title: Factors Associated with Acute and Chronic Hydrocephalus in Nonaneurysmal Subarachnoid Hemorrhage.
abstract: BACKGROUND
  Hydrocephalus requiring external ventricular drain (EVD) or shunt placement commonly complicates aneurysmal subarachnoid hemorrhage (SAH), but its frequency is not as well known for nonaneurysmal SAH (NA-SAH). Those with diffuse bleeding may have greater risk of hydrocephalus compared to those with a perimesencephalic pattern. We evaluated the frequency of hydrocephalus in NA-SAH and whether imaging factors could predict the need for EVD and shunting.
  
  
  METHODS
  We collected admission clinical and imaging variables for 105 NA-SAH patients, including bicaudate index (BI), Hijdra sum score (HSS), intraventricular hemorrhage (IVH) score, modified Fisher scale (mFS), and bleeding pattern. Hydrocephalus was categorized as acute (need for EVD) or chronic (shunt). We applied logistic regression to determine whether hydrocephalus risk was independently related to bleeding pattern or mediated through blood volume or ventriculomegaly.
  
  
  RESULTS
  Acute hydrocephalus was seen in 26 (25%) patients but was more common with diffuse (15/28, 54%) versus perimesencephalic (10/59, 17%, p < 0.001) bleeding. Patients developing acute hydrocephalus had worse clinical grade and higher BI, HSS, and IVH scores. Adjusting the relationship between hydrocephalus and diffuse bleeding for HSS (but not BI) nullified this association. Nine (35%) patients requiring EVD eventually required shunting for chronic hydrocephalus, which was associated with greater blood burden but not poor clinical grade.
  
  
  CONCLUSIONS
  Acute hydrocephalus occurs in one-quarter of NA-SAH patients. The greater risk in diffuse bleeding appears to be mediated by greater cisternal blood volume but not by greater ventriculomegaly. Imaging characteristics may aid in anticipatory management of hydrocephalus in NA-SAH.
authors.affiliation: Neurocritical Care Section, Department of Neurology, Washington University School of Medicine, 660 S. Euclid Ave, Campus Box 8111, St. Louis, MO, 63110, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Kang
authors.affiliation: Neurocritical Care Section, Department of Neurology, Washington University School of Medicine, 660 S. Euclid Ave, Campus Box 8111, St. Louis, MO, 63110, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Raya
authors.affiliation: Department of Neurological Surgery, Washington University School of Medicine, 660 S. Euclid Ave, Campus Box 8057, St. Louis, MO, 63110, USA.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Zipfel
authors.affiliation: Neurocritical Care Section, Department of Neurology, Washington University School of Medicine, 660 S. Euclid Ave, Campus Box 8111, St. Louis, MO, 63110, USA. dharr@neuro.wustl.edu.
authors.forename: Rajat
authors.identifier: http://orcid.org/0000-0002-5167-5097
authors.initials: R
authors.lastname: Dhar
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D004322:Drainage / Q000379:methods; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012720:Severity of Illness Index; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D017287:Ventriculoperitoneal Shunt / Q000379:methods
keywords: Angiogram negative; External ventricular drain; Hydrocephalus; Nonaneurysmal; Subarachnoid hemorrhage; Ventriculoperitoneal shunt