title: Gamma Knife rhizotomy-induced histopathology in multiple sclerosis-related trigeminal neuralgia.
abstract: OBJECTIVE
  In this report, the authors describe the pathological changes in the human trigeminal nerve after Gamma Knife radiosurgery.
  
  
  METHODS
  Three trigeminal nerves of patients with multiple sclerosis (MS)-related trigeminal neuralgia (MSTN) after Gamma Knife radiosurgery and other ablative procedures were examined by a neuropathologist. These cases were compared with 3 patients with typical TN who underwent partial surgical rhizotomy following recurrent symptoms after gasserian injury procedures, as well as with autopsy specimens from patients with and without MSTN.
  
  
  RESULTS
  The three irradiated MS-TN specimens exhibited axon loss, demyelination, myelin debris, and fibrosis. Mild lymphocytic infiltrate was present in all 3 samples from MS-TN patients. The nonirradiated trigeminal nerve samples were generally well myelinated with rare degenerating axons. The microscopic findings in trigeminal nerve autopsy specimens were normal in patients without TN, with MS but not TN, and MS-TN.
  
  
  CONCLUSIONS
  The inflammation observed in MS-TN specimens collected following Gamma Knife radiosurgery has not previously been described in the literature. These data provide new insight into the changes that occur in trigeminal nerve following stereotactic radiosurgery.
authors.affiliation: Section of Neurosurgery and.
authors.forename: David B
authors.initials: DB
authors.lastname: Phillips
authors.forename: Marc R
authors.initials: MR
authors.lastname: Del Bigio
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Kaufmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications* / Q000276:immunology / Q000473:pathology; D009410:Nerve Degeneration / Q000209:etiology / Q000276:immunology / Q000601:surgery; D009443:Neuritis / Q000188:drug therapy / Q000276:immunology / Q000601:surgery; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies; D019051:Rhizotomy / Q000379:methods*; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000209:etiology* / Q000276:immunology / Q000601:surgery*
keywords: Gamma Knife; MS = multiple sclerosis; TN = trigeminal neuralgia; histopathology; multiple sclerosis; pain; peripheral nerve; radiosurgery; rhizotomy; stereotactic radiosurgery; trigeminal neuralgia