Individual Differences in Secondary Hyperalgesia and Associated Neural Activity

Chronic pain is a leading cause of disability, yet it remains difficult to treat due to our limited understanding of its underlying mechanisms (Nijs et al., 2021). Central sensitization is a mechanism associated with chronic pain, and secondary hyperalgesia is a manifestation of central sensitization that reflects pain felt beyond the site of the injury (Nijs et al., 2021; Woolf, 2011). Secondary hyperalgesia is a stable physiological response, and previous research has identified group differences in neural activity associated with an individual’s propensity to develop a small or large area of secondary hyperalgesia (Asghar et al., 2015; Werner et al., 2013). In this study, I examined whether individual differences in the neural pain response are related to the area of secondary hyperalgesia that individuals develop. Participants (N = 75) completed one magnetic resonance imaging session and two measurements of secondary hyperalgesia within a two-week period. I performed a multilevel model to examine individual differences in the area of secondary hyperalgesia developed across sessions and found secondary hyperalgesia was stable within participants; however, they displayed significant interindividual differences in the area of secondary hyperalgesia developed. I then conducted a general linear model to examine whether participants exhibited patterns of neural activity related to the average area of secondary hyperalgesia they developed across sessions. Increased neural activity in the inferior parietal lobe and the premotor cortex during pain stimulation was associated with the development of larger areas of secondary hyperalgesia. Taken together, these findings suggest increased activation in brain regions contributing to multisensory integration, spatial representation, and motor response planning contributes to individual differences in the development of secondary hyperalgesia. Targeting aspects of sensory processing and motor responses through psychological and behavioural interventions may be effective for reducing secondary hyperalgesia and potentially, pain vulnerability.

Department dc:contributor.department

Psychology

Year dc:date.issued

2026

Author dc:creator

• Millar, Kayla Ann

Advisor dc:contributor.supervisor

• Salomons, Tim

• secondary hyperalgesia
• central sensitization
• chronic pain
• functional magnetic resonance imaging
• individual differences

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1974/36050

OAI identifier oai:identifier

oai:queensu.scholaris.ca:1974/36050