title: Trigeminal Neuralgia Caused by Venous Angioma: A Case Report and Review of the Literature.
abstract: BACKGROUND
  Trigeminal neuralgia typically occurs in the middle-aged to elderly population, is believed to be related to abnormal conduction within the trigeminal nerve, and is possibly is attributable to changes in myelin induced by pulsatile mechanical trauma from an adjacent vessel. At the point just before it enters the brainstem, there is a short segment at which nerve axons are still ensheathed in central myelin (produced by oligodendrocytes), but after a few millimeters, there is a transition to peripheral myelin (produced by Schwann cells). The region of this transition is called the Obersteiner-Redlich zone. It is thought that the area of the nerve containing the central form of myelin is especially susceptible to pathologic changes from vascular contact that result in demyelination and altered conduction. When associated with a venous angioma at the root entry zone, trigeminal neuralgia usually presents at a younger age.
  
  
  METHODS
  We report a 34-year-old man with a complaint of left hemifacial stabbing pain in maxillomandibular area that was triggered by chewing and speaking. On examination, no neurologic deficit was detected. The pain was not relieved significantly, even with the administration of carbamazepine. Magnetic resonance imaging demonstrated venous angioma in the left cerebello-pontine region.
  
  
  RESULTS
  Microvascular decompression was performed uneventfully. The patient's pain was completely relieved without neurologic deficits.
  
  
  CONCLUSIONS
  It seems that the trigeminal neuralgia caused by venous angioma may occur in the younger population. In most cases, the vessel that caused compression can be identified with magnetic resonance imaging without the need for intensive conventional angiography.
authors.affiliation: Department of Neurosurgery, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Samadian
authors.affiliation: Department of Neurosurgery, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address: mehrdaada@yahoo.com.
authors.forename: Mehrdad Hosseinzadeh
authors.initials: MH
authors.lastname: Bakhtevari
authors.affiliation: Department of Neurosurgery, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Masood Asghari
authors.initials: MA
authors.lastname: Nosari
authors.affiliation: Department of Neurosurgery, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Armin Jahangiri
authors.initials: AJ
authors.lastname: Babadi
authors.affiliation: Department of Neurosurgery, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Omidvar
authors.initials: O
authors.lastname: Razaei
mesh_terms: D000328:Adult; D015901:Angiography, Digital Subtraction; D020787:Central Nervous System Venous Angioma / Q000150:complications* / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D061145:Microvascular Decompression Surgery; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000209:etiology* / Q000601:surgery*
keywords: Caput medusae; Microvascular decompression; Trigeminal neuralgia; Venous angiomas