Evaluation of the Risk of Cognitive Deficit After Surgery of Epilepsy by Dynamic Spectral Imaging (ISD) of the Cognitive Functions in Patients Explored in StereoElectroEncephaloGraphy (SEEG) (ISD SEEG)

Epilepsy affects between 0.5 and 0.7% of the European population. Despite the availability of numerous drug treatments, one third of patients still have seizures, which are associated with significant cognitive and social complications and excess mortality. In these patients, surgical treatment to remove the epileptogenic zone (EZ), the region of the brain responsible for seizures, is the only approach that can allow control of the disease. However, before investigating this surgery, investigations have to answer two questions: (i) what is the location and extension of the EZ and (ii) what functional risks, both motor and cognitive, would represent the resection of this Cortical region? As it is a functional surgery, it is in fact inconceivable that the surgery will result in an over-handicap. For these reasons, all candidates for surgery benefit from a complete assessment including imaging examinations, a neuropsychological assessment and a long-term video-EEG recording to record seizures. Nevertheless, in some patients, this assessment does not give us a formal answer. In these subjects, it is then necessary to carry out a second step, consisting of an invasive exploration by implantation of intracerebral electrodes during a stereoencephalography (SEEG). Due to its temporal and spatial resolution, the SEEG allows, besides the precise determination of the EZ, to carry out a functional mapping of the cortical regions likely to be included in cortectomy. Conventionally, this mapping is carried out on the basis of the cortical electrical stimulations applied to the implanted electrodes. If this approach is very robust for exploring primary functions such as motor skills or language, it cannot be used to evaluate more complex cognitive tasks such as face recognition or attention Effective cognitive treatment on a daily basis. This has led to the development in recent years, in Lyon and Grenoble, of a complementary approach to cerebral stimulation: dynamic spectral imaging (ISD). Numerous experimental paradigms have demonstrated that the realization of a cognitive task associates with the generation within the cortical regions involved in its treatment of a particular cortical activity. This activity is characterized by oscillations of the cortical rhythm in high frequencies (> 30 Hz), called gamma activities. The ISD thus consists in mapping this gamma activity during various cognitive tasks, thus making it possible to study more widely the complexity of the cognitive functions. Correlations between gamma activity and cognitive tasks have so far been exclusively performed in the non-epileptic cortex explored at the periphery of the EA during SEEG. Nevertheless, the cortical oscillatory pattern study associated with a specific cognitive task within the EZ could better anticipate complex cognitive deficits that could be generated by the resection of a cortical region.

The main objective of this project is to establish the predictive character of the gamma cortical oscillatory pattern associated with a specific cognitive task on the risk of occurrence of a cognitive disorder after surgery of epilepsy.

Study Overview

• Status: Recruiting
• Conditions: Epilepsy
• Intervention / Treatment: Procedure: Dynamic Spectral Imaging (ISD)

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Sylvain RHEIMS, MD; Phone Number: +33 472359343; Email: sylvain.rheims@chu-lyon.fr
• Study Contact Backup: Name: Anne-Laure CHARLOIS

Study Locations

• France
  • Bron, France, 69500
    • Recruiting
    • Hospices Civils de Lyon
    • Contact: Sylvain RHEIMS, MD; Phone Number: +33 472359343; Email: sylvain.rheims@chu-lyon.fr
    • Contact: Anne-Laure CHARLOIS
    • Principal Investigator: Sylvain RHEIMS, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• patient adult (18-65 y/o) without legal protection measures
• Patient with a drug-resistant focal epilepsy
• Patient with a SEEG exploration as part of pre-surgical assessment of epilepsy
• patient with a consent form signed
• Intellectual capacities compatible with cognitive tasks and the signing of informed consent
• Affiliation to the social security

Exclusion Criteria:

• Pregnant women: this is already a contraindication to the realization of a SEEG study
• Subjects under 18 years of age or over 65 years of age
• Patient not suffering from EFPR, or not scheduled for SEEG
• Intellectual capacities incompatible with the cognitive tasks and / or the signature of a consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dynamic Spectral Imaging (ISD); Evaluation of cognitive functions by ISD	Procedure: Dynamic Spectral Imaging (ISD); cerebral stimulation: dynamic spectral imaging (ISD)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
predictive character of the cortical gamma oscillatory pattern associated with a specific cognitive task on the risk of occurrence of a cognitive disorder after epilepsy surgery	Relation between the presence in the epileptogenic zone of a gamma activation in at least 1 of the cognitive tasks performed during the ISD and the occurrence of a postoperative neuropsychological deficit (Wilcoxon test)	12 months post-surgery compare to preoperative assessment (SEEG)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
database on the dynamics of large cerebral networks underlying the main cognitive functions	Comparison of mapping of pre-surgical gamma activity with preoperative neu-ropsychological evaluation	pre-surgical assessment (SEEG)
spatio-temporal organization of these networks with that predicted by fMRI	Pre-surgical comparison of the performances for the functional cartography of gamma activity performed during SEEG, fMRI and cortical stimulation at preoperative assessment.	preoperative assessment (SEEG, fMRI and cortical stimulations)
effect of intracerebral electrical stimulations	Pre-surgical comparison of the performances for the functional cartography of gamma activity performed during SEEG, fMRI and cortical stimulation at preoperative assessment.	preoperative assessment (SEEG, fMRI and cortical stimulations)
macro-electrophysiological recordings	The relation between the presence in the epileptogenic zone of an activation in the other frequency bands (theta, alpha, beta) in at least 1 of the cognitive tasks performed during the ISD and the occurrence of a post neuropsychological deficit	12 months post-surgery compare to preoperative assessment (SEEG)
micro-electrophysiological recordings	The relation between the presence in the epileptogenic zone of an activation in the other frequency bands (theta, alpha, beta) in at least 1 of the cognitive tasks performed during the ISD and the occurrence of a post neuropsychological deficit	12 months post-surgery compare to preoperative assessment (SEEG)

Collaborators and Investigators

• Sponsor: Hospices Civils de Lyon
• Investigators: Principal Investigator: Sylvain RHEIMS, MD, Hospices Civils de Lyon

Study record dates

Study Major Dates

• Study Start (Actual): June 23, 2017
• Primary Completion (Estimated): January 23, 2027
• Study Completion (Estimated): January 23, 2027

Study Registration Dates

• First Submitted: March 9, 2017
• First Submitted That Met QC Criteria: March 22, 2017
• First Posted (Actual): March 29, 2017

Study Record Updates

• Last Update Posted (Estimated): January 26, 2024
• Last Update Submitted That Met QC Criteria: January 25, 2024
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Keywords: SEEG; epilepsy surgery; cognitive disorder; ISD
• Additional Relevant MeSH Terms: Mental Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurocognitive Disorders; Epilepsy; Cognitive Dysfunction; Cognition Disorders
• Other Study ID Numbers: 69HCL16_0644; 2017-A00464-49 (Other Identifier: ID-RCB)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No