Background & Aims
Borderline personality disorder (BPD) is characterized by reduced pain sensitivity (Fales et al., 2021) which co-varies with levels of dissociation (Ludäscher et al., 2007). Previous studies related altered activity in fronto-limbic brain areas to disturbed pain processing in BPD (Schmahl & Baumgärtner, 2015). However, the multidimensional nature of dissociation, including its manifestation in altered body awareness in BPD (Löffler et al., 2020), suggests that temporo-parietal networks, contributing to the integration of multimodal sensory information (Tsakiris, 2010) might also be involved in altered pain perception in BPD. The present study aimed to investigate the effect of facilitatory or inhibitory modulation of the right temporo-parietal junction (rTPJ) neural activity by theta-burst stimulation (TBS) on pain perception and dissociation.
Methods
We investigated 15 participants with BPD. In order to define individual targets for TBS, participants first underwent magnetic resonance imaging to obtain an anatomical scan and a functional localizer task involving the rTPJ (Blanke et al., 2005). Afterwards, participants received a continuous TBS protocol (cTBS) and an intermittent TBS protocol (iTBS), known to decrease and increase cortical excitability, respectively (Huang et al, 2005), over the rTPJ and the left visual cortex (lV1) as a control region in 4 separate sessions. Before and after TBS stimulation we assessed electrical perception and pain thresholds as well as state dissociation levels by using the Dissociation-Tension-Scale Acute (Stiglmayr et al., 2009). We performed a 2 (time point, pre vs post) ×2 (brain area, TPJ vs lV1) ×2 (kind of stimulation, facilitation vs inhibition) repeated measures analysis of variance on perception threshold, pain threshold, and state dissociation.
Results
For pain thresholds, preliminary results suggest a significant interaction between time point and stimulated brain area, F1,14 = 6.61, p = .022, ?2 = .32. Post hoc tests showed that there was a significant reduction in pain thresholds after rTPJ stimulation (independent of kind of stimulation), t14 = 2.49, p = .026, d = 0.64, while there was no significant difference for lV1 stimulation, t14 = -0.61, p = .55, d = -.16. There were no other significant main (all F1,14 ? 2.14, p ? .17, ?2 ? .13) or interaction effects (all F1,14 ? 1.35, p ? .26, ?2 ? .09) for pain thresholds. For state dissociation and perception thresholds there were no significant effects (all p ? .06).
Conclusions
The results of our study suggest that disturbed sensory processing at the rTPJ contributes to altered pain perception in BPD. Modulation of its activity seems to normalize these processes, with facilitating stimulation being descriptively more effective than inhibiting stimulation. These processes seem to be independent of self-reported dissociation levels suggesting that there might be multiple neural mechanisms contributing to altered pain processing and dissociation in BPD.
References
Blanke, O., Mohr, C., Michel, C. M., Pascual-Leone, A., Brugger, P., Seeck, M., … & Thut, G. (2005). Linking out-of-body experience and self processing to mental own-body imagery at the temporoparietal junction. Journal of Neuroscience, 25(3), 550-557.
Huang, Y. Z., Edwards, M. J., Rounis, E., Bhatia, K. P., & Rothwell, J. C. (2005). Theta burst stimulation of the human motor cortex. Neuron, 45(2), 201-206.
Löffler, A., Kleindienst, N., Cackowski, S., Schmidinger, I., & Bekrater-Bodmann, R. (2020). Reductions in whole-body ownership in borderline personality disorder–a phenomenological manifestation of dissociation. Journal of Trauma & Dissociation, 21(2), 264-277.
Ludäscher, P., Bohus, M., Lieb, K., Philipsen, A., Jochims, A., & Schmahl, C. (2007). Elevated pain thresholds correlate with dissociation and aversive arousal in patients with borderline personality disorder. Psychiatry research, 149(1-3), 291-296.
Schmahl, C., & Baumgärtner, U. (2015). Pain in borderline personality disorder. Pain in Psychiatric Disorders, 30, 166-175.
Stiglmayr, C., Schmahl, C., Bremner, J. D., Bohus, M., & Ebner-Priemer, U. (2009). Development and psychometric characteristics of the DSS-4 as a short instrument to assess dissociative experience during neuropsychological experiments. Psychopathology, 42(6), 370-374.
Tsakiris, M. (2010). My body in the brain: a neurocognitive model of body-ownership. Neuropsychologia, 48(3), 703-712.
Presenting Author
Annette Löffler
Poster Authors
Annette Löffler
MSc
Scientific Center for Neuropathic Pain Aachen (SCN)
Lead Author
Carolin Paulus
Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Germany
Lead Author
Jamila Andoh
PhD
Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Germany
Lead Author
Herta Flor
Interdisciplinary Center for Clinical Trials, Johannes Gutenberg University Medical Center Mainz
Lead Author
Robin Bekrater-Bodmann
RWTH Aachen
Lead Author
Topics
- Treatment/Management: Interventional Therapies – Neuromodulation