SPECT Scanning for Epileptic Seizures

There is a long history of the association of cerebral blood flow changes during epileptic seizures. The advent of radiopharmaceutical agents to measure cerebral perfusion during seizures has enabled a clinically feasible way to measure ictal cerebral blood flow changes. Studies show that ictal SPECT findings, especially with the use subtraction ictal SPECT techniques, correlate well with other measures of seizure onset and the epileptogenic zone. Ictal SPECT studies are also helpful in predicting outcome after epilepsy surgery. Applications of parametric mapping using ictal SPECT studies have helped to further define regions of perfusion changes in groups of patients with specific regions of seizure onset. Application of parametric mapping techniques in subjects with temporal lobe epilepsy has yielded interesting common patterns of ictal hyperperfusion and hypoperfusion. These studies help define expected patterns of ictal perfusion changes in TLE, as well as shed light on the associated pathophysiology of aspects of ictalsemiology, such as the associated changes in consciousness during temporal lobe epileptic seizures.