Subcortical Stimulation for Functional Brain Mapping: A Systematic Review

Area of Science:

• Neurosurgery
• Neuroscience
• Functional Brain Mapping

Background:

• Subcortical functional brain mapping is crucial for preserving motor and language functions during surgery near white matter tracts.
• Damage to these tracts can lead to significant neurological deficits and poorer patient outcomes.
• Current approaches to subcortical mapping exhibit considerable variability.

Purpose of the Study:

• To systematically review existing literature on subcortical functional brain mapping.
• To understand the indications for this technique.
• To identify optimal electrical stimulation parameters.

Main Methods:

• Systematic review adhering to PRISMA guidelines.
• Searches conducted in PubMed, Scopus, and Medline databases.
• Included studies involving adults undergoing subcortical electrical stimulation for functional brain mapping.

Main Results:

• 55 articles (249 patients) were analyzed, with brain tumors being the most common pathology.
• Key mapped tracts included the arcuate fasciculus, corticospinal tract, and inferior fronto-occipital fasciculus.
• Bipolar stimulation was preferred; 89.1% of patients had no permanent adverse outcomes, though long-term data were limited.

Conclusions:

• Methodological variability and insufficient long-term follow-up hinder the determination of optimal stimulation parameters.
• Functional brain mapping strategies should consider the specific tracts and networks involved.
• Standardization and further research are necessary to establish definitive guidelines.