Transient Abnormalities on Magnetic Resonance Imaging after Absence Seizures / 대한소아신경학회지

Magnetic resonance imaging (MRI) is recommended for patients with epileptic seizures to rule out an underlying focal lesion. However, abnormalities in idiopathic generalized epilepsy, including childhood absence epilepsy, cannot usually be identified using brain imaging modalities such as MRI. Peri-ictal MRI abnormalities have been most commonly reported secondary to status epilepticus and are rarely observed in patients with focal seizures and generalized tonic-clonic seizures. Transient peri-ictal MRI abnormalities in absence epilepsy are extremely rare. A five-year-old girl presented with a three-day history of absence seizures that persisted despite continued treatment with sodium valproate. Electroencephalography showed bursts of generalized 3-Hz spike-and-wave discharges, during and after hyperventilation. Abnormal cortex thickening in the left perisylvian region was detected on T2-weighted brain MRI, and cortical dysplasia or a tumor was suspected. The patient started treatment with lamotrigine and was seizure-free after one month. The abnormal MRI lesion was completely resolved at the two-month follow-up. We report on a patient with childhood absence epilepsy and reversible brain MRI abnormalities in the perisylvian region. To our knowledge, this is the first report of transient MRI abnormalities after absence seizures. Transient peri-ictal MRI abnormalities should be considered for differential diagnosis in patients with absence seizures and a focal abnormality on brain MRI.

Dynamic Changes of MRI Findings after Seizures / 대한간질학회지

INTRODUCTION: Magnetic resonance imaging has demonstrated reversible peri-ictal MRI changes suggestive of hemodynamic changes or cytotoxic edema. We were to investigate the dynamic peri-ictal MRI changes in patients with seizures. METHODS: We retrospectively reviewed the medical records, electroencephalography, and initial and follow-up MRI of 5 patients with single seizure or status epilepticus. We analyzed the patterns and locations of MRI abnormalities and their relationship with characteristics of seizures. RESULTS: Two patients with complex partial seizures (CPS) and versive or unilateral tonic seizures showed high signal changes in frontal cortex on T2-weighted (T2WI), fluid attenuated inversion recovery (FLAIR) and DWI. Three patients had MRI changes in mesial temporal structures including hippocampus after single generalized tonic-clinic seizure without encephalitic features clinically. One patient had multiple signal abnormalities in the left temporo-parietal, mesial temporal, insular cortices and thalamus on T2WI and FLAIR after frequent CPS. All of the lesions disappeared or resolved partially on the follow-up MRI. CONCLUSION: Our results showed that variable MRI changes in peri-ictal phase are possible at cortical as well as at subcortical areas. The dynamic MRI changes can be associated even in patients with single clinical seizure, suggesting that these changes are not related to the seizure frequency.