The Effects of Acupuncture on Cerebral and Muscular Microcirculation: A Systematic Review of Near-Infrared Spectroscopy Studies

Table 5

(a) Cerebral hemodynamic response. Comparative view of articles studying the cerebral hemodynamic response with NIRS. Brief details of populations and interventions are provided, with articles arranged by response to acupuncture. (b) Muscular hemodynamic response. Comparative view of articles studying the muscular hemodynamic response with NIRS. Brief details of populations and interventions are provided, with articles arranged by target of measurement.

(a)  

Population			Stimulation type	Parameter^†	Response
Type	Size (f : m ratio)	Age (mean)
Stroke [28]	20 7 : 13	41–75	Needling: multipoint, multisession, intensive	rCBV	+
Healthy [29]	20 10 : 10	25–53 46	Electric moxibustion: single point, single session	rCBV	+
Healthy [27]	88 50 : 38	19–38 25.7	Needling or needling + strong laser: multipoint, 1.86 average sessions/subject^a	O2Hb	+
Healthy [30]	1 m	25	Needling: multipoint	O2Hb	+
Healthy [32]	2 f	23, 27	Electrical ear stimulation^b	O2Hb	+
Healthy [33]	12 4 : 8	26–41 35.2	Needling: single session, multipoint	rSO2 (INVOS 3100)	0+
Healthy [38]	34 24 : 10	20–35 25.2	Separate needling, acupressure, laser at two points (ICP)	rcSO2 (INVOS 5100)	0
Dementia^c [34]	1 f	77	Needling: multisession, multipoint	rcSO2 (INVOS 5100)	−
Neonates [37]	20 8 : 12	<1	Laser: single session, single point	O2Hb	−
Healthy [35]	20 5 : 15	19–30 23.5	Needling: trigger points and nontrigger	O2Hb (OMM 3000)	−/0^d
Healthy [31]	16 9 : 7	19–45 23.9	Needling: single session, single point	O2Hb	−

+: significant increase; 0: no significant change; −: significant decrease; 0+: slight increase in parameter.
^†The parameter measures either tissue-level oxygenation or regional blood volume. See Table 4 for definitions. Except for one case, all measurements for O₂Hb use the NIRO 300.
^a164 instances of acupuncture chosen from 7 possible schemes (including placebo needling) randomly applied to the pool of 88 subjects.
^bElectrical ear stimulation at a frequency of 100 Hz.
^cCerebrovascular dementia.
^dOxygenation response significant only during de-qi-inducing stimulations.

(b)  

Population			Target	Stimulation	Probe location	Parameter	Response
Type	Size (f : m)	Age (mean)
Healthy [40]	9 7 : 2	36	Trapezius	Needling: single point	Needling at center of probe	O2Hb HHb t-Hb	+ + 0
Neck pain [41]	9 7 : 2	22–48 35.1	Trapezius	Tender point dry needling	Needles angled under probe^a	t-Hb; SdO2	0
Neck pain [41]	13 8 : 5	24–48 36.5	Trapezius	Tender point dry needling	During exercise^b		−
Healthy [39]	12 5 : 7	23.8	Knee	Acupressure: single session, single point	Near stim point and away^c	rSO2	+
Healthy [42]	33 m	26.6	Forearm	Laser: single session, single point	M. flexor carpi ulnaris^d	O2Hb t-Hb	0 0
Healthy [36]	2 1 : 1	20, 39	Hand	Needling: 3 sessions, two points	Whole hand	Perfusion rate	0+

+: significant increase; 0: no significant change; −: significant decrease; 0+: slight increase in parameter.
^aSix needles angled obliquely to 20 mm under the center of the probe.
^b is calculated during maximal exertion of trapezius conducted once before and again one day after needling. Needles angled perpendicularly. See Table 4 for definition.
^cTwo probes: one 2 cm from the stimulation point at Xiyangguan (GB 33) and the other on the opposite side of the patella.
^dThe stimulation site, Neiguan (Pe 6), is located 2 cm proximal to the midpoint of the carpal fold between the tendons of M. flexor carpi radialis and M. palmaris longus.