Imaging the pain of low back pain: functional magnetic resonance imaging in combination with monitoring subjective pain perception allows the study of clinical pain states

• Published in: Neuroscience letters Vol. 299; no. 1; pp. 57 - 60
• Main Authors: Apkarian, A.Vania, Krauss, Beth R., Fredrickson, Bruce E., Szeverenyi, Nikolaus M.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 16.02.2001; Elsevier
• Subjects: back; Biological and medical sciences; Brain Mapping; Cerebral Cortex - pathology; Cerebral Cortex - physiopathology; Cortex pain; Diseases of the osteoarticular system; Diseases of the spine; Functional brain imaging; Hemodynamic responses; Human; Humans; Low Back Pain - pathology; Low Back Pain - physiopathology; Low Back Pain - psychology; Magnetic Resonance Imaging; Male; Medical sciences; Pain Measurement - psychology; Perception; Posture - physiology; Radiculopathy - pathology; Radiculopathy - physiopathology; Radiculopathy - psychology; Sciatic pain; Human; Hemodynamic responses; Functional brain imaging; Perception; Cortex pain; Sciatic pain; Lumbar spine; Low back pain; Central nervous system; Diseases of the osteoarticular system; Spine disease; Nuclear magnetic resonance imaging; Pain; Imaging; Rachialgia; Hemodynamics; Brain (vertebrata); Functional imaging
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/S0304-3940(01)01504-X

Most brain imaging studies of pain are done using a two-state subtraction design (state-related design). More recently event-related functional magnetic reasonance imaging (fMRI) has also been used for studying pain. Both designs severely limit the application of the technology to clinical pain states. Recently we demonstrated that monitoring time fluctuations of perceived pain could be used with fMRI to identify brain regions involved in conscious, subjective perception of pain. Here we extend the methodology to demonstrate that the same approach can be used to study clinical pain states. Subjects are equipped with a finger-spanning device to continuously rate and log their perceived pain during fMRI data collection. These ratings are convolved with a canonical hemodynamic response function to generate predictor waveforms with which related brain activity can be identified. Chronic low back pain patients and a normal volunteer were used. In one series of fMRI scans the patient simply lies in the scanner and indicates spontaneous fluctuations of the subjective pain. In other fMRI scans, a straight-leg raising procedure is performed to exacerbate the back pain. In the normal volunteer, fMRI scans were done during painful and non-painful straight-leg raisings. The results indicate the feasibility of differentiating between different pain states. We argue that the approach can be generalized to identify brain circuitry underlying diverse clinical pain conditions.