Recording "Fast Ripples" Using Microelectrodes During Stereo-encephalography in Patients With Drug-resistant Partial Epilepsy (Epi-FaR)

Feasibility and Interest of Recording "Fast Ripples" Using Microelectrodes During Stereo-encephalography in Patients With Drug-resistant Partial Epilepsy

The main objective of this study is to evaluate the feasibility of recording fast-ripples, a potential new biomarker of epilepsy, using the new micro-macroelectrodes developed by Dixi-Medical.

Study Overview

• Status: Completed
• Conditions: Epilepsy
• Intervention / Treatment: Device: intracerebral micro-macroelectrodes

Detailed Description

Partial epilepsies are refractory to medical treatment in 30% of the cases (Refractory Partial Epilepsy or RPE). Patients with RPE suffer from social and occupational disability, an increased risk associated with seizures (traumatic brain injury, accidents), but also a higher risk of sudden unexplained death (2 to 3 times higher) than the general population. Moreover, the medical and social burden of these patients is heavy, representing a significant cost to society.

In some cases, surgical treatment with resection of the epileptogenic zone (EZ) can be proposed. The presurgical evaluation includes various investigations seeking to clarify the location of the EZ; but this approach is sometimes insufficient and the definition of the EZ then requires invasive exploration through intracerebral EEG recording (stereo-EEG, SEEG). This latter technique is currently the preferred standard to define the EZ. It involves implanting electrodes in the brain areas suspected to belong to the seizure network. 50 to 70% of patients investigated with this technique will have epilepsy surgery.

In recent years, a series of studies in animals and humans have suggested that some oscillations, very short and at very high frequency (> 250 Hz), called "fast ripples" (FRs) could be a good biomarker of the EZ (for a review see Zijlmans et al, 2012). The FRs are more easily recorded from microelectrode (diameter: 20-40 microns).

The purpose of this study is to evaluate a new medical device designed by DixiMedical to record FRs, combining micro and regular clinical electrodes.

• Study Type: Interventional
• Enrollment (Actual): 54
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Midi-Pyrenees
    • Toulouse, Midi-Pyrenees, France, 31059
      • University Hospital Toulouse

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 12 years to 65 years (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patient with RPE in whom SEEG is required to precisely localize the seizure focus

Exclusion Criteria:

Patients with SEEG contra-indication:

• severe psychiatric disorders,
• severe agitation during their crisis
• contraindication for performing an MRI: claustrophobia, a cardiac or neural stimulator, ferromagnetic surgical clips, cochlear implants, intraocular metallic foreign body or in the nervous system,
• contraindication to intracerebral investigation (macro-electrodes): ongoing infection, severe associated pathology (cardiac, pulmonary, renal, hepatic), pregnant or nursing women,
• anti thrombotic ongoing treatment.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• 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: micro-macroelectrodes; All patients will be implanted with usually 4 intracerebral micro-macroelectrodes(replacing the regular clinical macroelectrodes). The primary and secondary outcomes will then be assessed.	Device: intracerebral micro-macroelectrodes; All patients will be implanted with usually 4 micro-macroelectrodes (replacing the regular clinical macroelectrodes). The primary and secondary outcomes will then be assessed.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation of the feasibility of recording Fast Ripples (FRs)	Proportion of patients who are registered more than 60 FRs per hour the day 3 and the day 4 on the micro-macro electrode in the presumed epileptogenic zone, compared to the number of patients included	During 5 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluation of the interest of FRs	Sum of FRs recorded over the 5 days.	During 5 days
Evolution of the hourly frequency of FRs	The evolution of the hourly frequency of FRs recorded by the microelectrodes depending on the day of recording.	During 5 days
Effectiveness of microelectrodes and macroelectrodes	Number of FRs stored on the macro-blocks immediately adjacent to the microelectrodes located in the EZ.	During 5 days
safety of micro-macroelectrodes	A quantitative and qualitative description of the side effects associated with the procedure.	During 5 days

Collaborators and Investigators

• Sponsor: University Hospital, Toulouse
• Collaborators: CerCo, CNRS Cerco UMR5549 CHU Purpan Toulouse France; DIXI Medical, Besançon, France
• Investigators: Principal Investigator: luc valton, MD, University Hospital, Toulouse

Publications and helpful links

General Publications

• Despouy E, Curot J, Denuelle M, Deudon M, Sol JC, Lotterie JA, Reddy L, Nowak LG, Pariente J, Thorpe SJ, Valton L, Barbeau EJ. Neuronal spiking activity highlights a gradient of epileptogenicity in human tuberous sclerosis lesions. Clin Neurophysiol. 2019 Apr;130(4):537-547. doi: 10.1016/j.clinph.2018.12.013. Epub 2019 Jan 30.

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2015
• Primary Completion (Actual): August 18, 2022
• Study Completion (Actual): September 18, 2022

Study Registration Dates

• First Submitted: June 1, 2015
• First Submitted That Met QC Criteria: July 7, 2015
• First Posted (Estimated): July 8, 2015

Study Record Updates

• Last Update Posted (Actual): May 6, 2026
• Last Update Submitted That Met QC Criteria: April 29, 2026
• Last Verified: June 1, 2023

More Information

Terms related to this study

• Keywords: Safety; Device; Electrodes; StereoElectroencephalograph; Epileptogenic zone; Fast ripples
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Epilepsy
• Other Study ID Numbers: RC31/13/6899; 2014-A00747-40 (Other Identifier: ID-RCB)