The relationship of clinical and anamnestic characteristics of patients with classical trigeminal neuralgia with the anatomical characteristics of neurovascular conflict

. Classical trigeminal neuralgia (TN) is a common disease, largely diagnosed by measuring the anatomical parameters of the trigeminal nerve and the adjacent artery using MRI. For an adequate assessment the significance of the identified changes, it may be necessary to adjust for the individual characteristics of the patient, such as gender, age, duration of the TN, and clinical severity of TN. The aim of the study was to identify the relationship of anatomical changes in the intercisternal portions of the trigeminal nerves and adjacent arteries with the clinical and anamnestic data of patients with classic trigeminal neuralgia. Materials and methods . The FIESTA MR sequences of 133 patients were analyzed: 86 patients with verified trigeminal neuralgia (55±11 years) and 47 patients of the control group (51±16 years). The cross-sectional areas (CSA) and diameter ratio of nerves, diameters of adjacent arteries and neurovascular distances were measured in the context of gender, age, duration and therapy of neuralgia. Results. After dividing the group of TN patients into three conditional age groups (up to 50 years old, 50–65 years old, and over 65 years old), the ANOVA analysis revealed a decrease in the CSA in older age groups (medians 3,2 mm 2 ; 2,15 mm 2 ; 1,85 mm 2 ; p=0,0193) and an increase in the diameter of the adjacent artery (median 1 mm; 1,3 mm; 1,2 mm; p=0,018). At the same time, on the opposite sides of the TN, only a tendency towards a decrease in the CSA remained (median 4,45 mm2; 3,45 mm 2 ; 3,05 mm 2 ; p=0,0016). The CSA of the nerves in the operated patients were less than ones in the patients with conservative treatment (median 2,9  mm 2 and 2  mm 2 ; p<0,05). In patients with TN, right-sided lesion prevailed. The duration of the TN was 9±7,8 years (from 1 year to 33 years) for patients who had an accurately documented date of manifestation of TN (N=56), no direct correlations of the MR-parameters with the duration of TN were found. A simple correlation analysis between MR-parameters and the patients age revealed a linear relationship only for the decrease of the CSA: on the right side (p=0,014) in patients with TN and on both sides in control patients (р=0,005–0,013). Conclusion. Theas data make it possible to more clearly distinguish significant MR changes in TN, taking into account the clinical and anamnestic data of patients.The revealed MR patterns of an increase in the caliber of the adjacent artery and a decrease in the CSA, which are pathognomonic for a clinically significant neurovascular conflict, are often asymptomatic age-related changes in elderly patients, which reduces their potential diagnostic value. In connection with this circumstance, the comparison of seemingly significant anatomical changes with similar ones on the opposite side of the lesion is of exceptional importance.