Electrical stimulation of the central gray for pain relief in human: autopsy data

Anatomopathological studies are reported of 5 brains in which electrical stimulation of the periventricular--periaqueductal gray was applied for the treatment of chronic pain. It was found that the recommended target was reached in 4 cases (only 1 case out of 5 was successful as far as a pain relief is concerned). PtIr electrodes caused little tissue reaction. The chronic stimulation had not provoked lesions observable by light-microscopy.