rCBF landscapes during motor performance and motor ideation of a graphic gesture.

The regional cerebral blood flow (rCBF) distribution was measured by 133xenon inhalation using a gamma camera in 18 right-handed volunteers, 6 subjects performing a graphic task (writing numbers in letters) with the right hand, 6 subjects imagining the same task, and 6 subjects were assessed during two rest periods to determine the reproducibility of the technique. The mean rCBF increased between 10% and 25% (P less than 0.01) during both motor performance and motor ideation. However, there were regional differences. While motor performance activated mainly the rolandic regions bilaterally, motor ideation gave prefrontal and premotor rCBF augmentations. In both situations there was significant bilateral increase in regions corresponding to the cerebellum.