Seizure recurrence after antiepileptic drug withdrawal and the implications for driving: further results from the MRC Antiepileptic Drug Withdrawal Study and a systematic review

Background In the UK, patients with epilepsy in remission, who withdraw antiepileptic drug (AED) treatment, are advised not to drive during withdrawal and for 6 months thereafter, assuming the risk of recurrence in the next 12 months is below 20%. Those with a seizure recurrence currently have to be seizure-free for 12 months before returning to drive, whether treatment is restarted or not. New EU regulations recommend returning to driving 3 months after restarting treatment. Methods Regression modelling of data from the Medical Research Council AED withdrawal study was undertaken to estimate the risk of seizure recurrence in the next 12 months at various time points following: completion of drug withdrawal; AED reinstatement for those with a recurrence. A systematic review of prospective studies was also undertaken. Results Immediately following treatment withdrawal, the recurrence risk in the next 12 months was 30% (95% CI 25% to 35%) and at 3 months after withdrawal was 15% (95% CI 10% to 19%). At 3 months following the recommencement of treatment following a seizure recurrence, the risk of a seizure in the next 12 months was 26% (95% CI 17% to 35%), at 6 months 18% (95% CI 10% to 27%) and at 12 months 17% (95% CI 3% to 27%). Systematic review results were similar. Conclusion Current UK legislation concerning time off driving after withdrawing AED treatment may be too conservative. For those restarting treatment after a recurrence, current UK guidance may be too conservative but the new EU guidance too liberal.