Significance of different offending vessels and development of a potential screening tool for trigeminal neuralgia.

OBJECTIVES

This study was performed amongst trigeminal neuralgia (TN) patients with neurovascular contact (NVC) to 1) investigate the association of the demographic and radiologic factors/variables with TN occurrence, and 2) develop a screening tool for TN/TN-affected nerves based on the factors/variables associated with it.

METHODS

Eighty-five TN patients were recruited, and 121 trigeminal nerves with NVC were derived from them. Based on MRI sequences, including balanced turbo field echo and enhanced T1 high-resolution isotropic volume excitation, radiologic factors/variables for each nerve, from the offending vessel to the presence of nerve displacement, were identified by a neuroradiologist and a neurosurgeon. Demographic and clinical data were obtained from clinical notes. Logistic regression was performed to assess the association of the factors/variables with TN occurrence (i.e., affected vs. unaffected nerves).

RESULTS

Three factors/variables were significantly (p < 0.05) associated with TN occurrence amongst patients with NVC: nerve laterality, vertebral artery (VA) involvement, and the presence of nerve displacement. The nerves with VA involvement, those on the right side, and those with nerve displacement exhibited a significantly higher likelihood/odd of being affected by TN, compared to those without VA involvement, those on the left side, and those without nerve displacement, respectively. Based on these factors/variables, a screening tool/nomogram with acceptable accuracy was established (C-statistic/AUC = 0.80).

CONCLUSIONS

This study revealed an association of the three radiologic factors/variables with TN occurrence. A screening tool for TN/TN-affected nerves was established based on them. The findings may lay a foundation for an improvement of the diagnosis and clinical management of TN.

KEY POINTS

• VA involvement and nerve displacement could be identified using MRI, and are significantly associated with TN occurrence. • A potential objective screening tool/nomogram for TN/TN-affected nerves could be established based on the three radiologic factors/variables: VA involvement, the presence of nerve displacement, and nerve laterality. • The screening accuracy of the tool/nomogram is acceptable as the C-statistic is 0.80.