Various pathophysiological states of acute symptomatic seizures immediately after ischemic stroke, namely “onset seizures,” shown by complementary use of peri‐ictal magnetic resonance imaging and electroencephalography

Abstract

AbstractBackground“Onset seizures” are acute symptomatic seizures occurring within 24 h after the onset of ischemic stroke, and their pathophysiological states are unknown. Electroencephalography is commonly used to diagnose epileptic activities; however, it is limited for use with acute stroke. Magnetic resonance imaging, including diffusion‐weighted imaging and perfusion imaging with arterial spin labeling, are applied mainly in an emergency. Ictal hyperperfusion on arterial spin labeling and cortical hyperintensity of cytotoxic edema on diffusion‐weighted imaging, peri‐ictally, can be obtained from an epileptically activated cortex.AimWe aimed to show pathophysiological states of onset seizures by complementary use of peri‐ictal magnetic resonance imaging and electroencephalography.MethodsFour patients diagnosed as onset seizures underwent an initial magnetic resonance imaging and subsequent electroencephalography.ResultsIn case 1, having persistent non‐convulsive status epilepticus after control of onset seizures, ictal magnetic resonance imaging and electroencephalography findings clearly showed the topographical relationship between the acute atherothrombotic infarction and the peri‐infarction activated cortex. In case 2, with multiple embolic strokes in the bifrontal lobes, prolonged arterial spin labeling hyper signals were observed in the perirolandic area of the right leg; cortical hyperintensity on diffusion‐weighted imaging and paroxysmal activities on electroencephalography were not shown. In cases 3 and 4, postictal hypoperfusion was shown in the large extent involving the multiple embolic infarctions. Because the epileptic cortex was located in the convexity, electroencephalography clearly showed inter‐ictal paroxysms in case 3, and localized slow wave in case 4.ConclusionThe present study shows that the complementary use of peri‐ictal arterial spin labeling/diffusion‐weighted imaging and electroencephalography potentially offers the ability to document the various pathophysiological states of onset seizure.