Table 3.

Summary of selected human imaging studies on the role of mPFC in chronic pain responses

STUDY	SPECIES	BRAIN REGION	METHOD	MODEL	FINDINGS
Baliki et al., 2006	Human	mPFC (including rostral anterior cingulate)	fMRI	Chronic back pain patients (trying to identify spontaneous pain)	Sustained chronic back pain resulted in increased activity in the mPFC; mPFC activity was strongly related to the intensity of chronic back pain.
Baliki et al., 2010	Human	NAc, mPFC	fMRI	Thermal noxious stimulus on healthy (control) subjects and chronic back pain patients	Distinct NAc activities in healthy versus chronic pain subjects after relief of acute stimulation Functional Connectivity of NAc to mPFC is stronger in chronic back pain subjects
Baliki et al., 2012	Human	NAc, insula, mPFC	fMRI	Sub-acute back pain patients followed for a year NSAID, Steroids, SNRIs, Muscle Relaxants.	NAC-mPFC functional connectivity positively correlates with pain chronification
Seminowicz et al., 2011	Human	DL PFC	fMRI	Chronic back pain patients before and 6 months after (spine surgery or facet joint injections)treatment.	Increased cortical thickness in the left dorsolateral prefrontal cortex (DLPFC) after spine surgery
Khan et al., 2014	Human	mPFC, Hippocampus	fMRI	Burning mouth syndrome	Patients show decreased grey matter volume in the mPFC and increased connectivity between mPFC and anterior cingulate cortex, occipital cortex, ventromedial PFC, and bilateral Hp/amygdala