Sex-dependent posterior fossa anatomical differences in trigeminal neuralgia patients with and without neurovascular compression: a volumetric MRI age- and sex-matched case-control study

Abstract

OBJECTIVEThe pathophysiology of trigeminal neuralgia (TN) in patients without neurovascular compression (NVC) is not completely understood. The objective of this retrospective study was to evaluate the hypothesis that TN patients without NVC differ from TN patient with NVC with respect to brain anatomy and demographic characteristics.METHODSSix anatomical brain measurements from high-resolution brain MR images were tabulated; anterior-posterior (AP) prepontine cistern length, cerebellopontine angle (CPA) cistern volume, nerve-to-nerve distance, symptomatic nerve length, pons volume, and posterior fossa volume were assessed on OsiriX. Brain MRI anatomical measurements from 232 patients with either TN type 1 or TN type 2 (TN group) were compared with measurements obtained in 100 age- and sex-matched healthy controls (control group). Two-way ANOVA tests were conducted on the 6 measurements relative to group and NVC status. Bonferroni adjustments were used to correct for multiple comparisons. A nonhierarchical k-means cluster analysis was performed on the TN group using age and posterior fossa volume as independent variables.RESULTSWithin the TN group, females were found to be younger than males and less likely to have NVC. The odds ratio (OR) of females not having NVC compared to males was 2.7 (95% CI 1.3–5.5, p = 0.017). Patients younger than 30 years were much less likely to have NVC compared to older patients (OR 4.9, 95% CI 1.3–18.4, p = 0.017). The mean AP prepontine cistern length and symptomatic nerve length were smaller in the TN group than in the control group (5.3 vs 6.5 mm and 8.7 vs 9.7 mm, respectively; p < 0.001). The posterior fossa volume was significantly smaller in TN patients without NVC compared to those with NVC. A TN group cluster analysis suggested a sex-dependent difference that was not observed in those without NVC. Factorial ANOVA and post hoc testing found that findings in males without NVC were significantly different from those in controls or male TN patients with NVC and similar to those in females (female controls as well as female TN patients with or without NVC).CONCLUSIONSPosterior fossa volume in males was larger than posterior fossa volume in females. This finding, along with the higher incidence of TN in females, suggests that smaller posterior fossa volume might be an independent factor in the pathophysiology of TN, which warrants further study.

Comparative Analysis of Trigeminal Neuralgia Caused by Sole Arterial and Venous Compression: Clinical Features and Surgical Outcomes From 222 Cases

“…Subsequently, we performed a sex-dependent analysis ( Table 3 ). As a result, we revealed that the volume of PCF and its substructure in female was smaller than that in male (X, Z, and volume: p < 0.001; Y: p = 0.002), which was in line with the previous publications ( 18 ). Moreover, a more flat-shaped PCF was identified in both female and male cases with venous NVC compared with arterial NVC.…”

“…Previous studies indicated that the PCF morphometry might be similar in healthy subjects and classic TN patients (18,28,29). In addition, a smaller PCF was merely characterized as TNs without NVC, so-called idiopathic TNs (18). However, there were differences regarding the study design between previous works and our present work.…”

“…During the past decades, the PCF morphometry has been widely explored in TN. Previous studies indicated that the PCF morphometry might be similar in healthy subjects and classic TN patients (18,28,29). In addition, a smaller PCF was merely characterized as TNs without NVC, so-called idiopathic TNs (18).…”

Neuraxial dysraphism in EPAS1- associated syndrome due to improper mesenchymal transition

“…We used the previously described methods to measure posterior fossa structures. 9,[19][20][21][22][23][24][25] Details in e-methods (links.lww. com/NXG/A252).…”

Contemporary concepts of pain surgery

“…75 We have now demonstrated that the size of the posterior fossa seems to have a striking impact on the development of TN1 in males and females. 40 We have also recently reported that knowledge of only two parameters prior to surgery, i.e., the diagnosis of TN1 and the grade of NVC (I-III), can accurately predict the pain-free outcome and durability of microvascular decompression postoperatively. 39 In general, most pains that are the consequence of nervous system injury (peripheral or central) are not improved by further injury to the nervous system, and may, in fact, worsen.…”