Related Experiment Video
Updated: Mar 28, 2026
Stimulus-specific Cortical Visual Evoked Potential Morphological Patterns
Published on: May 12, 2019
Axono-cortical evoked potentials: A proof-of-concept study
E Mandonnet1, Y Dadoun2, I Poisson3
1Department of Neurosurgery, Lariboisière Hospital, 75010 Paris, France; Université Paris Diderot Sorbonne Paris Cité, 75010 Paris, France; IMNC, UMR 8165, 91400 Orsay, France.
Abstract:
Awake surgery is currently considered the best method to tailor intraparenchymatous resections according to functional boundaries. However, the exact mechanisms by which electrical stimulation disturbs behavior remain largely unknown. In this case report, we describe a new method to explore the propagation toward cortical sites of a brief pulse applied to an eloquent white matter pathway. We present a patient, operated on in awake condition for removal of a cavernoma of the left ventral premotor cortex. At the end of the resection, the application of 60Hz stimulation in the white matter of the operculum induced anomia. Stimulating the same site at a frequency of 1Hz during 70seconds allowed to record responses on electrodes put over Broca's area and around the inferior part of central sulcus. Axono-cortical evoked potentials were then obtained by averaging unitary responses, time-locked to the stimulus. We then discuss the origin of these evoked axono-cortical potentials and the likely pathway connecting the stimulation site to the recorded cortical sites.
Insights
This study introduces a novel method to track electrical signal spread in the brain during awake surgery. Researchers successfully mapped brain pathways by observing responses to direct electrical stimulation of white matter during tumor removal.
Area of Science:
- Neurosurgery
- Neurophysiology
- Cognitive Neuroscience
Background:
- Awake surgery is optimal for precise tumor removal based on functional areas.
- The precise mechanisms of how electrical stimulation affects brain function are not fully understood.
- Investigating direct electrical stimulation of white matter pathways is crucial for understanding brain connectivity.
Observation:
- A novel technique was used to explore signal propagation from white matter pathways to cortical sites.
- During awake surgery for a left ventral premotor cortex cavernoma, 60Hz stimulation of opercular white matter induced anomia.
Findings:
- Stimulating the same white matter site at 1Hz allowed recording of axono-cortical evoked potentials (ACEPs) in Broca's area and the central sulcus.
- ACEPs were obtained by averaging time-locked unitary responses, providing insights into signal propagation.
Implications:
- This method offers a new way to investigate the functional connectivity of white matter tracts during neurosurgical procedures.
- Findings contribute to a better understanding of the neural mechanisms underlying speech arrest induced by white matter stimulation.
