Complications of epilepsy surgery after 654 procedures in Sweden, September 1990-1995: A multicenter study based on the Swedish National Epilepsy Surgery Register

OBJECTIVE: To present the first national multicenter study on complications after epilepsy surgery procedures to include all epilepsy surgery centers in Sweden: Goteborg, Linkoping, Lund, Stockholm, Umea, and Uppsala. METHODS: Every epilepsy surgery procedure in Sweden is reported to the Swed ish National Epilepsy Surgery Register. The report includes relevant social and medical items and complications. A complication is defined as minor if it resolves within 3 months and major if it affects activities of daily li ving and lasts longer than 3 months. Follow-up data are recorded for 2 year s after the operation. Intrinsic checkpoints and external revision validate the register data. RESULTS: During the inclusion period (September 1990-December 1995), 654 su rgical procedures were performed (age range, 6 mo-67 yr). Of these, 205 wer e invasive electrode procedures (182 first investigations and 23 reinvestig ations), and 449 were therapeutic procedures (375 first operations and 74 r eoperations). After invasive electrode procedures, only minor complications were reported (6.3%). For all 449 therapeutic procedures (including reoper ations), minor complications were reported in 8.9% and major complications in 3.1%. Only one major complication was reported in a patient under the ag e of 35 years. CONCLUSION: This is the first national multicenter study on complications a fter epilepsy surgery. It demonstrates that these procedures as performed a t six different centers in Sweden are safe, but also that risk is related t o age. In patients younger than age 35 years, the risk for a major complica tion after invasive subdural strip electrode investigation and epilepsy sur gery is low.