Spatial Memory and Temporal Lobe Epilepsy

Temporal lobe epilepsy (TLE) can cause memory disorders, including long-term forgetfulness due to a failure to consolidate verbal but also spatial information. The forgetting phenomenon presented by these epileptic patients is called accelerated forgetting in the literature and remains difficult to objectify during cognitive assessments. It is indeed particularly complicated to evaluate long-term spatial memory and to account for the topographical complaint, although recurrent, of patients with this TLE.

A navigation task being proposed as part of the neuropsychological assessment of patients with a spatial memory complaint, it is interesting to study the performance pattern of patients with TLE by comparing them to a group of control subjects matched in age and gender in order to verify whether there is significant long-term forgetting and whether there is a significant difference between Right TLE and Left TLE. Indeed, several studies have demonstrated this accelerated long-term forgetting in epileptic patients (Cassel et al., 2016; Lemesle et al., 2017; Landry et al., 2022; Blake et al., 2020) but few with a retention delay of several weeks (Tramoni et al., 2009). Our study allows us to statistically analyze the effects of these two groups: epileptic patients and healthy volunteers, but also to combine the effect of the laterality of epilepsy specifically on spatial memory performance.

In order to assess the long-term spatial memory capacities of epileptic patients with memory complaints, a navigation task was proposed as part of the neuropsychological assessment. This task corresponds to learning a route within the hospital. It is composed of a learning phase and then the patient is asked to repeat the route one hour later and then six weeks later, in order to check for the presence or absence of long-term forgetting. We wanted to study the results of patients with temporal lobe epilepsy (TLE) by comparing them to a group of healthy volunteers matched in age and gender in order to check whether there is significant long-term forgetting and whether there is a significant difference between Right TLE and Left TLE. Our study therefore aims to statistically analyze the effects of these two groups: epileptic patients and healthy volunteers, but also to combine the effect of the laterality of epilepsy specifically on spatial memory performance. It will also be interesting to observe whether there is a difference between men and women in the healthy volunteer group for spatial memory learning.

Eligibility Criteria:
Inclusion Criteria:

- healthy volunteers meeting each of the following criteria:

* Aged over 18 years
* Right-handed\*
* Free of known neurological pathology
* Signed consent
* Matched in age (+ or - 5 years) and gender with epileptic patients presenting the characteristics below:

  * Right-handed\*
  * adult
  * presenting temporal lobe epilepsy, whose lateralization of the epileptogenic focus (right or left) has been objectified by an examination (EEG and/or MRI),
  * having carried out a neuropsychological assessment including the navigation task,
  * having been informed of the study, and consenting to the processing of their data

Exclusion Criteria:

* Person referred to in Article L1121-5 of the Public Health Code: Pregnant, parturient, or breastfeeding women
* Person referred to in Article L1121-6 of the Public Health Code: persons deprived of their judicial or administrative freedom
* Person referred to in Article L1121-8 of the Public Health Code: persons subject to a legal protection measure or unable to express their consent
* Person referred to in Article L1121-8-1 of the Public Health Code: persons not affiliated to a social security scheme
* Left-handed participants
* Participants familiar with the premises of the Centre Hospitalier Métropole Savoie
* Not speaking French

Exclusion criteria

Patients who have undergone epilepsy neurosurgery between the initial visit and the secondary visit of the neuropsychological assessment will not be paired with a healthy volunteer. Their data will not be studied.

Volunteers whose pretest scores reveal a cognitive disorder (pathological threshold \> 1.65) will not perform the navigation task. They will then be referred to a neurologist.