Modeling dermatome selectivity of single-and multiple-current source spinal cord stimulation systems

Area of Science:

• Biomedical Engineering
• Computational Neuroscience
• Neurosurgery

Background:

• Computational modeling predicted multiple current source (MCS) spinal cord stimulation (SCS) could increase dorsal column (DC) stimulation points over single current source (1 CS).
• The clinical relevance of this prediction for dermatomal selectivity remains unestablished.

Purpose of the Study:

• To compare the dermatomal zone selectivity of MCS and 1 CS systems in SCS.
• To evaluate the potential incremental therapeutic benefit of MCS over 1 CS.

Main Methods:

• A finite element method (FEM) model of the spinal cord with a 2 × 8 paddle electrode array was constructed.
• FEM simulations calculated DC field potentials for both MCS and 1 CS configurations.
• Activation regions were determined using a biophysical nerve fiber model and mapped to dermatomal zones.

Main Results:

• Marginal differences were observed in the activated dermatomal zones between 1 CS and MCS systems.
• The study found limited variation in coverage despite using different current source configurations.

Conclusions:

• MCS SCS systems demonstrated no substantial improvement in dermatomal zone selectivity compared to 1 CS systems.
• The findings question the previously suggested incremental therapeutic benefit of MCS in SCS applications.