033 - Clinical characteristics of neonatal seizures and post-neonatal epilepsy in children with trisomy 18

Publication Number: 33.4120

Tatsuya Fukasawa, Anjo Kosei Hospital, Anjo, Aichi, Japan; Hiroyuki Kidokoro, Nagoya University, Nagoya, Aichi, Japan; Toshiki Takeo, Anjo kosei hospital, Anjo, Aichi, Japan; Tamiko Negoro, Anjo Kosei Hospital, Nagoya, Aichi, Japan; Tetsuo Kubota, Anjo Kosei Hospital, Anjo, Aichi, Japan

Background: Despite advances in the management of children with trisomy 18, the associated risk for neonatal seizures and epilepsy remains prevalent among long-term survivors. Therefore, a reassessment of the clinical presentation of these neurological conditions is needed.

Objective: We evaluated the clinical features of neonatal seizures and post-neonatal epilepsy in children with trisomy 18.

Design/Methods: We retrospectively analyzed 27 children with trisomy 18 born at Anjo Kosei Hospital between April 2009 and May 2024. Medical records were reviewed to assess the incidence, age at onset, seizure type, electroencephalographic findings, anti-seizure medication, and seizure outcomes of neonatal seizures and post-neonatal epilepsy. Neonatal seizures were diagnosed based on electroencephalographic findings during seizure episodes, whereas post-neonatal epilepsy was diagnosed using interictal electroencephalographic findings and seizure manifestations.

Results: Neonatal seizures occurred in 8 of the 27 patients. Table 1 presents the treatment regimens and seizure types. Eight patients experienced seizure resolution during the neonatal period. No epileptiform discharges were observed in interictal electroencephalography. In total, 10 (37%) patients died in the neonatal period. Of the 17 survivors, 5 developed post-neonatal epilepsy (Table 2). Notably, 3 of these 5 patients had a history of neonatal seizures and received phenobarbital at the time of post-neonatal epilepsy onset. The median age at epilepsy onset was 44 (34–107) months, with 5 patients exhibiting focal motor onset seizures. All patients who survived beyond 5 years of age developed post-neonatal epilepsy. Interictal electroencephalograms revealed focal epileptiform discharges in four patients and hypsarrhythmia in one. Despite treatment with phenobarbital and perampanel in four patients, levetiracetam in three, clobazam in two, and valproic acid and topiramate in one, all patients continued to experience seizures.

Conclusion(s): Although neonatal seizures were resolved, post-neonatal epilepsy persisted in affected patients. Notably, epilepsy developed in three patients while on phenobarbital. All children with trisomy 18 who survived beyond 5 years developed epilepsy, suggesting a potential age-related progression of epileptogenesis.

Table 1; Characteristics of neonatal seizures


Table 2; Characteristics of post-neonatal epilepsy


Table 1; Characteristics of neonatal seizures


Table 2; Characteristics of post-neonatal epilepsy