title: Ventricular and lumbar cerebrospinal fluid concentrations of Alzheimer's disease biomarkers in patients with normal pressure hydrocephalus and posttraumatic hydrocephalus.
abstract: BACKGROUND
  Little information is available on the rostro-caudal concentration gradient of Alzheimer's disease (AD) biomarkers.
  
  
  OBJECTIVE
  We studied the concentrations of amyloid-β (Aβ) peptides 1-42 and 1-40 as well as the Tau and pTau proteins in simultaneously collected ventricular and lumbar cerebrospinal fluid (CSF) samples.
  
  
  METHODS
  The samples were simultaneously collected from the ventricle and the lumbar spinal canal in two groups of patients: 10 subjects being treated for normal pressure hydrocephalus (NPH) by the placement of a ventriculo-peritoneal shunt and 5 patients treated simultaneously with an external ventricular drain and a lumbar CSF drain due to posttraumatic hydrocephalus (PTH).
  
  
  RESULTS
  The ventricular-lumbar (V/L) concentration ratio for Aβ1-40 was 0.81 in NPH patients and 0.71 in PTH patients. The V/L-ratio for Aβ1-42 was 0.84 in NPH, reflecting significantly higher concentrations in lumbar CSF than in ventricular CSF, and 1.02 in PTH patients. The V/L-ratios for Tau and pTau differed significantly depending on the diagnostic group: the median V/L-ratio for Tau was 6.83 in NPH patients but only 0.97 in PTH patients. The median V/L-ratio for pTau was 2.36 in NPH patients and 0.91 in PTH patients.
  
  
  CONCLUSIONS
  We conclude that the rostro-caudal concentration gradient for brain-derived proteins (Tau and pTau in this study) depends on the diagnosis and clinical status of the patient, which were largely neglected in the previously postulated models.
authors.affiliation: Department of Neurosurgery, Universitätsklinikum Erlangen, and Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Brandner
authors.affiliation: Department of Neurosurgery, Universitätsklinikum Erlangen, and Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Thaler
authors.affiliation: Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen, and Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Natalia
authors.initials: N
authors.lastname: Lelental
authors.affiliation: Department of Neurosurgery, Universitätsklinikum Erlangen, and Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Buchfelder
authors.affiliation: Department of Neurosurgery, Universitätsklinikum Erlangen, and Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Kleindienst
authors.affiliation: Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen, and Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Maler
authors.affiliation: Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen, and Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Kornhuber
authors.affiliation: Department of Psychiatry and Psychotherapy, Universitätsklinikum Erlangen, and Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Piotr
authors.initials: P
authors.lastname: Lewczuk
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid* / Q000150:complications; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000134:cerebrospinal fluid* / Q000145:classification / Q000150:complications / Q000601:surgery; D006850:Hydrocephalus, Normal Pressure / Q000134:cerebrospinal fluid*; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D016875:tau Proteins / Q000134:cerebrospinal fluid*
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42); D016875:tau Proteins
keywords: Amyloid-β; biomarker; cerebrospinal fluid; rostro-caudal gradient; tau