Article

Intensity Dependence of Auditory-Evoked Cortical Potentials in Fibromyalgia Patients: A Test of the Generalized Hypervigilance Hypothesis

Departamento de Psicología Clínica y Psicobiología, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
Journal of Pain (Impact Factor: 4.01). 08/2006; 7(7):480-7. DOI: 10.1016/j.jpain.2006.01.452
Source: PubMed

ABSTRACT

On the basis of recent evidence concerning the amplification of incoming stimulation in fibromyalgia (FM) patients, it has been proposed that a generalized hypervigilance of painful and nonpainful sensations may be at the root of this disorder. So far, research into this issue has been inconclusive, possibly owing to the lack of agreement as to the operational definition of "generalized hypervigilance" and to the lack of robust objective measures characterizing the sensory style of FM patients. In this study, we recorded auditory-evoked potentials (AEPs) elicited by tones of increasing intensity (60, 70, 80, 90, and 105 dB) in 27 female FM patients and 25 healthy controls. Fibromyalgia patients presented shorter N1 and P2 latencies and a stronger intensity dependence of their AEPs. Both results suggest that FM patients may be hypervigilant to sensory stimuli, especially when very loud tones are used. The most noteworthy difference between patients and control subjects is at the highest stimulus intensity, for which far more patients maintained increased N1-P2 amplitudes in relation to the 90-dB tones. The larger AEP amplitudes to the 105-dB tones suggest that defects in an inhibitory system protecting against overstimulation may be a crucial factor in the pathophysiology of FM. Because a stronger loudness dependence of AEPs has been related to weak serotonergic transmission, it is hypothesized that for many FM patients deficient inhibition of the response to noxious and intense auditory stimuli may be due to a serotonergic deficit. PERSPECTIVE: The study of auditory-evoked potentials in response to tones of increasing intensity in FM patients may help to clarify the pathophysiology of this disorder, especially regarding the role of inhibition deficits involving serotonergic dysfunction, and may be a useful tool to guide the pharmacologic treatment of FM patients.

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Available from: María T Carrillo-de-la-Peña, Apr 23, 2014
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    • "Nevertheless, the integration of our findings in the existing literature is challenging. First, we did not find an association between altered sensory responsiveness and predominant somatic symptoms whereas most previous studies did333435363738. Contradictory, other studies with subjects diagnosed with somatic symptoms reported that their symptoms were less related to physiological perception than those of controls in rebreathing tasks[58], and patients with severe somatoform symptoms were not more accurate in heartbeat discrimination and mental tracking tasks than controls[59,60]. "
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    ABSTRACT: Somatoform Disorders or Somatic Symptom and Related Disorders are a major public health problem.The pathophysiology underlying these disorders is not yet understood. The aim of this study was to explore if sensory responsiveness could contribute to a better understanding of pathophysiological mechanisms underlying two key symptoms of Somatoform Disorders, namely somatic symptoms and illness anxiety. We measured vibrotactile perception thresholds with the HVLab Perception Meter and examined their association with somatic symptoms, illness anxiety and trait anxiety. A sample of 205 volunteers participated in the study. Sensory responsiveness was neither associated with somatic symptoms (β = -0.01; 95 % confidence interval (CI), -0.37, 0.39) nor trait anxiety (β = -0.07; 95 % CI, -0.30, 0.07). However, lower vibrotactile perception thresholds were associated with increased scores of the overall illness anxiety scale (β = -0.65; 95 % CI, -1.21, -0.14) and its constituent subscale disease conviction (β = -2.07; 95 % CI, -3.94, -0.43). Our results suggest that increased sensory responsiveness is associated with illness anxiety and hence should be examined further as potential target within the etiopathology of somatoform disorders.
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    • "Dysfunctional attentional processes have been implicated in the pathogenesis of chronic pain syndromes [1], [17]. In patients with fibromyalgia syndrome (FMS), hypervigilance as an abnormal increase of attention to external stimuli has been inferred from an increase in sensitivity to a large variety of painful [18]–[23] and non-painful stimuli [24]–[29]. Alternatively, but not mutually exclusively, a central augmentation of sensory input in terms of central sensitization [30] or deficient inhibitory control mechanisms [31], [32] may also account for the hypersensitivity in FMS. "
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    • "Since similar descending control systems, including attentional and emotional regulatory circuitry, affect multiple sensory modalities [113–119], a dysfunction (or saturation) in these systems could lead to the hypersensitivity in multiple sensory modalities. FM patients show reduced habituation to nonpainful tactile stimuli and increased cortical response to intense auditory stimuli, both of which have been linked to deficient inhibition of incoming sensory stimuli [120, 121]. Also in support of the idea of a central dysregulation or saturation of pain modulation are changes in the opioid and dopamine neurotransmitter systems, both known to be involved in hedonic regulation [122]. "
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