Rationale:
Mechanisms by which Retraining and Control Therapy (ReACT) is effective for the treatment of pediatric functional seizures (FS) are unclear. One potential mechanism could be via reduction in symptom catastrophizing. This study aims to assess the effect of ReACT on change in cortisol reactivity, a valid biological marker of pain catastrophizing, and self-reported pain catastrophizing after a pain stimulus.
Methods:
Thirty-four children with video electroencephalogram-confirmed FS (M age= 15.0, 84% female, 71% White, 13% Multiracial, 11% Black) and at least four FS per month competed 12 sessions of ReACT. Seven days before and seven days after ReACT,
children completed the cold pressor test (CPT) in which they held their hand in cool water (7֯C) for as long as possible up to three minutes. Immediately before, immediately after (0) and after 15 and 30 minutes after the CPT, children provided a saliva sample for cortisol analyses. Cortisol reactivity was assessed by calculating area under the curve with respect to intensity. The Pain Catastrophizing Scale for Children (PCS-C) was completed immediately after the CPT. FS frequency was measured via prospective FS diary in the 30 days before and after ReACT. FS improvement after ReACT was assessed via therapist, parent and child report on the Clinical Global Index (CGI) which asks, "Compared to their condition at baseline, how much have they changed?" Outcomes of this pilot study were assessed via effect sizes for change in cortisol reactivity controlling for difference in the patients’ pre-CPT cortisol and change in PCS-C. For change in FS frequency, clinically meaningful differences were assessed via 1) percent change in FS from before to after ReACT and 2) responses to the CGI.Results:
Participants had a 94% reduction in FS frequency from 30 days before to 30 days after ReACT with 59% achieving remission. Using 50% reduction in FS frequency as a metric of responder rate, 32/34 (94%) classified as treatment responders. Responses of "Much Improved" and "Very Much Improved" on the CGI indicated a clinically meaningful change for 33/34 of participants (97%) as reported by therapists, 33/34 (97%) as reported by parents and 29/33 (88%) as reported by the child participants.
When controlling for difference in pre-CPT cortisol, there was a medium effect size (ηp2= 0.05) in the difference between AUCi before (M=0.47, SD=1.46) and after (M=0.19, SD=1.57) ReACT, indicating lower cortisol reactivity after treatment (i.e., smaller spike in cortisol at 15 timepoint; Figure 1). Change in PCS-C from before (M=19.75, SD=12.29) to after (M=12.22, SD=9.47) ReACT produced a medium effect size (Cohen’s d=0.6), indicating lower pain catastrophizing after treatment.
Conclusions:
This pilot study provides evidence that symptom catastrophizing is reduced after successful treatment of FS. This supports the need for a future fully powered randomized controlled trial assessing symptom catastrophizing as a mechanism by which treatment of FS is effective, which can be used to enhance FS treatment efficacy.
Funding:
NIMH R61MH127155