CEST-based Biomarkers to Delineate the Epileptogenic Zone
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: CEST sequence on a 7-Tesla MRI.
- Who it may be relevant to
- Registry conditions: Epilepsy (Treatment Refractory). Basic parameters: 18 years — 65 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Center list to be confirmed — check the primary protocol.
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
Epilepsy is a common neurological disorder with an incidence of 1%. Although many anti-seizure medications are available, about 30% of patients are resistant to drug treatments. Epilepsy surgery is an effective treatment for some of these patients. It involves removing the brain region responsible for generating seizures, called the epileptogenic zone (EZ). A pre-surgical evaluation is performed to locate and delineate the region where seizures originate (the seizure onset zone \[SOZ\]) and to confirm that this zone is unique and accessible for surgery-that is, that the potential benefits outweigh the risks of functional deficits resulting from its removal. The lesion itself is identified and characterized through post-operative histological examination and, in some cases, based on MRI criteria. During pre-surgical evaluation, in cases where no lesion is visible on MRI or when surface EEG suggests that a large or multiple epileptic networks may be involved, stereo-electroencephalography (SEEG) is the method of choice to delineate the area for resection. However, SEEG has limitations: it is invasive and records from a restricted brain volume. Despite advances in neuroimaging techniques, the localization of the epileptogenic zone and mapping of functional brain alterations still need improvement beyond what morphological MRI anomalies can reveal. Because epileptic tissue is characterized by increased neuronal excitability and metabolic abnormalities, techniques that allow precise evaluation of these changes could deepen our understanding of the disease and provide new tools for epilepsy surgery. An alternative MRI approach based on metabolite quantification using chemical exchange saturation transfer (CEST) has been suggested to aid in localizing the epileptogenic zone in preliminary studies. However, limited availability of ultra-high-field MRI, low localization precision of the epileptogenic zone, and lack of systematic validation in patients have delayed its clinical use. This study aims to explore a cohort of patients with temporal lobe epilepsy who are candidates for surgery using CEST MRI. We will quantify glutamate and glucose concentrations using glu-CEST and gluco-CEST, respectively, and correlate the results with the localization of the epileptogenic zone determined by pre-surgical evaluation, and where applicable, SEEG and post-operative outcomes.
Interventions
- Other CEST sequence on a 7-Tesla MRI
CEST sequence on a 7-Tesla MRI
Primary outcome measures
- Glucose concentration measured by CEST in the the seizure onset zone (SOZ) [Time frame: Day 0]
Secondary outcome measures (5)
- Glucose concentration measured by CEST in the irritative zone (IZ) [Time frame: Day 0]
- Glucose concentration measured by CEST in the propagation zone [Time frame: Day 0]
- Glutamate concentration measured by CEST in the seizure onset zone (SOZ) [Time frame: Day 0]
- Glutamate concentration measured by CEST in the irritative zone (IZ) [Time frame: Day 0]
- Glutamate concentration measured by CEST in the propagation zone [Time frame: Day 0]
Eligibility criteria
Inclusion criteria
- Patients with drug-resistant temporal lobe epilepsy (mesial or lateral)
- Requiring a pre-surgical evaluation including long-term video EEG
- At least 5 of them will be recruited after surface video EEG indicates the need for further exploration by SEEG
- With or without a radiologically visible lesion
Exclusion criteria
- Absolute or relative contraindication to MRI (metallic implants, including intrauterine devices other than the MIRENA® brand, claustrophobia, etc.)
- Expected inability to remain still for 90 minutes in a 7T MRI
- Diabetic individuals
- Individuals under legal protection measures
- Pregnant or breastfeeding women
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- N/A
- Model
- Single group
- Masking
- Open label
- Primary purpose
- Other
Study locations
Center list to be confirmed — check the primary protocol.
Identifiers
NCT: NCT07316972 · MQS_2024_10