Superior accuracy and precision of SEEG electrode insertion with frame-based vs. frameless stereotaxy methods

Area of Science:

• Neurosurgery
• Epileptology
• Medical Devices

Background:

• Stereotactic electroencephalography (SEEG) is a preferred method for intracranial seizure localization in epilepsy.
• Manual frame-based and frameless SEEG electrode insertion techniques are widely used.
• Comparison of accuracy, precision, and safety between frame-based and frameless SEEG insertion is lacking.

Purpose of the Study:

• To compare the accuracy and precision of frame-based SEEG insertion using a CRW frame versus frameless SEEG insertion using the StealthStation™ S7 navigation system.
• To evaluate the clinical utility of electrode contacts obtained by both methods for common temporal SEEG targets.

Main Methods:

• Retrospective analysis of SEEG electrode targets in patients implanted with either frame-based or frameless techniques.
• Focus on amygdala and hippocampal head targets.
• Comparison of actual electrode tip coordinates to ideal coordinates using merged pre-operative MRI and post-operative CT images.

Main Results:

• Frame-based SEEG insertion demonstrated higher accuracy and precision compared to frameless insertion.
• 18% of frameless electrodes missed their target, versus 0% for frame-based.
• Average Euclidean distance error was significantly lower for frame-based (7.1 mm amygdala, 8.5 mm hippocampus) vs. frameless (11.0 mm amygdala, 12.4 mm hippocampus) techniques.

Conclusions:

• Frame-based SEEG insertion is significantly more accurate and precise than frameless insertion.
• Frame-based techniques result in a higher proportion of clinically useful electrode contacts.
• Findings have implications for epilepsy centers considering SEEG electrode placement methods.