Decreased Probability of Initial Pain Cessation in Classic Trigeminal Neuralgia Treated With Gamma Knife Surgery in Case of Previous Microvascular Decompression: A Prospective Series of 45 Patients With >1 Year of Follow-up. Issue 1 (23rd March 2015)

• Record Type: Journal Article
• Authors: Tuleasca, Constantin; Carron, Romain; Resseguier, Noémie; Donnet, Anne; Roussel, Philippe; Gaudart, Jean; Levivier, Marc; Régis, Jean
• Is Part Of: Neurosurgery. Volume 77:Issue 1(2015)
• Page Start: 87
• Page End: 95
• Publication Date: 2015-03-23
• Subjects: Gamma knife surgery -- Previous MVD -- Recurrent trigeminal neuralgia; Nervous system -- Surgery -- Periodicals; 617.48005
• DOI: 10.1227/NEU.0000000000000739
• Languages: English
• ISSNs: 0148-396X

Abstract

Abstract: BACKGROUND: Microvascular decompression (MVD) is the reference technique for pharmacoresistant trigeminal neuralgia (TN). OBJECTIVE: To establish whether the safety and efficacy of Gamma Knife surgery for recurrent TN are influenced by prior MVD. METHODS: Between July 1992 and November 2010, 54 of 737 patients (45 of 497 with >1 year of follow-up) had a history of MVD (approximately half also with previous ablative procedure) and were operated on with Gamma Knife surgery for TN in the Timone University Hospital. A single 4-mm isocenter was positioned in the cisternal portion of the trigeminal nerve at a median distance of 7.6 mm (range, 3.9–11.9 mm) anterior to the emergence of the nerve. A median maximum dose of 85 Gy (range, 70–90 Gy) was delivered. RESULTS: The median follow-up time was 39.5 months (range, 14.1–144.6 months). Thirty-five patients (77.8%) were initially pain free in a median time of 14 days (range, 0–180 days), much lower compared with our global population of classic TN ( P = .01). Their actuarial probabilities of remaining pain-free without medication at 3, 5, 7, and 10 years were 66.5%, 59.1%, 59.1%, and 44.3%. The hypoesthesia actuarial rate at 1 year was 9.1% and remained stable until 12 years (median, 8 months). CONCLUSION: Patients with previous MVD showed a significantly lower probability of initial pain cessation compared with our global population with classic TN ( P = .01). The toxicity was low (only 9.1% hypoesthesia); furthermore, no patient reported bothersome hypoesthesia. However, the probability of maintaining pain relief without medication was 44.3% at 10 years, similar to our global series of classic TN ( P = .85).