The evolution of epilepsy surgery in tuberous sclerosis in Sweden: A national registry study.

PURPOSE: This study aimed to characterize the Swedish cohort of surgically treated patients with TSC and explore differences in preoperative investigation and outcome over time.

METHODS: Data on patient and seizure characteristics were retrieved from the Swedish National Epilepsy Surgery Register. Two-year follow-up results were compared between the years 1997-2010 and 2011-2018. Preoperative investigations were re-evaluated.

RESULTS: Eighteen tuberectomies and seven callosotomies were identified. Seizure freedom after tuberectomy was achieved in 11 % (1/9) 1997-2010 and 56 % (5/9) 2011-2018. The number of tuberectomies increased each decade. Patients operated on in 1997-2010 had higher seizure frequency (median 175 seizures/month vs. 102) and incidence of infantile spasms (4/9 vs. 1/9, none after 2011). There was a trend towards surgery at a younger age (median 86 months 1997-2010 vs. 48 months 2011-2018). None with >200 seizure/month, SEGA, or history of infantile spasms achieved seizure freedom. Two patients underwent anterior callosotomy (1992 and 1994) and became free of drop attacks. Five callosotomies were performed between 2011 and 2013, one patient became free of drop attacks. Two complications with new neurological deficits were reported. The median age at surgery was higher in the callosotomy group (14 years) than in the tuberectomy group (5 years).

CONCLUSION: Seizure freedom after tuberectomy in patients with TSC has increased over time in our cohort. Signs of a heavier disease burden were more frequently observed 1997-2010 and associated with worse outcomes. Callosotomy operations were prevalent at the beginning of the 2010s.