Trigeminal neuralgia: peripheral and central mechanisms

Abstract

ABSTRACT BACKGROUND AND OBJECTIVES: Trigeminal neuralgia is one of the most common neuropathic pains that compromise head and neck. It manifests as shock or burning pain normally evoked by non-noxious facial stimulations. Its etiopathology is not totally understood, but it is known that different mechanisms contribute to the establishment and maintenance of pain. This study aimed to address current contexts of epidemiology, diagnosis, management and pathophysiological mechanisms underlying trigeminal neuralgia in peripheral and central nervous systems. CONTENTS: Inflammation and release of inflammatory mediators, neuropeptides and neurotrophic factors, as well as degenerative changes of nervous fibers caused by direct nervous injury are relevant peripheral mechanisms which lead to altered sensitivity of nociceptive neurons, development of spontaneous and exacerbated activity, allodynia and hyperalgesia. Among central mechanisms, exacerbated activation of central nociceptive neurons, neuroplasticity, changes in electrophysiological properties and neuronal hyperexcitability, in addition to changes in modulatory pain controls, lead to pain establishment and maintenance. CONCLUSION: Several mechanisms are involved in neuropathic pains, both in peripheral and central levels, although specific trigeminal neuralgia events are not totally described. Studies concerning its specific neurobiology are needed to understand functional and behavioral changes, which can contribute to trigeminal neuralgia clinical management and treatment.

Keywords

• central sensitization
• etiopathology
• neuropathic pain
• peripheral sensitization
• trigeminal nerve
• trigeminal neuralgia