Abstracts

Rationale: It is widely thought that surgery reduces the risk of epilepsy- related mortality, including SUDEP. Data from existing surgical series are conflicting, and SUDEP has been reported even in patients thought to be seizure-free post- operatively.  We sought to test whether SUDEP is reduced as a result of epilepsy surgery procedures when compared with appropriately matched controls. Methods: Using existing local epilepsy surgery databases and data discovery searches through Columbia/New York Presbyterian (NYP) hospital records, we identified all epilepsy surgery procedures performed at this institution dating back to 1987.  A control population, made up of individuals who were evaluated for epilepsy surgery and declined or were determined not to be surgical candidates, was identified from epilepsy surgery case conference records.  We used a combination of medical record review, direct physician reports, and a National Death Index (NDI) query (with data through 2014) to verify decedent status and cause of death. Results: Among 746 patients (9095 patient-years of follow up) who underwent surgical procedures prior to 2014, there were 41 deaths, including 16 definite, probable, or possible SUDEP cases. The all-cause mortality rate in this group was 4.40/1000 patient-years, with a SUDEP rate of 1.76/1000 patient-years.  When we considered only patients who had surgery with intent to cure seizures, (595 patients, 7724 patient-years), 36 deaths were recorded (4.66/1000 patient years), fourteen of which were SUDEP (1.81/1000 patient years). The all-cause mortality rate in the control group (120 patients) was 9.50/1000 patient-years, with a SUDEP rate of 1.90/1000 patient years.  We were not able to identify specific surgical populations (ie. side or lobe of seizure origin, underlying pathology or cause of seizures) who were at specifically higher risk.  However, none of the SUDEP cases were known to be seizure-free after surgery and all had a history of secondarily generalized seizures.  Conclusions: All-cause mortality appears to be reduced after epilepsy surgery in our series, but the risk of SUDEP was not, even when considering only surgeries performed with curative, rather than palliative intent.  Our findings are important for patients and physicians to consider when making epilepsy surgery decisions, particularly if patients are not expected to be seizure-free after surgery.  Funding: Citizens United for Research in Epilepsy (CURE) - Henry Lapham Memorial Award