Propofol-induced Changes in α-β Sensorimotor Cortical Connectivity

Area of Science:

• Neuroscience
• Anesthesiology
• Systems Neuroscience

Background:

• Anesthetics are known to affect brain functional connectivity.
• Network-level analyses of anesthesia's effects, especially in humans, are limited.
• This study investigates propofol's impact on human sensorimotor network connectivity.

Purpose of the Study:

• To test the hypothesis that propofol-induced loss of consciousness functionally disconnects human sensorimotor cortices.
• To explore the underlying mechanisms of anesthetic-induced loss of volitional motor control.

Main Methods:

• Local field potentials were recorded from sensorimotor cortices in patients with Parkinson disease and essential tremor.
• Recordings were taken before and after propofol-induced loss of consciousness.
• Local spectral power and interregional connectivity (coherence, imaginary coherence) were analyzed.

Main Results:

• Propofol anesthesia increased spectral power in sensorimotor cortices (2-100 Hz) and shifted dominant peaks to lower frequencies.
• Despite increased local power, sensorimotor cortical coherence decreased with propofol.
• Suppression of coherence was observed in beta frequencies for Parkinson disease and alpha/beta frequencies for essential tremor.

Conclusions:

• Propofol causes functional disconnection of sensorimotor cortices, characterized by increased local activity and decreased interregional connectivity.
• This sensorimotor network disruption may underlie the loss of volitional control during anesthesia.
• The findings suggest generalizable effects of propofol in patients with movement disorders and potentially other populations.