Functional neurosurgery

Abstract

Trigeminal neuralgia, also known as painful tic, is a repetitive and unilateral facial pain and is due to various causes. It most frequently involves the right side and affects, mainly adult women in the sixth-seventh decades of life. Trigeminal neuralgia can be caused by several diseases affecting the homolateral trigeminal system. In most cases this neuralgia is essential and seems to be caused by a compression of the trigeminal nerve, at its exit from the pons, by an artery or a tortuous vein nearby. In 5%–8% of cases, the pain is caused by a ponto-cerebellar angle tumor, such as the neurinoma, the meningioma or the epidermoid. In 2%–3% of cases, the pain is caused by multiple sclerosis. Many theories have been formulated to explain the onset of the painful crisis. For example, some believe that demyelinization, due to nerve compression caused by a tumor or a vessel (neurovascular conflict) or due to multiple sclerosis, allows the transmission between close axons. Even if this hypothesis is suggestive, it does not explain why there are long periods of pain remission during the disease evolution.