INFLUENCE OF SPINAL-CORD INJURY ON CEREBRAL SENSORIMOTOR SYSTEMS - A PET STUDY

Objectives-To assess the effect of a transverse spinal cord lesion on cerebral energy metabolism in view of sensorimotor reorganisation. Met hods-PET and F-18-fluorodeoxyglucose were used to study resting cerebr al glucose metabolism in 11 patients with complete paraplegia or tetra plegia after spinal cord injury and 12 healthy subjects. Regions of in terest analysis was performed to determine global glucose metabolism ( CMRGlu). Statistical parametric mapping was applied to compare both gr oups on a pixel by pixel basis (significance level P = 0 . 001). Resul ts-Global absolute CMRGlu was lower in spinal cord injury (33 . 6 (6 . 6) mu mol/100 ml/min (mean (SD)) than in controls (45 . 6 (6 . 2), Ma nn-Whitney P = 0 . 0026). Statistical parametric mapping analysis disc losed relatively increased glucose metabolism particularly in the supp lementary motor area, anterior cingulate, and putamen. Relatively redu ced glucose metabolism in patients with spinal cord injury was found i n the mid-brain, cerebellar hemispheres, and temporal cortex. Conclusi ons-It is assumed that cerebral deafferentiation due to reduction or l oss of sensorimotor function results in the low level of absolute glob al CMRGlu found in patients with spinal cord injury. Relatively increa sed glucose metabolism in brain regions involved in attention and init iation of movement may be related to secondary disinhibition of these regions.