Regional cerebral hyperperfusion associated with postictal paresis.

The pathophysiology of postictal paresis and other symptoms of Todd's phenomenon are not fully understood. Various hypotheses about its mechanism include exhaustive neuronal firing, desensitization, and active suppression. This case series demonstrates CT perfusion findings of two patients with postictal paresis that show hyperperfusion, increased cerebral blood flow, increased cerebral blood volume, and decreased mean transit time in the intracranial distribution corresponding with neuronal symptoms. These findings may suggest an active process requiring adequate perfusion during Todd's phenomenon.