Background & Aims
The insula is a key area for pain processing. We have preliminary evidence that direct stimulation of the anterior insula increases heat pain threshold in humans [1]. We aim to investigate the safety and feasibility of insula deep brain stimulation (DBS) for chronic neuropathic pain management.
Methods
A two-staged clinical trial was designed for twelve patients with medication-refractory chronic neuropathic pain. Phase 1 of the clinical trial involves stereotactic implantation of multi-contact intracerebral depth electrodes for brain mapping and multi-day continuous electroencephalogram (EEG) monitoring of the bilateral insula. Subjects who ‘respond’ (increase in heat pain threshold and/or decrease in clinical or experimental pain) to the direct insular stimulation in phase 1 will advance to phase 2 for permanent DBS system implantation and a randomized, sham-stimulation controlled trial. Subjects’ pain experience will be collected in their natural environments and social contexts via ecological momentary assessment (EMA) methodologies.
Results
Four subjects have completed phase 1. Stimulating posterior insula commonly evoked numbness or tingling sensations (n=4). Afterdischarges (n=4) and clinical seizure (n=1) were seen with higher current stimulations. All subjects met the responder’s criteria. Exploratory EEG spectral analysis showed that high chronic pain is associated with excessive slower alpha oscillations in the posterior insula that were reversed following direct anterior insula stimulation (p < 0.05, n=3).
Conclusions
Stimulation of the insula is well tolerated in the hospital setting. Acute anti-nociceptive responses to electrical stimulation of the anterior insula have been consistently observed. The long-term effects of anterior insula DBS neuromodulation on clinical pain severity and chronicity are still under investigation.
References
1. Anterior insula stimulation increases pain threshold in humans: a pilot study. 2021. Liu CC, Moosa S, Quigg M, Elias WJ. Journal of Neurosurgery; 135(5):1487-1492.
Presenting Author
Chang-Chia Liu
Poster Authors
Chang-Chia Liu
Ph.D.
University of Virginia
Lead Author
Shayan Moosa
M.D.
University of Virginia School of Medicine
Lead Author
Patrick Finan
Ph.D.
University of Virginia School of Medicine
Lead Author
Mark Quigg
M.D.
University of Virginia School of Medicine
Lead Author
W. Jeff Elias
M.D.
University of Virginia School of Medicine
Lead Author
Topics
- Mechanisms: Biological-Systems (Physiology/Anatomy)