Pupillary Reaction in Children with Recurrent Abdominal Pain

Experimental Pain Responses in Children with Chronic Pain and in Healthy Children: How Do They Differ?

“…One study found that a clinical group of children with RAP and anxiety disorders evidenced higher heart rate at baseline compared with controls; elevated heart rate was also reported in the clinical group during the CPT (16). Others have similarly found increased physiological responses following pain induction among children with RAP relative to control children (17)(18)(19). Our findings contradict one investigation in which children with RAP did not differ from controls in blood pressure or heart rate responses following the CPT (20).…”

“…In contrast, an analysis comparing healthy children with a clinical group comprised of children with RAP and children with anxiety disorders (16) found no differences in tolerance or pain intensity for the cold pressor task, although the clinical group exhibited higher heart rate at baseline and during the pain task. Although others have reported similar findings of increased physiological responses to the cold pressor task among children with RAP compared with controls (17)(18)(19), at least one study found no differences in blood pressure or heart rate among RAP children and control children in relation to the cold pressor task Les réponses expérimentales à la douleur chez les enfants souffrant de douleur chronique et les enfants en santé : comment diffèrent-elles? HISToRIQuE : Des recherches étendues comparant les réponses à la douleur en laboratoire des enfants souffrant de douleur chronique à celles de sujets témoins en santé sont mitigées, certaines études indiquant une sensibilité à la douleur plus faible chez les sujets témoins et d'autres ne démontrant aucune différence.…”

Guidelines for the cold pressor task as an experimental pain stimulus for use with children

“…36 Children with elevated anxiety and with recurrent abdominal pain were reported to have greater physiologic responses to CPT than control children. 1,8,28 Children who responded to the CPT with a hyperreactive blood pressure response have also been found to be at increased risk of developing fixed hypertension later in life. 46 Given that the CPT is a painful stimulus lasting up to 3 or 4 minutes, it is likely to be most comparable with acute somatic clinical pains lasting from a few minutes to several hours (eg, postoperative pain), rather than visceral or chronic pain.…”

Pupillary Reactivity in Children With Recurrent Abdominal Pain

“…An autonomic dysfunction in children with RAP was postulated many years ago: in two different studies a modified pupillary reactivity in response to stress induced by the cold pressor test was found. 18,19 In both studies no differences in pupillary diameter between RAP children and controls were found at rest or during the application of a cold pressor test, but recovery of pupillary size following the cold pressor test was significantly delayed among the RAP patients.…”

“…Pupillometric studies comparing pupillary reactions in response to stress induced by the cold pressor test have shown that normal pupillary reactions are modified in children with RAP in comparison with controls, suggesting a chronic autonomic dysfunction in these patients. 18,19 More recently, a sympathetic hypofunction affecting the iris neuromuscular junction has been shown with pupillometry in subjects suffering from migraine. 20,21 The same finding has subsequently been reported in subgroups of young migrainous patients.…”