New research suggests that a significant proportion of adults with epilepsy who fail to respond to two initial antiepileptic drugs (AEDs) can achieve seizure freedom with further drug therapy.
The aims of the study, led by Columbia University in New York and published in the medical journal Epilepsia, were to examine the seizure response of adults with drug-resistant epilepsy to a third AED, and to identify factors/characteristics that might help doctors to predict a positive outcome.
A total of 403 adults who had failed to respond to their first two prescribed AEDs, and who were starting treatment with a third AED a tertiary epilepsy centre, were recruited to the investigation. Subjects were then followed up for an average of 65 months whilst taking the new therapy and their seizure course was monitored.
The seizure outcomes observed were divided into four categories: 1) constant seizures; (2) fluctuating seizures; (3) delayed seizure freedom (after 12 months) and (4) early seizure freedom (within 12 months).
The data showed that 53% of the cohort never achieved a seizure-free period of a year or more, and that 16% had a complex, fluctuating seizure course. A further 16%, however, attained seizure freedom within 12 months (early seizure freedom), and 15% had  delayed seizure freedom, meaning that seizure control was reached at some point after one year.
Factors associated with a more favourable seizure outcome included the length of the follow-up period and the type of epilepsy involved. Specifically, it was shown that people with occipital lobe epilepsy, generalised epilepsy or both focal and generalised epilepsy were more likely to experience a better seizure outcome than those with temporal lobe epilepsy.
The research concludes: “Examination of patterns of seizure trajectory of patients with incident drug-resistant epilepsy showed that 31% were in continuous seizure freedom at the end of the observation period.”
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