title: Cerebrospinal fluid creatine kinase-BB isoenzyme activity and outcome after subarachnoid hemorrhage.
abstract: BACKGROUND
  The brain is rich in creatine kinase-BB isoenzyme activity (CK-BB), which is not normally present in cerebrospinal fluid (CSF). Results of previous studies have shown that CK-BB can be detected in the CSF of patients with aneurysmal subarachnoid hemorrhage (SAH), but whether CK-BB levels correlate with patients' neurologic outcomes is unknown.
  
  
  OBJECTIVE
  To evaluate the relationship between CSF CK-BB level and outcome after SAH.
  
  
  METHODS
  Prospective observational cohort.
  
  
  METHODS
  University-affiliated tertiary care center.
  
  
  METHODS
  Convenience sample of 30 patients seen for cerebral aneurysm clipping.
  
  
  METHODS
  We sampled and assayed CSF for CK isoenzymes a median of 3 days after SAH in 27 patients, and at the time of unruptured aneurysm clipping in 3 patients.
  
  
  METHODS
  Without knowledge of CK results, we assigned the Glasgow Outcome Scale score early (approximately 1 week) and late (approximately 2 months) after surgery.
  
  
  RESULTS
  Higher CSF CK-BB levels were associated with higher Hunt and Hess grades at hospital admission (Spearman rank correlation, p = 0.69; P<.001), lower Glasgow Coma Scale scores at hospital admission (p = -0.72; P<.001), and worse early outcomes on the Glasgow Outcome Scale (p = -0.64; P<.001). For patients with a favorable early outcome (Glasgow Outcome Scale score, 3-5), all CK-BB levels were less than 40 U/L. With a cutoff value of 40 U/L, CK-BB had a sensitivity of 70% and a specificity of 100% for predicting unfavorable early outcome (Glasgow Outcome Scale score, 1-2). Having a CK-BB level greater than 40 U/L increased the chance of an unfavorable early outcome, from 33% (previous probability) to 100%, whereas a CK-BB level of 40 U/L or less decreased it to 13%. Similar findings were obtained when considering late outcomes.
  
  
  CONCLUSIONS
  The level of CSF CK-BB may help predict neurologic outcome after SAH.
authors.affiliation: Department of Neurology, School of Medicine, University of Washington, Seattle, USA. wcoplin@med.wayne.edu
authors.forename: W M
authors.initials: WM
authors.lastname: Coplin
authors.forename: W T
authors.initials: WT
authors.lastname: Longstreth
authors.forename: A M
authors.initials: AM
authors.lastname: Lam
authors.forename: W L
authors.initials: WL
authors.lastname: Chandler
authors.forename: T S
authors.initials: TS
authors.lastname: Mayberg
authors.forename: J S
authors.initials: JS
authors.lastname: Fine
authors.forename: H R
authors.initials: HR
authors.lastname: Winn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003402:Creatine Kinase / Q000134:cerebrospinal fluid*; D005260:Female; D005500:Follow-Up Studies; D015600:Glasgow Coma Scale; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000601:surgery; D007527:Isoenzymes; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis* / Q000209:etiology; D013997:Time Factors; D016896:Treatment Outcome; D014696:Ventriculostomy / Q000379:methods
chemical_list: D007527:Isoenzymes; D003402:Creatine Kinase