Are invasive cortical stimulations effective in brain atrophy?

Area of Science:

• Neuroscience
• Biomedical Engineering

Background:

• Electrical brain stimulation is a treatment for brain disorders.
• Brain atrophy is common in severe brain disorder patients.
• The impact of brain atrophy on electrical brain stimulation efficacy is unclear.

Purpose of the Study:

• To investigate the effects of brain atrophy on cortical stimulation.
• To quantify the relationship between brain atrophy and stimulation effectiveness.
• To compare the sensitivity of subdural and epidural cortical stimulation to brain atrophy.

Main Methods:

• Developed anatomical head models with varying degrees of brain atrophy.
• Simulated subdural and epidural cortical stimulations.
• Quantified the effective stimulation volume and its correlation with brain atrophy and cerebrospinal fluid (CSF) volume.

Main Results:

• Effective stimulation volumes decreased significantly with increasing brain atrophy.
• A strong correlation (0.9989) was found between CSF volume and brain atrophy.
• Increased CSF volume due to brain atrophy likely caused a decrease in stimulation effectiveness.

Conclusions:

• Brain atrophy significantly reduces the effective volume of cortical electrical brain stimulation.
• Epidural cortical stimulation is more sensitive to brain atrophy than subdural stimulation.
• Increased CSF volume due to brain atrophy contributes to reduced stimulation efficacy.