SPECT findings in autism spectrum disorders and medically refractory seizures.

A high rate of seizures and electroencephalogram abnormalities has been noted in individuals with autism spectrum disorders (ASDs). Common underlying neurodevelopmental abnormalities may exist in the brains of individuals with both ASDs and epilepsy. Single-photon emission computed tomography (SPECT) studies of the brain have provided sensitive brain function findings. Such studies often reveal not only localized areas of hyperperfusion, which could be related to the seizure-onset zone, but also localized areas of hypoperfusion that may correlate with the focal reductions in function observed in the prefrontal lobes, cingulate gyrus, superior temporal gyrus, and mesial temporal lobes of many individuals with both ASDs and epilepsy. The focal neuronal dysfunction revealed by SPECT could be caused by aberrant neuronal connectivity. This article is part of a Special Issue entitled "Autism and Epilepsy".