Central pain in a hemispherectomized patient

We have examined a hemispherectomized patient who complained of touch-evoke d pricking and burning pain in her paretic hand, especially when the hand w as cold. Psychophysical examination showed that for the paretic side she co nfused cool and warm temperatures, and confirmed that she had a robust allo dynia to brush stroking that was enhanced at a cold ambient temperature. Fu nctional magnetic resonance imaging (fMRI) showed that during brush-evoked allodynia, brain structures implicated in normal pain processing (viz. post erior part of the interior cingulate cortex, secondary somatosensory cortex , and prefrontal cortices) were activated. The fMRI findings thus indicate that the central pain in this patient was served by brain structures implic ated in normal pain processing. Possible pathophysiological mechanisms incl ude plasticity as well as thalamic disinhibition. (C) 2001 European Federat ion of Chapters of the International Association for the study of pain.