The "frontal syndrome" revisited: lessons from electrostimulation mapping studies

Area of Science:

• Cognitive Neuroscience
• Neurosurgery
• Neurology

Background:

• The localizationist view traditionally attributes "frontal syndrome" to frontal lobe damage.
• This perspective is challenged by new insights into brain organization and function.

Purpose of the Study:

• To challenge the traditional localizationist view of the "frontal syndrome".
• To propose a hodotopical approach to lesion mapping based on connectivity and plasticity.

Main Methods:

• Review of intraoperative electrostimulation mapping data from awake brain surgery for tumors.
• Analysis of data from the last decade challenging modular brain organization.

Main Results:

• "Frontal symptoms" can arise from damage to areas outside the frontal lobes, including white matter pathways and deep gray nuclei.
• Specific fascicle stimulations (superior longitudinal, inferior fronto-occipital, subcallosal) and striatal stimulation elicit distinct neurological deficits.
• Extensive frontal lobectomies can occur without "frontal syndrome," supporting a network-based model.

Conclusions:

• Brain organization is based on dynamic interrelationships within distributed networks, emphasizing connectivity and plasticity.
• A hodotopical approach offers a renewed model for understanding brain processing and clinical applications in neurosurgery and rehabilitation.
• Strengthened links between cognitive neuroscience and clinical neurology/neurosurgery are essential.