Ultrasound-Navigated Multiple Hippocampal Transections: An Anatomical Study

Area of Science:

• Neurosurgery
• Epileptology
• Anatomical Studies

Background:

• Multiple hippocampal transection (MHT) treats drug-resistant mesial temporal lobe epilepsy, aiming to spare memory circuits.
• Current MHT relies on electrocorticography, not anatomical completeness, potentially leading to epilepsy recurrence.
• This study challenges the standard approach, hypothesizing complete hippocampal transection is key to durable epilepsy termination.

Purpose of the Study:

• To evaluate the feasibility of achieving complete hippocampal transection using ultrasound neuronavigation.
• To develop and propose novel instruments for a more minimally invasive complete MHT.

Main Methods:

• Anatomical study involving five cadaveric brains.
• Multiple hippocampal transection (MHT) performed bilaterally, with and without ultrasound neuronavigation.
• Magnetic resonance imaging (MRI) used to quantify the percentage of hippocampal cross-section transected.

Main Results:

• Ultrasound-guided MHT achieved complete hippocampal transection in 73% of cases, significantly higher than non-navigated MHT (58%).
• The study facilitated the design of specialized instruments to minimize invasivity.
• Statistical significance was demonstrated (p < 0.01).

Conclusions:

• Ultrasound neuronavigation enhances the completeness of MHT.
• Modified instruments can improve the safety and efficacy of this epilepsy surgery.