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Spinal and supraspinal processing of thermal stimuli: An fMRI study
Author(s) -
Rempe Torge,
Wolff Stephan,
Riedel Christian,
Baron Ralf,
Stroman Patrick W.,
Jansen Olav,
Gierthmühlen Janne
Publication year - 2015
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.24627
Subject(s) - rostral ventromedial medulla , allodynia , nociceptor , spinal cord , medicine , noxious stimulus , neuroscience , diffuse noxious inhibitory control , spinal trigeminal nucleus , hyperalgesia , nociception , anatomy , anesthesia , psychology , receptor
Purpose To assess and characterize responses to innocuous/noxious thermal stimuli and heat allodynia using functional spinal magnetic resonance imaging (spinal fMRI). Materials and Methods Spinal/supraspinal activation patterns of 16 healthy subjects were investigated by applying painful and nonpainful heat stimuli to dermatome C6 baseline and after sensitization with the heat/capsaicin model using fMRI (3T, single‐shot TSE, TR 9000 msec, TE 38 msec, FOV 288 × 144 × 20 mm, matrix 192 × 96, voxel size 1 × 1 × 2 mm). Results Increased activity was observed in ipsi‐ and contralateral ventral and dorsal spinal horn during noxious heat and heat allodynia. During noxious heat, but not during heat allodynia, activations were visible in the periaqueductal gray, ipsilateral cuneiform nucleus, and ipsilateral dorsolateral pontine tegmentum (DLPT). However, during heat allodynia activations were observed in bilateral ruber nuclei, contralateral DLPT, and rostral ventromedial medulla oblongata (RVM). Activations in contralateral subnucleus reticularis dorsalis (SRD) were visible during both noxious heat and heat allodynia (T >2.5, P < 0.01 for all of the above). After sensitization, activations in RVM and SRD correlated with activations in the ipsilateral dorsal horn of the spinal cord (R = 0.52–0.98, P < 0.05). Conclusion Spinal fMRI successfully demonstrates increased spinal activity and secondary changes in activation of supraspinal centers involved in pain modulation caused by peripheral nociceptor sensitization. J. Magn. Reson. Imaging 2015;41:1046–1055 . © 2014 Wiley Periodicals, Inc .