A device for cooling localized regions of human cerebral cortex. Technical note

Area of Science:

• Neurosurgery
• Neuroscience
• Cerebral Cortex Mapping

Background:

• Current neurosurgical mapping relies on invasive electrical stimulation, which has limitations.
• Focal cooling is a technique used in animal models for controlled cortical disruption.
• There is a need for advanced tools to understand functional neuroanatomy during surgery.

Purpose of the Study:

• To describe the experience and evaluate the safety and utility of a novel cooling probe device in patients undergoing neurosurgery.
• To assess the effectiveness of focal cooling in disrupting local synaptic activity and physiological functions.
• To compare the neurological deficits induced by cooling with those from electrical stimulation.

Main Methods:

• A cooling probe with thermocouples and EEG contacts was developed.
• Active cooling was achieved by infusing chilled saline onto the pial surface.
• Experiments were conducted on 18 patients, measuring temperature gradients and EEG activity.

Main Results:

• Temperature measurements confirmed cooling of gray matter sufficient to disrupt synaptic activity.
• Statistically significant, reversible changes in spontaneous and evoked EEG activity were observed during cooling.
• Preliminary findings in Broca area mapping showed qualitative differences between cooling and electrical stimulation effects.

Conclusions:

• The cooling probe is a safe and useful research tool for neurosurgical functional mapping.
• Focal cooling provides a reversible disruption of cortical functions with distinct characteristics compared to electrical stimulation.
• Further rigorous studies are recommended to correlate cooling, electrical stimulation, and focal lesioning effects.