Functional Neuroimaging of Pain Using EEG and fMRI

Functional imaging of brain networks associated with pain processing is of vital importance
to aid developing new pain-relief therapy and to better understand the mechanisms of brain
function. The pain response in the brain is a complex process, which involves multiple
cortical brain regions, such as primary and secondary somatosensory cortices, anterior
cingulate cortex, and insular cortex . Recent advancement in neuroimaging techniques suggests
the possibility to map the brain structure and networks that involve pain processing.
Electroencephalography (EEG) is a noninvasive monitoring technique, which is widely used to
probe neurological disorders with high temporal resolution. Few attempts have been made to
use EEG to map the active brain regions in pain patients. Functional MRI (fMRI) measures the
hemodynamic brain response and could image the active brain regions with high spatial
resolution. Studies have shown that fMRI is a useful tool to delineate the brain regions
associated with pain processing. Recent studies from simultaneous EEG and fMRI recording have
suggested that the EEG response to the pain may be correlated with the fMRI response, and
both EEG and fMRI could be used to image the brain pain processing regions, such as the
primary somatosensory cortex and anterior cingulate cortex.

The aim of this research is to develop and evaluate a functional neuroimaging approach using
EEG, fMRI and EEG-fMRI, in pain study. EEG, fMRI, or simultaneous EEG-fMRI will be collected
in healthy subjects who receive external thermal stimulation inducing pain. The painful
stimuli will be delivered at different intensity levels and the subject pain rating will be
collected. The imaging technique combines the EEG signal with high temporal resolution and
the fMRI signal with high spatial resolution to obtain a spatiotemporal imaging of the brain
electrophysiological and hemodynamic activity in response to different levels of pain. Cross
validation between this method and subject pain score will be used to quantitatively and
qualitatively evaluate the technique. The successful completion of the current protocol will
help establish an important imaging technology accessing pain level in an objective way.

Inclusion Criteria:

- Healthy subjects with no known neurological disorders

- Sickle cell patients with no metal implants

Exclusion Criteria:

- Age over 65 in either group