Human Cervical Epidural Spinal Electrogram Topographically Maps Distinct Volitional Movements.

Area of Science:

• Neuroscience
• Spinal Cord Physiology
• Motor Control

Background:

• The electrophysiologic activity of the intact human spinal cord during volitional movement remains largely uncharacterized.
• Understanding spinal cord activity is crucial for developing effective neurostimulation and rehabilitation strategies.

Purpose of the Study:

• To analyze epidural spinal recordings during volitional upper extremity movements.
• To identify spectral signatures of movement, rest, and sensation in the human spinal cord.
• To explore the potential for topographic mapping of movements onto the cervical spinal cord.

Main Methods:

• Epidural spinal recordings were obtained from five human subjects during various upper extremity movements.
• Spectral analysis of electrograms was performed to identify distinguishing features.
• Theta phase to gamma amplitude coupling was analyzed.
• Movement-specific spectral changes were correlated with myotome maps.

Main Results:

• Spinal epidural electrograms contained spectral information differentiating movement, rest, and sensation.
• Cervical epidural electrograms showed spectral changes time-locked with movement.
• Increased power in the theta (4-8 Hz) band and enhanced theta phase to gamma amplitude coupling were key findings.
• Increased theta power allowed for topographic mapping of upper extremity movements onto the cervical spinal cord.

Conclusions:

• Electrophysiologic activity in the intact human spinal cord during movement exhibits distinct spectral characteristics.
• Theta band activity and phase-amplitude coupling are crucial indicators of volitional movement.
• This approach enables topographic mapping of upper extremity movements on the cervical spinal cord, with implications for neurostimulation and motor rehabilitation.