Trigeminal neuralgia caused by contralateral supratentorial meningioma.

Most trigeminal neuralgia is attributable to vascular compression of the root entry zone of the trigeminal nerve at the pons. Only about 5-10% of trigeminal neuralgia cases are caused by direct compression by ipsilateral cerebellopontine angle tumors. Trigeminal neuralgia caused by contralateral posterior fossa tumors are extremely rare. Cases in which neuralgia is caused by a contralateral supratentorial tumor have been seldom reported. This report describes a case of large meningioma in the left occipital region. The patient's right facial pain subsided gradually after tumor excision. This neuralgia is likely due to a displaced adjacent vessel that developed following brainstem distortion by the tumor.