Related Experiment Video
Updated: Mar 19, 2026
Anteromesial Temporal Lobectomy for Medically Intractable Temporal Lobe Epilepsy: An Operative Study
Published on: August 15, 2025
Well preserved versus severely impaired memory 10-44 years after temporal lobe epilepsy surgery: "How did the
Eli B Kyte1, Annette Holth Skogan2, Jugoslav Ivanovic3
1National Centre for Epilepsy, Oslo University Hospital, Oslo, Norway; Full member of ERN EpiCare Network; Department of Clinical Medicine, University of Oslo, Oslo, Norway.
Purpose:
This study aimed to identify factors influencing long-term memory outcomes after temporal lobe epilepsy surgery, focusing on patients with well-preserved functioning versus those with severe impairments.
Method:
Ninety-nine patients underwent epilepsy surgery and completed neuropsychological assessments preoperatively (T1) and two years postoperatively (T2), with follow-up 10-44 years after surgery (T3). Memory scores were categorized as severely impaired (>2 SD below the mean) or good (≥ average).
Results:
At T3, 46% of patients reported surgery-related memory decline and 9% reported later decline. Objectively, verbal memory was severely impaired in 21% and good in 14%, while figural memory was severely impaired in 34% and good in 12%. Continuous seizure freedom occurred in 45%, late seizure freedom in 24%, relapse in 11%, and ongoing seizures in 20%. Seizure-free patients performed better. Among those severely impaired in verbal memory at T3, 45% had declined by T2 and 20% declined later; among good performers, 79% improved late. For figural memory, 8% declined by T2 and 65% declined later; among good performers, 27% improved after surgery and 64% improved later. Surgical side, education, and age predicted outcomes.
Conclusion:
Many years after temporal lobe epilepsy surgery, 45% of patients achieved continuous seizure freedom and 20% late seizure freedom. Only 9% reported late memory decline. Verbal memory tended to decline shortly after surgery but showed recovery over time, whereas figural memory more often declined later. These patterns suggest late mechanisms of functional recovery, compensation, and reorganization.
