Cerebral dysfunction in fibromyalgia: evidence from regional cerebral blood flow measurements, otoneurological tests and cerebrospinal fluid analysis

Oculomotor Disturbances in Patients with Chronic Nonspecific Spinal Pain

Objective

There is increasing evidence that the cerebellum has a role in pain processing. The present study investigates whether chronic pain patients, who are likely to have altered pain processing, exhibit signs of subtle cerebellar dysfunction. We used oculomotor tasks to assess dysfunction of the associated neuronal networks, including the cerebellum.

Methods

Thirty patients with chronic nonspecific spinal pain and 30 age- and sex-matched controls were enrolled. Using a head-mounted eye tracker (EyeSeeCam), eye movements were quantified during predictable and unpredictable saccade and smooth pursuit tasks in the horizontal plane.

Results

The initial latency and the velocity variability of smooth pursuit were significantly increased in the chronic spinal pain patients compared with controls (initial latency: 198 ± 20 vs 185 ± 11 ms, P < 0.01; slow phase velocity standard deviation: 3.31 ± 1.02 vs 2.70 ± 0.83°/s, P < 0.05). Moreover, the latency of predictable saccades was prolonged in patients (rightward: 161 ± 20 vs 152 ± 12 ms, P < 0.05; leftward: 164 ± 22 vs 153 ± 18 ms, P = 0.05).

Conclusions

Our results show that chronic spinal pain patients display subtle but significant oculomotor changes as compared with healthy controls. Considering the networks involved in the generation of saccades and smooth pursuit, the results would be consistent with a dysfunction of cerebellar regions, especially parts of the cerebellar hemispheres. Alternatively, they could also point toward a dysfunction in the frontal eye field and/or pontine oculomotor nuclei.

Effects of short and long term electromagnetic fields exposure on the human hippocampus

The increasing use of mobile phones may have a number of physiological and psychological effects on human health. Many animal and human studies have reported various effects on the central nervous system and cognitive performance from of exposure to electromagnetic fields (EMF) emitted by mobile phones. The aim of the present study was to evaluate the effects of mobile phones on the morphology of the human brain and on cognitive performance using stereological and spectroscopic methods and neurocognitive tests. Sixty healthy female medical school students aged 18-25 years were divided into a low exposure group (30 subjects, <30 min daily use by the head) and high exposure group (30 subjects, >90 min daily use by the head). Magnetic resonance images (MRI) of the brain analysed on OsiriX 3.2.1 workstation. Neuropsychological tests were performed for each subject. In addition, three dominant specific metabolites were analysed, choline at 3.21 ppm, creatine at 3.04 ppm and N-acetyl aspartate at 2.02 ppm. Analysis of the spectroscopic results revealed no significant difference in specific metabolites between the groups (p > 0.05). There was also no significant difference in terms of hippocampal volume between the groups (p > 0.05). In contrast, the results of the stroop and digit span (backward) neurocognitive tests of high exposure group for evaluating attention were significantly poorer from low exposure group (p < 0.05). Based on these results, we conclude that a lack of attention and concentration may occur in subjects who talk on mobile phones for longer times, compared to those who use phones relatively less.

EEG biofeedback treatment improves certain attention and somatic symptoms in fibromyalgia: a pilot study

Fibromyalgia (FMS) is a chronic, painful disorder often associated with measurable deficiencies in attention. Since EEG biofeedback (EEG-BF) has been used successfully to treat attention problems, we reasoned that this modality might be helpful in the treatment of attention problems in FMS. We also speculated that improvement in central nervous system (CNS) function might be accompanied by improvement in FMS somatic symptoms. We studied fifteen FMS patients with attention problems, demonstrated by visual and auditory continuous performance testing (CPT), while completing 40 or more EEG-BF sessions. Training consisted of a "SMR protocol" that augmented 12-15 Hz brainwaves (sensory motor rhythm; SMR), while simultaneously inhibiting 4-7 Hz brainwaves (theta) and 22-30 Hz brainwaves (high beta). Serial measurements of pain, fatigue, psychological distress, morning stiffness, and tenderness were also obtained. Sixty-three FMS patients who received standard medical care, but who did not receive EEG-BF, served as controls. Visual, but not auditory, attention improved significantly (P < 0.008). EEG-BF treated subjects also showed improvement in tenderness, pain and fatigue. Somatic symptoms did not change significantly in controls. Visual attention parameters and certain somatic features of FMS appear to improve with an EEG-BF SMR protocol. EEG-BF training in FMS deserves further study.

Insular hypometabolism in a patient with fibromyalgia: a case study

BACKGROUND

Neuroimaging studies have demonstrated differential involvement of a variety of brain centers in fibromyalgia both at baseline and in response to stimulation. The insular cortex is one such structure.

FINDINGS

A 46-year-old woman with chronic widespread pain underwent positron emission tomography utilizing 18F-fluorodeoxyglucose while participating as a healthy control subject in a brain imaging study. Analysis of the scan revealed metabolic hypoactivity within the left insular cortex as an incidental finding. Soon after her scan, she underwent further clinical evaluation and was subsequently diagnosed with fibromyalgia.

DISCUSSION

The potential contribution of insular dysfunction to the development of hyperalgesia has been demonstrated in rat models via local manipulations of dopaminergic, gamma-aminobutyric acid (GABA) ergic, and opioidergic neurotransmission within this region. Thus, our demonstration of insular hypometabolism in this patient's case may have bearing on her experience of chronic widespread pain.

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

AIM

To assess the effect of tonic pain stimulation on auditory processing of speech-relevant acoustic signals in healthy pain-free volunteers.

METHODS

Sixty university students, randomly assigned to either a thermal pain stimulation (46 degrees C/6 min) group (PS) or no pain stimulation group (NPS), performed a rate change detection task (RCDT) involving sinusoidally frequency-modulated vowel-like signals. Task difficulty was manipulated by changing the rate of the modulated signals (henceforth rate). Perceived pain intensity was evaluated using a visual analog scale (VAS) (0-100).

RESULTS

Mean pain rating was approximately 33 in the PS group and approximately 3 in the NPS group. Pain stimulation was associated with poorer performance on the RCDT, but this trend was not statistically significant. Performance worsened with increasing rate of signal modulation in both groups (p < 0.0001), with no pain by rate interaction.

CONCLUSIONS

The present findings indicate a trend whereby mild or moderate pain appears to affect auditory processing of speech-relevant acoustic signals. This trend, however, was not statistically significant. It is possible that more intense pain would yield more pronounced (deleterious) effects on auditory processing, but this needs to be verified empirically.

Imaging pain of fibromyalgia

Brain imaging studies have provided objective evidence of abnormal central regulation of pain in fibromyalgia (FM). Resting brain blood flow studies have reported mixed findings for several brain regions, whereas decreased thalamic blood flow has been noted by several investigators. Studies examining the function of the nociceptive system in FM have reported augmented brain responses to both painful and non-painful stimuli that may be influenced by psychologic dispositions such as depressed mood and catastrophizing. Treatment approaches are beginning to demonstrate the potential for brain imaging to improve our understanding of pain-alleviating mechanisms. Data from other chronic conditions suggest that idiopathic pain may be maintained by similar central abnormalities as in FM, whereas chronic pain conditions with a known nociceptive source may not be. Future neuroimaging research in FM is clearly warranted and should continue to improve our understanding of factors involved in pain maintenance and symptom exacerbation.

Retrospenial cortical deactivation during painful stimulation of fibromyalgic patients

To study fibromyalgic pain this article contrasts positron emission tomographic measures of regional cerebral blood flow (rCBF) during externally induced acute pain and rest in eight fibromyalgia syndrome patients. An expected pattern of frontal and parietal cortical activation during acute pain as compared to rest was observed. However, reduced rCBF was additionally found in the retrosplenial cortex during acute pain as compared to rest. This may reflect that externally induced pain inhibits fibromyalgic pain and syndrome-related evaluative processes located in the retrosplenial cortex, and that fibromyalgic pain results from exaggerated attention to sub-noxious pain signaling, that is, secondary hyperalgesia.

Psychosomatic Pain: New Insights and Management Strategies

At least 40 to 60 percent of women and at least 20 percent of men with chronic pain disorders report a history of being abused during childhood and/or adulthood. This incidence of abuse is two to four times higher than in the general population. Patients with more severe or frequent abuse, usually during childhood and worse if sexual in nature. often develop specific syndromes or combinations of syndromes. These syndromes include posttraumatic stress disorder, fibromyalgia, and other conditions characterized by repression, somatization, and increased utilization of medical care. Psychosomatic symptoms and dysfunctional behaviors may emerge as these patients seek attention and validation of their suffering, while paradoxically repressing painful memories of trauma. Behavioral observations and key features of the physical examination may greatly help the clinician identify both the presence and severity of psychosomatic disease. In addition, it is very interesting that various studies document physiologic changes in the brains of patients with a history of abuse and in patients with a diagnosis of fibromyalgia. These studies suggest that abuse may physiologically and developmentally increase a person's susceptibility to pain and that some organic changes may be associated with psychogenic disease. Diagnosis and treatment of even the most challenging patients with chronic pain is much more effective if it includes (a) careful inquiry about any history of past or present abuse or other severe trauma, (b) empathy and constructive validation of disease and suffering, (c) recognition of dysfunctional pain behaviors and personality traits, (d) documentation of nonanatomic as well as anatomic features on examination, (e) multidisciplinary treatments including psychotherapy whenever indicated, and (f) noninvasive procedures and alternatives to potentially habit-forming medications whenever possible and appropriate. Furthermore, it has been shown that helping patients gain insight about the relationship between abuse and their current symptoms leads to decreased health care utilization. Practical guidelines are provided for identifying psychopathology, communicating effectively, and achieving better treatment outcomes for these unfortunate patients.

The possible effect of clinical recovery on regional cerebral blood flow deficits in fibromyalgia: a prospective study with semiquantitative SPECT

OBJECTIVES

Regional deficits in cerebral blood flow have been reported in a few studies of fibromyalgia; however, there is no information on the effects of treatment and clinical recovery on these abnormalities. We evaluated the effects of amitriptyline treatment and consequent clinical recovery on cerebral blood flow changes in fibromyalgia.

METHODS

We assessed cerebral blood flow with a semiquantitative functional brain mapping technique of single-photon emission computed tomography in 14 patients with primary fibromyalgia before and after 3 months of amitriptyline treatment. Patients were followed by visual analog scale, tender point count, and Beck Depression Inventory for clinical improvement.

RESULTS

There was statistically significant improvement in visual analog scale and tender point count after treatment. Beck Depression Inventory did not change significantly. Statistically significant blood flow increase in bilateral hemithalami and basal ganglia and decrease in bilateral temporal, left temporo-occipital, and right occipital lobes were observed on single-photon emission computed tomography after treatment.

CONCLUSIONS

We speculate that these findings could indicate that deficits in cerebral blood flow in fibromyalgia improve parallel to clinical recovery.

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.

Retrosplenial cortical activation in the fibromyalgia syndrome

To study the CNS in chronic muscular pain typical of fibromyalgia we compared PET measures of regional cerebral blood flow (rCBF) in eight fibromyalgic patients and controls at rest. Higher rCBF for patients than controls was found bilaterally in the retrosplenial cortex. Lower rCBF for patients than controls were seen in the left frontal, temporal, parietal, and occipital cortices. The higher retroplenial rCBF in patients than controls may reflect increased attention towards sub-noxious somatosensory signaling, and agrees with the notion that fibromyalgic pain reflects secondary hyperalgesia. The brain regions with lower rCBF in fibromyalgic patients than controls participate in the normal cognitive processing of pain, which may be dysfunctional in fibromyalgia.

Prevalence of post-traumatic stress disorder in fibromyalgia patients: overlapping syndromes or post-traumatic fibromyalgia syndrome?

OBJECTIVES

The primary aim of this study was to assess the frequency of post-traumatic stress disorder (PTSD) in patients with the fibromyalgia syndrome (FMS). The influence of gender on measures of PTSD in fibromyalgia (FM) patients also was examined.

METHODS

Seventy-seven consecutive patients (40 women and 37 men) who fulfilled the criteria for FM were asked to complete questionnaires measuring the prevalence and severity of symptoms of PTSD, anxiety, and depression. The subjects were divided in 2 groups based on the presence or absence of PTSD symptoms.

RESULTS

In this study, 57% of the FM sample had clinically significant levels of PTSD symptoms. The FM patients with PTSD reported significantly greater levels of avoidance, hyperarousal, reexperiencing, anxiety, and depression than did the patients without clinically significant levels of PTSD symptoms. The prevalence of PTSD among the FM patients in this study was significantly higher than in the general population. Women with FM and PTSD reported a greater number of past traumatic events than did their male counterparts.

CONCLUSIONS

The results represent the first comprehensive study applying structured clinical assessment of trauma exposure and PTSD to a group of FM patients. This study shows a significant overlap between FM and PTSD, according to the currently accepted diagnostic criteria for each.

Neurotologic manifestations of the fibromyalgia syndrome

The purpose was to assess otologic symptoms, and audiologic and vestibular findings in fibromyalgia (FM) syndrome. Twenty-four female patients with FM syndrome (FMS) were included in the study. The assessments were based on history, physical examination, audiometry, bithermal caloric testing and auditory brainstem response (ABR) testing. Dizziness was the most common complaint of the patients, and was followed by tinnitus, hearing loss and vertigo. Almost 50% of the patients had some sort of otologic symptoms.Dix-Halpike maneuver proved positional rotary vertigo in 5 (20.8%) patients. The audiometry results of 23 patients were normal. None of the patients had abnormal bithermal caloric testing. Although there were a variety of ABR abnormalities, the ABR results of the patients with and without cochleovestibular symptoms were not significantly different (p<0.05). In conclusion, FM patients can complain otologic symptoms even though they do not have any clinically or audiologically detectable ear disease. A neural disintegration or some other events related to neural mediators may be the mechanisms involved in the pathogenesis of otoneurologic as well as systemic manifestations of the disease that possibly leads to abnormal perception of the stimuli coming from internal or external environment.

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.

Nociceptive aspects of fibromyalgia

Although characterized by a variety of symptoms, chronic widespread pain is the primary complaint bringing most patients with fibromyalgia syndrome (FMS) into the clinic. The etiology of this painful condition is unknown, and any possible relationship between pain and the many other symptoms of FMS is unclear. This article focuses on the unique characteristics of nociception in patients with FMS. The intent is to present criteria that should be considered in the search for biological events that contribute to FMS pain. Based on this approach, examples are proposed of factors that fulfill some criteria and may, therefore, deserve further study for their possible role in pain associated with FMS.

Treatment of fibromyalgia incorporating EEG-Driven stimulation: a clinical outcomes study

Thirty patients from a private clinical practice who met the 1990 American College of Rheumatology criteria for fibromyalgia syndrome (FS) were followed prospectively through a brainwave-based intervention known as electroencephalograph (EEG)-driven stimulation or EDS. Patients were initially treated with EDS until they reported noticeable improvements in mental clarity, mood, and sleep. Self-reported pain, then, having changed from vaguely diffuse to more specifically localized, was treated with very modest amounts of physically oriented therapies. Pre- to posttreatment and extended follow-up comparisons of psychological and physical functioning indices, specific FS symptom ratings, and EEG activity revealed statistically significant improvements. EDS appeared to be the prime initiator of therapeutic efficacy. Future research is justified for controlled clinical trials and to better understand disease mechanisms.

Fibromyalgia and other unexplained clinical conditions

Several unexplained clinical conditions frequently coexist with fibromyalgia; these include chronic fatigue syndrome, irritable bowel syndrome, temporomandibular disorder, tension and migraine headaches, and others. However, only recently have studies directly compared the physiological parameters of these conditions (eg, fibromyalgia vs irritable bowel syndrome) to elucidate underlying pathogenic mechanisms. This review summarizes data from comparative studies and discusses their implications for future research.

Vegan diet alleviates fibromyalgia symptoms

The effect of a strict, low-salt, uncooked vegan diet rich in lactobacteria on symptoms in 18 fibromyalgia patients during and after a 3-month intervention period in an open, non-randomized controlled study was evaluated. As control 15 patients continued their omnivorous diet. The groups did not differ significantly from each other in the beginning of the study in any other parameters except in pain and urine sodium. The results revealed significant improvements in Visual analogue scale of pain (VAS) (p=0.005), joint stiffness (p=0.001), quality of sleep (p=0.0001), Health assessment questionnaire (HAQ) (p=0.031), General health questionnaire (GHQ) (p=0.021), and a rheumatologist's own questionnaire (p=0.038). The majority of patients were overweight to some extent at the beginning of the study and shifting to a vegan food caused a significant reduction in body mass index (BMI) (p=0.0001). Total serum cholesterol showed a statistically significant lowering (p=0.003). Urine sodium dropped to 1/3 of the beginning values (p=0.0001) indicating good diet compliance. It can be concluded that vegan diet had beneficial effects on fibromyalgia symptoms at least in the short run.

[Sleep in fibromyalgia: review of clinical and polysomnographic data]

Fibromyalgia syndrome is a common chronic pain syndrome that is often associated with sleep disturbances characterized by subjective experience of non-restorative sleep. The complaints of sleep disturbances are correlated with polysomnographic features showing clear abnormalities in the continuity of sleep as well as in the sleep architecture. Sleep-recording abnormalities are characterized by a reduced sleep efficiency with increased number of awakenings, a reduced amount of slow wave sleep and an abnormal alpha wave intrusion in non rapid eye movement, termed alpha-delta sleep. These data were confirmed by spectral analysis of sleep showing an increased EEG power density in the higher frequency band and a reduced EEG power density in the lower frequency bands. Moreover, other microstructural aspects of sleep were modified with high frequency of arousals and alpha-K complex reported, both indicators of fragmented sleep. The fibromyalgia symptoms may relate to a non-restorative sleep disorder associated with the alpha-EEG sleep anomalies. However, alpha-EEG sleep anomaly is non-specific for fibrositis, also seen in normal controls during stage 4 sleep deprivation. Moreover, fibromyalgia patients may also experience primary sleep disorder such as sleep apnea or periodic leg movements. The etiology of this common condition is incompletely understood and the existence of a specific entity of fibromyalgia is still a matter of debate. However, several studies have found abnormal brain metabolism of substances such as serotonin implicated in sleep arousal and pain mechanisms and administration of tricyclic antidepressants and selective serotonin reuptake inhibitors may be useful in fibromyalgia. Pain, poor sleep quality and anxiety may contribute to the clinical picture. Several factors such as psychological, environmental, genetic factor, altered serotonin metabolism and altered sleep physiology are involved in the pathogenesis of fibromyalgia.

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

Memory functioning was assessed in 25 primary fibromyalgia (FM) patients by comparing them with 22 major depressed patients and 18 healthy controls. A broad range of short- and long-term memory tasks were included. Both major depressed and FM patients were significantly impaired on long-term memory tasks requiring effortful processing, compared to healthy controls. When the depressive status of the fibromyalgia patients was accounted for, only the subsample with a lifetime major depressive disorder showed memory impairment as compared with the healthy controls.