PMID- 22537561
OWN - NLM
STAT- MEDLINE
DCOM- 20121002
LR  - 20131121
IS  - 1528-8447 (Electronic)
IS  - 1526-5900 (Linking)
VI  - 13
IP  - 6
DP  - 2012 Jun
TI  - Spatial pain propagation over time following painful glutamate activation of 
      latent myofascial trigger points in humans.
PG  - 537-45
LID - 10.1016/j.jpain.2012.03.001 [doi]
AB  - The aim of this present study was to test the hypothesis that tonic nociceptive 
      stimulation of latent myofascial trigger points (MTPs) may induce a spatially 
      enlarged area of pressure pain hyperalgesia. Painful glutamate (.2 mL, 1M) 
      stimulation of latent MTPs and non-MTPs in the forearm was achieved by an 
      electromyography-guided procedure. Pain intensity (as rated on the visual analog 
      scale [VAS]) and referred pain area following glutamate injections were recorded. 
      Pressure pain threshold (PPT) was measured over 12 points in the forearm muscles 
      and at the mid-point of tibialis anterior muscle before and at .5 hour, 1 hour, 
      and 24 hours after glutamate injections. The results showed that maximal pain 
      intensity, the area under the VAS curve, and referred pain area were 
      significantly higher and larger following glutamate injection into latent MTPs 
      than non-MTPs (all, P < .05). A significantly lower PPT level was detected over 
      time after glutamate injection into latent MTPs at .5 hour (at 4 points), 1 hour 
      (at 7 points), and 24 hours (at 6 points) in the forearm muscles. However, a 
      significantly lower PPT was observed only at 24 hours after glutamate injection 
      into non-MTPs in the forearm muscles (at 4 points, P < .05) when compared to the 
      pre-injection PPT. PPT at the mid-point of the tibialis anterior was 
      significantly decreased at 1 hour only as compared to the pre-injection PPT in 
      both groups (< .05). The results of the present study indicate that nociceptive 
      stimulation of latent MTPs is associated with an early onset of locally enlarged 
      area of mechanical hyperalgesia. PERSPECTIVE: This study shows that MTPs are 
      associated with an early occurrence of a locally enlarged area of pressure 
      hyperalgesia associated with spreading central sensitization. Inactivation of 
      MTPs may prevent spatial pain propagation.
CI  - Copyright (c) 2012 American Pain Society. Published by Elsevier Inc. All rights 
      reserved.
FAU - Wang, Chao
AU  - Wang C
AD  - Laboratory for Musculoskeletal Pain and Motor Control, Center for Sensory-Motor 
      Interaction (SMI), Department of Health Science and Technology, Aalborg 
      University, Aalborg, Denmark.
FAU - Ge, Hong-You
AU  - Ge HY
FAU - Ibarra, Jose Miota
AU  - Ibarra JM
FAU - Yue, Shou-Wei
AU  - Yue SW
FAU - Madeleine, Pascal
AU  - Madeleine P
FAU - Arendt-Nielsen, Lars
AU  - Arendt-Nielsen L
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20120425
PL  - United States
TA  - J Pain
JT  - The journal of pain
JID - 100898657
RN  - 3KX376GY7L (Glutamic Acid)
SB  - IM
MH  - Area Under Curve
MH  - Electromyography
MH  - Female
MH  - Forearm
MH  - Glutamic Acid/toxicity
MH  - Humans
MH  - Hyperalgesia/chemically induced/physiopathology
MH  - Male
MH  - Muscle, Skeletal/*physiopathology
MH  - Myofascial Pain Syndromes/chemically induced/*physiopathology
MH  - Pain Measurement
MH  - Pain Threshold/drug effects/*physiology
MH  - Pain, Referred/physiopathology
MH  - Trigger Points/physiopathology
MH  - Young Adult
EDAT- 2012/04/28 06:00
MHDA- 2012/10/04 06:00
CRDT- 2012/04/28 06:00
PHST- 2011/12/09 00:00 [received]
PHST- 2012/01/26 00:00 [revised]
PHST- 2012/03/01 00:00 [accepted]
PHST- 2012/04/28 06:00 [entrez]
PHST- 2012/04/28 06:00 [pubmed]
PHST- 2012/10/04 06:00 [medline]
AID - S1526-5900(12)00528-7 [pii]
AID - 10.1016/j.jpain.2012.03.001 [doi]
PST - ppublish
SO  - J Pain. 2012 Jun;13(6):537-45. doi: 10.1016/j.jpain.2012.03.001. Epub 2012 Apr 
      25.