BRAIN GLUCOSE-UTILIZATION IN ACQUIRED CHILDHOOD APHASIA ASSOCIATED WITH A SYLVIAN ARACHNOID CYST - RECOVERY AFTER SHUNTING AS DEMONSTRATED BY PET

Regional brain glucose utilisation was investigated with PET and fluor odeoxyglucose (FDG) in a case of epileptic aphasia (Landau-Kleffner sy ndrome) associated with a left sylvian arachnoid cyst. CT and MRI had failed to disclose any mass effect of the cyst on surrounding brain St ructures. Sequential metabolic measurements showed a comparable pronou nced hypometabolism in cortical regions around the cyst, involving spe ech areas, and suggested mild but chronic compression of the developin g brain. After placement cyst-peritoneal shunt system, significant met abolic improvement occurred in all cortical regions, especially the in ferior frontal gyrus and the perisylvian area, with predominant residu al deficit in the left superior temporal gyrus. These findings were co rrelated with a pronounced increase in word fluency and slower progres s in verbal auditory comprehension. This report suggests that PET is a ble to evaluate the functional disturbances associated with expanding arachnoid cysts, and to follow the neurological improvement after drai nage.