history of MDD in patients with FM.

Are the Contents of Treatment Outcomes in Fibromyalgia Trials Represented in the International Classification of Functioning, Disability, and Health?

OBJECTIVES

To identify the concepts contained in treatment outcomes of randomized controlled trials (RCTs) for interventions in patients with fibromyalgia (FM) using the International Classification of Functioning, Disability, and Health (ICF) as external reference.

METHODS

RCTs between 1992 and 2001 were located in MEDLINE and selected according to predefined eligibility criteria. The outcome measures were extracted and the concepts within the outcome measures were identified and linked to the ICF using a content-analytical approach.

RESULTS

Forty-two trials on FM were included. Twenty-seven different questionnaires were extracted. Of all, 79.2% (N=236) of the clinical and physiologic outcomes could be linked to 31 different ICF categories and 84.7% (N=964) of the concepts contained in the health-status questionnaire to 113 ICF categories.

CONCLUSIONS

The ICF provides a useful external reference to identify the concepts contained in outcome measures used in RCTs in FM.

An internet survey of 2,596 people with fibromyalgia

Background

This study explored the feasibility of using an Internet survey of people with fibromyalgia (FM), with a view to providing information on demographics, sources of information, symptoms, functionality, perceived aggravating factors, perceived triggering events, health care utilization, management strategies, and medication use.

Methods

A survey questionnaire was developed by the National Fibromyalgia Association (NFA) in conjunction with a task force of "experts in the field". The questionnaire underwent several rounds of testing to improve its face validity, content validity, clarity and readability before it was mounted on the internet. The questionnaire consisted of 121 items and is available online at the website of the National Fibromyalgia Association.

Results

The questionnaire was completed by 2,569 people. Most were from the United States, with at least one respondent from each of the 50 states. Respondents were predominantly middle-aged Caucasian females, most of whom had FM symptoms for ≥ 4 years. The most common problems were morning stiffness, fatigue, nonrestorative sleep, pain, concentration, and memory. Aggravating factors included: emotional distress, weather changes, insomnia, and strenuous activity. Respondents rated the most effective management modalities as rest, heat, pain medications, antidepressants, and hypnotics. The most commonly used medications were: acetaminophen, ibuprofen, naproxen, cyclobenzaprine, amitriptyline, and aspirin. The medications perceived to be the most effective were: hydrocodone preparations, aprazolam, oxycodone preparations, zolpidem, cyclobenzaprine, and clonazepam.

Conclusion

This survey provides a snap-shot of FM at the end of 2005, as reported by a self-selected population of people. This descriptive data has a heuristic function, in that it identifies several issues for further research, such as the prescribing habits of FM health care providers, the role of emotional precipitants, the impact of obesity, the significance of low back pain and the nature of FM related stiffness.

A Meta-Analytic Review of Verbal Fluency Deficits in Depression

A prominent view in the neuropsychological literature is that depression is particularly associated with deficits in executive control processes. A meta-analysis of 42 studies with 2306 participants was therefore conducted to investigate the sensitivity of tests of verbal fluency to the pressure of this disorder, as there is a great deal of evidence that theses measures are valid markers of executive dysfunction. When the methodology adopted by other meta-analytic reviews was employed, semantic fluency deficits were found to be substantially larger than the phonemic fluency deficits. However, when a more rigorous method of meta-analysis was adopted, this indicated that the measure are in fact broadly equivalent in their sensitivity to depression, as has been found for patients with focal frontal lobe lesions. However, in contrast to patients with focal frontal lobe injuries, neither deficit qualified as a differential deficit relative to psychomotor speed. Therefore, for patients with depression, deficits on tests of phonemic and semantic fluency may not reflect executive dysfunction, but a more generalized impairment. Evidence is presented that tests of phonemic and semantic fluency may aid in the differential diagnosis of patients with depression and those in the early stages of dementia of the Alzheimer's type.

Musculoskeletal pain complaints and performance on cognitive tasks over the adult life span

The present study aimed at comparing participants with and without self reported musculoskeletal pain in a normal population with regard to performance on a range of tests for episodic memory, semantic memory, and other cognitive functions and to see if expected differences interacted with age. The results showed that participants with pain performed worse on a range of tasks as compared to participants without pain, and that these differences occurred regardless of age. The most robust effects of pain were displayed on tests for vocabulary and construction ability as these were the only effects that remained significant after controlling for years of education and reported depression in separate analyses. When depression and education were controlled for in the same analysis, even these effects were eliminated, suggesting interplay between pain, depressive status, and educational level in the negative effects on cognitive functioning.

Predictors of Incident Chronic Widespread Pain Among Veterans Following the First Gulf War

OBJECTIVE

We sought to determine the predictors of incident chronic widespread pain (CWP), specifically, the effect of preexisting symptoms, stress, and psychosocial factors in the subsequent development of CWP among veterans from the first Gulf War (GW).

METHODS

We conducted a structured telephone survey (baseline) of military personnel originally from Iowa who were either eligible for or deployed to Operation Desert Shield/Desert Storm, approximately 5 years postconflict. We conducted a follow-up, clinical, in-person study of those who met a priori-defined outcomes of symptoms of cognitive dysfunction, depression, or CWP, and also a sample of those who did not meet any of the outcomes of interest.

RESULTS

A total of 370 of 602 evaluated GW veterans were free of CWP 5 years postconflict. At follow-up, 69 (19%) of these had developed CWP. A positive family history of medically unexplained persistent symptoms [odds ratio (OR)=4.8 (2.3, 13.2)] was strongly associated with CWP. At baseline, individuals who reported preexisting symptoms of bronchitis [OR=4.9 (1.9, 12.3)] and cognitive dysfunction [OR=2.1 (1.1, 4.2)] were more likely to develop CWP. Alcohol use [OR=0.2 (0.1, 0.7)] was protective against CWP. Rather than combat-related exposure per se, the perception of stress at the time of the GW [OR=1.6 (1.1, 2.3)] correlated with CWP.

DISCUSSION

Among the GW veterans evaluated longitudinally in this study, family history, predeployment symptoms, and the level of perceived stress during the GW were associated with subsequent development of CWP.

Chronic fatigue syndrome: a systematic review

OBJECTIVE

A systematic review of the literature about chronic fatigue syndrome (CFS).

METHODS

A search of the Medline database (via Ovid and PubMed) with the key words chronic fatigue syndrome, diagnosis, classification, epidemiology, etiology, physiopathology, metabolism, microbiology, immunology, virology, psychology, drug therapy, rehabilitation, and therapy. The reference lists of each article were examined for additional related articles.

RESULTS

CFS was defined in 1988 by the US Centes for Disease Control and Prevention. The prevalence of chronic fatigue syndrome has ranged from 0.2% to 0.7% in the general population. In 1994, the definition of CFS was revised by Fukuda et al. Despite various research in several topics (e.g. infection, immune systems, neuroendocrinology, autonomic activity, neuromuscular involvement), the pathophysiology remains unknown.

CONCLUSION

CFS, with its various major clinical and functional impacts, should be associated with a "biopsychosocial model". Progressive muscular rehabilitation, combined with behavioral and cognitive treatment, is an essential part of therapy.

SSRIs and cognitive performance in a working sample

BACKGROUND

Studies of the impact of antidepressant use on cognitive performance have frequently been carried out among the elderly or on healthy volunteers. Comparatively little research has considered their impact on a relatively young, working population, particularly within the context of everyday life.

AIMS

To examine any association between SSRI use and cognitive performance, mood and human error at work.

METHODS

SSRI users and controls completed a battery of laboratory based computer tasks measuring mood and cognitive function pre- and post-work at the start and end of a working week. They also completed daily diaries reporting their work performance.

RESULTS

SSRI use was associated with memory impairment: specifically poorer episodic, though not working or semantic memory. Effects of SSRI use on recognition memory seemed to vary according to the underlying psychopathology, while effects on delayed recall were most pronounced among those whose symptoms had not (yet) resolved. There were no detrimental effects on psychomotor speed, attention, mood or perceived human error at work.

CONCLUSIONS

The findings lend support to the SSRIs comparative safety, even among workers, particularly as the symptoms of the underlying psychopathology are successfully addressed. Possible memory impairments may, however, be found in those taking SSRIs.

Health related quality of life and quantitative pain measurement in females with chronic non-malignant pain

The aim of the present study was to assess, compare, and correlate the pain response to an experimental pain stimulus (hyperalgesia to pressure pain threshold (PPT) measured from different body sites), the pain intensity (VAS) of the habitual pain, and quality of life parameters (SF-36) in groups of females with chronic non-malignant pain syndromes. Forty female pain patients with fibromyalgia/whiplash (n = 10), endometriosis (n = 10), low back pain (n = 10), or rheumatoid arthritis (n = 10), as well as 41 age-matched healthy female controls participated in the study. The fibromyalgia/whiplash patients scored significantly higher (p < 0.04) VAS ratings (median rating = 7.0) than the endometriosis (6.0), low back pain (6.0), and rheumatoid arthritis (3.5) patients. All fours patient groups had significantly lower PPTs at all sites as compared with controls. The fibromyalgia/whiplash patients experienced the highest influence of pain on their overall health status, particularly vitality, social function, emotional problems, and mental health. A significant negative correlation was found between VAS rating and quality of life (p < 0.04). Significant correlation (p < 0.05) was found between pressure hyperalgesia measured at lowest PPT sites and the impairment of SF-36 physical function as well as mental health parameters. This study demonstrates significant generalised pressure hyperalgesia in four groups of chronic pain patients, correlations between degree of pressure hyperalgesia and impairment of some quality of life parameters, and increased pain intensity of the ongoing pain is associated with decreased quality of life.

Cognitive Complaints Are Associated With Depression, Fatigue, Female Sex, and Pain Catastrophizing in Patients With Chronic Pain

OBJECTIVE

To examine the relation between demographic, pain-related, psychosocial, affective, and treatment factors and complaints of cognitive dysfunction among patients with chronic pain.

DESIGN

Cross-sectional survey.

SETTING

A university hospital outpatient multidisciplinary chronic pain program.

PARTICIPANTS

Chronic pain patients (N=222; 135 women, 87 men) completed a battery of psychometric questionnaires as part of an initial evaluation on referral to the program.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Cognitive impairment was assessed with items from the Brief Symptom Inventory; measures of depressive symptoms, pain intensity, posttraumatic stress disorder (PTSD), and pain catastrophizing were obtained from the Beck Depression Inventory (negative affect, negative self, somatic/physical function), McGill Pain Questionnaire, Modified Posttraumatic Chronic Pain Test, and Coping Strategies Questionnaire, respectively; and measures of subjective sleep disturbance, fatigue, opiate use, compensation/litigation status, pain location, and relevant demographic data were obtained from an open-ended questionnaire.

RESULTS

Correlational analysis indicated that female sex, pain intensity, PTSD symptoms, depressive symptoms, catastrophizing, pain location (neck), and fatigue were all positively related to cognitive complaints. Simultaneous regression analysis showed that all factors combined accounted for 52% of the variance in self-report of cognitive difficulties and that 6 variables had a significant unique contribution to the report of cognitive complaints in the following order of importance: depression-negative affect (beta=.28, P <.05), fatigue (beta=.17, P <.05), depression-somatic/physical function (beta=.16, P <.05), depression-negative self (beta=.14, P =.05), pain catastrophizing (beta=.12, P =.08), and female sex (beta=.12, P <.05).

CONCLUSIONS

Complaints of cognitive impairment among chronic pain patients appear to be associated with multiple factors, with particular attention to depressive symptoms, fatigue, and catastrophizing. Our results also suggest that women with chronic pain are particularly vulnerable to cognitive dysfunction.

Memory beliefs and function in fibromyalgia patients

OBJECTIVE

The aim of this study was to investigate memory beliefs and their relationship to actual memory function in fibromyalgia (FM) patients.

METHODS

Twenty-three FM patients, 23 age- and education-matched controls, and 22 older controls completed the Metamemory in Adulthood (MIA) questionnaire, which assessed beliefs about seven aspects of memory function. Group differences on the seven scales were assessed, and scores on the capacity scale were correlated with objective memory performance.

RESULTS

FM patients reported lower memory capacity and more memory deterioration than did either control group. Patients reported lower control or self-efficacy over memory, higher achievement motivation, higher strategy use, and higher anxiety about memory than age-matched controls did. Among the patients, perceived capacity, achievement motivation, and self-efficacy were significantly correlated with objective memory performance on a recall task.

CONCLUSION

FM patients' complaints about memory function have some accuracy.

The Prevalence and Clinical Impact of Reported Cognitive Difficulties (Fibrofog) in Patients With Rheumatic Disease With and Without Fibromyalgia

Cognitive dysfunction in patients with rheumatic disease encompasses a range of impairment. Their prevalence, co-occurrence, and impact on symptom severity were assessed in 57 patients with fibromyalgia (FMS) and 57 patients with rheumatic disease without FMS. Information pertaining to memory decline, mental confusion, and speech difficulty was extracted from questions embedded in a health questionnaire and a blind retrospective chart review. Pain, morning stiffness, fatigue, and sleep difficulty were established on a 0- to 100-mm visual analog scale. Variables of mental confusion, fatigue, tension, depression, anger, and vigor were assessed using the Profile of Mood States.Compared with the non-FMS sample, patients with FMS complained more often of memory decline (70.2-24.6%), mental confusion (56.1-12.3%), and speech difficulty (40.4-3.5%). Memory decline and mental confusion were coupled more often in patients with FMS (50.9-8.8%). Patients with FMS with this combination of cognitive problems reported more pain (76.0-45.4%), stiffness (79.7-43.7%), fatigue (79.6-52.6%), and disturbed sleep (59.2-36.6%) compared with patients with FMS with memory problems alone. Patients with rheumatic disease substantially differ in cognitive vulnerability, with patients with FMS at considerably higher risk for cognitive difficulty. More importantly, the prevalence of a combined disturbance in memory and mental clarity is high and closely associated with the perception of increased illness severity and diminished mental health in FMS. That this linkage has the possibility of having a great deal to do with an important clinical variant of FMS underscores the need for greater clinical recognition of this underrecognized pattern and for further research.Patients with fibromyalgia frequently report memory and concentration problems, especially if asked about them. Clinicians could judge these complaints as similar to adult attention deficit syndrome and reassure the patient. Trying medication to improve attention and concentration is sensible but untested in fibromyalgia.

Predictors of neurocognitive performance in chronic pain patients

In a sample of 70 chronic pain patients, hierarchical multiple regression analyses were utilized to assess the additive and interactive contributions of pain severity and psychological distress variables to neurocognitive performance across attention and concentration, memory, and reasoning ability domains. Although the full model predicting attention and concentration was found to be significant, there was no significant contribution of pain severity, psychological distress, or the Pain Severity x Psychological Distress interaction to the prediction of attention and concentration scores after controlling for the effect of years of formal education. After controlling for the effect of years of formal education, pain severity and psychological distress did make separate and significant contributions to the prediction of memory scores; however, the Pain Severity x Psychological Distress interaction did not significantly affect memory scores. After controlling for the effect of years of formal education, there was no significant contribution of pain severity, psychological distress, or the Pain Severity x Psychological Distress interaction to reasoning ability scores. Results suggest the importance of assessing memory function when managing psychologically distressed chronic pain patients.

Auditory event-related brain potentials in fibromyalgia syndrome

OBJECTIVE

The aim of this study was to investigate cognitive functions using auditory event-related brain potentials (ERP) in fibromyalgia syndrome (FMS).

METHODS

The P300 component of ERP was studied in 36 female FMS patients and 22 control subjects. The short form 36 (SF-36) medical outcome study was used to determine quality of life. Number of tender points and disease duration were noted. Cognitive functions were evaluated with P300.

RESULTS

The symptoms were discrepant in FMS (P<0.001). The scores of the eight SF-36 subgroups in FMS patients were significantly lower than in the control group (P<0.001). Fibromyalgia syndrome patients had prolonged latency and reduced amplitude of P300 (P<0.001). No correlation was found between the subgroups of SF-36, tender point count, disease duration, and P300.

CONCLUSION

The results of our study reveal that FMS affects quality of life and dysfunction in cognitive abilities can be determined by brain event-related potentials.

Neuropsychological impairment in fibromyalgia: relation to depression, fatigue, and pain

OBJECTIVE

The present study assessed the relationship of depression, pain, and fatigue to subjective cognitive complaints and objective impairment in patients with fibromyalgia (FM), patients with other chronic pain disorders, and healthy controls.

METHOD

Neuropsychological assessment was conducted on 28 FM patients, 27 chronic pain patients, and 21 healthy controls. Five FM patients and five chronic pain patients were excluded due to poor effort on cognitive tasks. Assessment included measures of depression, pain, fatigue, subjective cognitive complaints, memory, executive functioning, intellect, attention, and psychomotor speed. Analysis of covariance was used to assess group differences in cognitive complaints and cognitive test performance, after controlling for depression, pain, and fatigue. Hierarchical regression was used to assess whether objective test performance was related to subjective cognitive complaints, after controlling for depression, pain, and fatigue.

RESULTS

FM patients had more memory complaints and reported more fatigue, pain, and depression than other groups. Groups were not different in cognitive performance, after controlling for fatigue, pain, and depression; depression was related to memory performance and fatigue was related to psychomotor speed. Neuropsychological test results did not add significantly to the variance accounted for in subjective cognitive complaints, after accounting for depression, pain, and fatigue.

CONCLUSION

Psychological factors, particularly effort, depression, and fatigue, are important in understanding both subjective cognitive complaints and objective cognitive impairment in FM and other chronic pain disorders.

Auditory P300 event related potentials and serotonin reuptake inhibitor treatment in patients with fibromyalgia

BACKGROUND

The P300 components of auditory event related potentials (ERPs) are objective measures related to information and cognitive processing.

OBJECTIVES

To assess P300 ERPs in female patients with fibromyalgia (FM) in comparison with healthy age matched controls. To investigate the relationship between P300 potentials and pain threshold levels of patients, and subsequent effect of sertraline treatment on P300 potentials.

METHODS

P300 auditory ERPs were studied in 13 untreated female patients with FM and 10 healthy controls matched for age, sex, and education. Pain pressure thresholds and total myalgic scores (TMS) were assessed with an algometer. Patients were evaluated for clinical measures and P300 potentials (recorded from the vertex) at the first visit, and then in the fourth and eighth weeks of sertraline treatment.

RESULTS

Patients with FM had significantly lower P300 amplitudes, but not significantly different P300 latencies, than controls at entry. P300 latencies in patients correlated negatively with TMS (r(s)=-0.79, p<0.01) and P300 amplitudes correlated significantly with TMS (r(s)=0.53, p<0.05). Anxiety and depression scores did not correlate significantly with P300 latencies or amplitudes at the study entry. P300 auditory ERPs had increased amplitudes that had reached nearly the same levels as those of the controls at the eighth week without any significant change in their latencies.

CONCLUSION

The results show reduced P300 amplitudes in patients with FM. Further studies assessing the relationship between P300 ERPs and neuropsychiatric tests are required for better clarification of the clinical relevance of P300 potentials in FM.

Cognitive impairment in patients with chronic pain: the significance of stress

This review article examines the role of emotional distress and other aspects of suffering in the cognitive impairment that often is apparent in patients with chronic pain. Research suggests that pain-related negative emotions and stress potentially impact cognitive functioning independent of the effects of pain intensity. The anterior cingulate cortex is likely an integral component of the neural system that mediates the impact of pain-related distress on cognitive functions, such as the allocation of attentional resources. A maladaptive physiologic stress response is another plausible cause of cognitive impairment in patients with chronic pain, but a direct role for dysregulation of the hypothalamic-pituitary-adrenocortical axis has not been systematically investigated.

Biological and Psychological Factors Associated With Memory Function in Fibromyalgia Syndrome

Fibromyalgia is a stress-related disorder characterized by chronic pain, memory impairment, and neuroendocrine aberrations. With the hypothesis that biological and psychological symptoms may underlie the cognitive problems, the relative influences of neuroendocrine function and psychological factors on declarative memory were examined among 50 women with fibromyalgia. This within-group analysis controlled for age, education, pain, and relevant medications. Neuroendocrine function and depression had significant independent associations with memory function. Higher log-transformed mean salivary cortisol levels were associated with better performance on both immediate and delayed visual recall and with delayed verbal recall. Depressive symptoms were negatively associated with verbal recall. These findings suggest that a basic disorder of endocrine stress responses may contribute to the cognitive symptoms experienced by fibromyalgia patients.

The SSRIs drug Fluoxetine, but not the noradrenergic tricyclic drug Desipramine, improves memory performance during acute major depression

Accumulating evidence suggests that noradrenergic and serotonergic drugs are equally effective in ameliorating the depressive symptoms of major depression. Major depression is associated also with memory impairments, but the comparative effects of the antidepressant drugs on memory are not clear. We previously found that serotonergic neurotransmission is of particular importance for some aspects of episodic memory. We set out to test whether treatment with the selective serotonergic drug Fluoxetine (Prozac) would be advantageous in this respect over treatment with the selective noradrenergic tricyclic antidepressant drug Desipramine (Deprexan). Seventeen patients with major depressive episode, randomly assigned for treatment with either Fluoxetine (n = 8) or Desipramine (n = 9), were assessed for their clinical situation and for memory performance at the beginning of treatment, after 3 weeks, and after 6 weeks of pharmacological treatment. We found that although clinically both drugs were equally effective, the improvement of memory performance in the Fluoxetine-treated patients was significantly greater compared with that of the Desipramine-treated patients. The results support the role of serotonin in memory. More studies in larger samples of patients are required, but it may be that in cases where memory impairment is a major symptom, it would be beneficial to consider serotonergic antidepressant drugs for treatment. Furthermore, in cases where, for various reasons, the treatment of choice is noradrenergic, it may be worthwhile to consider a supplementary serotonergic drug to improve memory deficits.

The rational management of fibromyalgia patients

The exponential increase in pain research over the last 10 years has established fibromyalgia (FM) as a common chronic pain syndrome with similar neurophysiologic aberrations to other chronic pain states. As such, the pathogenesis is considered to involve an interaction of augmented sensory processing (central sensitization) and peripheral pain generators. The notion, that FM symptomatology results from an amplification of incoming sensory impulses, has revolutionized the contemporary understanding of this enigmatic problem and provided a more rational approach to treatment. To date, the management of FM has been mainly palliative, with the aims of reducing pain, improving sleep, maintaining function, treating psychologic distress and diminishing the impact of associated syndromes. The rapidly evolving neurophysiologic, psychophysiologic and molecular biologic basis for chronic pain states has already opened up new avenues for management which should be applicable to this difficult group of patients. Indeed, it is now possible to think about a "rational" approach to managing FM patients that was unthinkable just a few years ago.

Evaluation and management of endocrine dysfunction in fibromyalgia

Fibromyalgia-like symptoms such as muscle pain and tenderness, exhaustion, reduced exercise capacity, and cold intolerance, resemble symptoms associated with endocrine dysfunction like hypothyroidism, and adrenal or growth hormone insufficiency. To investigate the potential of management of endocrine abnormalities for relieve of symptoms of patients with fibromyalgia, we reviewed experimental and clinical studies of endocrine functioning and endocrine treatment. Serum GH, androgen, and 24-hour urinary cortisol levels of patients with fibromyalgia tend to be in the lower part of the normal range, while serum levels of thyroid hormone, female sex hormones, prolactin, and melatonin are normal. With exception of GH, these conclusions are based on studies in small samples. With respect to dynamic responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis, the dexamethasone suppression test and stimulation with ACTH show normal results, while patients show marked ACTH hypersecretion in response to severe acute stressors, perhaps indicative of chronic CRH hyposecretion. This finding and slightly altered responsiveness of growth hormone, thyroid hormone, and prolactin in pharmacologic stimulation tests suggest a central rather than peripheral origin of endocrine deviations. Because hormone level deviations were not severe, occurred in subgroups of patients only, and few controlled clinical trials were performed, there is--unless future research shows otherwise--little support for hormone supplementation as a general therapy in the common patient with fibromyalgia. In patients with clinically overt hormone deficiency, hormonal supplementation is an option. In patients with hormone levels that are in the lower part of the normal range, interventions aimed at pain, fatigue, sleep or mood disturbance, and physical deconditioning may indirectly improve endocrine functioning.

Rational and targeted pharmacologic treatment of fibromyalgia

Despite disappointing results when subjected to randomized clinical trials, pharmacologic agents remain an important component of FM management. Addressing the main symptoms of pain, disturbed sleep, mood disturbances, fatigue, and associated conditions is essential to improve patient functioning and enhanced quality of life. However, much work remains to design clinical trials which address the complexity of FM, while satisfying evidence based medicine paradigms.

Cognitive and Dissociative Manifestations in Fibromyalgia

Memory decline and mental confusion frequently complicate the clinical presentation of fibromyalgia; however, formal cognitive examination often does not support deterioration. This paradox was examined in the context of dissociation, a condition with many cognitive similarities. Dissociation refers to the separation of parts of experience from the mainstream of consciousness. A common example is highway hypnosis. Eighty-nine fibromyalgia (FM) patients and 64 other rheumatic disease patients were screened for memory decline and mental confusion using a questionnaire format. Pain, dissociation, affective distress, fatigue, sleep difficulty, and mental confusion were also assessed. Cognitive complaints (76.4%-43.8%) and dissociative symptoms (37.1%-1.9%) were overrepresented in patients with FM. Among FM patients with high dissociation, cognitive difficulties were reported by 95%; 100% of these cases reported that both memory and mental clarity were affected, a condition referred to as fibrofog. Dissociation in combination with fibrofog was associated with higher levels of FM symptom intensity and decreased mental well being. These findings suggest that dissociation may play a role in FM symptom amplification and may aid in comprehending the regularity of cognitive symptoms. Separating cases of fibrofog from cognitive conditions with actual brain damage is important. It may be prudent to add a test of dissociation as an adjunct to the evaluation of FM patients in cases of suspected fibrofog. Otherwise, test results may prove normal even in patients with disabling cognitive symptoms.

Attention and the Stages of Pain Processing

OBJECTIVE

Explore the relationships between the four stages of pain processing and attention in chronic pain sufferers.

DESIGN

A cross-sectional, retrospective study of 736 subjects participating in an outpatient university-based tertiary care pain treatment program.

METHODS

Self-report measures of pain, pain-related unpleasantness, and suffering (Pain Experience Visual Analog Scales) in conjunction with a structured interview assessing illness behavior (adaptation of the Psychosocial Pain Inventory) and attention (Digit Span subtest of the Wechsler Adult Intelligence Scale-Revised) were employed.

OUTCOME MEASURES

Separate step-wise multiple regression analyses were conducted using variables that measure each of the four stages of pain processing as predictors, with Digit Span being the criterion variable.

RESULTS

Multiple regression analyses showed that, of the four pain stages, only suffering and pain behavior were related to attentional performance. Specifically, an individual's perception of lifestyle interference due to pain, level of depression, and the degree of solicitous responses from others each uniquely contributed to Digit Span performance.

CONCLUSIONS

Treatment interventions specifically targeting suffering and pain behavior may prove efficacious in addressing the attentional problems in chronic pain.

Cognitive function in fibromyalgia patients

OBJECTIVE

To evaluate fibromyalgia (FM) patients for the presence of cognitive deficits and to test the hypothesis that abnormalities would fit a model of cognitive aging.

METHODS

We studied 3 groups of patients: FM patients without concomitant depression and in the absence of medications known to affect cognitive function (n = 23), age- and education-matched controls (n = 23), and education-matched older controls who were individually matched to be 20 years older (+/- 3 years) than the FM patients (n = 22). We measured speed of information processing, working memory function, free recall, recognition memory, verbal fluency, and vocabulary. We correlated performance on cognitive tasks with FM symptoms, including depression, anxiety, pain, and fatigue. We also determined if memory complaints were correlated with cognitive performance.

RESULTS

As expected, older controls performed more poorly than younger controls on speed of processing, working memory, free recall, and verbal fluency. FM patients performed more poorly than age-matched controls on all measures, with the exception of processing speed. FM patients performed much like older controls, except that they showed better speed of processing and poorer vocabulary. Impaired cognitive performance in FM patients correlated with pain complaints, but not with depressive or anxiety symptoms. FM patients reported more memory problems than did the older and younger controls, and these complaints correlated with poor cognitive performance.

CONCLUSION

Cognitive impairment in FM patients, particularly memory and vocabulary deficits, are documented in the study. Nevertheless, the intact performance on measures of information processing speed suggests that the cognitive deficits are not global. FM patients' complaints about their memory are likely to be legitimate, since their memory function is not age appropriate.

Cognitive dysfunction in fibromyalgia

Fibromyalgia is a puzzling syndrome of widespread musculoskeletal pain. In addition to pain, patients with fibromyalgia frequently report that cognitive function, memory, and mental alertness have declined. A small body of literature suggests that there is cognitive dysfunction in fibromyalgia. This article addresses several questions that physicians may have regarding cognitive function in their patients. These questions concern the types of cognitive tasks that are problematic for patients with fibromyalgia, the role of psychological factors such as depression and anxiety, the role of physical factors such as pain and fatigue, the nature of patients' perceptions of their cognitive abilities, and whether patients can be tested for cognitive dysfunction. Critical areas for further investigation are highlighted.

The postconcussion syndrome after mild head trauma part II: is migraine underdiagnosed?

The evidence for post-traumatic migraine as the cause of the postconcussion syndrome in a proportion of patients is reviewed.

CONCLUSION

patients suffering recurrent post-traumatic headaches or other elements of the postconcussion syndrome should be treated for migraine.

Chronic pain and neuropsychological functioning

This review article examines the effect of chronic pain on neuropsychological functioning. Primary attention is given to studies that include patient groups without a history of traumatic brain injury (TBI) or neurologic disorders. Numerous studies were identified that demonstrate neuropsychological impairment in patients with chronic pain, particularly on measures assessing attentional capacity, processing speed, and psychomotor speed. Despite suggestive findings, further studies are needed to clarify the variables that mediate the impact of pain on neuropsychological functioning and the unique role of various symptoms often associated with chronic pain.

Neurocognitive performance and emotional status in chronic pain patients

The following study examined the association between neurocognitive performance and emotional status in chronic pain patients. Seventy-three chronic pain patients recruited consecutively from services in a general medical hospital completed a battery of 10 neurocognitive measures and the Symptom Checklist-90-Revised (SCL-90-R; a gross measure of emotional distress). Cluster analytic procedures were used to identify a three-cluster group solution based on the SCL-90-R. Results indicate that subjects highest in emotional distress experienced more neurocognitive difficulties in intellectual functioning, immediate and delayed recall of verbal and nonverbal material, abstract thinking and problem solving, and cognitive efficiency than subjects lowest in emotional distress. The differences in neurocognitive functioning among the three cluster groups were not confounded by any differences on a number of background variables. These results suggest that level of emotional distress is associated with difficulties in a range of neurocognitive domains and have implications for the assessment and management of chronic pain patients.