Table 1.

Summary of in-human DBS studies published since 2017 (participants enrolled) targeting the affective sphere of pain (CmPf, ACC, VS/ALIC) for chronic pain

References	No.	Study	DBS target	Indication	FU	Outcome	SAE/AE
Invasive DBS (reversible)
(Abdallat et al. 2021) [33]	40	PT	Unilateral VPM/VPL or CmPf alone	Facial pain	63 months	Average pain relief 63 months > 50% in 10/18 patients	11 hardware SAE
				CRPS		No differences between VPM/VPL and CmPf
				CPSP
				Spinal cord lesion
				Brachial plexus injury
				Postherpetic pain
				FBSS
				Nerve lesions
				Phantom limb
(Ten Brinke et al. 2020) [51]	1	CR	Unilateral VS/ALIC	CPSP	NA	Mean pain relief at the end of observation (VAS): 50%	NA
(Lempka et al. 2017) [12]	10	RCT	Bilateral VS/ALIC	CPSP	24 months (6 months sham/verum + open-label phase 18 months)	Primary endpoint failure	Seizure (DBS “on”/“off”)
						Improvement in affective pain scores
(Levi et al. 2019) [10]	5	PT	Bilateral ACC	Thalamic pain syndrome	28 months	Mean pain relief 6 months (NRS): 37.9%	None
						Mean pain relief 18 months (VAS): 35%
(Boccard et al. 2017) [43]	22	PT	Bilateral ACC	Neuropathic pain	39 months	Mean pain relief 6 months (NRS): 60%	Seizure (DBS “on”/“off”)
						Mean pain relief 12 months (VAS): 43%

DBS deep brain stimulation, PT pilot study, RCT randomized controlled trial, CR case report, VPL nucleus ventrolateralis of the thalamus, VPM nucleus ventromedialis of the thalamus, CmPf centromedian-parafascicular complex of the thalamus, PVG periventricular grey, PAG periaqueductal grey, VC ventrocaudal nucleus of the thalamus, PLIC posterior limb of the capsula interna, ACC anterior cingulate cortex, CRPS complex regional pain syndrome, CPSP chronic post-stroke pain, FBSS failed back surgery syndrome, VAS visual analogue scale, NRS numeric rating scale, FU follow-up, SAE/AE serious adverse event, NA not applicable