Decision Making and Fibromyalgia: A Systematic Review

Fibromyalgia (FM) is characterized by chronic (for more than 3 months) widespread musculoskeletal pain for which no alternative cause can be identified (Sluka & Clauw, 2016). The syndrome is associated with fatigue, sleep disturbances, and other cognitive and somatic symptoms that can be debilitating and challenging (Wolfe et al., 1990; Bair & Krebs, 2020). FM mainly involves women and has an estimated prevalence in the general population between 0,2 and 6,6%, reaching 11,4% in urban areas (Marques et al., 2017). Cognitive difficulties were marked as a priority by both patients and doctors during surveys designed to investigate subjective aspects considered particularly relevant in Fibromyalgia (Mease et al., 2008). Effectively, the literature shows that cognitive functioning can be impacted by mechanisms related to chronic pain caused by Fibromyalgia Syndrome, which captures part of the patient's resources at the expense of some abilities (Eccleston & Crombez, 1999; Glass et al., 2011; Napadow et al., 2010). Particularly, the prefrontal cortex (PFC) is the brain area responsible for pain processing but results also relevant to executive functions (Ong et al., 2019). The PFC is the area most frequently activated during chronic pain (Kummer et al., 2020; Staud, 2011) and in general responsible for integrating pain information with other input (including memories, mood, spatial awareness, and many more). The result of this integration is used to control pain at the peripheral level through the modulation to nociceptive stimuli. (Almeida et al., 2004; Ong et al., 2019). The PFC is also the key structure that underlies executive functions such as planning, problem-solving, and social control. It has the ability to represent information not currently in the environment, and this representational knowledge is used to guide thought, actions, and emotions, including the inhibition of inappropriate thoughts, distractions, actions, and feelings (Dixon et al., 2017; Goldman-Rakic, 1996; Lin et al., 2020; Ong et al., 2019). This region plays a critical role in the decision making (DM) because it is involved in the generation and regulation of emotions, and therefore in assignation of value or meaning to specific types of inputs: exteroceptive sensations, episodic memories and imagined future events, viscero-sensory signals, viscero-motor signals, actions, others' mental states, self-related information, and ongoing emotions (Dixon et al., 2017; Lin et al., 2020). The overlap of some of these brain networks, can cause patients with chronic pain to have limited access to executive functioning resources, because are engaged in pain-related mechanisms (Glass et al., 2011). This evidence, in addition to lower cognitive performances found in fibromyalgia patients compared to healthy groups of subjects, contributes to support that the cognitive difficulties or “FibroFog” are self-reported, but also an objective problem regarding the skills of patients (Bell et al., 2018). This aspect is a clinically important but comparatively less studied and includes primarily loss of mental clarity (mental fogginess), in conjunction with difficulties that includes decreased ability to concentrate, decreased immediate recall/short-term memory, inability to multitask. Although until recently cognitive symptoms have been less included in the researches, these can be more disturbing than the widespread pain and can change these patients’ lives, sometimes dramatically so (Kravitz & Katz, 2015). Among the difficulties highlighted in patients with fibromyalgia, were significant deficits in decision-making performance (Bechara et al., 1994; Verdejo-Garcia et al., 2009; Walteros et al., 2011). The DM impairment in FM subjects compared with healthy controls, have been made manifest in a famous task assessing the performance of learning about rewards and punishments under conditions of risk, ambiguity, and reversing contingencies (Bechara, 2000; Bechara et al., 1994; Verdejo-Garcia et al., 2009). Anyway, despite the supporting evidence of DM importance as a major skill in daily life (Morelli et al., 2021), few previous studies have examined decision-making in FM.