Investigating the Functional Characteristics During Wakefulness and Sleep Based on SEEG

Capital Medical University

Status: Enrolling

Conditions: Refractory Epilepsy; Sleep

Treatments: Procedure: SEEG recordings and SPES

Study type: Interventional

Funder types: Other

Identifiers

NCT06524479

2024-208-002

Details and patient eligibility

About

This study aims to collect electrophysiological and clinical data from patients aged 14-65 with drug-resistant epilepsy who underwent SEEG. The collected data will be analyzed to investigate the functional connectivity during wakefulness and sleep states.

Full description

Sleep serves as a fundamental physiological state whose disruption has profound implications for neurological health. The daily alternation between sleep and wakefulness reflects an intrinsic circadian rhythm that orchestrates critical fluctuations in cortical excitability and functional connectivity throughout the brain. The cerebral cortex, comprising approximately 80% of total brain volume, forms the neural substrate for higher-order cognitive functions including sensory perception, executive control, and memory processes. Importantly, sleep acts as a global brain modulator that dynamically reorganizes patterns of neural communication across distributed cortical and subcortical networks.

Stereoelectroencephalography (SEEG) provides direct access to intracranial electrophysiological activity with exceptional spatiotemporal resolution. When combined with single-pulse electrical stimulation (SPES), this powerful methodology enables quantitative assessment of inter-regional connectivity through analysis of evoked potentials, allowing precise characterization of both connection strength and directionality. This integrated approach offers unique opportunities to examine how different vigilance states modulate cortical excitability and reorganize functional brain networks, particularly in clinical populations with neurological disorders. The ability to track state-dependent changes in network dynamics provides crucial insights into both normal brain function and pathological conditions.

Enrollment: 20 estimated patients

Sex: All

Ages: 14 to 65 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Drug-resistant focal epilepsy
• Justified SEEG exploration in the context of presurgical assessment of epilepsy
• Subjects will be a part of the epilepsy-monitoring unit for long-term SEEG recordings and analysis
• Written non-opposition to study participation

Exclusion criteria

• Pregnant women (Contraindication to SEEG exploration)
• Subjects that experience surgical complications during the implant procedure will be excluded from the study

Trial design

Primary purpose: Basic Science

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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20 participants in 1 patient group

SEEG recordings and SPES effects

Experimental group

Description:

Single-pulse electrical stimulation (SPES) evokes transient neuronal responses that propagate through functional networks, providing a powerful tool to map brain connectivity. When delivered at low frequencies (0.05 Hz, every 20 s), SPES allows quantitative assessment of dynamic network interactions while avoiding long-term synaptic modifications. These stimulation-induced responses, recorded via stereoelectroencephalography (SEEG), reveal both local and distributed neural activity with millisecond precision.

Treatment:

Procedure: SEEG recordings and SPES