Focused Ultrasound (FUS) for Chronic Pain Management: Approved and Potential Applications

Table 2

LILFUS for pain management.

Site	Guide	FUS application	Target	Ongoing CT	Published results	Stage
CNS	MR	Functional mapping of cerebral pain networks	Brain	—	—	†
	MR	Targeted drugs and gene delivery through the Blood-Brain Barrier for pain relief	Blood-Brain Barrier	—	—	†
	MR or US	Tissues targeted delivery of temperature-sensitive drugs for pain relief	Target tissue	—	—	†
PNS	US	Assessment of pain thresholds: (1) Diagnosis of neuropathies; (2) Evaluation of effectiveness of analgesics; (3) Study of the diurnal variation of pain; (4) Localization of deep sources of pain	Peripheral nerves, skin, deeper structures	—	[129–134]; Preclinical:[135–138]	Human studies and preclinical
	MR or US	Chronic neuropathic pain, spasticity-associated pain (reversible conduction block/pain fiber selective ablation)	Peripheral nerves	—	[139–147]	Preclinical
	No	Knee osteoarthritis related chronic pain	Knee joint	—	[148]	Human
	No	Noninvasive stimulation of acupoints	Skin	—	[149]	Human
	MR	Chronic trigeminal neuralgia	Trigeminal root entry zone	—	[150]	Cadaveric and in vitro model
	NA	Chronic migraine	Occipital nerve	—	[151]	Preclinical

† = speculative application (no studies on pain ongoing currently). CL = central lateral, CNS = central nervous system, CT = clinical trial, FUS = focused ultrasound, LILFUS = low-intensity, low-frequency ultrasound; MRg = magnetic resonance-guided, NA = not applicable, USg = ultrasound-guided, PNS = peripheral nervous system.