title: Initial CSF total tau correlates with 1-year outcome in patients with traumatic brain injury.
abstract: OBJECTIVE
  We investigated if tau, microtubular binding protein, in serum and ventricular CSF (vCSF) in patients with severe traumatic brain injury (TBI) during the initial posttraumatic days correlated to 1-year outcome.
  
  
  METHODS
  Patients with severe TBI (n = 39, Glasgow Coma Scale score <or=8) were included. We measured serum and vCSF total tau on days 0 to 14, using ELISA. vCSF total tau correlated to 1-year Extended Glasgow Outcome Scale (GOSE), the NIH Stroke Scale (NIHSS) neurologic status, and the Bartel Daily Living Index. Patients (n = 20) with normal pressure hydrocephalus (NPH) served as reference.
  
  
  RESULTS
  Higher levels of tau were found in TBI patients vs patients with NPH. A correlation was found between initial vCSF total tau and GOSE levels (R = 0.42, p < 0.001) but not between vCSF total tau and NIHSS or Bartel scores at 1 year. A vCSF total tau level of >2,126 pg/mL on days 2 to 3 discriminated between dead and alive (sensitivity of 100% and a specificity of 81%). A vCSF total tau level of >702 pg/mL on days 2 to 3 discriminated between bad (GOSE 1 to 4) and good (GOSE 5 to 8) outcome (sensitivity of 83% and a specificity of 69%). Patients with GOSE 1 (dead) had higher vCSF total tau levels on days 2 to 3 (p < 0.001) vs both surviving patients (GOSE 2 to 8) and those with NPH. Total tau was not detected in serum throughout the study.
  
  
  CONCLUSIONS
  The increase in ventricular CSF (vCSF) total tau probably reflects axonal damage, known to be a central pathologic mechanism in traumatic brain injury (TBI). These results suggest that vCSF total tau may be an important early biochemical neuromarker for predicting long-term outcome in patients with a severe TBI.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden. martin.ost@vgregion.se
authors.forename: M
authors.initials: M
authors.lastname: Ost
authors.forename: K
authors.initials: K
authors.lastname: Nylén
authors.forename: L
authors.initials: L
authors.lastname: Csajbok
authors.forename: A Olsson
authors.initials: AO
authors.lastname: Ohrfelt
authors.forename: M
authors.initials: M
authors.lastname: Tullberg
authors.forename: C
authors.initials: C
authors.lastname: Wikkelsö
authors.forename: P
authors.initials: P
authors.lastname: Nellgård
authors.forename: L
authors.initials: L
authors.lastname: Rosengren
authors.forename: K
authors.initials: K
authors.lastname: Blennow
authors.forename: B
authors.initials: B
authors.lastname: Nellgård
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001369:Axons / Q000378:metabolism / Q000473:pathology; D001921:Brain / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D001930:Brain Injuries / Q000134:cerebrospinal fluid* / Q000175:diagnosis* / Q000503:physiopathology; D002556:Cerebrospinal Fluid Proteins / Q000032:analysis / Q000378:metabolism*; D020833:Diffuse Axonal Injury / Q000134:cerebrospinal fluid / Q000175:diagnosis / Q000503:physiopathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D020547:Lateral Ventricles / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D008870:Microtubules / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D013995:Time; D014855:Wallerian Degeneration / Q000134:cerebrospinal fluid / Q000175:diagnosis / Q000503:physiopathology; D016875:tau Proteins / Q000032:analysis / Q000097:blood / Q000134:cerebrospinal fluid*
chemical_list: D002556:Cerebrospinal Fluid Proteins; D016875:tau Proteins