Factors Associated with Seizure Recurrence:
- Abnormal EEG
- Hard to control seizures
- Neurological deficits
Antiepileptic drugs may not have to be taken for a lifetime. When seizures have been reliably controlled over a period of time (usually a year or two), there is a good chance that a timed, careful withdrawal from the medication will be successful and that the seizures will remain in remission without further treatment. Studies in children show that 65 to 70% of children who are free of seizures for several years on antiepileptic drugs will remain seizure free after the drugs are withdrawn. However, like so much in epilepsy treatment, the risks vary between individuals and between types of epilepsy. Juvenile myoclonic epilepsy, for example, is not associated with successful drug withdrawal, while childhood absence is.
The major risk associated with discontinuing AED therapy is seizure recurrence. In children, almost half the recurrences occur within 6 months of medication withdrawal, and 60-80% occur within 1 year of stopping the drugs. More than 80% of recurrences occur within the first 5 years.
The risk of recurring seizures increases when the EEG is abnormal despite treatment, when control has been difficult to achieve, and when there are other neurological deficits in addition to the epilepsy. However, even among these children, between 40 and 60% will remain free of seizures after medication withdrawal. Children with the best chance of remaining seizure free are those with idiopathic epilepsy, with a history of only a few seizures, whose condition came quickly under control. Even among this group, however, there is a 10% chance of the seizures returning.
Clinicians try to minimize the risk of recurrence by making sure the drugs are withdrawn slowly, usually over a 1-3 month period. Abrupt cessation of antiepileptic drugs is always risky and may precipitate not only a return of seizures, but even a bout of prolonged or status seizures.
The decision on whether to try a phased withdrawal from antiepileptic drugs is more difficult for adults than for children, especially when the adult drives or has a job in which an unexpected seizure would have severe social and career implications. Many adults who might benefit are hesitant to take the risk. In general, the adult who has only one type of primary generalized seizures, who is younger than 30 years of age, whose seizures are promptly controlled with medication, who has a series of normal EEGs on medication and who has been seizure-free for 2-5 years has the best chance of successful withdrawal from antiepileptic drugs.
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