Correlation of Prepontine Cisternal Space Thickness with the Severity of Neurovascular Conflict and its Role in Predicting Outcome of Medical Management in Cases of Trigeminal Neuralgia.

Abstract

Trigeminal neuralgia (TN) is a debilitating disorder that presents with sudden onset of severe, unilateral, paroxysmal, and lancinating pain usually lasting for few seconds to few minutes. The main aim of our study was to correlate the prepontine cisternal space thickness, with a severity of neurovascular compression (NVC) and percentage reduction of pain (patient outcome). Ours is an observational prospective study of 40 patients presenting with TN for magnetic resonance imaging in our department. Patients were followed up on medical treatment and their pain severity evaluated on their follow-up visit. Patients were divided into two groups based on prepontine cisternal space (Group A: ≤4 mm, Group B: >4 mm) and into three groups based on the percentage reduction of pain, Group 1 (0-35%), Group 2 (36-70%), and Group 3 consisted of patients with pain reduction of more than 70%. Ipsilateral prepontine cisternal space thickness was correlated with grade of NVC and percentage reduction of pain. Mean percentage of pain reduction in group A and group B was 34.12 and 60.68%, respectively. Approximately 23.80% of grade1 NVC were seen in group A and 76.20% in group B, while 80% of grade 3 NVC were seen in group A and only 20% were seen in group B. There was poor response to medical treatment, in patients with narrowed prepontine cisternal space thickness with an inverse relationship between the grade of NVC and cisternal space thickness.