Seizure course of PCDH19 clustering epilepsy in female children: A multicentre cohort study in China

Aim To investigate the seizure course of PCDH19 clustering epilepsy (PCDH19‐CE) in a cohort of female children in China. Method This ambidirectional cohort study examined 113 female patients with PCDH19‐CE through multicentre collaboration. Prognostic factors for seizure freedom were evaluated by multivariate Cox regression analysis. Results The median seizure course period from seizure onset was 6 years 6 months. Of 113 patients, 78% and 56% experienced seizure freedom for at least 1 year and at least 2 years respectively. In patients younger than 5 years (n = 30), 5 to 10 years (n = 52), and older than 10 years (n = 31), 57%, 81%, and 94% experienced at least 1 year of seizure freedom, and 32%, 52%, and 84% experienced at least 2 years of seizure freedom, respectively. However, 58% (65 out of 113) relapsed at least once after more than 1 year of seizure freedom without trigger exposure (40%) or because of common triggers, including fever (43%) and antiseizure medication (ASM) reduction (29%). There was an 84% risk of seizure relapse after ASM reduction attempts. The likelihood of seizure freedom decreased with early age at seizure onset and developmental delay. Interpretation Patients with PCDH19‐CE exhibit increasing seizure freedom with age, but there is a risk of relapse. ASM reduction in children younger than 10 years old requires caution. Patients with early seizure onset and developmental delay have a reduced chance of seizure freedom. What this paper adds The seizure freedom rate in PCDH19 clustering epilepsy gradually increases with age. The disease course is characterized by relapsing–remitting seizures. Antiseizure medication reduction requires caution for patients younger than 10 years of age. Patients with early seizure onset and developmental delay are less likely to achieve seizure freedom. What this paper adds The seizure freedom rate in PCDH19 clustering epilepsy gradually increases with age. The disease course is characterized by relapsing–remitting seizures. Antiseizure medication reduction requires caution for patients younger than 10 years of age. Patients with early seizure onset and developmental delay are less likely to achieve seizure freedom.