Advanced SPECT image processing in MRI-negative refractory focal epilepsy

Abstract

The phenomenon of hyperemia at the region of the seizure focus has been known for decades. Perfusion SPECT is utilized to image patterns of altered regional cerebral blood flow (rCBF) for localizing the seizure onset zone. Thus far, perfusion SPECT is the only test that could image the altered physiology of all peri-ictal states (i.e., interictal, ictal, and postictal states). The alteration during the interictal state is typically one of baseline hypoperfusion at the focus of seizure activity. In contrast, hyperperfusion transiently characterizes ictal activity, at the longest probably for 2 to 3 minutes beyond seizure termination. Ictal hyperperfusion switches to hypoperfusion during the e..