ABSTRACT
However, very little is known about the cortical representations of itch, or whether these, if identified, can be discriminated from those involved in the processing of pain. In contrast, the cortical response to pain, particularly its affective-motivational and sensory-discriminative components, has been studied excessively over the past few years. The first investigations, employing positron emission tomography (PET) during thermally induced pain, revealed the activation of the cingulate cortex and thalamus (8,9). Further research broadened this knowledge and demonstrated activation contralateral to the stimulation site in the secondary somatosensory cortex (SII) (10), the frontal lobe, and the prefrontal cortex (10,11). These results have been confirmed by studies using functional magnetic resonance imaging (fMRI) during heat-induced pain. The data from these studies demonstrated a contralateral activation of the primary and secondary cortices (SI and SII) (12,13), insula, thalamus, cerebellum, and prefrontal cortex (14,15).
