Cognitive changes in people with temporal lobe epilepsy over a 13-year period

•We evaluated cognitive decline in people with TLE over a period of 13 years.•Working verbal memory and verbal and verbal-logical delayed recall did not change.•Long-term verbal memory declined for one-fifth of participants.•Long-term nonverbal memory worsened for half of the participants.•Decline was associated with seizure frequency, epilepsy duration, and mood.

ObjectivesThe aims of our study were to evaluate cognitive decline in people with temporal lobe epilepsy over a period of 13 years and to determine what clinical and treatment characteristics may have been associated with these.Materials and methodsThirty-three individuals with temporal lobe epilepsy underwent the same neuropsychological assessment of verbal and nonverbal memory, attention, and executive functions using the same cognitive test battery as one used 13 years ago. Long-term verbal and nonverbal memory was tested four weeks later. Results were compared with those carried out 13 years earlier.ResultsThere was no significant change in verbal and verbal-logical memory tests; however, nonverbal memory worsened significantly. Long-term verbal memory declined for 21.9% of participants, long-term verbal-logical memory for 34.4%, and long-term nonverbal memory for 56.3%. Worsening of working verbal and verbal-logical memory was associated with longer epilepsy duration and lower levels of patients' education; worsening of verbal delayed recall and long-term verbal-logical memory was associated with higher seizure frequency. Decline in long-term nonverbal memory had significant association with a longer duration of epilepsy. The worsening of reaction and attention inversely correlated with the symptoms of depression.ConclusionOver a 13-year period, cognitive functions did not change significantly. Good seizure control and reduced symptoms of depression in this sample of people with temporal lobe epilepsy were associated with better cognitive functioning. The predictors of change of cognitive functions could be complex and require further study.