Background & Aims

The default (mode) network (DMN) has been shown to be involved in somatic and affective information processing. These information-processing mechanisms are essential to cope with continuous pain. Consequently, they may influence both pain perception and mood over an extended period in individuals exposed to continuous pain. Although previous studies have revealed alterations in the DMN in individuals with chronic pain compared to healthy controls, the precise nature of the associations between DMN changes and pain/mood remains incompletely understood. Furthermore, it is unclear whether these associations evolve over time, contingent on the duration of the pain experience.

Methods

Therefore, we performed functional magnetic resonance imaging at rest in 57 patients with back pain (40 with subacute and 17 with chronic back pain) and assessed pain (West Haven-Yale Multidimensional Pain Inventory (H. Flor et al., 1990)) and mood (Hospital Anxiety and Depression Scale (Snaith & Zigmond, 1995)), both at a baseline time point and a follow-up 6 months later. We determined the degree of DMN alteration using mean shortest path, mean nodal degree, closeness centrality, and global efficiency as common graph-theoretic indices of network function. We then predicted the percentage change of pain as well as mood from baseline to follow-up by DMN perturbation in structural equation models, while grouping patients by their years lived with back pain (YLP) using a sliding window approach (window size = 25).

Results

In the patient groups with meanYLP=.91a-3.94a (max(YLP)=10.39a , min(YLP)=.08a,) DMN perturbation significantly predicted pain reduction (max(path weight)=.-694****), but not in groups with higher YLP. In contrast, in the patient groups with mean(YLP) 19.95a-28.97a (min(YLP)=3.3a; max(YLP)=28.97a) DMN perturbation significantly predicted mood worsening (max(path weight)=.455**).

Conclusions

Our findings reveal significant associations of DMN alterations with shifts in pain perception and mood among individuals with back pain. Intriguingly, when individuals experienced shorter durations of pain, DMN alterations were linked to a decrease in pain. However, in cases where pain persisted for a longer period, alterations in the DMN were associated with a deterioration in mood. This suggests that DMN alterations may serve as distinct indicators of adaptations to various stages of back pain, potentially reflecting different coping stages. These findings could be valuable for developing prevention and intervention strategies informed by neuromodulation.

References

H. Flor, T. E. Rudy, N. Birbaumer, B. Streit, & M. M. Schugens. (1990). Zur Anwendbarkeit des West Haven-Yale Multidimensional Pain Inventory im deutschen Sprachraum. Der Schmerz, 4(2), 82–87. https://doi.org/10.1007/BF02527839
Snaith, R. P., & Zigmond, A. S. (1995). Hospital Anxiety and Depression Scale—Deutsche Version. Huber.

Presenting Author

Nils Jannik Heukamp

Poster Authors

Nils Jannik Heukamp

MSc

University Medical Center Kiel

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Vera Moliadze PhD

Institute of Medical Psychology and Medical Sociology, University Medical Centre Schleswig-Holstein,

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Mina Kandi?

Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Facult

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Katrin Usai PhD

Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Facult

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Martin Löffler

Clinical Psychology, Department of Experimental Psychology, Heinrich Heine University Düsseldorf

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Herta Flor

Interdisciplinary Center for Clinical Trials, Johannes Gutenberg University Medical Center Mainz

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Frauke Nees

University Medical Center Schleswig-Holstein, Kiel University

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Topics

  • Pain Imaging