Abstracts

Rationale: It is speculated that children with severe congenital heart disease (CHD) tend to have a higher risk of developing epilepsy than the general population. There are, however, few in-depth studies on the characteristics and actual prevalence of epilepsies associated with severe CHD. Herein, we report that a disproportionally high number of patients with hypoplastic left heart syndrome (HLHS), a type of severe CHD, developed Panayiotopoulos syndrome-like epilepsy. Methods: Children with HLHS who were born between January 2006 and March 2016 and underwent cardiac surgery at Okayama University Hospital were investigated. We retrospectively examined the number of patients with epilepsy and their clinical characteristics, including seizure types, electroencephalogram (EEG), neuroimaging studies, clinical course, and treatment response. Patients who died before one year of age were excluded from the study. Results: The subjects were 79 children with HLHS, and comorbid epilepsy was confirmed in 10 patients (12.7%). The age of epilepsy onset ranged from 11 months to 7 years, 2 months. Eight of these ten patients exhibited focal seizures with autonomic symptoms such as vomiting during the clinical course, and five of these patients experienced status epilepticus. Interictal EEG showed occipital spikes at least once during the clinical course in eight patients. Five patients had more than ten seizures, while three had only one seizure. In neuroimaging, two patients exhibited signs of periventricular leukomalacia, and another patient showed repeated intracranial hemorrhage due to warfarin administration. The remaining patients exhibited no specific neuroimaging abnormalities. In regard to development, mild to moderate delay was observed in three patients. For comparison, we also investigated the similar clinical characteristics related to epilepsy in 36 pediatric patients with univentricular hearts associated with asplenia. We found that only two patients (5.6%) developed epilepsy that lacked characteristics shared with Panayiotopoulos syndrome. Conclusions: The rate of children with HLHS and comorbid epilepsy is high at 12.7% in this study. In addition, it is of note that many patients had clinical characteristics in common with Panayiotopoulos syndrome, including focal seizures with autonomic, particularly emetic, symptoms, a high rate of status epilepticus, and occipital EEG paroxysms. This phenomenon may be related to the high sensitivity of the autonomic nervous center in young children. Funding: No funding