Patients suffering from central neuropathic pain have thermal sensory deficits within the painful area. Prior research proposed that the loss of thermal sensation in regions of central neuropathic pain may reflect similar central nervous system interaction between warm and cold sensory inputs that underlie the Thermal Grill Illusion (TGI) in which burning pain is felt while reduced warm/cold sensations are reported.

This work presents a portable and reliable device that was used to systematically evaluate the characteristics of the TGI in healthy individuals. The results suggest that the spatial distribution of the warm and cool stimuli significantly affected the quality of perceived TGI. Additionally, simultaneous tactile and thermal stimulation was shown to be significantly less painful than thermal stimulation alone. A high correlation was also seen in the subject‘s TG intensity scores and their cold pain threshold. These results are useful for future TGI studies for central neuropathic pain.