BREAST IMPLANTS AND RISK OF NEUROLOGIC DISEASE - A POPULATION-BASED COHORT STUDY IN SWEDEN

Objective: To examine the risk of neurologic disorders among women wit h breast implants. Background: Case reports in the literature have rai sed concern about a possible link between silicone breast implants and some types of neurologic disorders, but there is a dearth of epidemio logic studies in this area. Methods: Through the nationwide Swedish ho spital discharge register, we identified a population-based cohort of 7433 women with breast implants. A similarly identified cohort of 3351 women who underwent breast reduction surgery served as a comparison. The women were followed from 1972 (or date of breast surgery if it occ urred later) through 1993 by means of record linkages and review of in patient medical records. Ratios of observed to expected numbers, and r elative risks (RR) with 95% confidence intervals (CI), were calculated as measures of the risk of neurologic diseases among women with impla nts. Results: A direct comparison of the exposed (implant) versus comp arison (breast reduction) groups, after exclusion of patients with pre -existing disease or incorrect neurologic diagnoses, showed no excess risk among implant patients (RR = 0.8; 95% CI = 0.5 to 1.4). When exte rnal rates derived from the background population were used as compari son, we found a small, statistically nonsignificant excess of neurolog ic disorders both in the breast implant (RR = 1.3; 95% CI = 0.9 to 1.9 ) and the breast reduction (RR = 1.5; 95% CI = 0.9 to 2.4) cohorts. Co nclusion: Our results provide no support for the conjecture that breas t implants cause neurologic disease.