Introduction: Minimally invasive neuromodulation such as spinal cord stimulation (SCS) and occipital nerve stimulation (ONS) have shown to be successful for treatment of different types of pain such as chronic back or leg pain, complex regional pain syndrome (CRPS), and fibromyalgia. Recently, novel stimulation paradigm called burst stimulation was developed that suppresses pain to better extent than classical tonic stimulation (1). From clinical point of view, burst stimulation is very promising; however, little is known about its underlying mechanism. Hence, in this work we investigate mechanism of action for burst stimulation in different patient groups and controls using different neuroimaging multimodalities such as EEG, fMRI and PET.

Methods: Control subjects and patients with chronic back or leg pain, CRPS, or fibromyalgia enrolled for study. Both controls and patients received SCS or ONS and sham, tonic, and burst stimulation in fMRI, PET, and EEG.

Results: EEG shows significant changes for burst stimulation compared to tonic and sham stimulation; evident by increased activity at dorsal anterior cingulate cortex (dACC), dorsolateral prefrontal cortex (dPFC), primary somatosensory cortex, and posterior cingulate cortex (PSC) in alpha frequency band. PET further confirmed by showing increased tracer capitation for burst in dACC, pregenual anterior cingulate cortex (pgACC), parahippocampus, and fusiform gyrus. Furthermore, fMRI showed burst changes in dACC, dPFC, pgACC, cerebellum, hypothalamus, and premotor cortex. A conjunction analysis between tonic and burst stimulation demonstrated theta activity is commonly modulated in somatosensory cortex and PSC.

Conclusions: Our data suggest that burst and tonic stimulation modulate ascending lateral and descending pain inhibitory pathways. Burst stimulation adds by modulating the medial pain pathway, possibly by direct modulation of spinothalamic pathway, as suggested by animal research. Burst normalizes an imbalance between ascending pain via medial system and descending pain inhibitory activity, which could be a plausible reason it’s better than to tonic stimulation (1-9).

Patient Care: Burst stimulation have shown to treat chronic leg back or leg pain. Along with suboccipital stimulators burst stimulation can be effectively used for treating fibromyalgia, migraine or cluster headaches.

Learning Objectives: 1)Multitarget brain structures have been investigated to understand the pain matrix for burst stimulation in ONS. 2)Multimodalities explored for understanding mechanism of action of ONS in control and fibromyalgia patients for burst stimulation.

References: 1.De Ridder D, Vanneste S, Plazier M, van der Loo E, & Menovsky T (2010) Burst spinal cord stimulation: toward paresthesia-free pain suppression. Neurosurgery 66(5):986-990. 2.De Ridder D, et al. (2014) A Two Center Comparative Study on Tonic Versus Burst Spinal Cord Stimulation: Amount of Responders and Amount of Pain Suppression. The Clinical journal of pain. 3.De Ridder D, Plazier M, Kamerling N, Menovsky T, & Vanneste S (2013) Burst Spinal Cord Stimulation for Limb and Back Pain. World Neurosurg. 4.De Ridder D, Plazier M, Menovsky T, Kamerling N, & Vanneste S (2013) C2 subcutaneous stimulation for failed back surgery syndrome: a case report. Neuromodulation 16(6):610-613. 5.De Ridder D, Vancamp T, Lenders MW, De Vos CC, & Vanneste S (2015) Is preoperative pain duration important in spinal cord stimulation? A comparison between tonic and burst stimulation. Neuromodulation 18(1):13-17; discussion 17. 6.De Ridder D, Vanneste S, Plazier M, & Vancamp T (2015) Mimicking the brain: evaluation of St Jude Medical's Prodigy Chronic Pain System with Burst Technology. Expert Rev Med Devices 12(2):143-150. 7.de Vos CC, Bom MJ, Vanneste S, Lenders MW, & de Ridder D (2014) Burst spinal cord stimulation evaluated in patients with failed back surgery syndrome and painful diabetic neuropathy. Neuromodulation : journal of the International Neuromodulation Society 17(2):152-159. 8.Van Havenbergh T, Vancamp T, Van Looy P, Vanneste S, & De Ridder D (2015) Spinal cord stimulation for the treatment of chronic back pain patients: 500-Hz vs. 1000-Hz burst stimulation. Neuromodulation 18(1):9-12; discussion 12. 9.Schu S, et al. (2014) A Prospective, Randomised, Double-blind, Placebo-controlled Study to Examine the Effectiveness of Burst Spinal Cord Stimulation Patterns for the Treatment of Failed Back Surgery Syndrome. Neuromodulation.