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.

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.