Electrophysiological indices of pain expectation abnormalities in fibromyalgia patients

Abstract

Fibromyalgia is a chronic pain syndrome characterized by dysfunctional processing of nociceptive stimulation. Neuroimaging studies have pointed out that pain-related network functioning seems to be altered in these patients. It is thought that this clinical symptomatology may be maintained or even strengthened because of an enhanced expectancy for painful stimuli or its forthcoming appearance. However, neural electrophysiological correlates associated with such attentional mechanisms have been scarcely explored. In the current study, expectancy processes of upcoming laser stimulation (painful and non-painful) and its further processing were explored by event-related potentials (ERPs). Nineteen fibromyalgia patients and twenty healthy control volunteers took part in the experiment. Behavioral measures (reaction times and subjective pain perception) were also collected. We manipulated the pain/no pain expectancy through an S1–S2 paradigm (cue-target). S1 (image: triangle or square) predicted the S2 appearance (laser stimulation: warmth or pinprick sensation). Laser stimuli were delivered using a CO2 laser device. Temporal and spatial principal component analyses were employed to define and quantify the ERP component reliability. Statistical analyses revealed the existence of an abnormal pattern of pain expectancy in patients with fibromyalgia. Specifically, our results showed attenuated amplitudes at posterior lCNV component in anticipation of painful stimulation that was not found in healthy participants. In contrast, although larger P2 amplitudes to painful compared to innocuous events were shown, patients did not show any amplitude change in this laser-evoked response as a function of pain predictive cues (as occurred in the healthy control group). Additionally, analyses of the subjective perception of pain and reaction time indicated that laser stimuli preceded by pain cues were rated as more painful than those signaling non-pain expectancy and were associated with faster responses. Differences between groups were not found. The present findings suggest the presence of dysfunction in pain expectation mechanisms in fibromyalgia that eventually may make it difficult for patients to correctly interpret signs that prevent pain symptoms. Furthermore, the abnormal pattern in pain expectancy displayed by fibromyalgia patients could result in ineffective pain coping strategies. Understanding the neural correlates of pain processing and its modulatory factors is crucial to identify treatments for chronic pain syndromes.

REAC Neurobiological Modulation as a Precision Medicine Treatment for Fibromyalgia

“…The main finding of this study highlights the complex pathophysiological mechanisms that underlie fibromyalgia, including alterations in neurotransmission [ 4 , 6 , 22 , 98 ], perception modulation [ 2 , 100 , 104 ], environmental stress [ 6 , 54 , 107 ], and epigenetic modifications [ 17 , 110 , 112 , 113 , 114 ], all of which may affect the EBA [ 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 ].…”

“…This sensitivity may be due to alterations in the way that pain signals are processed in the central nervous system. Studies have shown that individuals with fibromyalgia have changes in the way that their brains respond to pain stimuli [ 2 , 3 , 99 , 102 , 103 , 104 , 105 ], which may contribute to the heightened pain sensitivity and chronic pain experienced by these individuals.…”

The Effectiveness of ACT and DBT-Based Interventions with and without Exercise on Pain Outcomes and Desire for Treatment in Substance-Dependent Patients with Chronic Pain

“…Chronic pain can have both physical and psychological repercussions for patients, as well as significant healthcare and economic burdens and diminished productivity (11). Patients with chronic pain often face an increased risk of developing complications, including alterations in cognitive processes such as memory and attention (12), changes in brain chemistry and neocortical gray matter (13), and challenges in accurately perceiving chronic pain and related behavioral aspects (14) Chronic pain is linked to elevated rates of major depressive disorder in American adults (15), suicidal ideation and attempts (16), sleep disturbances (17), sexual dysfunction (18), and conditions like hypertension (19). Despite these challenges, maintaining functional abilities despite chronic pain is a key goal of various treatment interventions.…”