Functioning heterotopic grey matter? Increased blood flow with voluntary movement and sensory stimulation.

A 66-year-old woman with a right hemiplegia due to cerebral haemorrhage was found to have heterotopic grey matter in the left frontal and right frontal and parietal lobes. She had no neurological disturbance prior to the haemorrhage. Regional cerebral blood flow (rCBF) was measured by xenon-CT (Xe-CT) in the zones of heterotopic grey matter during voluntary movement and sensory stimulation of her left limbs. During voluntary movement, rCBF increased markedly in the heterotopic grey matter of the frontal lobes and the overlying cortex. During sensory stimulation, rCBF increased in the right parietal heterotopic grey matter and the overlying cortex. This strongly suggests that the heterotopic grey matter is functional.