Effect of botulinum toxin on endplate noise in myofascial trigger spots of rabbit skeletal muscle.
OBJECTIVE
To assess the effect of botulinum toxin type A (BTX-A) on the endplate noise prevalence in rabbit myofascial trigger spots to confirm the role of excessive acetylcholine release on the pathogenesis of myofascial trigger points and to develop an objective indicator of the effectiveness of BTX-A in the treatment of myofascial trigger points.


METHODS
Eighteen adult New Zealand rabbits were divided into three groups that received a single bolus of BTX-A over a myofascial trigger spot region on one side of the biceps femoris muscle. Another 10 rabbits received multiple-point injections in a myofascial trigger spot where endplate noises were found. A control study was performed on the other side of the biceps femoris muscle. The endplate noise prevalence in a myofascial trigger spot region was assessed.


RESULTS
It was found that injection of BTX-A reduced the prevalence of endplate noise. No significant differences between a single bolus injection and multiple-point injections were noted, although there was some evidence that multiple-point injections might maintain the endplate noise decreasing effect much longer than a single injection.


CONCLUSIONS
This study demonstrated the suppressive effect of BTX-A on endplate noise prevalence in a myofascial trigger spot region. The prevalence of endplate noise in the myofascial trigger point region may be a useful objective indicator for evaluating the therapeutic effectiveness of BTX-A injection to treat myofascial trigger points.
Department of Physical Medicine and Rehabilitation, College of Medicine, National Cheng Kung University, Tainan, Taiwan, Republic of China.
Ta-Shen
TS
Kuan
Jo-Tong
JT
Chen
Shu-Min
SM
Chen
Chi-Hsien
CH
Chien
Chang-Zern
CZ
Hong
D000109:Acetylcholine / Q000378:metabolism / Q000502:physiology; D000818:Animals; D019274:Botulinum Toxins, Type A / Q000494:pharmacology*; D007273:Injections, Intramuscular; D009045:Motor Endplate / Q000187:drug effects* / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000187:drug effects / Q000503:physiopathology; D009209:Myofascial Pain Syndromes / Q000188:drug therapy* / Q000503:physiopathology; D009465:Neuromuscular Agents / Q000494:pharmacology*; D011817:Rabbits
D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A; D000109:Acetylcholine