title: Reversal of increased intracranial pressure with removal of a torcular epidermoid: case report.
abstract: OBJECTIVE
  Venous obstruction has been postulated as a cause of increased intracranial pressure, but it has been documented rarely. We present a case of obstruction of the torcula by a slow-growing epidermoid. The tumor caused increased intracranial pressure, which was relieved when it was excised. In addition, the torcular epidermoid is associated with a bifid straight sinus.
  
  
  METHODS
  A 35-year-old man presented with a headache and a lump on the back of the head. Physical examination revealed a firm, bony lesion approximately 4 x 4 cm in size. Lumbar puncture demonstrated an intraspinal pressure of 39 cm H2O. Neuroradiological studies revealed an epidermoid that compressed and almost completely occluded the torcula.
  
  
  METHODS
  After the tumor was resected, the intraspinal pressure decreased to 19 cm H2O and remained stable 6 months later.
  
  
  CONCLUSIONS
  Pure venous obstruction causes increased intracranial pressure. Removal of the obstruction relieves the intracranial hypertension. In addition, computed tomographic venography is a safe and easy method of documenting torcular anatomy, and it was useful in the follow-up of this patient. Computed tomographic venography can demonstrate a double straight sinus, which is a congenital variant that may be associated with the epidermoid.
authors.affiliation: Department of Neurosurgery, University of Minnesota, Minneapolis 55455, USA.
authors.forename: C H
authors.initials: CH
authors.lastname: Lam
authors.forename: R K
authors.initials: RK
authors.lastname: Solomon
authors.forename: H B
authors.initials: HB
authors.lastname: Clark
authors.forename: S O
authors.initials: SO
authors.lastname: Casey
mesh_terms: D003937:Diagnosis, Differential; D004814:Epidermal Cyst / Q000150:complications / Q000601:surgery*; D006801:Humans; D019586:Intracranial Hypertension / Q000209:etiology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009777:Occipital Bone / Q000473:pathology / Q000601:surgery*