title: Gamma knife radiosurgery for trigeminal neuralgia secondary to benign lesions.
abstract: BACKGROUND
  Investigate the clinical outcomes of gamma knife radiosurgery (GKS) in patients with benign intracranial lesions and accompanying trigeminal neuralgia (TN).
  
  
  METHODS
  From February 2002 to November 2011, 50 patients (11 males, 39 females) underwent GKS for intracranial lesions accompanied by TN. Pathological diagnoses included meningioma in 30 patients, vestibular schwannoma in 11, trigeminal schwannoma in 7, epidermoid cyst in 1, and arteriovenous malformation in 1. Twenty-two (44%) had a lesion dominantly located in the middle fossa and 26 patients (52%) in the posterior fossa. Twenty-five (50%) patients complained of type I pain, and 18 patients (36%) suffered from type II pain. The other 7 patients (14%) presented with facial pain that could not be determined. Pain was assessed retrospectively by subjective descriptions and with the Barrow Neurological Institute pain intensity score before and after GKS.
  
  
  RESULTS
  Tumor control was evaluated with magnetic resonance imaging in 44 (95.7%) of 46 patients over a median follow-up period of 54.8 months (range, 13-142 months). Initial improvement in pain after GKS was observed in 46 (92%) patients. The percentage of patients with improved Barrow Neurological Institute score was 73.5% at 1 year, 70.7% at 2 years, and 76.5% at 3 years. Complete pain relief at the final follow-up was achieved in 18 patients (36%). Pain recurred in 13 patients (28.3%) after initial improvement. Pathological diagnosis, location of the lesion, and type of facial pain did not influence the initial pain response after GKS. Pain recurred more frequently in patients with meningioma than in those with schwannoma (P = .045). Type II pain showed better response to the treatment (P = .006).
  
  
  CONCLUSIONS
  The majority of patients with facial pain secondary to a benign intracranial lesion showed improvement after GKS. However, a substantial proportion of the patients experienced incomplete pain relief and recurrence. GKS needs to be combined with an additional modality or the technique must be modified to achieve complete and durable pain control.
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Kyung Rae
authors.initials: KR
authors.lastname: Cho
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Min Ho
authors.initials: MH
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Yong Seok
authors.initials: YS
authors.lastname: Im
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Doo-Sik
authors.initials: DS
authors.lastname: Kong
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Ho Jun
authors.initials: HJ
authors.lastname: Seol
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Do-Hyun
authors.initials: DH
authors.lastname: Nam
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jung-Il
authors.initials: JI
authors.lastname: Lee
keywords: gamma knife radiosurgery; secondary neuralgia; trigeminal neuralgia