Sodium lactate infusion in fibromyalgia patients

Altered dopamine D2 receptor function in fibromyalgia patients: a neuroendocrine study with buspirone in women with fibromyalgia compared to female population based controls

BACKGROUND

To what extent fibromyalgia belongs to affective spectrum disorders or anxiety spectrum disorders remains disputed. Buspirone induces a hypothermic response, which most likely is due to 5-HT(1A) autoreceptor stimulation, and growth hormone (GH) release, which probably is related to postsynaptic 5-HT(1A) receptor stimulation. The prolactin response to buspirone has been suggested to be mediated through dopamine (DA) antagonistic effects.

OBJECTIVES

Based on the assumption that fibromyalgia is more strongly related to stress and anxiety than affective spectrum disorders, we hypothesized that compared to population controls, fibromyalgia patients should demonstrate an increased prolactin response (DA sensitivity) to buspirone challenge test, but no difference in hypothermic response or GH release (5HT sensitivity).

METHOD

A 60-mg dose of buspirone was given orally to 22 premenopausal women with fibromyalgia and 14 age and sex matched healthy control subjects. Core body temperature, growth hormone and prolactin levels were analyzed at baseline and after 60, 90, and 150 min.

RESULTS

Fibromyalgia patients showed an augmented prolactin response to buspirone compared to controls. Temperature and growth hormone responses did not differ from controls.

CONCLUSIONS

Dopaminergic rather than serotonergic neurotransmission is altered in fibromyalgia, suggesting increased sensitivity or density of dopamine D(2) receptors in fibromyalgia patients. Stress and anxiety is an important modulator of dopaminergic neurotransmission. Our results suggest that fibromyalgia is related to anxiety and associated with disturbance in the stress response systems.

Mutilation anxiety differs among females with fibromyalgia and functional dyspepsia and population controls

BACKGROUND

Studies using self-report rating scales suggest a considerable overlap regarding symptom complaints in patients with fibromyalgia (FM) and functional dyspepsia (FD), while clinical assessments point to important psychological differences.

PURPOSE

To test the hypothesis that measurement of psychological state by means of content analysis of speech will demonstrate differentiation between the two patient groups and between patients with these disorders and age-matched population-based random sample controls.

METHOD

The Giessener Symptom Complaints Checklist assessed somatic complaints. The computerised Gottschalk-Gleser content analysis method assessed psychological state in 42 females with FM, 17 females with FD and 48 population-based, randomly selected control subjects.

RESULTS

FM patients score higher on mutilation anxiety than FD and control subjects. FD patients had the highest score for death anxiety. Mutilation anxiety and low hope score identified FM patients (sensitivity 68%, specificity 81%, overall classification 75%), but only 19% of the variation in total somatic complaints could be predicted from these or other psychological state scores. In FD patients, however, death anxiety explained 59% of the variance in gastrointestinal complaints.

INTERPRETATION

Psychological state was differentiated among the three groups. Mutilation anxiety may be a psychological marker of an underlying neurobiological vulnerability for FM or may represent a secondary long-term consequence of chronic illness. In FD, death anxiety is directly related to symptom complaints, suggesting a stronger etiological association between emotions and somatic complaints in this disorder.

Factors explaining variance in perceived pain in women with fibromyalgia

BACKGROUND

We hypothesized that a substantial proportion of the subjectively experienced variance in pain in fibromyalgia patients would be explained by psychological factors alone, but that a combined model, including neuroendocrine and autonomic factors, would give the most parsimonious explanation of variance in pain.

METHODS

Psychometric assessment included McGill Pain Questionnaire, General Health Questionnaire, Hospital Anxiety and Depression Rating Scale, Eysenck personality Inventory, Neuroticism and Lie subscales, Toronto Alexithymia Scale, and Multidimensional Health Locus of Control Scale and was performed in 42 female patients with fibromyalgia and 48 female age matched random sample population controls. A subgroup of the original sample (22 fibromyalgia patients and 13 controls) underwent a pharmacological challenge test with buspirone to assess autonomic and adrenocortical reactivity to serotonergic challenge.

RESULTS

Although fibromyalgia patients scored high on neuroticism, anxiety, depression and general distress, only a minor part of variance in pain was explained by psychological factors alone. High pain score was associated with high neuroticism, low baseline cortisol level and small drop in systolic blood pressure after buspirone challenge test. This model explained 41.5% of total pain in fibromyalgia patients. In population controls, psychological factors alone were significant predictors for variance in pain.

CONCLUSION

Fibromyalgia patients may have reduced reactivity in the central sympathetic system or perturbations in the sympathetic-parasympathetic balance. This study shows that a biopsychosocial model, including psychological factors as well as factors related to perturbations of the autonomic nervous system and hypothalamic-pituitary-adrenal axis, is needed to explain perceived pain in fibromyalgia patients.

Fibromyalgia is associated with panic disorder and functional dyspepsia with mood disorders. A study of women with random sample population controls

BACKGROUND

We compared ICD-10 psychiatric disorders in female patients with fibromyalgia (n=45) or functional dyspepsia (n=18) with age-matched random sample controls (n=49).

METHOD

Version 2 of The Schedules for Clinical Assessment in Neuropsychiatry (SCAN) was used for present state examination and lifetime diagnoses.

RESULTS

Current psychiatric disorders (somatoform pain disorder and specific phobia omitted) were diagnosed in 80% of fibromyalgia patients (OR=8.3), 83% of functional dyspepsia patients (OR=10.3) and 33% controls. Among fibromyalgia patients 27% had lifetime panic disorder. Lifetime mood disorders were found in 83% of functional dyspepsia patients. First-degree relatives with psychiatric disorder were found in 16% of the fibromyalgia patients, 50% of functional dyspepsia patients and 20% of controls.

CONCLUSIONS

Fibromyalgia is associated with panic disorder and functional dyspepsia with mood disorders in substantial subgroups. Psychiatric symptoms and somatic complaints are closely related in these disorders.