Olfactory training reduces pain sensitivity in children and adolescents with primary headaches

Gudrun Gossrau; Laura Zaranek; Anna Klimova; Rainer Sabatowski; Thea Koch; Matthias Richter; Antje Haehner

doi:10.3389/fpain.2023.1091984

Olfactory training reduces pain sensitivity in children and adolescents with primary headaches

Front Pain Res (Lausanne). 2023 Feb 13:4:1091984. doi: 10.3389/fpain.2023.1091984. eCollection 2023.

Authors

Gudrun Gossrau¹, Laura Zaranek^{1

2}, Anna Klimova³, Rainer Sabatowski^{1

4}, Thea Koch⁴, Matthias Richter², Antje Haehner⁵

Affiliations

¹ Comprehensive Pain Center, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany.
² Department of Pediatrics, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany.
³ NCT Partner Site Dresden, Institute for Medical Informatics and Biometrics, Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany.
⁴ Departement of Anesthesiology and Intensive Care Medicine, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany.
⁵ Smell & Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany.

Abstract

Objective: Headache prevalence among children and adolescents has increased over the last few years. Evidence-based treatment options for pediatric headaches remain limited. Research suggests a positive influence of odors on pain and mood. We investigated the effect of repeated exposure to odors on pain perception, headache-related disability, and olfactory function in children and adolescents with primary headaches.

Methods: Eighty patients with migraine or tension-type headache (mean 13.1 ± 3.29 years) participated, of whom 40 underwent daily olfactory training with individually selected pleasant odors for 3 months and 40 received state-of-the-art outpatient therapy as a control group. At baseline and after a 3-month follow-up, olfactory function [odor threshold; odor discrimination; odor identification; comprehensive Threshold, Discrimination, Identification (TDI) score], mechanical detection and pain threshold (quantitative sensory testing), electrical pain threshold, patient-reported outcomes on headache-related disability [Pediatric Migraine Disability Assessment (PedMIDAS)], pain disability [Pediatric Pain Disability Index (P-PDI)], and headache frequency were assessed.

Results: Training with odors significantly increased the electrical pain threshold compared to the control group (U = 470.000; z = -3.177; p = 0.001). Additionally, olfactory training significantly increased the olfactory function (TDI score [t(39) = -2.851; p = 0.007], in particular, olfactory threshold, compared to controls (U = 530.500; z = -2.647; p = 0.008). Headache frequency, PedMIDAS, and P-PDI decreased significantly in both groups without a group difference.

Conclusions: Exposure to odors has a positive effect on olfactory function and pain threshold in children and adolescents with primary headaches. Increased electrical pain thresholds might reduce sensitization for pain in patients with frequent headaches. The additional favorable effect on headache disability without relevant side effects underlines the potential of olfactory training as valuable nonpharmacological therapy in pediatric headaches.

Keywords: olfactory training; pediatric headache; pediatric migraine; primary headache; smell training.