Premium
Functional MRI of the rat lumbar spinal cord involving painful stimulation and the effect of peripheral joint mobilization
Author(s) -
Malisza Krisztina L.,
Stroman Patrick W.,
Turner Allan,
Gregorash Lori,
Foniok Tadeusz,
Wright Anthony
Publication year - 2003
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.10339
Subject(s) - medicine , spinal cord , joint mobilization , ankle , lumbar spinal cord , lumbar , stimulation , hyperalgesia , peripheral , anesthesia , spinal cord stimulator , capsaicin , lumbosacral joint , functional magnetic resonance imaging , magnetic resonance imaging , nociception , anatomy , surgery , spinal cord stimulation , radiology , range of motion , receptor , psychiatry
Purpose: To examine neuronal activation in the spinal cord due to secondary hyperalgesia resulting from intrajoint capsaicin injection, and the effect of physiotherapy manipulation, using functional magnetic resonance imaging (fMRI), in α‐chloralose anesthetized rats. Materials and Methods: FMRI of the rat lumbar spinal cord was performed at 9.4 Tesla. Stimuli included injection of 25 μL of capsaicin (128 μg/mL in 7.5% dimethyl sulfoxide [DMSO]) into the right forepaw or 75 μL into the right ankle joint followed by a light touch stimulus, with and without physiotherapy manipulation. Results: Activation of pain areas of the spinal cord (dorsal horn) was found in all animals after injection of capsaicin into the plantar surface of the rat hindpaw and ankle joint. Overlay maps depicting activations and deactivations showed significant reproducibility between experiments. Greater overlay of activations were observed for intrajoint compared to intradermal capsaicin injection. The distribution of activations after stimulation of the hindpaw using a light touch stimulus was somewhat more varied; activation of the dorsal horn was evident, with greater overlap resulting when joint mobilization was not performed. Conclusion: Results suggest a trend toward decreased areas of activation in the spinal cord associated with pain, as a result of hyperalgesia, following physiotherapy joint mobilization. J. Magn. Reson. Imaging 2003;18:152–159. © 2003 Wiley‐Liss, Inc.