title: Conus perimedullary arteriovenous fistula with intracranial drainage: case report.
abstract: OBJECTIVE
  Perimedullary arteriovenous fistulae (AVFs) do not commonly present with subarachnoid hemorrhage or intracranial venous drainage causing neurological symptoms. We present a case with both of these features. The patient was inadvertently treated for an unruptured intracranial aneurysm before his true problem was recognized.
  
  
  METHODS
  A 65-year-old man presented with sudden-onset lower-extremity weakness, diplopia, nausea, and dysarthria on the day of admission. A lumbar puncture documented subarachnoid hemorrhage, and imaging studies revealed a left middle cerebral artery aneurysm. It was noted during surgery that this aneurysm was unruptured, and the patient did not exhibit improvement after surgery.
  
  
  METHODS
  Spinal angiography demonstrated a spinal perimedullary AVF feeding from the left T12 radicular artery; venous drainage extended rostrally into the posterior fossa venous system. The AVF was surgically occluded via a posterior laminectomy at the level of the AVF. After surgery, the patient's symptoms began to abate.
  
  
  CONCLUSIONS
  Conus perimedullary AVFs can have venous drainage that extends as far as intracranial veins, which can lead to confusing clinical findings because the symptoms may suggest an intracranial process, although the lesion is in the spine. Surgeons must be aware of this confusing presentation.
authors.affiliation: Department of Neurological Surgery, University of California, San Francisco, USA.
authors.forename: G E
authors.initials: GE
authors.lastname: Vates
authors.forename: A
authors.initials: A
authors.lastname: Quiñones-Hinojosa
authors.forename: V V
authors.initials: VV
authors.lastname: Halbach
authors.forename: M T
authors.initials: MT
authors.lastname: Lawton
mesh_terms: D000368:Aged; D015901:Angiography, Digital Subtraction; D001164:Arteriovenous Fistula / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D002550:Cerebral Veins / Q000503:physiopathology*; D004388:Dura Mater; D006801:Humans; D007796:Laminectomy; D008279:Magnetic Resonance Imaging; D008297:Male; D013116:Spinal Cord / Q000098:blood supply*; D013345:Subarachnoid Hemorrhage / Q000209:etiology