Peri-ictal Hyperperfusion Revealed by Arterial Spin Labeling Perfusion Images in 2 Patients with Post-aneurysmal Subarachnoid Hemorrhage Epilepsy and Associated Old Infarction in the Middle Cerebral Artery Territory

Abstract

To make a pathophysiological diagnosis of post-aneurysmal subarachnoid hemorrhage epilepsy, which has complex pathologies, in a neuro-emergency setting, peri-ictal magnetic resonance imaging including arterial spin labeling perfusion images was conducted in 2 patients with associated old infarction due to vasospasm in the middle cerebral artery territory. In patient 1, who had a localized infarction and no apparent circulatory disturbance in the middle cerebral artery territory on interictal magnetic resonance imaging, focal to bilateral tonic–clonic seizures developed twice within 1 year after the subarachnoid hemorrhage onset. In both events, peri-ictal hyperperfusion was observed in a tight anatomical relationship with the infarction. In patient 2, who had extensive infarction and circulatory disorders in the middle cerebral artery area, the fourth focal to bilateral tonic–clonic seizures developed 27 years after the subarachnoid hemorrhage. In this event, peri-ictal hyperperfusion was observed predominantly in the ipsilateral frontal interhemispheric cortex in the anterior cerebral artery territory, slightly away from the infarction. Further case observations with peri-ictal magnetic resonance imaging, in addition to electroencephalography, would help to clarify the complex pathologies of post-subarachnoid hemorrhage epilepsy.