Vascular Compression in Trigeminal Neuralgia Discloses Trigeminal Root Somatotopic Organization (S11.005)

Objective: In this combined clinical, neuroimaging and neurophysiological study we aim to explain classical trigeminal neuralgia symptoms and neurophysiological responses through the disclosure of trigeminal root somatotopic organization. Background: In Trigeminal Neuralgia (TN) pain is localized in the distribution of one or more branches of the trigeminal nerve. A hallmark of TN is the presence of discrete skin areas able to trigger pain attacks when touched. In classical TN trigeminal reflexes are normal but dedicated MRI studies can recognize a vascular compression with morphological changes of trigeminal root. Design/Methods: We enrolled 53 patients with a definite diagnosis of classical TN. From MRI images we measured the polar coordinates of the impacting vessel on the trigeminal root circumference and then correlate it with pain distribution, trigger zones and latencies of the early components of the trigeminal reflexes. Results: Pain in V1, V2 and V3 is associated, respectively, with vascular compression in the medial, superior and lateral aspect of the nerve (p