Medline ® Abstract for Reference 128

OBJECTIVE: To assess the hypothesis that use of anterior temporal lobectomy (ATL) for temporal epilepsy has diminished over time.

DESIGN: Population-based cohort study.

SETTING: The Rochester Epidemiology Project based in Olmsted County, Minnesota.

PARTICIPANTS: Residents of Olmsted County.

MAIN OUTCOME MEASURES: Poisson regression was used to evaluate changes in ATL use over time by sex.

RESULTS: Over a 17-year period, from 1993 to 2009, 847ATLs were performed with the primary indication of epilepsy(average, 50 procedures/y). Of these, 26 occurred among Olmsted County residents. The use rates declinedsignificantly between 1993 and 2000 (8 years) and 2001 and 2009 (9 years) according to Poisson regression analysis, from 1.9 to0.7 per 100 000 person-years(P=.01). The rate of ATL use among Olmsted County residents was 1.2 (95% CI, 0.9 to 2.4) per 100 000 person years of follow-up over this 17-year period. The sex specific rates were 1.6 (95% CI, 0.9 to 2.4) and 0.7 (95%CI, 0.2 to 1.3) per 100 000 person-years for females and males, respectively.

CONCLUSIONS: In this community-based cohort, the rate of ATL use was 1.2 per 100 000 person-years of followup.Use of this procedure has declined over time; the reasons for this are unknown but do not include referral pattern changes.