The incidence of trigetninal neurinomas is estimated to be between 0.07% and 0.36% of all intracranial tumors and between 0.8% and 1.8% of intracranial neurinomas. They may originate at any point on the trigeminal nerve from the root to the extracranial portion of its branches and tend to involve the neighboring anatomical structures (cranial nerves, cavernous sinus) as they grow, although the majority of cases develop in the middle and/or posterior cranial fossa. In 1955 Jefferson classified them into 3 types: 1) those localized mainly in the middle cranial fossa: 2) those localized mainly in the posterior cranial fossa: 3) those with large portions in both the middle and posterior cranial fossae (dumb-bell neurinomas). Nowadays, the majority of authors concord that a fourth group exists, consisting of neurinomas of the peripheral extracranial branches with intracranial extension, usually involving the orbit and the middle cranial fossa. In 1986 Lesoin proposed a new classification, based on the site of origin of the lesion: I) neurinoma of the posterior cranial fossa roots; II) neurinoma of the Gasserian ganglion. III) neurinoma of the trigeminal branches. The lower postoperative mobidity and mortality in these patients is largely the result of recent advances in neuroimaging, elctrophysiological monitoring, microsurgical techniques and skull base approaches.
|Journal||Nuova Rivista di Neurologia|
|Publication status||Published - 1998|
ASJC Scopus subject areas
- Clinical Neurology