Limb loss experience evoked by electric cortical stimulation.

Area of Science:

• Neuroscience
• Somatosensory Perception
• Epilepsy Research

Background:

• Limb loss experience is a body illusion involving the sensation of a missing body part.
• Understanding the neural basis of such somatosensory experiences is crucial for neuroscience.

Purpose of the Study:

• To investigate the specific brain areas responsible for evoking limb loss experiences.
• To explore the role of cortical stimulation in mapping somatosensory perception.

Main Methods:

• Retrospective review of stereo-electroencephalography (SEEG) data from epilepsy patients (October 2015 - December 2020).
• Analysis of electric cortical stimulation during SEEG for epileptogenic zone localization and functional mapping.
• Inclusion of patients who reported limb loss sensations during stimulation.

Main Results:

• Three patients reported limb loss experiences during electric cortical stimulation.
• Limb loss sensations (affecting right hand, upper limb, or body side) were evoked by stimulating the left posterior insula, posterior dorsal cingulate, and parietal operculum.
• These experiences were linked to stimulation of the posterior insula, parietal operculum, and posterior cingulate cortex.

Conclusions:

• Electric cortical stimulation of the posterior insula, parietal operculum, and posterior cingulate cortex can evoke limb loss experiences.
• These brain regions are integral to the integration of body sensory perception.
• The study provides further evidence for the role of these cortices in somatosensory processing and body representation.