Neuropharmacological imaging in epilepsy with PET and SPECT.

Functional neuroimaging with positron and single photon emitter-labeling has added considerably to the understanding of epileptic seizure activity and of the postictal and interictal cerebral dysfunctions that accompany many epilepsies. Some of these functional alterations cannot be studied in humans by any other technique, and in other instances the information is complementary to that provided by other techniques, some of which are invasive or even require tissue destruction. Available radiotracer imaging techniques have yet to be fully applied to several important epileptic syndromes (including the Lennox-Gastaut syndrome and other secondary generalized epilepsies), to physiological aspects of the natural history of temporal lobe epilepsy or any other commonly occurring epilepsy, and to the assessment of mechanisms of action and adverse effects of antiepileptic drugs and other epilepsy therapies. New radiotracers should be developed to permit study of specific excitatory amino acid receptors and other receptor sites that are known to be relevant to the development of epilepsy, to the onset of individual seizures, and to interictal dysfunctions.