Neurovascular Compression at the Root Entry Zone Correlates with Trigeminal Neuralgia and Early Microvascular Decompression Outcome.

BACKGROUND: Trigeminal neurovascular contact (NVC) is hypothesized to be the etiology of classical trigeminal neuralgia (TGN). We aimed to seek a correlation between types of NVCs and the presence of TGN as well as early surgical outcome in patients with TGN treated with trigeminal microvascular decompression (MVD). METHODS: We blindly analyzed preoperative high-resolution magnetic resonance images with respect to the degree (none, "touch," or compression) and location of bilateral NVC in 57 retrospectively identified Burchiel Type 1 TGN patients treated by MVD. Location of NVC was noted as either at the root entry zone or distal to it. Using a logistic regression model, we assessed the degree and location of trigeminal NVC for correlation with the symptomatic side. Furthermore, the NVC characteristics on the symptomatic side were correlated with early postoperative pain relief. RESULTS: Although the degree and location of NVC were not statistically correlative independently, a combined interaction analysis of both statistically correlated with the symptomatic side and with early postoperative pain relief. CONCLUSIONS: We conclude that in TGN patients treated with MVD, magnetic resonance imaging identified neurovascular compression at the root entry zone (correlates with the affected side and early postoperative pain relief.