Event-related fMRI of pain: entering a new era in imaging pain.
Previous imaging studies of pain used a block design of prolonged (up to 1 min) noxious stimulation that are not well tolerated and subject to temporal interactions. We describe an adaptation of event-related fMRI to study pain with short duration stimuli. Functional images were acquired with a spiral sequence on a 1.5T GE echospeed MRI system of the thalamus, anterior cingulate, insula and second somatosensory cortex during brief (1-3 s) noxious thermal stimulation of the hand of normal volunteers. An MRI-compatible computerized rating system continuously monitored subjects' pain. Brief pain-related activations were clearly identified in the cortex and thalamus with a hemodynamic delay of 3-6 s. These findings demonstrate that brief stimuli combined with on-line pain ratings can be used to study pain with fMRI.
Davis
K D
KD
Department of Surgery, University of Toronto, Toronto Hospital (Western Division), The Toronto Hospital Research Institute, Ontario, Canada.
Kwan
C L
CL
Crawley
A P
AP
Mikulis
D J
DJ
D000161:Acoustic Stimulation; D000328:Adult; D001921:Brain / Q000502:physiology; D001931:Brain Mapping / Q000379:methods; D002540:Cerebral Cortex / Q000502:physiology; D003080:Cold Temperature; D006179:Gyrus Cinguli / Q000502:physiology; D006358:Hot Temperature; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010146:Pain / Q000503:physiopathology*; D010812:Physical Stimulation / Q000295:instrumentation / Q000379:methods; D013003:Somatosensory Cortex / Q000502:physiology; D013788:Thalamus / Q000502:physiology; D013997:Time Factors