Cognitive reserve as a modulating factor in the impact of surgery on visual memory and naming in temporal lobe epilepsy patients

Introduction. Temporal lobe epilepsy (TLE) surgery is an effective procedure that produces cognitive changes. Factors modulating such changes have been proposed, but the influence of cognitive reserve remains unclear. Objective. To examine the effect of intellectual quotient (IQ) on postsurgical changes in verbal fluency, naming, and verbal and visual memory in a sample of patients with TLE. Patients and methods. 64 adult patients with drug-resistant TLE (mean age +/- SD: 39.16 +/- 11.67) underwent a neuropsychological evaluation before and one year after surgery. Results. Patients with high IQ showed better immediate visual memory before surgery than those with medium IQ, as well as an absence of postsurgical changes. Patients with high manipulative IQ had better naming before surgery than those with medium manipulative IQ, as well as a significant postsurgical worsening. Both before and after surgery, patients with high IQ showed better phonemic and semantic verbal fluency and short- and long-term verbal memory than those with medium IQ. Conclusions. IQ is a relevant factor in the evolution of immediate visual memory and naming after surgery in patients with TLE. Surgery does not impact on the advantage of high IQ patients in verbal fluency and verbal memory, suggesting that cognitive reserve has a positive effect on cognitive function, even after TLE surgery.