Central sensitization in knee osteoarthritis and fibromyalgia: Beyond depression and anxiety.

OBJECTIVES: To determine the psychopathological profile of patients with central sensitization (CS) in a sample of knee osteoarthritis, with and without CS, and fibromyalgia, and to compare their psychopathological profiles. METHODS: The final sample consists of 19 patients with osteoarthritis and CS (mean 66.37 years ± 8.77), 41 osteoarthritis patients without CS (mean 66.8 ± 7.39 years), 47 fibromyalgia patients (mean 46.47 years ± 7.92) and 26 control subjects (mean 51.56 years ± 11.41). The psychopathological profile was evaluated with the Millon Multiaxial Clinical Inventory. RESULTS: The average score of MCMI-III reflect higher scores in the fibromyalgia and osteoarthritis-CS groups. Patients with osteoarthritis-CS are more likely to report larger scores in Borderline and Major Depression scales. Fibromyalgia patients are more likely to report more increased scores in Somatoform and Major Depression, versus osteoarthritis-CS group. Fibromyalgia patients versus osteoarthritis without CS are more likely to report higher scores in Schizoid, Depression, Histrionic, Sadistic, Borderline, Somatoform, Posttraumatic Stress Disorder and Major Depression scales. DISCUSSION: Patients with CS have less differences in their psychopathological profiles as well as in both osteoarthritis groups and greatest differences are obtained between the fibromyalgia and osteoarthritis without CS, so perhaps presence of CS is the key to differentiate those groups and not chronic pain. An exhaustive assessment brings more accurate psychopathological profiles, thus better psychological treatment could be applied.

Vulnerability to Psychopathology and Dimensions of Personality in Patients With Fibromyalgia.

OBJECTIVE: Fibromyalgia (FM) patients may present psychopathology and some characteristic personality traits that may affect their adaptation to the disease. The aim of this paper was to study the relationship between personality dimensions according to the psychobiological model of Cloninger and the presence of psychopathology. MATERIALS AND METHODS: The study sample consisted of 42 patients with FM and 38 pain-free controls. The assessment instruments administered were the Temperament and Character Inventory-Revised and the Millon Clinical Multiaxial Inventory. RESULTS: A higher proportion of clinical psychopathologic syndromes (CPS) was observed in the FM group than in the control group, the most prevalent being anxiety disorder and dysthymia. Patients with FM (with CPS or without CPS) presented higher Harm Avoidance than the control group, and the presence of a CPS also increased Harm Avoidance scores. FM patients with CPS had low Self-directedness (SD) compared with both the control group and with their FM peers without CPS. Purposefulness and Anticipatory worry-Pessimism explained 38% of the variance of dysthymia, and anticipatory worry-Pessimism explained 18% of the variance of anxiety disorders. CONCLUSIONS: Patients with FM have a high probability of anxious-depressive-type psychopathologic alterations. Their vulnerability to these conditions may be determined by personality traits. The SD character dimension may have implications for therapy, as low SD is associated with the presence of psychopathology and with a low capacity to cope with the disease.

Cloninger's psychobiological model of personality and psychological distress in fibromyalgia.

AIM: Personality can play an important role in the clinical symptoms of fibromyalgia (FM). The aim of this study is to identify personality profiles in FM patients and the possible presence of personality disorder (PD) from the Temperament and Character Inventory-Revised (TCI-R), and to assess whether personality dimensions are related to psychological distress in FM. METHOD: The sample consisted of 42 patients with FM and 38 healthy controls. The TCI-R, Hospital Anxiety and Depression Scale, State-Trait Anxiety Inventory, Short-Form-36 Health Survey, Fibromyalgia Impact Questionnaire and McGill Pain Questionnaire were administered. RESULTS: The personality profile of the FM group based on the TCI-R is defined by high Harm Avoidance (HA), low Novelty Seeking (NS), and low Self-Directedness (SD). Only one-third of patients with FM present a possible psychometric PD, principally from Cluster C. In the FM group, HA and SD are associated positively and negatively, respectively, with indicators of emotional distress. Patients with higher HA present higher perceived pain intensity rated via a verbal-numerical scale while Determination (SD2) reduced the perceived level of pain induced by the stimulus. NS is negatively related to the number of work absences caused by FM. CONCLUSIONS: The study suggests that HA and SD play an important role in psychological distress in FM. The fact that SD is prone to modification and has a regulatory effect on emotional impulses is a key aspect to consider from the psychotherapeutic point of view.

Altered functional magnetic resonance imaging responses to nonpainful sensory stimulation in fibromyalgia patients.

OBJECTIVE: Fibromyalgia (FM) is a disorder characterized by chronic pain and enhanced responses to acute noxious events. However, the sensory systems affected in FM may extend beyond pain itself, as FM patients show reduced tolerance to non-nociceptive sensory stimulation. Characterizing the neural substrates of multisensory hypersensitivity in FM may thus provide important clues about the underlying pathophysiology of the disorder. The aim of this study was to characterize brain responses to non-nociceptive sensory stimulation in FM patients and their relationship to subjective sensory sensitivity and clinical pain severity. METHODS: Functional magnetic resonance imaging (MRI) was used to assess brain response to auditory, visual, and tactile motor stimulation in 35 women with FM and 25 matched controls. Correlation and mediation analyses were performed to establish the relationship between brain responses and 3 types of outcomes: subjective hypersensitivity to daily sensory stimulation, spontaneous pain, and functional disability. RESULTS: Patients reported increased subjective sensitivity (increased unpleasantness) in response to multisensory stimulation in daily life. Functional MRI revealed that patients showed reduced task-evoked activation in primary/secondary visual and auditory areas and augmented responses in the insula and anterior lingual gyrus. Reduced responses in visual and auditory areas were correlated with subjective sensory hypersensitivity and clinical severity measures. CONCLUSION: FM patients showed strong attenuation of brain responses to nonpainful events in early sensory cortices, accompanied by an amplified response at later stages of sensory integration in the insula. These abnormalities are associated with core FM symptoms, suggesting that they may be part of the pathophysiology of the disease.

The contribution of sensory system functional connectivity reduction to clinical pain in fibromyalgia.

Fibromyalgia typically presents with spontaneous body pain with no apparent cause and is considered pathophysiologically to be a functional disorder of somatosensory processing. We have investigated potential associations between the degree of self-reported clinical pain and resting-state brain functional connectivity at different levels of putative somatosensory integration. Resting-state functional magnetic resonance imaging was obtained in 40 women with fibromyalgia and 36 control subjects. A combination of functional connectivity-based measurements were used to assess (1) the basic pain signal modulation system at the level of the periaqueductal gray (PAG); (2) the sensory cortex with an emphasis on the parietal operculum/secondary somatosensory cortex (SII); and (3) the connectivity of these regions with the self-referential "default mode" network. Compared with control subjects, a reduction of functional connectivity was identified across the 3 levels of neural processing, each showing a significant and complementary correlation with the degree of clinical pain. Specifically, self-reported pain in fibromyalgia patients correlated with (1) reduced connectivity between PAG and anterior insula; (2) reduced connectivity between SII and primary somatosensory, visual, and auditory cortices; and (3) increased connectivity between SII and the default mode network. The results confirm previous research demonstrating abnormal functional connectivity in fibromyalgia and show that alterations at different levels of sensory processing may contribute to account for clinical pain. Importantly, reduced functional connectivity extended beyond the somatosensory domain and implicated visual and auditory sensory modalities. Overall, this study suggests that a general weakening of sensory integration underlies clinical pain in fibromyalgia.