Deep Brain Stimulation Electrode Deviations are Associated With Brain Stiffness Interfaces Measured by Magnetic...

Area of Science:

• Neurosurgery
• Biomedical Engineering
• Medical Imaging

Background:

• Deep brain stimulation (DBS) efficacy depends on precise electrode placement.
• Electrode deviation, often due to bending, necessitates revision surgery in 3-8% of patients.
• The internal capsule's (IC) dense fibers are implicated as a factor in DBS electrode deviation.

Purpose of the Study:

• To investigate the relationship between the angle of planned DBS electrode trajectories and target deviation.
• To test the hypothesis that the angle relative to internal capsule (IC) tissue interfaces induces deviation.
• To evaluate the utility of magnetic resonance elastography (MRE) in quantifying brain tissue stiffness and its relation to electrode deviation.

Main Methods:

• Preoperative 3T MRE was used to measure brain tissue stiffness in 10 Parkinson disease patients.
• The internal capsule stiffness interface (ICSI) and its rate of transition were defined.
• Postoperative CT measured target deviation; the angle of approach relative to the ICSI was calculated and correlated with deviation.

Main Results:

• A significant positive correlation (r=0.57, P=.007) was found between the angle of approach and target deviation.
• Larger angles of approach were associated with greater electrode deviation.
• The rate of stiffness transition across the ICSI did not correlate with deviation (P=.874).

Conclusions:

• The angle between the planned trajectory and the ICSI significantly influences DBS electrode deviation.
• Tissue mechanics, specifically the angle of approach, play a role in electrode bending.
• MRE can quantify in vivo brain stiffness, offering potential to predict and mitigate DBS electrode deviation, thereby improving patient outcomes.