Microelectrode Implantation in Human Insula: Technical Challenges and Recording Insights

Area of Science:

• Neuroscience
• Epileptology
• Neurosurgery

Background:

• Intracranial macroelectrode implantation is crucial for evaluating drug-resistant epilepsy.
• It aids in localizing the epileptogenic zone and mapping eloquent cortical areas.
• Combining macro- and microelectrodes offers deeper insights into neural microcircuits and brain function.

Purpose of the Study:

• To report the experience and preliminary results of hybrid macro-micro electrode implantation in the insular region of epilepsy patients.
• To provide recommendations for hybrid electrode implantation in the insular cortex.
• To explore the potential of microelectrode recordings for understanding neuronal activity in epilepsy.

Main Methods:

• Stereoelectroencephalography (SEEG) was performed in 13 patients with refractory epilepsy.
• One or two hybrid macro-micro electrodes (23 total, 20 recorded) were implanted in the insular region.
• Spiking neural activity was detected and assessed using WaveClus3 software.

Main Results:

• No spiking activity was detected in the first seven patients.
• Successful recordings from 13 microcontacts (20.3%) were obtained in the anterior-inferior insula of the last four patients.
• Implantation was uneventful, but challenges included lack of spiking signals, microwire dispersion issues, and electrical noise.

Conclusions:

• Human microelectrode recording in the insula presents significant challenges.
• Despite difficulties, microelectrode recordings hold potential for understanding individual neuronal attributes and responses.
• Further refinement is needed to overcome obstacles and fully leverage this technology for epilepsy research.