Recurrent trigeminal neuralgia caused by an anomalous cerebellar artery arising from the persistent primitive trigeminal artery: illustrative case.

BACKGROUND

Persistent primitive trigeminal artery (PTA) and its related variants-the PTA family-are rare vascular anomalies that can cause trigeminal neuralgia through atypical neurovascular compression patterns, requiring careful anatomical evaluation. The authors describe a rare case of recurrent trigeminal neuralgia caused by an anomalous cerebellar artery arising from a PTA and further complicated by a long-standing Teflon granuloma.

OBSERVATIONS: A 79-year-old man developed recurrent trigeminal neuralgia 19 years after microvascular decompression. Imaging revealed an anomalous anterior inferior cerebellar artery (AICA) arising from a PTA and compressing the trigeminal nerve, along with a Teflon granuloma obscuring the vessel's course. Three-dimensional multimodal reconstruction clarified the neurovascular conflict. During surgery, dense adhesions due to the granuloma were encountered, and maximal granuloma removal enabled successful transposition of the anomalous AICA.

LESSONS: PTA family anomalies can produce trigeminal neuralgia through atypical patterns of neurovascular compression. In complex or recurrent cases, preoperative 3D reconstruction imaging can enhance understanding of aberrant vascular anatomy. Maximal safe removal of a Teflon granuloma is crucial to create sufficient space and facilitate adequate decompression of the offending vessel. https://thejns.org/doi/10.3171/CASE2699.