Background and Objectives. In normal humans, placing a hand on a therm
al grill containing warm elements separated by cool ones produces a bu
rning sensation. In this case report, responses to a thermal grill in
a patient with neuropathic pain were examined. Methods. The responses
of a 31-year-old woman with complex regional pain syndrome type I (ref
lex sympathetic dystrophy) to a thermal grill were evaluated before an
d after stellate ganglion block. Results. The patient experienced a bu
rning sensation when the unaffected hand was placed on the grill and c
ould distinguish which element was warm and which was cool. An intoler
able burning sensation caused the patient to quickly (within 4 seconds
) withdraw the affected hand when it was placed on the grill. Touching
cool elements with the affected hand produced an intense burning sens
ation (cold allodynia), whereas touching warm elements produced a plea
sant warm sensation. Stellate ganglion block with phenol, local anesth
etic, and steroid resulted in long-lasting absence of cold allodynia.
Conclusion. The thermal grill may be a useful a tool to help understan
d the pathophysiology of complex regional pain syndrome type I.