Objectives: To investigate the proportion of Chinese patients with intractable seizures and the risk factors leading to refractory epilepsy.
Methods: Consecutive patients over 14 years of age attending a Neurology clinic were evaluated. Patients with epilepsy were classified into two groups according to their seizure control: refractory or seizure-free. Epilepsy was classified as idiopathic as defined by age-related onset and typical electroclinical characteristics, symptomatic if secondary to a structural abnormality and cryptogenic if the cause was unknown. Age, sex, epilepsy syndrome classification, aetiology, presence of mental retardation and the number of drugs used were compared between patients with refractory epilepsy and those in remission.
Results: Among 260 adolescent and adult patients with a mean age of 34 years (range 15-79), complete seizure control was achieved in 157 (60%) cases. Multivariate binomial logistic regression analysis showed that patients with mesial temporal sclerosis (OR=7.6, 95% CI 3.53-16.4, p<0.01) and the presence of mental retardation (OR=9.39, 95% CI 3.98-22.12, p<0.01) were more likely to develop pharmacoresistant epilepsy.
Conclusion: In adults the underlying aetiology is an important factor as to whether patients develop intractable seizures. Poor control was also associated with the presence of mesial temporal sclerosis and mental retardation.