Ricerc@Sapienza

Trigeminal neuralgia (TN) is an exemplary condition of neuropathic facial pain. The most recent International Classification of Diseases (ICD-11) distinguishes three etiological types of TN: idiopathic, classical, and secondary. About 75% of the patients are diagnosed with classical TN. The cause of classical TN is a neurovascular compression, i.e. an artery with an anomalous course that gets in contact with the trigeminal root at its entry into the pons and induces mechanical demyelination of the trigeminal primary afferents. The demyelinated afferents become an ectopic generator of high-frequency discharges that the brain perceives as electric-shocks or paroxysms of stabbing pain. However, recent developments in the understanding of the pathophysiological mechanisms of TN led the international community to deny that a mere contact is sufficient to cause demyelination and to propose that the anomalous artery must cause major morphological changes to the trigeminal root, such as dislocation, distortion, or atrophy. Currently this view is generally accepted but there are no studies assessing quantitatively these major changes: all these morphological changes are qualitatively clear, nevertheless doubts may arise, particularly because the decision would also imply whether the patient is a natural candidate to microvascular decompression or not.
Our aim is to assess the impact of the various types of morphological changes of the trigeminal root (as assessed both by both standard and volumetric MRI) on neurophysiological measures of trigeminal function and pain.
We plan to recruit 70 patients with classical TN, who will undergo neurophysiological and neuroimaging studies, to find quantitative measures possibly yielding a more definite diagnosis of classical TN and thus a more adequate treatment strategy.