Introduction: Microvascular decompression (MVD) is the accepted surgical treatment of choice for patients with idiopathic trigeminal neuralgia (TN). The role of MVD in patients with multiple sclerosis (MS)-related TN is controversial.

Methods: Between July 1999 until January 2011, 9 patients (5 men, 4 women) having both areas of increased signal in the trigeminal pathways on long-TR imaging and neurovascular compression demonstrated on pre-operative MRI underwent MVD. All of the patients had failed medical therapy and no patient had other symptoms or signs of MS. One patient had failed prior percutaneous surgery; one patient had Burchiel Type 2 TN. Follow-up (median, 15 months) was censored at the time of additional surgery (n=6) or last clinic visit (n=3).

Results: The patients were similar with regard to age, gender, and pain duration compared to 350 patients with idiopathic TN having a MVD over the same time interval. At surgery, neurovascular compression was from the superior cerebellar artery (SCA) plus adjacent vein (n=4), venous alone (n=3), SCA alone (n=1), and SCA plus anterior inferior cerebellar artery (n=1). Initially, 7 patients (78%) were pain-free and able to discontinue medication use for TN. Five patients developed recurrent pain at a median of 5 months after surgery (range, 2-23). The actuarial rate of being pain-free without medications was 57% at 3-months and 17% at 2-years. Six patients underwent 9 additional operations including glycerol rhizotomy (n=4), radiosurgery (n=2), balloon compression (n=2), and repeat MVD (n=1). Five of these 6 patients were pain-free at last contact.

Conclusions: The facial pain outcomes after MVD in patients suspected to have MS-related TN are worse compared to patients with idiopathic TN. These results support the hypothesis of a central mechanism of pain production for some patients with suspected or proven MS-related TN.

Patient Care: This study will help physicians with surgical decision making for patients with suspected or proven multiple sclerosis-related trigeminal neuralgia.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the different causes of trigeminal neuralgia, 2) Understand the importance of pre-operative MRI in surgical decision making for patients with trigeminal neuralgia, 3) Discuss the appropriate surgical treatments for different types of trigeminal neuralgia.

References: 1. Broggi G, Ferroli P, Franzini A, Nazzi V, Farina L, La Mantia L, Milanese C. Operative Findings and Outcomes of Microvascular Decompression for Trigeminal Neuralgia in 35 Patients Affected by Multiple Sclerosis. Neurosurgery 55:830-839, 2004. 2. Nurmikko TJ. Pathophysiology of MS-related trigeminal neuralgia. Pain 143:165-166, 2009.