Tumor associated trigeminal neuralgia
Trigeminal neuralgia pathogenesis is uncertain. What is nominated as typically TN is idiopathic, but may be due to a structural lesion:
Posterior fossa tumors 1) 2) 3) 4) 5), contralateral posterior fossa tumors, 6) 7)ipsilateral and contralateral supratentorial tumors 8) 9) 10) 11) 12).
Trigeminal neuralgia in vestibular schwannoma 13).
Trigeminal neuralgia as the initial manifestation of temporal glioma 14).
A supratentorial tumor can initiate TN even without a direct involvement of the trigeminal ganglion or nerve. Such tumors may lead to increased intracranial pressure and brain shift generating a pressure cone that distorts the brain stemand displaces an adjacent vessel, compressing the trigeminal nerve root.
Another explanatory mechanism in a patient with supratentorial tumor and hydrocephalus can be that pressure over the trigeminal sensory root rather than stretching of the nerve fiber leads to TN 15).