Regional brain glucose utilization was investigated with positron emis
sion tomography and fluorodeoxyglucose in 2 patients with a seizure di
sorder associated with diffuse band heterotopia, a condition known as
''double cortex.'' Although 1 patient was examined shortly after the o
nset of the first seizures, the other had a long history of intractabl
e epilepsy before examination, Magnetic resonance imaging revealed a s
ymmetric and generalized band of ectopic gray matter and an overlying
normal-looking cortex, without focal abnormality, Metabolic studies yi
elded comparable results in both patients, with similar and even highe
r glucose uptake in the layer of gray matter heterotopia compared to t
he normal cortex, These data suggest the persistence of some synaptic
activity in the heterotopic neurons, which seems unaffected by age or
by the timecourse of epilepsy,