Abstracts

Rationale: A number of new antiepileptic drugs (AEDs) have been introduced in the past 10 years. Although they have expanded the choice of treatment, it is not known whether they have improved the overall outcome of epilepsy. Previous studies of newly diagnosed patients indicated that few responded after failure of the first 2 AED regimens, although recent studies of pharmacoresistant patients have suggested that a significant proportion might still become seizure free with further drug manipulation. However, studies in this population cannot document outcomes to successive regimens from the point of treatment initiation and are subject to selection bias. We evaluated whether the outcome has changed by examining the treatment response of an expanding cohort of patients with newly diagnosed epilepsy. Methods: Data have been collected on patients with newly diagnosed epilepsy in the Epilepsy Unit at the Western Infirmary, Glasgow, Scotland since 1982. We summarized the treatment outcome to successive AED regimens of consecutive patients who were given a diagnosis and started on their first ever AED between July 1982 and April 2006. In the subgroup of patients initiated on treatment before the end of 1997, we compared their outcomes in 1998 and in 2008. Likewise, in the subgroup of patients initiated on treatment before May 2001, we compared their outcomes in 2003 and 2008. Patients were considered to be seizure-free if they had not had any seizures for at least one year at the time of last follow up. Results: A total of 1098 patients (52% male) with a median age of 32 years (range 9 - 93) at start of treatment were included. The median duration of follow up was 8 years (range 2 - 26). At the last follow up, 750 (68%) patients were seizure-free, all but 70 were on monotherapy, of whom 67 were taking 2 drugs, 2 taking 3, and only 1 on 4 AEDs. 49% of patients were seizure-free on the first AED. Among the 398 patients who attempted a second regimen, 37% were seizure free on either alternative monotherapy or combination therapy. The corresponding seizure-free rates for the third and fourth regimens were 24% and 16%, respectively. Among those who attempted the fifth and subsequent regimens, 17% were seizure free (Table). Among the 470 patients who started treatment before the end of 1997, 64% were seizure-free in 1998. By 2008, a greater proportion had become seizure free (71%, p=0.04). Similarly, the proportion of patients seizure-free increased from 2003 to 2008 (64% vs. 70%, p=0.02; Figure). Conclusions: Outcomes in newly diagnosed epilepsy have shown a modest improvement over the past 10 years (particularly the past 5 years) with the introduction of a range of new AED with differing mechanisms of action. Around 50% of patients will respond to and tolerate their first AED. An appreciable proportion of patients will become seizure-free with their second, third, fourth and even subsequent regimens, either as alternative monotherapies or with a combination of 2 AEDs. Persevering with pharmacotherapy after failure of 2 treatment regimens can now be recommended in patients with difficult to control epilepsy who are not surgical candidates.