Remission of epilepsy as a function of time

- In epilepsy, both partial and terminal remission occurs
- Outside self-limited syndromes, remission typically occurs as a slow process
- Processes of epilepsy remission may take decades
- Therapeutic AED levels are useful biomarkers of seizure propensity
- First failure to terminate treatment does not predict outcome of later attempts

The modalities and mechanisms of remission in epilepsy are largely unknown apart from certain self-limited syndromes. In an earlier investigation, therapeutic antiepileptic drug (AED) plasma levels were used as biomarkers of seizure propensity, and their course was monitored during slow stepwise drug withdrawal in seizure-free patients. The findings indicated that remission typically was a slow quantitative process taking place over time. It was not possible to determine if this process was limited to an individual endpoint or continuous and open-ended. The present study addresses this question with 17 patients who in the previous study had suffered a relapse but participated in a second and, in some cases, third attempt to terminate treatment. Earlier relapse did not predict the outcome. Seven patients became seizure-free without drugs, five are seizure-free on a reduced dose and, only five required the same dose as before the second reduction. Thus, whereas remission in some cases is only partial and limited, in others, it appears as a slow but continuous process. In a prototypical example of idiopathic generalized epilepsy, terminal remission was reached after 27 years of treatment. We conclude that, in these cases, remission of epilepsy is primarily a function of time.