Gamma Knife Radiosurgery for Trigeminal Neuralgia Caused by a Cavernous Malformation: Case Report and Literature Review

Abstract

Objective: Trigeminal neuralgia (TN) related to a brainstem cavernous malformation (CM) is a rare entity. We present the first radiosurgical management of a patient with TN secondary to a CM. Clinical Presentation: An 80-year-old female presented with a 33-year history of progressively severe TN refractory to medications. Imaging confirmed a solitary CM located at the pontine dorsal root entry zone of cranial nerve 5. Treatment: Stereotactic radiosurgery of the trigeminal nerve was performed using the Leksell gamma knife. A single 4-mm isocenter of radiation was focused on the trigeminal nerve and a maximum dose of 80 Gy (40 Gy at the 50% isodose line) was delivered to the nerve. Results: At 1 year, the patient noted that the severe pain attacks had been reduced by 75%, although a background lingering discomfort persisted. Pain suppression medications had been significantly reduced to lamotrigine 100 mg twice daily. Her preoperative distribution of sensory dysfunction mildly increased. Conclusion: For medically refractory TN related to a CM, radiosurgery of the afferent nerve may ameliorate pain without a major decrease in sensation. The more than 30-year history of pain in our patient may have reduced the chance of more significant pain relief.

Case Report: Recurrent pediatric cavernous malformation of the trigeminal nerve

“…Majority of these cases presented with trigeminal neuralgia and were treated with surgical resection. Only 2 were treated with stereotactic radiosurgery and one with percutaneous balloon compression ( 10 , 13 , 19 ). Adachi et al classified these lesions into 4 types according to the origin of the CM: within the Gasserian ganglion, within the cisternal segment, within the intra-axial trigeminal nerve root in the pons, and within the spinal tract of the trigeminal nerve.…”

“…Trigeminal CM are extremely rare with only 17 cases reported in literature (2,4,(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Majority of these cases presented with trigeminal neuralgia and were treated with surgical resection.…”

An isolated cavernous malformation of the sixth cranial nerve: A case report and review of literature

“…[ 9 , 39 , 46 ] The CMs of the trigeminal nerve were also described in six cases, typically presenting with facial dysesthesia or hyperesthesia. [ 2 , 20 , 40 , 46 , 47 ] The trochlear nerve CMs have been only reported in five patients, with varying presentations. [ 27 , 46 , 55 ] Furthermore, only one case has been reported for the involvement of each hypoglossal, accessory, and abducens nerve.…”