Ultrasound guided, painful electrical stimulation of lumbar facet joint structures: an experimental model of acute low back pain.
Quantitative sensory testing has indicated generalized muscle hyperalgesia in patients with chronic low back pain. The temporal development of such hyperalgesia is not well understood. The aim of the present study was to demonstrate whether generalized muscle hyperalgesia can develop within minutes of acute low back pain using a new experimental model of lumbar facet joint pain. Thirteen healthy volunteers were included and baseline pressure pain thresholds were assessed at eight separate sites, outside the area of evoked low back and referred pain. Using ultrasonography, two electrode needles were placed either side of a lumbar facet joint (right L3-4) and used to induce experimental low back pain for 10 min with continuous stimulation. Thresholds, stimulus-response relationships, distribution and quality of the electrically induced pain were recorded. Electrical facet joint stimulation induced low back pain and pain referral into the anterior leg, ipsilaterally, proximal to the knee, similar to what is observed clinically. Pressure pain thresholds did not change significantly before, during and after facet joint stimulation. In conclusion, we describe a novel model of acute experimental low back pain and demonstrate that generalized hyperalgesia did not develop within minutes of acute low back pain.
Laboratory for Human Experimental Pain Research, Center for Sensorymotor Interaction, Department of Health Science and Technology, University of Aalborg, Fredrik Bajers Vej 7, Bld. D3, 9220 Aalborg, Denmark. soren@oneill.dk
Søren
S
O'Neill
Thomas
T
Graven-Nielsen
Claus
C
Manniche
Lars
L
Arendt-Nielsen
D000328:Adult; D000704:Analysis of Variance; D001703:Biophysics; D004558:Electric Stimulation / Q000009:adverse effects*; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology*; D008159:Lumbar Vertebrae / Q000294:innervation*; D008297:Male; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed; D014465:Ultrasonics; D014463:Ultrasonography / Q000379:methods; D055815:Young Adult; D021801:Zygapophyseal Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*