Related Experiment Video
Updated: Aug 15, 2026
The Double-H Maze: A Robust Behavioral Test for Learning and Memory in Rodents
Published on: July 8, 2015
Memory in patients with drug-responsive mesial temporal lobe epilepsy and hippocampal sclerosis
Ciğdem Ozkara1, Lütfü Hanoğlu, Cahit Keskinkiliç
1Department of Neurology, Istanbul University, Cerrahpasa Medical Faculty, Istanbul, Turkey. cigdemoz@anet.net.tr
Purpose:
Mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS) is the most common of the antiepileptic drug (AED)-resistant seizure syndromes that are remediable mostly with surgery, although a small group of patients have benign prognosis with fewer seizures. Material-specific memory impairment is an important feature in these patients and may be related to both the structural abnormality and the frequent seizures. In this study, we investigated the relation between memory deficit and HS by taking seizure frequency into account.
Methods:
The patients were evaluated according to a standard protocol and divided into two groups, considering their response to AEDs: the good-responder group (GRg, n = 18) and the pharmacoresistant group (PRg, n = 95). They were administered a neuropsychological test battery that included verbal and nonverbal memory tests, compared with each other and with a normal control group (n = 29). The responder group was evaluated by the same battery once again (mean, 23 months; SD, 8.25; range, 14-38 months).
Results:
Both GR and PR patient groups had poorer memory than the normal controls in all memory tests (p < 0.05). However, the comparison of GRg with PRg revealed that only the digit-span test was significantly worse in PRg (p = 0.0061), and no difference was found in any other memory scores. The reevaluation of the GRg showed no significant difference between the first and second evaluation.
Conclusions:
We concluded that the memory impairment in patients with MTLE-HS was permanent and might be related to the direct effect of HS itself. Therefore patients with good response to AEDs can be used as a model for investigating the memory problems in patients with MTLE-HS.
Insights
Memory deficits in mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) appear permanent and linked to hippocampal sclerosis itself, not seizure frequency. Patients responding well to antiepileptic drugs (AEDs) can model these memory issues.
Area of Science:
- Neurology
- Neuropsychology
- Epilepsy Research
Background:
- Mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS) is a common drug-resistant epilepsy syndrome.
- Material-specific memory impairment is a key feature in MTLE-HS, potentially linked to structural abnormalities and seizure frequency.
Purpose of the Study:
- Investigate the relationship between memory deficits and hippocampal sclerosis (HS) in MTLE-HS patients.
- Determine the influence of seizure frequency and antiepileptic drug (AED) response on memory impairment.
Main Methods:
- Patients with MTLE-HS were categorized into good-responder (GRg) and pharmacoresistant (PRg) groups based on AED response.
- A neuropsychological test battery assessing verbal and nonverbal memory was administered to patients and a normal control group.
- The GRg underwent reevaluation after a mean of 23 months.
Main Results:
- Both GRg and PRg exhibited poorer memory performance compared to normal controls across all tests.
- The pharmacoresistant group (PRg) showed significantly worse performance only on the digit-span test compared to the good-responder group (GRg).
- No significant memory changes were observed in the GRg upon reevaluation.
Conclusions:
- Memory impairment in MTLE-HS is likely permanent and directly attributable to hippocampal sclerosis (HS).
- Seizure frequency or AED response does not appear to significantly influence the extent of memory deficits beyond the direct effect of HS.
- Patients with a good response to AEDs serve as a valuable model for studying memory problems in MTLE-HS.
