title: The Cerebral Surfactant System and Its Alteration in Hydrocephalic Conditions.
abstract: BACKGROUND
  Pulmonary Surfactant reduces surface tension in the terminal airways thus facilitating breathing and contributes to host's innate immunity. Surfactant Proteins (SP) A, B, C and D were recently identified as inherent proteins of the CNS. Aim of the study was to investigate cerebrospinal fluid (CSF) SP levels in hydrocephalus patients compared to normal subjects.
  
  
  METHODS
  CSF SP A-D levels were quantified using commercially available ELISA kits in 126 patients (0-84 years, mean 39 years). 60 patients without CNS pathologies served as a control group. Hydrocephalus patients were separated in aqueductal stenosis (AQS, n = 24), acute hydrocephalus without aqueductal stenosis (acute HC w/o AQS, n = 16) and idiopathic normal pressure hydrocephalus (NPH, n = 20). Furthermore, six patients with pseudotumor cerebri were investigated.
  
  
  RESULTS
  SP A-D are present under physiological conditions in human CSF. SP-A is elevated in diseases accompanied by ventricular enlargement (AQS, acute HC w/o AQS) in a significant manner (0.67, 1.21 vs 0.38 ng/ml in control, p<0.001). SP-C is also elevated in hydrocephalic conditions (AQS, acute HC w/o AQS; 0.87, 1.71 vs. 0.48 ng/ml in controls, p<0.001) and in Pseudotumor cerebri (1.26 vs. 0.48 ng/ml in controls, p<0.01). SP-B and SP-D did not show significant alterations.
  
  
  CONCLUSIONS
  The present study confirms the presence of SPs in human CSF. There are significant changes of SP-A and SP-C levels in diseases affecting brain water circulation and elevation of intracranial pressure. Cause of the alterations, underlying regulatory mechanisms, as well as diagnostic and therapeutic consequences of cerebral SP's requires further thorough investigations.
authors.affiliation: Department of Neuroradiology, University Leipzig, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schob
authors.affiliation: Department of Neuroradiology, University Leipzig, Germany.
authors.forename: Donald
authors.initials: D
authors.lastname: Lobsien
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Leipzig, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Friedrich
authors.affiliation: Division of Neuropediatrics, University Leipzig, Germany.
authors.forename: Matthias K
authors.initials: MK
authors.lastname: Bernhard
authors.affiliation: Department of Neonatology, University Leipzig, Germany.
authors.forename: Corinna
authors.initials: C
authors.lastname: Gebauer
authors.affiliation: Department of Ophthalmology, University Leipzig, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Dieckow
authors.affiliation: Department of Neuroradiology, University Leipzig, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Gawlitza
authors.affiliation: Department of Neurology, University Leipzig, Germany.
authors.forename: Mandy
authors.initials: M
authors.lastname: Pirlich
authors.affiliation: Department of Neurology, University Leipzig, Germany.
authors.forename: Dorothee
authors.initials: D
authors.lastname: Saur
authors.affiliation: Institute of Anatomy, University of Erlangen-Nuremberg, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Bräuer
authors.affiliation: Institute of Anatomy, University Leipzig, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Bechmann
authors.affiliation: Department of Neuroradiology, University Leipzig, Germany.
authors.forename: Karl-Titus
authors.initials: KT
authors.lastname: Hoffmann
authors.affiliation: Department of Neurosurgery, University Leipzig, Germany.
authors.forename: Cynthia V
authors.initials: CV
authors.lastname: Mahr
authors.affiliation: Department of Neurosurgery, University Leipzig, Germany.
authors.forename: Ulf
authors.initials: U
authors.lastname: Nestler
authors.affiliation: Department of Neurosurgery, University Leipzig, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Preuß