Verbal memory decline after temporal epilepsy surgery?: A 6-year multiple assessments follow-up study

Area of Science:

• Neurosurgery
• Neuropsychology
• Epilepsy Research

Background:

• Temporal lobe epilepsy (TLE) is a common neurological disorder.
• Surgery is a treatment option for refractory TLE.
• Long-term cognitive effects, particularly on verbal memory, require detailed investigation.

Purpose of the Study:

• To evaluate the long-term impact of temporal lobe epilepsy surgery on verbal memory.
• To compare the effects of left vs. right temporal lobe resections.
• To identify factors influencing postoperative verbal memory outcomes.

Main Methods:

• A longitudinal study of 85 TLE patients undergoing amygdalo-hippocampectomy and temporal resection.
• Verbal memory assessed using the "15 Words Test" pre-surgery and at 6 months, 2 years, and 6 years post-surgery.
• Patients categorized by surgical side (left/right) and mesiotemporal (MTS) involvement.

Main Results:

• Left temporal lobe (LTL) surgery patients showed sustained verbal memory decline for up to 2 years.
• Right temporal lobe (RTL) surgery patients initially improved, with gains diminishing long-term.
• Mesiotemporal sclerosis (MTS) patients exhibited poorer verbal memory, especially LTL MTS patients.

Conclusions:

• Verbal memory shows a dynamic decline for up to two years after left temporal lobectomy, then stabilizes.
• Seizure freedom post-surgery did not guarantee better long-term verbal memory performance.
• Predictors of long-term verbal memory include surgical side, preoperative scores, and patient age.