Effect of application of anti-seizure medications on the development of chronic epilepsy after autoimmune encephalitis
Objective To investigate and analyze the use and duration of anti-seizure medications(ASMs)in patients with chronic epilepsy after autoimmune encephalitis(AE),as well as the effect of ASMs use on the formation of this epilepsy to provide relevant evidence for the choice of ASMs in patients with acute seizure or chronic epilepsy after AE.Methods A retrospective follow-up study was performed on AE patients(including patients with antibody-negative autoimmune limbic encephalitis)diagnosed in the Affiliated Brain Hospital of Nanjing Medical University from December 1,2013 to October 31,2022.The dates of the first seizure onset and the chronic epilepsy formation(defined as 1 year after immunotherapy)were recorded.The initial time,types and numbers of ASMs used in acute symptomatic seizure(ASS)and the maintenance time,types and numbers of ASMs in chronic epilepsy period(the continuation or the combined therapy of ASMs)were collected,respectively.A Logistic regression model was used to analyze multi-influencing factors on the formation of chronic epilepsy after AE.Results A total of 332 patients were enrolled in this study,of whom 32.5%(108/332)with antibody-negative autoimmune limbic encephalitis.In total,54.8%(182/332)of patients were males,and the age of onset was(40.7±19.7)years.Finally,81.0%(269/332)of participants manifested ASS,and 57.2%(190/332)developed chronic epilepsy up to the last follow-up.The follow-up time was 1-8 years,with a median of 2 years.All patients received ASMs treatment during ASS period.Among the ASS patients,48.0%(129/269)were prescribed monotherapy of ASMs,and 52.0%(140/269)were given the combined therapy of ASMs.Of all the patients with ASMs,70.3%(189/269)were given early ASMs treatment(within 24 hours of the seizure onset),and 29.7%(80/269)were given delayed ASMs treatment.Subsequently,81.0%(218/269)of the ASS patients continued the ASMs treatment(>6 months),and 19.0%(51/269)stopped use of ASMs.In the chronic epilepsy stage,79.5%(151/190)of thee epilepsy patients continued ASMs,of whom 37.1%(56/151)were treated with monotherapy,and 62.9%(95/151)were treated with combined therapy.The incidence of chronic epilepsy was 81.3%(65/80)in the delayed ASMs treatment group,higher than the 66.1%(125/189)in the early ASMs treatment group,with statistically significant difference(x2=6.189,P=0.013).There were no statistically significant differences in the ASMs types and whether combined therapy of ASMs was used between chronic epilepsy group and non-chronic epilepsy group.The Logistic regression model showed that delayed ASMs treatment(OR=2.306,95%CI 1.032-6.387,P=0.018),positive anti-neuronal intracellular antibodies(OR=2.626,95%CI 1.536-9.531,P=0.004,compared with anti-neuronal surface antibodies),abnormal brain magnetic resonance imaging(OR=9.883,95%CI 3.608-27.071,P<0.001),elevated cerebrospinal fluid protein(OR=2.874,95%CI 1.115-7.409,P=0.029),and abnormal electroencephalogram(OR=9.287,95%CI 3.767-22.896,P<0.001)were independent risk factors for chronic epilepsy after AE.Conclusions The development of chronic epilepsy after AE is associated with the occurrence of ASS and the delayed use of ASMs,but the type of ASMs or whether the combined ASMs therapy is used is not associated with the formation of chronic epilepsy after AE.It is concluded that early ASMs treatment for the AE patients with ASS may reduce the incidence of chronic epilepsy.For AE patients with ASS who have undergone early standardized treatment,long-term,combined ASMs treatment may not be necessary.