An Unusual Case of Megalencephalic Leukoencephalopathy Together with Giant Subcortical Cysts

Introduction: Megalencephalic leukoencephalopathy (MLC) is an uncommon neurodegenerative disorder affecting children. Common neurological findings include mental retardation, movement disorders related to cerebellar or extra-pyramidal dysfunction, macrocephaly, and epileptic seizures. Case Report: A 4-year-old male presented with sudden-onset generalized tonic-clonic seizure to the emergency department at our university hospital. After the patient regained consciousness, abnormal neurological signs including macrocephaly, dysarthria, ataxia, and spasticity were detected. There were convulsive episodes that were diagnosed as epilepsy in his past medical history. Macrocephaly had first been noticed when he was 7 months old. In his follow-up examination, brain magnetic resonance imaging (MRI) revealed primary giant subcortical cysts in the bilateral temporal and frontal regions in his coronal T1-weighted image. Written informed consent was taken from the patient's parents. Conclusion: Emergency physicians and pediatricians should maintain a high index of suspicion for MLC when treating children with macrocephaly and epileptic seizures in the emergency department or outpatient clinics. In particular, they should be considered in the differential diagnosis of subcortical cysts on performing brain MRI. Moreover, the early and accurate diagnosis of MLC will lead to genetic advisory assistance to the families of patients.