Localisation value of ictal arterial spin-labelled sequences in partial seizures

Perfusion-based magnetic resonance imaging (MRI) using pulsed arterial spin-labelled (ASL) sequences is becoming a more commonly used tool for the diagnosis of patients with focal epilepsy. We report a patient with post-traumatic epilepsy and cortical haemorrhage who had a complex partial seizure characterised mainly by ictal speech (verbalisation) during MRI acquisition. Ictal ASL showed focal hyperperfusion over the right temporal region which had resolved on follow-up MRI, two weeks later. Seizure semiology and interictal EEG suggested seizure origin in the non-dominant temporal lobe, which matched the increased ictal blood flow observed by ASL. The patient had language dominance in the left hemisphere, as observed by functional MRI. Our findings suggest that focal hyperperfusion, as observed by ASL, may have localising value in temporal epilepsies when performed in the ictal period.