Delayed Development of Trigeminal Neuralgia after Radiosurgical Treatment of a Tentorial Meningioma.

Trigeminal neuralgia is a known symptom of the tumors and aberrant vessels near the trigeminal nerve and the tentorial notch. There are very few reports of delayed development of trigeminal neuralgia after radiosurgical treatment of a tumor in these areas. This is a case report of a patient treated with radiosurgery for radiation induced meningiomas, 30 years after childhood whole brain radiation. The largest tumor was adjacent to the pons and left trigeminal nerve but did not cause any direct neurologic symptoms or facial pain. Nine months after radiosurgical treatment of the tumors, the patient developed left sided typical trigeminal facial pain and magnetic resonance imaging (MRI) demonstrated the marked reduction in the tumor size. The patient was subsequently treated with radiosurgery to the Gasserian ganglion with a resolution of facial pain. This article reviews the unique characteristics and unusual response to the radiation induced meningiomas to radiosurgery. This is a case of rapid shrinkage of the tumor seen on follow-up MRI scans, concurrent with the development of facial pain, suggests that the rapid shrinkage led to traction on adhesions and related microvasculature changes adjacent to the tumor and trigeminal nerve roots causing the subsequent trigeminal neuralgia.