title: Ventral transdural herniation of the thoracic spinal cord: surgical treatment in four cases and review of literature.
abstract: BACKGROUND
  A specific cause of progressive Brown-Sequard syndrome has been identified: a ventral herniation of the thoracic spinal cord through the dural sleeve on one side.
  
  
  METHODS
  Four female patients who were affected by a progressive Brown Sequard syndrome related to a transdural spinal cord herniation have been investigated and were submitted to surgery and postoperative evaluation.
  
  
  RESULTS
  The MRI scan showed atrophy and forward displacement of the spinal cord on one side and adhesion of the spinal cord to the dura mater. CT myelography demonstrated the disappearance of the premedullar rim at the level of the herniation and the shadow of the extradural herniation. Surgical treatment consisted in the excision of the arachnoid cyst when there was one, section of the dentate ligament, release of the adhesions, detachment of the spinal cord from the hernial orifice, and lastly suture of the dural tear or placement by a patch. Follow-up examination showed motor improvement with persistent sensory deficit in two cases and stabilisation in two cases.
  
  
  CONCLUSIONS
  The cause of the dural tear, either traumatic or congenital could not be confirmed in the four cases. Symptoms probably occur when herniation fills the orifice and strangulation happens which explains the late appearance and progressive evolution of this myelopathy. Mobilisation of the herniated spinal cord back into the intradural space can be achieved by surgery and may stop the evolution of the symptoms and signs.
authors.affiliation: Neurochirurgie C, Hôpital Neurologique Lyon, Cedex, France.
authors.forename: B
authors.initials: B
authors.lastname: Vallée
authors.forename: P
authors.initials: P
authors.lastname: Mercier
authors.forename: P
authors.initials: P
authors.lastname: Menei
authors.forename: F
authors.initials: F
authors.lastname: Bouhour
authors.forename: C
authors.initials: C
authors.lastname: Fischer
authors.forename: D
authors.initials: D
authors.lastname: Fournier
authors.forename: R
authors.initials: R
authors.lastname: Bougeard
authors.forename: S
authors.initials: S
authors.lastname: Diabira
authors.forename: K
authors.initials: K
authors.lastname: Mahla
mesh_terms: D000328:Adult; D018437:Brown-Sequard Syndrome / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery*; D019299:Decompression, Surgical / Q000379:methods*; D004388:Dura Mater / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009192:Myelography; D010148:Intractable Pain / Q000209:etiology / Q000601:surgery; D012727:Sex Characteristics; D013117:Spinal Cord Compression / Q000150:complications* / Q000175:diagnosis / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome