Abstracts

Rationale:
We tried to reveal the prognostic analysis focused on the age at epilepsy onset. Symptom duration and age at epilepsy onset could be implicated each other. Analysis through grouping according to the onset age was needed to reveal the prognostic significance.
Method:
Patient grouping according to age at epilepsy onset after withdrawal of antiepileptic drugs (AEDs) following four seizure-free years was done as follows: young adult before the age of 20, middle adult from 21 to 40 years, and late adult over the ageof 41. The pattern of relapse during at least 3 years of follow-up after planned withdrawal of AEDs was defined as follows: (1) patients with seizure free (SF) who continued to be seizure-free after AEDs withdrawal, (2) patients with a late relapse (LR) who experienced recurrence after completion of the AEDs discontinuation process. (3) patients with an early relapse (ER) who experienced recurrence during AEDs withdrawal. The association between age at epilepsy onset and relapse pattern was investigated using the multinomial logistic regression model. In addition to age at epilepsy onset according to onset age as the above grouping, conventional prognostic factors such as symptom duration more or less than 120 months, localization-related epilepsy, and relevant lesion of brain MRI scan, nocturnal preponderance were analyzed. Achievement of remission within one year from initiation of AEDs and total number of generalized seizure before remission were newly added as prognostic factors.
Results:
Total 472 patients were enrolled. Among them, 52.1% (246 patients) consisted of young adult group. Middle and late adult group were 28.2% (133 patients) and 19.2% (93 patients) respectively. Overall relapse rate was 63.3% and the proportions of LR and ER patients was 38.5% and 24.8% respectively. SF patients in each age group was 31.3%, 33.8%, and 54.8% in young, middle, and late adult group in order. The proportion of relapse among three age groups got statistical significance (P< 0.0001). Simple multinomial logistic regression analysis showed symptom duration over 120 months, achievement of remission within one year from initiation of AEDs, less than 10 times of total number of generalized seizure before remission, localization-related epilepsy, and relevant lesion of brain MRI scan as significant covariants. In multiple multinomial logistic regression analysis with based on SF patients as reference, the odds of ER relapse in middle adult group was 2.52-fold higher compared to late adult group in ER patients. Those of the patients without covariant as achievement of remission within one year from initiation of AEDs was 9.98-fold higher than the patients, if not, in ER patients. ER patients with each covariant as symptom duration over 120 months, localization-related epilepsy, and relevant lesion of brain MRI scan got 7.04-, 2.58-, and 1.84-fold higher odds of ER patients, respectively, compared to SF patients in descending order. Those of LR and ER patients without covariant as less than 10 times of total number of generalized seizure before remission was 1.72- and 2.58-fold higher than those of SF patients respectively.
Conclusion:
Middle adult group in ER patients got poor prognosis, compared to other age onset. Symptom duration over 120 months, localization-relatd epilepsy, and relevant lesion of brain MRI scan were poor prognostic factors in descending order irrespective of onset age. In contrast, achievement of remission within one year from initiation of AEDs and less than 10 times of total number of generalized seizure before remissionwere good prognostic factors.
Funding:
:None