Detection of slightly increased signals in temporal lobe on periictal arterial spin labeling perfusion image for initial suspicion of temporal lobe epilepsy

Abstract

Introduction: Magnetic resonance (MR) perfusion imaging with arterial spin labeling (ASL) can easily detect periictal hyperperfusion accompanying epileptic seizures. Herein, we report two cases in which ASL performed immediately after a seizure was useful for the initial suspicion of temporal lobe epilepsy (TLE).

Case report: Patients 1 and 2 developed focal-to-bilateral tonic-clonic and focal impaired awareness seizures, respectively, and were subsequently transferred to our facility for out-of-hours service. On emergent ASL MR perfusion imaging, a slight increase in signals from the hippocampus and lateral temporal lobe was observed in both patients. However, routine electroencephalography (EEG) performed from 12 h to two days later showed corresponding paroxysmal discharges only in Patient 2.

Conclusion: These cases suggest that MR imaging with ASL perfusion, which can be performed 24 hours a day, is useful for the initial suspicion of TLE, compensating for the limitation of routine EEG. However, to ensure a definitive diagnosis, it is important to evaluate the result together with clinical history, seizure semiology and findings of other modalities centered on EEG.