title: Acquired tonsillar herniation and syringomyelia after pleural effusion aspiration: case report.
abstract: OBJECTIVE
  We present a case of brachial plexus avulsion and reconstructive surgery with cerebrospinal fluid leak between the cervical subarachnoid space and the pleural cavity responsible for tonsillar herniation and syringomyelia.
  
  
  METHODS
  A 17-year-old man presented with headaches when he was positioned upright, simultaneously with a persistent right pleural effusion for about 4 months after reconstructive surgery for a right brachial plexus avulsion. In addition, the headaches had worsened considerably after two aspirations of the pleural effusion. Magnetic resonance imaging (MRI) demonstrated signs of chronic intracranial hypotension and tonsillar herniation with a presyrinx cavity from vertebral level C1 to C7. None of those abnormalities were seen on the MRI scan obtained a few days after the initial trauma 7 months previously. Plexus brachial MRI confirmed the presence of a cerebrospinal fluid leak between the avulsed root of C8 and the pulmonary apex.
  
  
  METHODS
  The leak was treated by surgical closure of the dural tear of the C8 root. Postoperatively, the patient's headaches immediately resolved, and MRI 4 months later showed resolution of cerebellar tonsil herniation and regression of the syrinx.
  
  
  CONCLUSIONS
  Resolution of acquired tonsillar herniation and syringomyelia can be achieved by closure of the dural tear responsible of the cerebrospinal fluid leak.
authors.affiliation: Department of Neurosurgery, University Hospital, University of Liège, Liège, Belgium.
authors.forename: Martin
authors.initials: M
authors.lastname: Scholsem
authors.forename: Felix
authors.initials: F
authors.lastname: Scholtes
authors.forename: Shibeshih
authors.initials: S
authors.lastname: Belachew
authors.forename: Didier
authors.initials: D
authors.lastname: Martin
mesh_terms: D000293:Adolescent; D020516:Brachial Plexus Neuropathies / Q000601:surgery*; D002531:Cerebellum / Q000473:pathology*; D002555:Cerebrospinal Fluid; D004388:Dura Mater / Q000473:pathology; D006261:Headache / Q000209:etiology; D006547:Hernia / Q000209:etiology*; D006801:Humans; D019585:Intracranial Hypotension / Q000209:etiology; D008279:Magnetic Resonance Imaging; D008297:Male; D019635:Neurosurgical Procedures / Q000009:adverse effects*; D010996:Pleural Effusion / Q000601:surgery*; D013396:Suction / Q000009:adverse effects; D013595:Syringomyelia / Q000209:etiology*