Exploring relationships for visceral and somatic pain with autonomic control and personality

Abstract

The autonomic nervous system (ANS) integrates afferent and motor activity for homeostatic processes including pain. The aim of the study was to compare hitherto poorly characterised relations between brainstem autonomic control and personality in response to visceral and somatic pain. Eighteen healthy subjects (16 females, mean age 34) had recordings during rest and pain of heart rate (HR), cardiac vagal tone (CVT), cardiac sensitivity to baroreflex (CSB), skin conductance level (SC), cardiac sympathetic index (CSI) and mean blood pressure (MBP). Visceral pain was induced by balloon distension in proximal (PB) and distal (DB) oesophagus and somatic pain by nail-bed pressure (NBP). Eight painful stimuli were delivered at each site and unpleasantness and intensity measured. Personality was profiled with the Big Five inventory. (1) Oesophageal intubation evoked "fight-flight" responses: HR and sympathetic (CSI, SC, MBP) elevation with parasympathetic (CVT) withdrawal (p<0.05). (2) Pain at all sites evoked novel parasympathetic/sympathetic co-activation with elevated HR but vasodepression (all p<0.05). (3) Personality traits correlated with slope of distal oesophageal pain-related CVT changes wherein more neurotic-introvert subjects had greater positive pain-related CVT slope change (neuroticism r 0.8, p<0.05; extroversion r -0.5, p<0.05). Pain-evoked heart rate increases were mediated by parasympathetic and sympathetic co-activation - a novel finding in humans but recently described in mammals too. Visceral pain-related parasympathetic change correlated with personality. ANS defence responses are nuanced and may relate to personality type for visceral pain. Clinical relevance of these findings warrants further exploration.

Effects of Skin-to-Skin Contact on Autonomic Pain Responses in Preterm Infants

“…Parasympathetic and sympathetic coactivation may be characteristic of a different type of pain response behavior, sometimes called tonicimmobility or hypervigilance. 48 In this type of response, sympathetic activation is initially constrained by parasympathetic activation, but is available if subsequently necessary for disinhibition of sympathetic activation from parasympathetic activity for fight/flight. 48 LF/HF ratio was found to have dropped significantly from Baseline to Heel Stick and increased from Heel Stick to Recovery phase, which is consistent with the findings of other studies 23,60 that painful procedures without pain intervention can be detrimental for young preterm infants and can be a cause of loss of sympatheticparasympathetic balance.…”

Pain in domestic animals and how to assess it: a review

“…For example, some cows exhibit an extreme sensitivity in the region of the sternum when they suffer from traumatic peritonitis caused by a wire or nail perforating the wall of the forestomach (Frandson et al 2009). Visceral pain is usually described as more diffuse and unpleasant than somatic pain (Paine et al 2009) and the diffuse nature of true visceral pain is probably caused by the low density of visceral sensory innervation and extensive divergence of the visceral input within the CNS (Giamberardino and Vecchiet 1997).…”

Anterior Insula Integrates Information about Salience into Perceptual Decisions about Pain

“…Importantly, it is the subjective interpretation of available information that influences perceptions and actions, regardless of whether it is factually true or not. For instance, the interpretation of an event as threatening has been shown to increase stimulus salience and to amplify the perception of pain and nonpainful stimuli (Smith et (Paine et al, 2009). An increased perception of threat has therefore been implicated in different processes associated with an amplified pain perception, including attention to pain (Eccleston and Crombez, 1999), anxiety or fear (Asmundson and Katz, 2009), and catastrophizing (Jackson et al, 2005).…”