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

Table 2

Common methods used to generate and compute TS.

Type of stimulus	Experimental paradigms	Variables used to quantify TS
Heat pulses	10–20 heat pulses (0.5–0.75 s each) delivered at 0.3–0.5 Hz either via a continuous contact thermode [44] or intermittent contact probe [60]	TS magnitude: the difference in pain ratings between first and last, or first and most painful pulse, slope of the first few pulses, or the magnitude of 5th pulse [42, 61]
Electrical stimulation	A single stimulus of a train of five 1-ms pulses at 200 Hz, repeated 5 times at 2 or 3 Hz [62, 63]	Electrical pain threshold (EP-T): intensity at which the subject begins to feel pain at the 4th or 5th pulse [62, 63], or nociceptive withdrawal reflex threshold (NWR-T), the intensity at which limb flexion occurs [64] in response to the electrical stimulation
Pin prick	10 stimuli of 56 or 128 mN are delivered, and pain ratings for all ten stimuli averaged versus that of a single stimulus are obtained [65]	Windup ratio: pain of train of 10 pricks delivered at 1 Hz over pain of a single prick [65]
Pressure	Ten 1-s pressure stimuli delivered by an algometer with 1 s between pulses [66, 67]	TS magnitude: difference in pain rating between the first and 10th stimuli [66, 67]