Understanding Central Mechanisms of Acupuncture Analgesia Using Dynamic Quantitative Sensory Testing: A Review

Table 1

Overview of TS and CPM.

	TS	CPM
Experimental construct	Repeats of brief noxious stimuli	A test stimulus measured before and after a conditioning stimulus
Typical magnitudes in healthy subjects	10–20 in a 0–100 visual analog scale (VAS) [42]	~29% reduction in pain rating [43]
Underlying CNS physiology	Windup: increased spinal WDR output due to repetitive C-fiber stimulation at >0.3 Hz	DNIC: global reduction of WDR sensitivity due to a single, heterotopic, noxious stimulation
Pain-processing pathways involved	Ascending facilitation of nociceptive input	Descending inhibition of nociceptive input
Augmenting factors	Advanced age [44], female sex [45, 46], pain catastrophizing [46–49], anxiety, fear of pain, and location (trunk > extremities) [50]
Reducing factors		Advanced age [44, 51, 52], female sex (mixed results [43, 45, 53]), pain catastrophizing [54, 55], poor sleep [56, 57], depression [58], and opioid use [59]