The correlation study between posterior fossa crowding and classical trigeminal neuralgia

Acta Neurochirurgica (2025) 167:14

Objective To explore the correlation between posterior fossa crowding and the occurrence of classical trigeminal neuralgia (TN).

Methods A total of 60 patients diagnosed with classical TN and 60 age- and sex-matched healthy volunteers were included as a control group for a case-control study. All subjects underwent high-resolution 3D magnetic resonance imaging (MRI) examinations (including 3D-FIESTA and 3D-TOF MRA sequences). The original data were subjected to 3D reconstruction and measurement of posterior fossa volume (PFV) and hindbrain volume (HBV) using 3D-slicer software. The posterior fossa crowding index (PFCI) was calculated as HBV/PFV × 100%. Finally, data were analyzed using SPSS 22.0 statistical software.

Results The average PFCI in patients with TN was 85.0% ± 3.9%, compared to 82.7% ± 3.9% in the control group, with a significant statistical difference (P = 0.025). Female patients with TN had a more crowded posterior fossa than male patients (86.4% ± 3.8% vs. 83.4% ± 3.4%, P = 0.033). Multiple linear regression analysis showed that a higher PFCI was associated with being female (P = 0.022), younger age (P = − 0.003), and being a patient with TN (P = − 0.023).

Conclusion Patients with PTN have a more crowded posterior fossa compared to the healthy control group. A higher PFCI is associated with being female, younger age, and being a patient with TN. Posterior fossa crowding may be a risk factor for neurovascular conflict (NVC), making it more likely to lead to the occurrence of TN.