Trigeminal neuralgia caused by a transfixed arterial loop: illustrative case

Trigeminal neuralgia (TN) is typically caused by vascular compression, often at the root entry zone (REZ) of the trigeminal nerve. While most cases involve extraneural compression, rare instances of intraneural transfixion exist, posing unique surgical challenges.

The authors report the case of a 77-year-old male with TN caused by intraneural vascular compression type 2, where a loop of the superior cerebellar artery (SCA) transfixed the portio major of the trigeminal nerve. MRI and intraoperative findings confirmed the SCA coursing through the nerve. He underwent microvascular decompression, during which internal neurolysis and Teflon pledget placement near the REZ were performed. Complete pain relief was achieved immediately postoperatively and sustained at the 7-month follow-up, with no associated postoperative numbness. A review of the literature reveals common themes of surgical intervention, including longitudinal dissection of the nerve, mobilization of penetrating artery outside of the REZ, and Teflon insertion.

For type 1 penetrations, the authors suggest separating the motor and sensory roots, then mobilizing the motor root and artery. For type 2, they recommend either internal neurolysis with distal movement of the artery or horizontal transection to free the artery from the nerve. Patient-centered planning that balances risk of sensory loss against symptom recurrence is essential. https://thejns.org/doi/10.3171/CASE25403.