Three cases of Dravet syndrome with electrical status epilepticus in sleep: Case reports

Background Interictal electroencephalography (EEG) findings in Dravet syndrome (DS) evolve with age. EEG is typically normal during early infancy; however, various abnormalities may later emerge, including generalized spike-and-wave activity. Nevertheless, cases of DS associated with electrical status epilepticus in sleep (ESES) are extremely rare. We report three cases of DS in which ESES developed during the disease course. Case presentation Case 1: A 10-year-old boy with DS presented with clonic seizures, focal impaired awareness seizures, generalized tonic–clonic seizures, myoclonic seizures, and atypical absence seizures. His interictal EEG demonstrated abnormal frontal epileptiform discharges at 7 years of age, and ESES subsequently developed at age 10. Case 2: An 11-year-old girl with DS presented with generalized tonic–clonic seizures, myoclonic seizures, and atypical absence seizures. Her interictal EEG revealed frontally predominant continuous spike-and-wave complexes during nonrapid eye movement sleep, consistent with ESES at age 8. Case 3: A 13-year-old girl with DS presented with generalized tonic–clonic seizures, right-sided tonic seizures, and myoclonic seizures. Her interictal EEG demonstrated ESES at age 5. Conclusion All three DS cases exhibited ESES, suggesting atypical ESES or isolated spike-and-wave activation in sleep because no immediate global cognitive decline was observed following ESES onset. Because ESES in patients with DS remains poorly understood, periodic evaluation using long-term sleep EEG monitoring is essential, as ESES may arise during the disease course. Further case accumulation and detailed investigation are warranted.